lindab we simplify construction AIR HANDLING UNITS INSTRUCTIONS FOR: TRANSPORT INSTALLATION COMMISSIONING OPERATION TESTING MAINTENANCE

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1 AIR HANDLING UNITS INSTRUCTIONS FOR: TRANSPORT INSTALLATION COMMISSIONING OPERATION TESTING MAINTENANCE

2 2 Table of contents 1 General Addresses of the manufacturer and authorised services Housing checking and maintenance Air handling unit transport Air handling unit mounting Servicing area Construction of an air handling unit foundation Mounting of an air handling unit without a foundation Air handling unit mounting procedure Installation procedure for an outdoor installation air handling unit Functional sections Fan section Electric motor connection Commissioning and testing Operation Maintenance Heater section with water heater Installation and commissioning Operation Maintenance Anti-freezing protection (FR) Connection, operation and maintenance Heater section with steam heater Installation and commissioning Operation Maintenance Heater section with electric heater Installation and commissioning Operation Maintenance Heater section with indirect gas heater Installation and commissioning Operation Maintenance Humidifying section with spray humidifier Installation and commissioning Water treatment Maintenance Humidifying section with steam humidifier Installation and commissioning Operation Maintenance Humidifying section with contact humidifier Installation and commissioning Operation Maintenance Humidifying section with high-pressure humidifier Installation and commissioning Operation Maintenance Cooling section with water cooler Installation and commissioning Operation... 41

3 Maintenance Water droplet eliminator Operation Maintenance Outlet siphon Sizing and installation Cooling section with direct evaporator Installation and commissioning Operation Maintenance Compressor section Installation and commissioning Operation Maintenance Control louvre Installation and commissioning Maintenance Filter section Installation and commissioning Operation Maintenance Metal filter section Installation and commissioning Operation Maintenance Active carbon filter section Installation and commissioning Operation Maintenance Absolute filter section Installation and commissioning Operation Maintenance Noise attenuator section Maintenance Fin recuperator section Installation and commissioning Operation Maintenance Piping installation Plate recuperator section Installation and commissioning Operation Maintenance Double plate recuperator section Installation and commissioning Operation Maintenance Rotational regenerator section Installation and commissioning Operation Maintenance Maintenance and cleaning of the hygienic type air handling units Eplosion-proof air handling units Maintenance... 63

4 4 1 General During transport, installation, commissioning, operation, testing and maintenance of the air handling units, please observe the following: Prior to any work on the unit, please study carefully the instructions in full. The air handling unit may only be installed, checked, commissioned and maintained by trained personnel, which shall, in their operations, observe the statutorily provided engineering standards and local safety regulations applicable at the time of the unit installation. In installing, commissioning and maintenance of functional elements produced by manufacturers other than Lindab, the manufacturer s instructions shall be followed. The instructions and electrical diagrams shall be stored and kept available to the person operating the unit. The air handling unit shall only be used for the purpose and under the operating conditions specified in the confirmation of order under which the unit has been manufactured. Any other use deviating from the intended use relieves the manufacturer from any obligation. The unit manufacturer shall not be kept liable in the cases of failure to observe the information provided in these instructions during the air handling unit installation, commissioning, testing and maintenance, or in the cases of alterations of electrical or mechanical unit components without a prior specific approval by the manufacturer. Any unauthorised intervention into the unit also voids the warranty.

5 5 2 Addresses of the manufacturer and authorised services Lindab IMP Klima d.o.o. Godovič 150, 5275 Godovič SLOVENIA Tel.: +386 (0) imp-klima@lindab.com Authorised service: Lindab IMP Klima d.o.o. Godovič 150, 5275 Godovič SLOVENIA Tel.: +386 (0) imp-klima@lindab.com HOUSING CHECKING AND MAINTENANCE The checking and maintenance shall be done according to the schedule set out in the following table. Air conditioning unit housing checking and maintenance schedule Action Inspect for contamination, damage and corrosion of the housing interior Inspect for water formation within the housing Check the hygiene condition Time interval (months) According to the hygiene inspection

6 6 3 Air handling unit transport Protect individual compact sections (shipment units) so as to prevent, during loading, transport or unloading, their damaging due to tumbling, sliding or uncontrolled release from the transport vehicle, and to prevent any safety or health hazards to eposed persons. Until the delivery to the installation site, the individual compact sections of the air handling unit are to remain secured with all guards and protective means (diagonal restraints, wooden supports pallets under the structural frame, protective foil etc.). During the transport, any handling of the device shall be carried out via the structural frame no pressure on the housing! Any crane hoisting of the airconditioning compact sections is to be done only via the structural frame provided underneath the section. Insert appropriate tubes (thick wall tube of outside diameter ø 48.3 mm and wall thickness of 10 mm) through the circular leads in the structural frame. For lifting, apply steel hoisting ropes or chains; in all cases, apply two spacer supports (Figure 1, detail A). The tubes shall be provided with appropriate guards at both ends (Figure 1, detail B). Figure 1 Figure 2 Hoisting without spacer supports (Figure 2) is not allowed, since this might damage the housing. All shipment units are factory protected by: - wooden beams (unit with the support base) Figure 3 or - wooden pallets (unit without the support base) Figure 4

7 7 Figure 3 Figure 4 When transport is carried out by forklift, always observe the weight and the position of the centre of gravity of the compact shipment unit. Pay special attention not to ecert any pressure to the bottom cover of the unit or the elements of the unit attached under the cover (e.g., the ground drain pipes Figure 6). Forks may only ecert pressure to the bottom frame whereby the forks should reach beyond the last part of the section frame Figure 5. 1 wooden beams 2 forks 3 transport unit Figure 5 Figure 6 In the cases of some functional units with short and disproportionately high section combinations, the transport packaging must be constructed so as to prevent the hazard of tumbling during transport or storage, to add to the safety of eposed persons. The shipment units of this kind are factory protected in the following ways (Figure 7): wooden pallets or support beams eceed, in length, the section length by H1/4 (H1 = total section height) to prevent unit tumbling (the wooden support beam depends on the shipment unit length and height); on their sides, the units are propped with etra diagonal supports, fied to the wooden pallet or beam on one end and to the unit itself on the other end (the length of these props depends on the length of the support beams and on the shipment unit height);

8 8 the base (structural frame) is provided with hoisting holes also along the longer (transversal) sections (view from the front side); Figure 7 Always place the shipment unit on even ground. Always lift the shipment unit applying the hoisting procedure described in this chapter paragraph three. No stripping of props or aids is allowed during transport; in an event of such stripping, the person having carried it out is held fully liable for any adverse consequences. Remove the props only before the installation on site. Until installation, store the air handling units in a roofed and dry area. 4 Air handling unit mounting 4.1 SERVICING AREA To allow maintenance interventions and operation (e.g. withdrawal of a heat echanger), always provide a clear area of a minimum width of 1.3 unit width on the air handling unit servicing side. To facilitate the installation, a clearance area of a minimum width of 0.5 m should be provided on the non-servicing side as well (Figure 8).

9 9 Figure 8 In the case of an air handling unit mounting on an elevated platform, provide safe access to the platform and the necessary servicing area on the platform. Also provide appropriate guards for the maintenance technician, in accordance with applicable regulations on safety at work. In the design and construction of electric installation and piping connections to the functional sections, the designer and the constructing contractor shall refrain from leading such installations and connections through servicing doors or servicing hatches. Failure to observe this requirement may render the servicing of air handling unit functional sections impracticable. With horizontal and parallel air-conditioning units of height H 1830 mm, and with two-stage air-conditioning units of height H 915 mm, provide for unimpeded and safe access by maintenance personnel to elevated unit parts, by means of mobile ladders or platforms, dimensioned, erected, protected and used in the manner preventing the personnel falls.

10 CONSTRUCTION OF AN AIR HANDLING UNIT FOUNDATION Mount the air handling unit onto an appropriately high and level concrete or steel foundation (or base). Level out any irregularities in the foundation surface. The minimum foundation height (in the case the unit does not include a spray humidifier section) is determined by the elevation of the drain siphon in the section set and shall be 150 mm. The foundation must be dimensioned according to the dimensions and masses of the devices listed in the Technical calculation. IMPORTANT: devices with widths of 1870 mm or more (B > 18) must be equipped with transverse supports under the air handling unit at the front and rear part of the device and at all joints between individual sections. If in doubt, consult the Lindab IMP Klima technical service in advance. In the case the air handling unit includes a spray humidifier section, adjust the foundation height to the elevation of the pool of this section, given in the assembly drawing of the particular unit. Figure 9 In the case of air handling unit including a spray humidifier section, either mount all other sections on a specially designed steel support or construct a suitably shaped foundation (Figure 10). The pool of the said section shall always be supported on the base and shall not hang freely on the unit housing.

11 11 Figure MOUNTING OF AN AIR HANDLING UNIT WITHOUT A FOUNDATION The foundation may be substituted by the mounting the unit onto Lindab type base legs fitted with a structural noise and vibration insulation bolt, allowing the levelling within a range of 30 mm (Figure 11). Figure 11 Figure 12 presents the mounting on legs for an air handling unit with a spray humidifier section.

12 12 Figure12 Figure 13: Leg in the AC unit corner Figure 14: Leg in the AC unit centre 4.4 AIR HANDLING UNIT MOUNTING PROCEDURE The air handling unit mounting and assembling procedure is as follows: Transport the unit to the place of installation. Remove protective screening and guards (diagonal restraints, wooden supports pallets under the structural frame, protective foil etc.). Check the evenness and levelness of the foundation. The section front faces shall be eactly perpendicular to the foundation and parallel one to another (see Figure 15). Apply self-adhesive EPDM rubber sealing tape of 19 5 mm cross-section (supplied with the unit) onto the contact front faces (housing frame). Draw the individual sections together by means of the tightening clamps, which you have mounted into the structural frame openings. No pressure on the unit housing!

13 13 Figure 15 Figure 16 Having drawn the sections together, join them by means of eccentric clamps fitted on the section frames. The eccentric clamps are fitted on both vertical and horizontal sides either outside or inside on the frame, depending on the unit type (parallel, two-stage, horizontal) (Figure 17) The TopAir housing includes clamps on the vertical and horizontal sides, as shown in Figure 18. Connect both clamps with M840 screws. Screw M8 40 Nut M8 Figure 17: Joining two sections with eccentric clamps Figure 18: Joining two TopAir air-conditioning sections with clamps 4.5 INSTALLATION PROCEDURE FOR AN OUTDOOR INSTALLATION AIR HANDLING UNIT Mount the air handling unit on a foundation of adequate height. In specifying the foundation height, take into account all factors that may potentially affect the unit operation: mounting location, depth of snow cover, requirements regarding the quality of suction of outside air, position of intake and ehaust air duct connections, design of heat echanger piping connections, installation of power cables etc. The foundation height should not be less than 500 mm.

14 14 Construct the foundation so as to protect the unit or its components against sliding or tumbling over under wind gusts. Check the wind strength for this purpose. The roofs are already factory mounted, therefore they do not need to be mounted on the building; however, roof joints must be sealed watertight. After the assembly of the sections, all individual roof joints must be sealed watertight with putty. Net, mount the ridge tiles on the joints with rust-proof rivets (Figure 19). The ridge tiles are factory sealed to the air handling unit sections. rivet 4,810 ridge tile Figure 19: Mounting the ridge tiles Seal watertight all the vertical joints between compact sections. All the joints between the connections and the intake and outflow air ducts shall be watertight. If the suction air and ehaust air run to/from the unit through ducts, the joints between the connections and the ducts shall be watertight as well. In the case of installing of the unit on the roof or at an elevation, arrange for safe access to the unit and construct a thread-on platform as required.

15 15 5 Functional sections The overpressure doors and de-mounting service covers are attached to the housing by blocators. To remove / attach the blocators apply: - Imbus key size 4 for the»topair«units - Imbus key size 5 for the»klimair2«units F Figure FAN SECTION belt driven fan plug fan (without spiral housing) Electric motor connection Prior to commissioning, check the conformity of the connection parameters specified on the electric load nameplates or in the a/c installation control cabinet with the site power mains parameters. The electric motor connection shall be carried out by a qualified technician in accordance with the technical regulations and standards, in accordance with the electric design specifications for the building in which the air handling unit with the fan section is to be installed, and following the electric motor manufacturer's instructions. The electric motor grounding is mandatory. With electric motors with capacities up to 7.5 kw, direct starting is allowed the connection diagram is provided on the motor nameplate. With electric motors of larger capacities, apply the star-delta connection start sequence: from zero to close to rated rpm's, the motor runs in a star connection, then it switches over to the delta connection. In the case of two-speed motors, apply the Y/YY combination connection (Dahlander connection) or the Y/Y connection for the startup. Electric motors shall be thermally protected, with the method selected according to the rated current, to provide overcurrent protection and thereby protection against overheating.

16 16 SINGLE-SPEED ASYNCHRONOUS ELECTRIC MOTORS capacities up to 3 kw capacities from 3 to 7.5 kw larger capacities star/delta connection Figure 21 Figure 22 Figure 23 TWO-SPEED ELECTRIC MOTORS WITH COMMUTABLE POLES ANS SINGLE WINDING DAHLANDER connection Y connection YY connection Y/YY connection Figure 24 Figure 25 Figure 26 S W X T R z u Z S T v y w Y U R V y T U W T Y z R u w v S Z V S X R M m V U 3 e2 c1 e1 W R S T Y 1 X Z Z U V W Y X c 2 T W w T y u R S v z Z Y S X V U R w Y R T u v z S U V S y T W X Z R U X Z 3 e3 1 c1 e Y R S T V W U e4 c2 e2 c 3

17 17 TWO-SPEED ELECTRIC MOTORS WITH COMMUTABLE POLES AND TWO SEPARATE WINDINGS U Y/Y connection R Y connection low rpm's X Z Y z u v y w T W V S R S T T Y X S R S T z u v y w Y connection high rpm's Z R Figure Comissioning and testing Prior to checking the correct fan installation and operation, switch off the repair switch of the fan section being the subject of the check, and lock it in the off state to disconnect the power supply to the drive electric motor. Prior to the fan startup, remove the mechanical block of the vibration insulators. Blocks may be wooden (Figure 28) or red colour steel joint brackets screwed on the bottom to the housing structural frame and on the top to the fan-electric motor assembly section. Check: the fastening of the fan to the frame and of the electric motor to the tensioner; parallelism of the electric motor and the fan shafts, and the drive belt running plane, which shall be perpendicular to the fan and motor shafts; in the case of misalignment, adjust the motor by means of the tensioner; retighten all the screw joints upon the completion of adjustment;

18 18 tension of the drive belt(s) according to their manufacturer's specifications; fastening of the rotor to the shaft and its uninterrupted rotation in the housing; fastening of the vibration insulator; correct grounding; correct electric connections and their function (proper fuse, contactor and thermal protection sizing); presence of any tools or other materials in the housing; fastening of all covers and doors. By briefly switching the motor on, check the correct direction of the fan impeller rotation. The impeller shall rotate in the direction of the arrow on the fan housing. In the case of rotation in the wrong direction, interchange two phases on the contactor terminals. The impeller rotation direction check shall be carried out with the fan section door closed. Monitor the direction of rotation through the servicing door window, with the section interior lamp on. 30 minutes after the startup, switch the electric motor off, check the belt(s) tension and adjust it as required. Check the temperature of the bearings; it should not eceed C. Following the startup, the fan should operate at all loads free of vibrations and noise. If not, dismount the fan driving belt(s) and check the electric motor run in idle operation. If irregular, consult the electric motor manufacturer Operation The airflow over the electric motors which are built into the air handling unit is allowed at min. 30 C, ma. +55 C and with relative humidity between 5% and 95% Maintenance Prior to any intervention into the fan section, switch off the repair switch of the fan section being the subject of the check, and lock it in the off state to disconnect the power supply to the drive electric motor. Once a month, check the belt(s) tension and the parallelism of the electric motor and fan shaft, and the running plane of the drive belt(s). Tension the belt(s) by means of the tensioning device in accordance with the belt manufacturer's instructions. Replace damaged bearings. If properly maintained, all our bearings are guaranteed a minimum service life of 20,000 hours. Observe the electric motor manufacturer's instructions for the motor maintenance.

19 19 Once a month, check: fitting of the impeller on the shaft; tightness of all screw joints; impeller run; fan electric motor assembly vibration insulators; fleible connections, and shaft bearing; in a case of any aial displacements of the shaft in its bearings, consult the fan manufacturer and remedy the fault. The checking and maintenance shall be done according to the schedule set out in the following table. Fan section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Cleaning of parts of the fan in contact with air and also the water drain to maintain functioning Check the hygiene condition Time interval (months) According to the hygiene inspection 5.2 HEATER SECTION WITH WATER HEATER Installation and commissioning The heating circuit piping and the heater connections shall not impede the withdrawal of the antifreezing section frame from the air-conditioning unit housing. Depending on the working medium, the heater connection piping and the collector and distribution manifold may reach high surface temperatures; therefore, take care not to touch these surfaces when working close to the heater, or wear personal protection means (leather gloves), or stop the air handling unit and shut off the supply of hot water and let the heater and the piping cool down prior to any work. With outdoor installation air handling units, the heater connection piping is mounted inside the housing, at the back non-servicing side, Figure 29.

20 20 empty unit for the GTK connection PRAZNA ENOTA ZA POVEZAVO GTK Figure 29 The method of connecting the piping to the heating circuit depends on the piping diameter, as follows: - with piping diameters of 3/4" up to and including 3", by means of threaded (Holland) nuts, and - with piping diameters 4" and larger, by means of flanges rated for nominal pressure 16 bar. With outdoor installation air handling units, install the piping circuit in the void chamber downstream the water heater. In this way, it is protected against freezing in the winter period. When installing the water heater, make sure to properly connect the piping installation (Figure 30) and observe the following: Provide the transfer medium / air counterflow configuration. Connect the piping and fittings so as to allow unobstructed access to and drawing out of the heat echanger for revision and maintenance works, without obstructing access to the adjacent sections. When tightening threaded joints, apply counterforce with an appropriate tool (pipe wrench padded), to avoid damaging the heater piping circuit. For easier dismounting, connect the heater by means of two pairs of flanges. Do not weld the connection. Arrange the two piping connections to the water heater observing the air flow direction, so that the air inflow to the heater is closer to the return pipe, to ensure medium/air counterflow. This applies for either horizontal or vertical air flow configuration. The pump may be installed in either the horizontal or in the vertical piping leg, provided that the pump shaft is horizontal.

21 21 The control/distribution or miing valve may be installed in either the supply or return pipe; the distance between the supply and return pipe and the distance between the control valve and the bypass pipe should not be less than 500 mm. Upstream the heater intake, install a dirt trap in the supply pipe to protect the control valve and the circulation pump. Figure 30 In the supply pipe downstream the connection stop valve, at the heater intake and outlet, install thermometers. At the lowest point of the piping installation, provide drain cocks for the transfer medium, to allow the heat echanger draining. At the highest point of the piping system, provide a bleeding device to ensure uninterrupted flow of the medium through the heater (as a rule, the heaters are supplied already fitted with the bleeding valve and drain cock at the highest / lowest point of the collector / distribution pipe). Clean the piping system of filings and other debris. Prior to the commissioning, check: proper operation of the heater automatic anti-freezing protection prior to the filling of the heater with the circulation medium; tightness of piping connections; proper operation of the automatic heating medium supply shut-off function, designed to protect the electric motor against overheating, at the heating medium temperature eceeding 70 C.

22 Filling and draining procedure transfer medium: warm, hot water Filling: partly open the transfer medium supply valve; let the fin register to heat up or cool down uniformly to avoid thermal stresses; fully open the transfer medium supply valve; bleed the system to ensure its achieving the full rated thermal capacity; switch the fan on. Draining: close the transfer medium supply valve; slowly open the drain cock until the heat echanger is depressurised; then full open both the bleeding valve and the drain cock Operation Protection of the heater against freezing The protection of the heater against freezing consists of a freezing thermostat, a thermostat installed in the heating medium return line, and an automatic controller. Set the air flow thermostat to 5 C, and the medium flow thermostat to 14 C. With the air handling unit supplied with the controls or automatic controls by Lindab, the unit comes with the anti-freezing protection function already fitted; in the case of the controls provided by the customer or a third person, make sure to provide the heater with the anti-freezing protection function. Protection of the heater against overheating In the configuration applying a high temperature heating medium (water above 70 C), the electric motor shall be protected against overheating by means of an automatic shut-off of the heating medium supply to the heater in an event of the unit shutdown, with the fan remaining in operation for a certain period after the shutdown (3 to 5 minutes) Maintenance To ensure proper functioning of the heat echangers, regularly carry out the following operations: Check the tightness of all water connections and air joint tightness. Check the operation of the bleeding valve. In an event of disturbed medium flow through the echanger, or presence of air in the circuit, bleed the piping system. Check the proper operation of the heater automatic anti-freezing protection.

23 23 Periodically, check the proper operation of the heating medium supply automatic shut-off upon the unit shutdown. To prevent the electric motor overheating, check the fan prolonged operation (3 to 5 minutes) following the unit shutdown. Regularly check any dust build-up on the heater fins. Dust or scale build-up on the fins result in a reduced heat echanger capacity. Periodically approimately every 500 hours of operation clean the fins. Clean the fins by blowing compressed air in the direction opposite to the air flow direction. If this cleaning method is not sufficient, dismount the heater and wash it with low pressure water or steam. Do not use high pressure water or steam, to avoid deforming the aluminium fins. When washing with water, the water pressure shall not eceed 15 bar, and the water jet shall be strictly perpendicular to the fin surfaces. Water jet at an angle will damage the fins. This applies in particular for the fins along the edges, which are more sensitive. Never use any hard object for cleaning. The checking and maintenance shall be done according to the schedule set out in the following table. Water heater section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Check the hygiene condition Time interval (months) According to the hygiene inspection 5.3 ANTI-FREEZING PROTECTION (FR) Connection, operation and maintenance The type, connection, operation and maintenance specifications for the frost sensor are provided in the electric control cabinet instructions. 5.4 HEATER SECTION WITH STEAM HEATER Installation and commissioning The heating circuit piping and the heater connections shall not impede the withdrawal of the antifreezing section frame from the air-conditioning unit housing. See also document section

24 24 When installing the steam heater, make sure to properly connect the piping installation (Figure 31) and observe the following: Provide the transfer medium / air counterflow configuration. Connect the steam supply line on the top, inclined towards the heater. The connection pipes and piping fittings shall not restraint the heater thermal epansion. For easier dismounting, connect the heater by means of two pairs of flanges. Do not weld the connection. In the supply pipe downstream the connection stop valve, at the heater intake and outlet, installation of thermometers is recommended. Install a medium drain cock at the lowest point of the piping installation. This enables the draining of the heater. At the highest point of the piping system, install a bleeding device to ensure uninterrupted fluid flow through the heat echanger. Ensure safe, continuous and immediate removal of condensate by means of appropriate condensate pipe inclination towards the condensate collector. The condensate collector shall be located so as to prevent condensate holdup in the heater. Install it under the lowest point of the steam heater. For proper steam heater functioning, always provide dry saturated steam at the inlet. The steam composition shall conform to the specifications of relevant standards. Regularly check the steam quality according to SIST EN Clean the piping system of filings and other debris. Prior to the commissioning, check: Figure 31 Proper operation of the heater automatic anti-freezing protection prior to the filling of the heater with the circulation medium; See also document section Filling and draining procedure heating medium: saturated water steam

25 25 Filling: partly open the steam valve and wait until steam begins to emerges from the draining and bleeding valves; shut the draining and bleeding valves and fully open the steam supply valve. Draining: shut the steam supply valve and open the drain valve; having finished the draining, reopen the steam valve and leave it open until all the condensate is drained from the device and steam emerges at the outlet; shut the steam valve; leave the drain valve open until the net startup; following the draining of the heat echanger, blow the tubing register with compressed air to eliminate the risk of any residual heating medium or condensate freezing in the tubing Operation Observe the instructions in the document section Apply ma. 9 bar of pressure to the steam heater Maintenance Observe the instructions in the document section Periodically check proper operation of the automatic condensate collector for the condensate removal. Regularly clean the condensate removal lines. 5.5 HEATER SECTION WITH ELECTRIC HEATER Installation and commissioning Connection of the electric heater to the mains shall be done by a properly qualified electrician, in conformance with the applicable regulations. Electric heating coils are connected to a 3220 V or 3380 V power supply; during operation, their surface reaches temperatures up to ~ 350 C.

26 Operation Air flow velocity across the heater shall not be less than 2 m/s, the air flow shall be evenly distributed across the entire cross section. The electric air heater shall start only with the fan already running and an adequate air flow volume established. Upon the heater switching off, the fan shall continue to operate for another 3 to 5 minutes to cool down the heater coils. The electric air heater is not of a water-tight construction; hence the electric heater section shall not be installed so as to be eposed to water or steam Maintenance Once a month, check: operation of the safety temperature limiter and thermostat; operation of the relays for the early switching on of the fan and the delayed switching off of the electric heater; proper and secure attachment of the guards (servicing cover, connection bo cover, protection grilles etc.). Electric heater section checking and maintenance schdule Time interval (months) Action According to the hygiene inspection Inspect for contamination, damage and corrosion Inspect electrical and safety eqipment Check the hygiene condition

27 HEATER SECTION WITH INDIRECT GAS HEATER combustion chamber 2. tubing register 3. connection to stack 4. gas burner with continuous control of thermal output 5. air flow director between the ceiling and the heater and the bottom and the heater 6. air flow director between the back panel and the heater 7. safety thermostat - set to 80 C, and safety temperature limitter - set to 90 C 7.1 safety thermostat and safety temperature limitter sensors 8. differential pressostat - range to 500 Pa 8.1 measuring tube - pressure pickoff 9. sensor entry sleeve (400 mm in length) 10. condensate drain from the heater tube register collection chamber 11. pan with floor drain Figure 32 4 Burner train diagram The burner train diagram is shown in Figure 33: thermal guard 2. shut-off cock 3. gas filter 4. gas pressure controller 5. gas pressure switch 6. gas solenoid valve 7. gas throttle damper 8. gas burner 1 3 Figure 33

28 Installation and commissioning An indirect gas heater section shall always be located in the positive pressure part of the A/C unit downstream of the supply fan, in order to prevent supply air and flue gas miing in a case of a heat echanger damage. The safety pressostat, safety thermostat and temperature limiter and the operation thermostat shall be installed outside on the section housing. In the cases of outdoor installation units, insulate them, complete with the burner, by means of water tight and thermally insulated protection chamber. The gas burner shall be mounted on the combustion chamber opening from the outside of the section housing. Apply the flange, which is provided to suit the type and size of the gas burner. With indoor installation type A/C units, always ensure adequate combustion air volume, natural ventilation of the machine room, and flue gas ehaust. In the cases of outdoor installation air handling units, with the section eposed to weather elements (wind, rain, snow,...), construct a watertight and thermally insulated protection chamber for the burner, fitted with a free opening at the bottom, for the supply of combustion air. The protection chamber shall be large enough to also accommodate the safety pressostat, safety thermostat, temperature limiter and the operation thermostat. The chamber shall be spacious enough (left and right to the gas burner) for the installation of the gas train. Consult the competent chimney sweep service as regards the design of the flue gas ehaust. If the supply of unit complete with stack is ordered, the stack shall be sized and constructed in compliance with applicable regulations, laws and standards. For the purpose of acquiring the fire service consent, a stack design file is required, which shall also specify the draining and neutralisation of the flue gas condensate. The gas burner connection to the stack shall be in accordance with the requirements applicable to gas fired systems. The stack connector to stack joint shall be water-tight, to prevent any uncontrolled condensate leakage to the environment in a case of condensation of flue gases. No laying of electric cables inside the section housing is allowed. In the cases of outdoor installation units, the gas burner protection chamber may be used for the laying of electric cables, provided that the cables shall be laid so as not to obstruct the servicing of the section, or the cables may be laid on the free outside surface (back panel, bottom etc.), in consultation with the designer/customer. Arrange the gas supply train so as not to obstruct the servicing of functional sections and to allow the drawing out of any functional element from the A/C unit housing when required. For a gas heater section, the design file shall specify a natural air connection (for the purposes of cooling) between the section interior and the environment. The top or side opening shall be fitted with a drive and spring louvre and connected, through a duct, to the building environment. The louvre and the duct shall be fitted with thermal insulation of incombustible material. The louvre shall, in an event of mains power blackout or any other failure that interrupts the section cooling, leading to its overheating, open and thus ensure natural cooling of the gas burner.

29 29 The sealing between the frame and the panels of the left and right adjacent sections, and the sealing of contact joints between the left and right adjacent sections and the gas heater shall be provided by means of a ceramic fibre sealing tape 19 5 mm, temperature resistant in the range -20 to C. If sealing with putty, apply a high temperature resistant glue-seal material with temperature resistance range 40 to +250 C (short term, +300 C). All the electric cables laid inside the housings of the right and left sections adjacent to the gas heater section shall be of a high temperature resistant insulation type. The same applies to cable sleeves and protection tubes. To isolate vibrations and noise between the housing and fan upstream of the gas heater, apply a fleible connection (canvas) of a high temperature resistant material according to DIN To equalise the potential of the fan upstream of the gas heater, apply an noninsulated Cu lead. The volume flow rate of the air passing the combustion chamber and across the coil set shall never be allowed to fall below the minimum value required for the cooling of heat echanger walls. For this purposes, carry out the following checks prior to the section commissioning: installation and operation of the thermostat provided to monitor and maintain the heat echanger outlet air temperature within the 50 C to 60 C range; the installation and operation of the electric motor drive and its limit switch, of the louvre, which shall, in an event of mains power blackout or any other failure that interrupts the section cooling, leading to its overheating, open and thus ensure natural cooling of the gas burner, motor drive limit switch actuated shut down of the gas burner and disabling its operation in the event of the 80-percent closure of the louvre controlling the cooling air flow through the heat echanger; installation and operation of the safety air flow rate gauge provided to shut down the gas burner in the event of inadequate air flow across the heat echanger; operation of the pressure switch provided to shut down the gas burner in the event of eceeding positive pressure in the combustion chamber; installation and operation of the protection thermostat provided to automatically shut down the gas burner in the event of the air temperature in the chamber above the heat echanger eceeding appro. 70 C; installation and operation of the protection thermostat (limiter) provided to shut down and disable the gas burner in the event of the air temperature in the chamber above the heat echanger eceeding appro. 90 C; gas burner restarting shall only be possible upon manual resetting intervention; installation and operation of the time relay that prolongs the running of the supply fan for a period after the switching off of the gas burner; tightness of the heat echanger and flue gas ehaust installation.

30 30 Connection to the gas supply and burner commissioning shall be carried out by authorised and qualified personnel following the gas burner manufacturer instructions, design specifications and regulations in force Operation Officially declared temperature of the environment at which the gas burner operates properly is min. -15 C Maintenance Prior to any intervention in the indirect gas heater section interior, in the gas burner, the burner train or the stack, shut the entire air handling unit down by switching off the main switch on the electric control cabinet. Lock the switch in the off position. Prior to the startup, clean the device interior and firmly tighten all electric connections, check the presence and proper positioning of the thermostat sensors, check the tightness of the gas installation, seal all air joints and attach guards (covers, duct flanges, protection grilles etc.). Once a month, check: operation of the thermostat provided to monitor and maintain the heat echanger outlet air temperature within the 50 C to 60 C range; operation of the bypass louvre electric motor drive and its limit switch; operation of the motor drive limit switch actuated shut down of the gas burner and disabling its operation in the event of the 80-percent closure of the part of the louvre controlling the air flow through the heat echanger; operation of the time relay that prolongs the running of the supply fan for a period after the switching off of the gas burner; operation of the safety air flow rate gauge provided to shut down the gas burner in the event of inadequate air flow across the heat echanger; operation of the pressure switch provided to shut down the gas burner in the event of eceeding positive pressure in the combustion chamber; operation of the safety thermostat provided to automatically shut down the gas burner in the event of the air temperature in the chamber above the heat echanger eceeding 70 C; operation of the safety thermostat (limiter) provided to shut down and disable the gas burner in the event of the air temperature in the chamber above the heat echanger eceeding 90 C; tightness of the heat echanger and flue gas ehaust installation. Maintain the gas burner in accordance with the manufacturer's instructions.

31 31 Gas heater section checking and maintenance schedule Time interval (months) Action According to the hygiene inspection Inspect for contamination, damage and corrosion Inspect electrical and safety eqipment Inspect tightness of the heat echanger Check the hygiene condition 5.7 HUMIDIFYING SECTION WITH SPRAY HUMIDIFIER The section is shown in Figure positive pressure line pressure gauge 2. shut-off cock upstream the pressure gauge 3. water droplet eliminator 4. electric switch 5. electric connection bo 6. lamp 7. manual blowdown valve 8. positive pressure line valve 9. door with window 10. air director 11. fast water filling valve 12. level switch low water level guard 13. overflow with siphon trap, for p 1000 Pa 14. suction bucket 15. drain pipe 16. housing 17. pressure nozzle 18. pool 19. positive pressure distribution 20. floater valve high water level guard 21. pump A dry air entry B humidified air outlet C fresh water supply connection D pool water draining connection Figure 34

32 Installation and commissioning Mount the humidifier section on special supports or an adapted foundation as described in sections 4.2 in 4.3. The pool shall not hang freely but shall be supported on the base. Arrange the water supply to the water collector through a shut-off valve and a dirt trap. Regarding the microbiological parameters, the filling water shall meet the potable water quality criteria and applicable regulations. Connect the water outlet from the overflow to a piping system of appropriate inclination through an eternal outlet siphon. The internal siphon in the overflow line allows water outflow at negative pressures up to 1000 Pa. Compensate the difference between any higher negative pressure and the 1000 Pa limit by means of an eternal siphon in the water drain connection (D). The siphon sizing is laid out in section Prior to the startup and operation, the pump shall be flooded with water. Its operation shall be linked with the operation of the air handling unit fan. With the fan being shut down, the pump shall be off as well, to prevent water spraying to the adjacent section. The nozzle pressure, not to eceed 3.5 bar, is to be set manually by means of the throttle valve and checked on the pressure gauge. Both these elements are installed in the pressure line between the pump and the nozzles. Prior to the commissioning, check: tightness of different screw joints and pipe connections; tight fitting, position and cleanliness of the nozzles on the spray register (replace any missing nozzles and clean any dirty nozzles); proper position and cleanliness of the suction bucket; operation of the floater valve and the level switch; water level in the pool; water tightness of the inspection door; proper installation of the pump and level switch electric connections; when filling the pool with clean water, check the proper operation of the floater valve during the water inflow open the floater valve level has been set in the shop; tightness of the pool; pump flooding with water; direction of the pump rotation (by briefly switching on the pump). By means of the throttle element (valve) and the pressure gauge in the pressure line, set the optimum operating pressure upstream the nozzles according to the

33 33 manufacturer's instructions; then check the direction and the proper pattern of the spray from the nozzles. Leave the section to run for a couple of minutes, then check the proper operation of the fresh water supply; this is considered proper if it has prevented the pool water level from dropping below the set value during this period Water treatment With the increasing concentration of salts in the spray water, a result of water evaporation (air humidifying), the risk of ecessive build up of deposits on the humidifier section water part and the tubing increases. Some typical methods of water treatment (softening) are given in the following table. Operational performance requirements Minimum Medium Maimum Raw water hardness degree 1* 2* 3* 1* 2* 3* 1* 2* 3* Non-treated water X X Addition of polyphosphates X X X Echange in the pool process X X X Decarbonisation X Water blowdown X X X X X X X X X Periodic removal of scale X X Note: 1* - soft 2* - medium 3* - hard Maintenance - Maintain the spray humidifier section so as to prevent the growth and reproduction of microorganisms on any air handling unit sections or the ventilation system as a whole. - The spray humidifier section pool water shall meet the minimum quality criteria for potable water. To avoid the build-up of scale in the droplet eliminator, the total water hardness shall not eceed 7 dh. - Prevent the growth of the bacteria count by means of an appropriate sterilisation system or regular and appropriate cleaning. - The recirculation water bacteria count shall not eceed the standard level of 1000 CFU/ml at the incubation temperature 20 C 1 C and 36 C 1 C. - Avoid the presence of Legionella type bacteria in the spray humidifier section pool water. The total count of these bacteria shall not eceed the level of 1 CFU/ml. - The total count of the aerobic and Legionella type bacteria shall not eceed the limits laid down by the applicable regulations for the region in which the spray humidifier section is installed. Check the bacteria count in water as required by the applicable regulations. - Apply a physical or chemical method of disinfection. The selected method shall be effective and not harmful to human health.

34 34 - Installation of automatic water draining and drying is recommended, for the cases of the spray humidifier section shutdowns eceeding one day. - Relative humidity of air in the system should not eceed 90 %. - The addition of chemicals to water should not result in deteriorated air quality after the spray humidifying. - When selecting the process, consult hygiene eperts. Periodically check: pool water level (if too low or too high, adjust it by means of the floater valve); operation of the floater valve; operation of the level switch; proper supply of fresh water to the collector; operation of the spray nozzles, through the inspection door; cleanliness of the droplet eliminator and air director; tightness and condition of the nozzles (change any damaged nozzles with new nozzles) keeping a minimum stock of replacement nozzles is recommended. - At least once a month, but preferably more often, change the total water inventory and thoroughly clean the pool and disinfect it as required. Clean the siphon and refill it with water. - Every 6 months or as appropriate, descaling and debris removal of the humidifying section is recommended (nozzles, spray register, droplet eliminator and air director blades, suction bucket, overflow pipe). Clean the components dismounted, by soaking in dissolved methane (formic) acid or hydrochloric acid. Thoroughly rinse the cleaned components with water to neutralise them. Never use any foaming cleaning agents or clean the nozzles with hard objects. Replace any damaged nozzles with new ones. - Handle any waste spent acids in accordance with their manufacturer's specifications and the environment protection regulations and legislation. - With the air handling unit shut down, the humidifier section, the piping and the pump shall be drained and cleaned of all limestone deposits and other contaminants. If not cleaned, the debris in the devices hardens and causes premature failure of the pump at the time of startup. - Maintain the water pump and its drive electric motor in accordance with their manufacturer's instructions.

35 35 The spray humidifier section checking and maintenance shall be done according to the schedule set out in the following table. Spray humidifier section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Check the bacterial count of the humidifier water where the bacterial count is > 1000 KBE/ ml, wash with cleaning agent, flush and dry the tank, disinfect if necessary. lnspect atomiser nozzles for deposits Inspect dirt traps for condition and functioning Check for flock formation in the bottom of the air humidifier tank Check the recirculation pump for dirt and coating of the inlet pipe. Carry out functional test of sterilisation system CIean the air humidifier if a shutdown of more than 48 hours occurs - wash with cleaning agent, flush and dry the washer tank. Inspect for contamination, damage, corrosion and demister (droplet eliminator) for coating Check the hygiene condition Time interval (months) According to the hygiene inspection every 14 days X X X X As required 5.8 HUMIDIFYING SECTION WITH STEAM HUMIDIFIER Installation and commissioning In the case of the steam distributor installation on the site, observe the instructions provided by the manufacturer of the steam distributor. Make sure an adequately sized siphon is installed in the condensate collection pan drain line. See section Operation Steam applied in steam humidifier shall contain no substances harmful to human health. The steam generation supply water shall meet the minimum quality criteria for potable water. The air-conditioning unit control system shall operate the unit so as to keep the relative humidity in the air-conditioning system below the 90 % level.

36 36 The steam humidifier shall start only upon the establishment of adequate air velocity and temperature. The steam humidifier shall shut down before the fan stops; in cases of air flow interruption due to the overall outage of the air-conditioning unit, relative humidity build up above the 90 % level or any other reasons Maintenance Steam applied for humidifying shall contain no substances harmful to human health. Maintain the steam humidifier in accordance with its manufacturer's instructions and in accordance with the schedule set out in the following table. Steam humidifier section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Wash with cleaning agent, flush and dry the humidilier chamber, disinfect if necessary Check for condensate precipitation in the humidifier chamber ciean the vapour humidifier Inspect the dirt traps for condition and functioning Check the vapour lance for deposits Check the condensate drain Functionally test control valve Check the hygiene condition * Check during the operation. Periodically check: tightness of air, steam and water joints. Time interval (months) According to the hygiene inspection * 5.9 HUMIDIFYING SECTION WITH CONTACT HUMIDIFIER Installation and comissioning For comission observe the instructions provided by the manufacturer of the contact humidifier. At filling, the supply water shall meet the microbiological parameters adequate for the potable water quality and the applicable regulation.

37 Operation Supply water requirements Circulation water Direct water Minimum pressure 500 kpa 150 kpa Maimum pressure 1000 kpa 1000 kpa Temperature 0 C 40 C 0 C 40 C Maintenance Maintain the contact humidifier in accordance with manufacturer's instructions. - Maintain the contact humidifier section so as to prevent the growth and reproduction of microorganisms on any air handling unit sections or the ventilation system as a whole. - The humidifier section pool water shall meet the minimum quality criteria for potable water. To avoid the build-up of scale in the droplet eliminator, the total water hardness shall not eceed 7 dh. - Prevent the growth of the bacteria count by means of an appropriate sterilisation system or regular and appropriate cleaning. - The recirculation water bacteria count shall not eceed the standard level of 1000 CFU/ml at the incubation temperature 20 C 1 C and 36 C 1 C. - Avoid the presence of Legionella type bacteria in the spray humidifier section pool water. The total count of these bacteria shall not eceed the level of 1 CFU/ml. - The total count of the aerobic and Legionella type bacteria shall not eceed the limits laid down by the applicable regulations for the region in which the contact humidifier section is installed. Check the bacteria count in water as required by the applicable regulations. - Apply the physical or chemical method of disinfection. The selected method shall be effective and not harmful to human health. - Relative humidity of air in the system should not eceed 90 %. - The addition of chemicals to water should not result in deteriorated air quality after the contact humidifying. - When selecting the process, consult hygiene eperts. - Prior to starting the humidifying function - fan, let the humidifier water supply pump run for 15 minutes. According to the humidifier manufacturer's recommendations, this ensures full wetting of the humidifier cartridges. - The minimum humidifier operation time from the start to the shutdown should be at least 10 to 15 minutes. Allow a period of the same duration from the shutdown to the net start. When the need for humidifying ceases and the humidifier has been shutdown (water supply to the humidifier shut off), the air handling unit should not be shut down before the humidifier cartridges dry out. If the contact humidifier is to

38 38 remain out of operation for 24 hours or more, drain water from the humidifier pan. Installation of automatic water draining and section drying equipment is recommended. - Carry out a microbiological analysis of the supply water. If the presence of bacteria is established, disinfect the supply water. Properly set the humidifier blowdown operation. For this purpose, obtain the required data by a supply water analysis: CaCO3 quantity (mg/l), Ca + quantity (mg/l), HCO3 - quantity (mg/l), ph value. Determine the blowdown factor fo from the water quality diagram provided in the contact humidifier manufacturer's instructions. Periodically check: tightness of air and water joints; With the air handling unit shut down, the humidifier section, the contact humidifier and the siphon shall be drained and cleaned of all limestone deposits and other contaminants. If not cleaned, the debris in the devices hardens and causes premature failure of the pump at the time of startup. The contact humidifier section checking and maintenance shall be done according to the schedule set out in the following table. Contact humidifier section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Check the bacterial count of the humidifier water where the bacterial count is > 1000 KBE/ ml, wash with cleaning agent, flush and dry the tank, disinfect if necessary. lnspect atomiser nozzles for deposits Inspect dirt traps for condition and functioning Check for flock formation in the bottom of the air humidifier tank Check the recirculation pump for dirt and coating of the inlet pipe. Carry out a functional test of blow down device Carry out a functional test of conductivity measuring cell. Carry out functional test of sterilisation system Clean the air humidifier if a shutdown of more than 48 hours occurs - wash with cleaning agent, flush and dry the washer tank Time interval (months) According to the hygiene inspection every 14 days X X X X X As required

39 39 Inspect for contamination, damage, corrosion and demister (droplet eliminator) for coating Check the hygiene condition 5.10 HUMIDIFYING SECTION WITH HIGH-PRESSURE HUMIDIFIER Installation and comissioning Observe the instructions provided by the manufacturer of the high-pressure humidifier. Make sure there is an adequately sized siphon in the condensate collection and removal pan drain line. See section 5.13 for instructions for the construction, installation and connection of siphons Operation Required water values: Parameter Symbol Unit Limit values Min Ma ph ph 6,5 8,5 Specific conductivity (at 20 o C) σr, 20 C μs/cm 0 50 Water hardness TH mg/l CaCO Current water hardness mg/l CaCO Total amount of dissolved substance cr mg/l (*) (*) Dry residue at 180 o C R180 C mg/l (*) (*) Iron + manganese mg/l Fe+Mn 0 0 Chlorides Ppm Cl 0 10 Silicon dioide mg/l SiO Chlorine ions mg/l Cl 0 0 Calcium sulphate mg/l CaSO Steam applied in the spray humidifier must contain no substances harmful to human health. The steam generation supply water shall meet the minimum quality criteria for potable water. The spray humidifier will only start upon the establishment of an adequate air velocity and temperature. The spray humidifier shall shut down before the fan stops in cases of air flow interruption due to the overall outage of the air-conditioning unit or for any other reasons.

40 40 Observe the manufacturer's instructions Maintenance Maintain the high-pressure humidifier in accordance with the steam humidifier manufacturer's instructions and in accordance with the schedule set out in the following table. High-pressure humidifier section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Wash with cleaning agent, flush and dry the humidifier chamber, disinfect if necessary Check for condensate precipitation in the humidifier chamber ciean the humidifier if necessary Check the spray register for deposits Check the droplet eliminator for deposits Check the condensate drain Check the hygiene condition * check only during operation Time interval (months) According to the hygiene inspection * 5.11 COOLING SECTION WITH WATER COOLER Installation and comissioning See the document section

41 41 An eample of proper connection is illustrated in Figure 35. Figure 35 Prior to the commissioning, check: proper operation of the cooler automatic anti-freezing protection prior to the filling of the cooler with the circulation medium; tightness of piping connections; cleanliness of the piping system and the installation of the dirt trap. Filling and draining procedure transfer medium: cold water, water with glycol additive Filling: fully open the transfer medium supply valve; bleed the system to ensure its achieving the full rated cooling capacity; switch the fan on. Draining: close the transfer medium supply valve; slowly open the drain cock until the cooler is depressurised; then full open both the bleeding valve and the drain cock Operation a) Cooling circuit filled with water: anti-freezing protection by means of the anti-freezing protection function of the heater section which shall be installed upstream the cooler section; anti-freezing protection is provided by fully draining the system before the cold (winter) period of non-operation. b) Cooling circuit filled with glycol and water miture:

42 42 anti-freezing protection is provided with an appropriate concentration of the glycol and water miture. In handling glycol, observe the glycol filling safety sheet. In an event of a prolonged power blackout, the unit shutdown or interruption of the cooling medium supply, drain the cooler to avoid its freezing Maintenance See also the document section Check the protection of the cooler to avoid its freezing. The checking and maintenance shall be done according to the schedule set out in the following table. Water cooler section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Inspect wet coolers, condensate tanks and demisters for contamination, corrosion and functioning Functionally test the siphon CIean wet cooler, demister and condensate tank Check the hygiene condition Time interval (months) According to the hygiene inspection 5.12 WATER DROPLET ELIMINATOR Operation The blades are permanently temperature resistant to 125 C Maintenance Blade cleanliness should be checked regularly; clean or change the droplet eliminator as required.

43 43 The checking and maintenance shall be done according to the schedule set out in the following table. Droplet eliminator section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Inspect condensate tanks and demisters for contamination, corrosion and functioning Clean demister and condensate tank Check the hygiene condition Time interval (months) According to the hygiene inspection 5.13 OUTLET SIPHON Sizing and installation Difference between the pressure inside the section and the atmospheric pressure p (Pa): p = pn pz pn pz = pressure in the section = atmospheric pressure The following cases are possible: An undersized siphon leads to jerky outflow of air and water. p < 0 negative pressure in the section; Fig. 36 and 39 p = 0 pressure in the section equal to the atmospheric pressure p > 0 positive pressure in the section; Fig. 40 and 41 If the available height difference from the drain pipe connection point to the machine room floor is less than the required siphon height, lead the condensate outlet deep into an outlet funnel. Do not connect the negative pressure and positive pressure siphon drain pipe directly to the sewage system piping. The outflow of condensate from the siphon to the sewage piping shall be free, through an open funnel. Never connect a positive pressure siphon and a negative pressure siphon to a common drain pipe.

44 44 Mount the siphon on the section outside. Otflow piping should be laid at a minimum 2% inclination in the outflow direction. Figure 36 The measure "A" corresponds to the total pressure drop in the section, specified in the section nameplate or in the fan nameplate. Divide the nameplate readout value (in Pa) by 10 to obtain the measure "A" in mm. C* Required foundation height for proper operation of the siphon. Prior to the airconditioning startup, make sure to flood the siphon with water. Flood it every beginning of the summer season, prior to the startup of the air handling unit. Figure 37 The use of negative pressure Lindab siphon (Figure 37) does not require flooding with water, since the siphon automatically fills up with condensate as this starts to accumulate.

45 45 Figure 38 The measure "A" corresponds to the total pressure drop in the section, specified in the section nameplate or in the fan nameplate. Divide the nameplate readout value (in Pa) by 10 to obtain the measure "A" in mm. C* Required foundation height for proper operation of the siphon. Prior to the airconditioning startup, make sure to flood the siphon with water. Flood it every beginning of the summer season, prior to the startup of the air handling unit maks. 350 maks. 300 Figure 39 The positive pressure Lindab siphon (Figure 39) does require flooding with water COOLING SECTION WITH DIRECT EVAPORATOR Installation and comissioning See also document section The most common joining method consists of soldering; connection by means of fast joints is even more preferable, since this method saves operational costs associated with blade cleaning.

46 46 The evaporator outlet pipe should be thermally insulated with the insulation fitted with vapour stopping according to applicable standards. Install the thermostat epansion valve following the manufacturer's instructions, to a horizontal piping leg as close as practicable to the DUF, upstream the pressure equalisation equipment and at a proper angle according to the pipe thickness. The sensor shall be insulated to avoid the ambient air interference with the measurement. The same applies to the pressure equalisation valve sensor. Application of eternal pressure equalisation valves is recommended, to avoid the interference of the pressure drop across the evaporator. The distribution head should be mounted vertical; if this is not practicable, make sure to install Venturi head. Since the air handling unit evaporator is not fitted with blade defrosting, arrange the electric connection so as to prevent the compressor from operating with the DUF fan not in operation. In the connection of a DUF to a compressor-condenser section, the required accessories include, in addition to a thermal epansion valve: a drying cartridge; a solenoid valve (high-low pressure boundary); inspection opening; collection pan, in particular in cases of long piping installations. In the laying of pipelines, pay attention to oil return and other freon flow associated phenomena. An eample of proper connection is illustrated in Figure distribution head 2. thermostat epansion valve 3. temperature sensor 4. TEV capillary 5. pressure equalisation line 6. moisture indicator 7. solenoid valve Figure drying cartridge 9. collection pan Rotolock valve 10. collection pan The cooling system connection and filling with the cooling medium may only be carried out by a qualified person. Apply copper pipes for the connection, the pipes having been cleaned, dried, purged with dry nitrogen and sealed on both ends.

47 47 Observe the following points during the installation: the maimum allowable distance of the DUF to the other cooling circuit part is 25 m; the condenser may be located maimum 2 m below the compressor; the outlet piping layout should be along the shortest practicable route, with the minimum number of bends (bend radius R > 3.5 times pipe diameter). Prior to the commissioning, check: the conformance of the electric connection with the electrical switching diagram; the condensate outlet; the successful completion of the freon line testing, drying, connection to an air cooled condenser and filling with cooling medium; proper setting of the cooling circuit protection elements, such as the high/low pressure protection switch. The same applies to the condensation pressure control switch. During the commissioning, check: tightness of the soldered joints; adequate quantity of freon (no droplets in the inspection opening); dryness of the equipment (inspection opening colour indicator; dry moist; following the manufacturer's instructions); achievement of the proper evaporation and condensation pressures. DUF filling Prior to the filling, vacuum the system. The vacuuming should continue until the piping system is dry and a proper vacuum is established. DUF evacuation Shut off the compressor-condensation section isolation valves and ehaust freon from the DUF section through a valve fitted specifically for this purpose (employing an environment compliant ehaust equipment according to the Montreal protocol) Operation Observe the instructions for safe operation, starting and maintenance of cooling equipment Maintenance To ensure proper functioning of the DUF, regularly carry out the following operations: check the condition of the soldered joints; periodically, check the inspection opening for bubbles and humidity; check the cooling circuit protection elements mechanical and electrical; see also the document section

48 48 The checking and maintenance shall be done according to the schedule set out in the following table. Direct evaporator section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Inspect wet direct evaporator, condensate tanks and demisters for contamination, corrosion and functioning Functionally test the siphon Clean wet direct evaporator, demister and condensate tank Check the hygiene condition Time interval (months) According to the hygiene inspection 5.15 COMPRESSOR SECTION Installation and commissioning Observe the instructions for safe operation, starting and maintenance of cooling equipment Operation Observe the instructions for safe operation, starting and maintenance of cooling equipment Maintenance Observe the instructions for safe operation, starting and maintenance of cooling equipment CONTROL LOUVRE Installation and comissioning Prior to the commissioning, check the correct louvre opening and closing. Install and commission the motor drive following the manufacturer's instructions and follow the electric cabinet commissioning instructions.

49 Maintenance Periodically check: the condition of gears and blades; tightness of screw joints on the spherical joints and drive levers; proper closing and opening of individual control louvres, and fitting of the motor drive. The checking and maintenance shall be done according to the schedule set out in the following table. Control louvre checking and maintenance schedule Action Inspect for contamination, damage and corrosion of control louvres Check the hygiene condition Time interval (months) According to the hygiene inspection 5.17 FILTER SECTION Cartridge filter Bag filter Installation and commissioning Cartridge filters, if not already installed, should be inserted into the structural frame, according to the following procedure (Figure 41): insert the filter cartridges into the structural frame; with a layer (across the entire unit cross section) filled up with filter cartridges, push the filter cartridges by means of the lock section against the guide with the sealing tape applied; make sure that sealing tape is applied to the L section against which the door will lean, and apply

50 50 the tape onto the door as well if required; close the servicing door; check the connection of pressure gauge pipes to the pressure measurement outlets and connect as required. Figure 41 Bag filters, If not already installed, should be inserted into the structural frame, according to the following procedure: mount the bag filter with the bags hanging through the frame opening, protected from squeezing, pinching or damaging; o the push profile variant (servicing from the clean side): same as with the cartridge filters; o the frames variant (servicing from the dirty side): insert the filter into the frame, then attach a spring clamp to each frame corner in order to fasten it (Figures 42, 43, 44) close the servicing door; check the connection of pressure gauge pipes to the pressure measurement outlets and connect as required. Figure 42 Figure 43 Figure Operation For each filter unit, regularly check: - pressure drop; - operating hours; - visual appearance (check any cracks in the filter material, leakage between the filter and its frame); - the pressure difference between the front and the end of the filter media should not eceed the values defined in the SIST EN standard.

51 Maintenance Prior to installing new filters, always check the complete, uniform and air-tight mounting of the sealing tape on the sealing seat between the filter and its frame. Only use filters declared conformant with the SIST EN 779 standard by their manufacturers. Handle the contaminated filters in compliance with applicable environment protection regulations. The checking and maintenance shall be done according to the schedule set out in the following table. Cartridge / Bag filter section checking and maintenance schedule Action Inspect for impermissible contamination and damage (Ieaks) Replace the defective air filter if the most recent filter stage replacement look place not more than 6 months ago, otherwise replace the complete filter stage Check the differential pressure Replacement of the first filter stage Replacement of the second filter stage Check the hygiene condition Time interval (months) According to the hygiene inspection 5.18 METAL FILTER SECTION Installation and comissioning If not already installed, insert the filter cartridges into the frame, according to the following procedure: place filter cartridges net to each other to fill up the entire section volume; make sure sealing tape is applied to the section servicing door; check the presence of the pan at the bottom, below the metal filter; close the servicing door, and check the connection of pressure gauge pipes to the pressure measurement outlets and connect as required Operation See the document section

52 Maintenance See the document section A contaminated metal filter cartridge may be washed in hot water with added cleaning agent, observing the hot water temperature and the cleaning agent manufacturer's instructions ACTIVE CHARCOAL FILTER SECTION Installation and comissioning If not already installed, insert the filter cartridges into the base plate, according to the following procedure: push the cartridge into the base plate until the clamps click in the openings, then turn it in the direction opposite to the arrow on the cartridge; repeat the procedure to fill up all the positions in all the base plates base plate 2. fiter frame Figure Operation The adsorption capacity depends on the substance concentration. SUBSTANCE Adsorption capacity * (kg) Methyl alcohol (CH2SH) 0,4 0,8 1,2 Hydrogen sulphide (H2S) 0,5 1,0 1,6 Benzol (C6H6) and similar substances 2,5 5,0 8,0 * values applicable at average relative humidity 70 % and only in presence of a single substance. For a combination of substances, a practical test is required. See also the document section

53 Maintenance See the document section The required frequency of cleaning or changing the filter medium depends on the air flow rate and contamination ABSOLUTE FILTER SECTION Installation and comissioning If not already installed, insert the absolute filters into the structural frame, according to the following procedure: open the door on absolute filter section and on the void section upstream of the absolute filter section; check the presence of the sealing tape along the filter structural frame; insert the absolute filter ensuring firm fitting of the filter housing against the sealing tape; mount the sealing sections and tighten the screws to ensure air-tight contact between the filter structural frame and the absolute filter housing; close the servicing door; check the connection of pressure gauge pipes to the pressure measurement outlets and connect as required Operation See the document section Maintenance See the document section

54 SOUND ATTENUATOR SECTION Maintenance The checking and maintenance shall be done according to the schedule set out in the following table. Sound attenuator section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Check the hygiene condition Time interval (months) According to the hygiene inspection X 5.22 FIN RECUPERATOR SECTION Fin recuperator - Heater Description, installation and commissioning, operation, maintenance: see the document section 5.2. Fin recuperator - Cooler Description, installation and commissioning, operation, maintenance: see the document section Installation and commissioning See the document sections and Prior to the section filling, thoroughly purge the device to remove any foreign particles from the piping. Fill the device with transfer medium of appropriate concentration. It is recommended to start by pouring the antifreezing agent and then topping the system with water. During the filling, the cross flow valve shall be in its middle position to ensure simultaneous filling of both heat echangers Operation See the document sections and To avoid the risk of condensate freezing on the fin package, the inlet temperature of the medium in the ehaust air stream heat echanger should never fall below -3 C.

55 Maintenance See the document sections and Regularly check the operation of the circulation pump and proper bleeding of the heat echanger interconnection piping. Twice a year, check the operation of controls. At the beginning of the winter period, check the transfer medium resistance to freezing and change it if necessary. Regularly change the medium every two years. In preparing the water and antifreezing agent miture, observe the instructions and make sure to prepare just the specified concentration Piping installation The piping installation shall be done in compliance with the project design specifications and safety regulations. The piping installation shall comprise an adequately sized epansion tank, a safety valve and other components required with the applied control method. Figure 46 shows the piping installation of a glycol recuperator. Figure 46

56 PLATE RECUPERATOR SECTION Installation and commissioning Prior to the commissioning, check the fitting and linking of the control louvre to the electric motor drive and its operation. Make sure the droplet eliminator withdrawal from the air-conditioning unit housing is unimpeded. Make sure an adequately sized siphon is installed in the condensate collection pan drain line. See section 5.13 for the instructions for the construction, installation and connection of siphons Operation Check the functioning of the control louvre and the electric motor drive Maintenance Regularly clean the plate recuperator. In a case of fouling with dry dust, the insert can be cleaned without dismounting, by blowing it with compressed air with a pressure up to 10 bar maimum through the servicing openings; always wear personal protection equipment during such an operation. If fouled with greasy or sticky debris, the insert shall be withdrawn from the recuperator section housing and cleaned by means of a hot water jet (temperature up to 90 o C, pressure up to 6 bar) with appropriate cleaning detergent added. Since the insert filler is made of very thin aluminium foil, be careful not to damage the insert face surface during dismounting. The sequence of dismounting an insert from the section housing is as follows Figure 47: remove the servicing covers (Pos. 1), remove the partition sections (Pos. 3, 4) on the servicing side, by unscrewing the fiing screws (Pos. 2), unscrew the top guide section fiing screws, loosen the side guide section screws and remove the top guide section; draw the insert out of the section housing; after cleaning, install the inserts back in the section in the opposite order.

57 servicing cover 2. fiing screw 3. partition section Figure partition section 5. insert interconnection screw The checking and maintenance shall be done according to the schedule set out in the following table. Plate recuperator section checking and maintenance schedule Action Inspect for contamination, damage and corrosion Check the seal between the incoming air and outgoing air Inspect the condensate tank and demister for contamination, corrosion and functioning Check the louvre and motor drive Functionally test the siphon Clean the recuperator part, condensate tank and demister Check the hygiene condition Time interval (months) According to the hygiene inspection

58 DOUBLE PLATE RECUPERATOR SECTION Installation and commissioning See the document section Operation See the document section Maintenance See the document section Since the double plate recuperator is most commonly used in combination with the adiabatic humidifying of ehaust air, it is installed with a watertight seal. In this case, the recuperator cannot be dismantled from the housing ROTATIONAL REGENERATOR SECTION Installation and commissioning Mount and install the regenerator in accordance with the manufacturer's instructions, attached to these instructions. If a frequency rotation controller is used, observe its manufacturer's instructions for the installation, operation and maintenance. Prior to the commissioning, check: free rotation of the rotor; proper tension of the drive belt; air-tightness between the rotor and the housing; operation of the electric motor drive, control and protection functions (fuses, thermal protection); functioning of the frequency controller 1 honeycomb plate 2 drive belt 3 pulley 4 belt clutch 5 electric motor 6 tension plate 7 tension spring Figure 48