Indholdsfortegnelse. Danvent Air Handling Units SERVICE MANUAL

Transcription

1 Indholdsfortegnelse Danvent Air Handling Units SERVICE MANUAL

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3 Service Servicing of the Air Handling Unit Your ventilation system is equipped with a Danvent Air Handling Unit (AHU) which will contribute to creating a good indoor climate for the building for many years to come. To ensure the best possible indoor climate it is important that the performance of your AHU does not deteriorate because of neglected service and inspection. This can be the cause of running problems and reduced efficiency. Such deteriorations can have a great impact on the total running costs and safety aspects of the ventilation system. It is therefore strongly advised to service the system on a regular basis. These instructions list the few necessary service and maintenance procedures required to ensure optimal AHU running performance.! NB! Remember to switch off the main power supply The design and construction of the AHU ensures that necessary service and maintenance is reduced to an absolute minimum. Large inspection doors ensure quick and easy access to all components requiring service and inspection. The following 2 pages give a simple summary as a guide to planning the necessary service and maintenance work on the AHU. The remaining pages give a closer look at servicing and maintaining the AHU s individual components. 3

4 Service Summary The service intervals stated are intended as a guide only, and apply for operating with normal air quality for comfort ventilation. In operating conditions that are particularly dusty or humid, for example, or where the air is aggressive, shorter service intervals may be required. Inspection and check Service work to be carried out! NB! Remember to switch off the main power supply To be carried out once a year To be carried out when the recommended pressure drop is exceeded To be carried out after every 5000 running hours or at least once a year To be carried out four times a year Air Handling Unit Clean the AHU Check the seals and closing mechanisms Dampers Check the air-tightness Bag filters Replace the filter cells and check the seals at the filter cells Compact filter Replace the filter cells Rotary heat exchanger Check the condition of the rotor and that it turns easily Check the brush seals Check the Varimatic drive system Check and tighten the belt drive 4

5 Service Summary Plate heat exchanger Check the heat exchanger Check the air-tightness of the by-pass damper Clean the drip tray, drain and water trap Run-around coil heat exchangers Check the condition of the coils Vent the coils and piping system Clean the drip tray, drain and water trap (exhaust air) Check the droplet eliminator (exhaust air) Pump Heating coil Check the condition of the coil Vent the coil Check the safety thermostats (electrical coil) Cooling coil Check the condition of the coil Vent coil which use water and brine as cooling medium Clean the drip tray, drain and water trap Check the droplet eliminator Fan Check the fan impeller Check the vibration isolators and flexible connections Lubricate bearings for the large motor sizes Lubricate bearings for the large fan sizes Check and tighten the belt drive Sound attenuator Check the condition of the attenuator Clean the cleanable baffles Air distributor Check the condition of the distributor Volumeter Check the condition of the Volumeter 5

6 Air Handling Unit Air Handling Unit The unit should be cleaned once a year when operating with normal air quality for comfort ventilation with no special hygiene requirements. To clean the unit, dry it off with a dry cloth, or use water mixed with a noncorrosive cleaning medium. Any corrosion i.e. at the filters should be cleaned off immediately, and the surface treated. In special operating conditions, where the air is aggressive or very humid, for example, or where there are special hygiene requirements, the unit shall be cleaned more frequently as required. Cleaning medium and method should be adapted to the relevant conditions. Any corrosion should be cleaned off immediately, and the surface treated. Grilles, for air intake and exhaust air outlet, are to be cleaned at least once a year to prevent blockage. Closing mechanisms are to be lubricated at least once a year. Synthetic door hinges are service free. Seals around inspection doors are to be cleaned at least once a year and are to be checked for leakage. It is recommended to treat the seals with a moisture repellent agent. Connecting pieces for the unit sections, including the Disc-Lock types, are to be checked for tightness at least once a year. All seals are to be inspected at least once a year and are to be repaired if necessary. 6

7 Damper and Mixing Damper Damper and mixing damper Rubber seals between the damper blades themselves and between the damper blades and the frame are to be checked once a year. These seals are not to be lubricated or treated in any other way. Each damper blade is connected by a pivoting system. The steel rods and brass bushes do not require lubrication. The damper blades are fitted with synthetic bearings requiring no lubrication. Air-tightness of the damper, when the damper motor is in the closed position, must be visually checked once a year. The damper motor is to be adjusted if the damper does not close tightly. 7

8 Filter Filter The intervals for the replacement of the filter are very dependant on the concentration of dust in the air passing through the filter. The easiest ways to determine the time for replacing the filter cells are: A. Pressure difference manometer which shows the filter pressure drop. B. Pressure difference switch which gives an electronic signal when the filter is to be replaced. Compact filter The filter are to be replaced when the pressure drop exceeds the recommended level. The filter cells are to be taken out and replaced. The filter cell guide rails are to be cleaned before fitting the new filters. Bag filter The filter are to be replaced when the pressure drop exceeds the recommended level. Release the bagfilter cells by activating the handles and pull out the filter cells of the unit casing. The frame profiles are to be cleaned and all seals checked for damage. The handles and locking guide rails are also to be checked to ensure that they can operate unobstructed. The new filter bags should be pushed carefully into the unit in order to ensure that they are sealed properly. The various filter sizes should be placed in an order corresponding to the way in which the unit is divided up, and the filters should have vertical bags. 8

9 Rotary Heat Exchanger Rotary heat exchanger Rotor The rotor is to be checked at least once a year to ensure that it can turn freely and easily. This can be done by removing the belt drive at the motor and then turning the rotor manually with a hand on the peripheral rotor casing. At the same time the brush seals are to be checked for damage. The bearings are factory lubricated and do not require any service lubrication. During operation the rotor can become dirty. The rotor can be cleaned by blowing through with compressed air. To ease inspection and service the rotor can be pulled out of the unit housing on smaller AHU sizes. Cleaning must be carried out with care so as not to damage the rotor material. Motor and belt drive The bearings are factory lubricated and do not require any service lubrication. The belt drive is to be checked four times a year for correct tightness and that it is undamaged. On smaller AHU sizes with variable speed, the rotor is fitted with an elastic belt drive and supplied with a reserve belt on the rotor. This belt drive does not require service and cannot be shortened. A new belt can be fitted using specialist tools. On all other heat exchangers the rotor has a V-belt with a belt connector. If the belt is no longer tight, it must be shortened to a length which enables the motor base frame tightening spring to hold the belt tight. If new screws are used for the belt connector, they must not have a length which exceeds the thickness of the belt and connector. Remove the excess, if any, with a file. Varimatic system A test switch is positioned behind the cover to the electronic box. The test switch is to be activated once a year in order to ensure that the system functions correctly. In the test situation the rotor must rotate slowly and gradually increase up to maximum speed.! NB! Remember to switch off the main power supply 9

10 Plate Heat Exchanger Plate heat exchanger Once a year the edges of the heat exchanger plates are to be checked for cleanliness and damage. If there is dust on the edges of the plates, remove it with a soft brush. If grease or other such substances are present, then the edges must be washed using grease dissolving detergents. The heat exchanger can be cleaned using a high pressure cleaner with a fine spray nozzle, or by blowing through with compressed air. On the opposite side of the exchanger dirt and water can be removed with a water vacuum cleaner. In order to avoid damaging the plate surfaces, washing and cleaning must be carried out with the utmost care. The surfaces must never be scraped with hard objects. When the heat exchanger is fitted into an AHU which handles air with grease particles, such as exhaust air from kitchens, the grease filter fitted before the AHU must be cleaned every day. The AHU must be stopped when the grease filter has been removed. By-pass damper The damper blades are fitted with synthetic bearings requiring no lubrication. Each damper blade is connected by a pivoting system. The steel rods and brass bushes do not require lubrication. Air-tightness of the dampers, when the damper motor is in the closed position, must be visually checked once a year. The damper motor is to be adjusted if the damper does not close tightly. Condense water drain Once a year clean the drip tray beneath the heat exchanger, as well as the drain and the water trap. 10

11 Run-around Coil Heat Exchangers Run-around coil heat exchangers A heat recovery system of this type consists of a heating coil in the supply airflow and a cooling coil in the exhaust airflow. After an extended running period (normally a few years) dust particles can accumulate on the surface of the coils. This can reduce the efficiency of the coils. The coils can be cleaned using a high pressure cleaner with a fine spray nozzle, or by blowing through with compressed air. Cleaning must be carried out with the utmost care to ensure that the coil fins are not damaged. The piping system must be vented once a year as air in the system can significantly reduce the capacity of the coils. Pump and expansion vessel The service instructions issued by the pump manufacturer must be followed. The pressure expansion system must be checked once a year. If necessary, the pressure must be increased to the correct level. Condense water drain Once a year clean the drip tray beneath the cooling coil, as well as the drain and the water trap. If a droplet eliminator has been fitted to the cooling coil, this must be checked once a year and cleaned if necessary. 11

12 Heating and Cooling Coils Heating and cooling coils! Be careful of hot heating coil and pipe surfaces. Remember to turn off the supply of hot water, steam or electricity before beginning inspection and service. After an extended running period (normally a few years) dust particles can accumulate on the surface of the coil. This can reduce the efficiency of the coil. The coil can be cleaned using a high pressure cleaner with a fine spray nozzle, or by blowing through with compressed air. Cleaning must be carried out with the utmost care to ensure that the coil fins are not damaged. The piping system must be vented once a year as air in the system can significantly reduce the capacity of the coil. Cooling coil Once a year clean the drip tray beneath the cooling coil, as well as the drain and the water trap. If a droplet eliminator has been fitted to the cooling coil, this must be checked once a year and cleaned if necessary. Electrical heating coil The coil has a built-in safety thermostat with an automatic reset function and an overheat thermostat with manually resetting. Both thermostats are positioned behind the inspection door.! NB! Remember to switch off the main power supply 12

13 Fan About the fans in general For the smaller sized units the motor and fan are assembled on guide rails allowing easy extraction from the AHU. Dust can accumulate on the fan impeller which can cause imbalance and vibrations. The fan impeller must therefore be checked once a year and cleaned, if necessary. Vibration isolators and flexible connectors should be checked at the same time. If the vibration isolators are damaged in any way they must be replaced. Motor The motor are usually fitted with factory lubricated bearings which require no futher labrication. Larger motors can be fitted with greasing nipples and bearings which require regular lubrication. Lubricating these types of bearings must be carried out according to the manufacturer s instructions. Fan with V-belt drive Bearings Smaller fans are usually fitted with closed factory lubricated bearings which require no futher labrication. The bearings are fitted into vibration absorbing rubber bushes which should be checked for wear and tear. Larger fans are fitted with factory lubricated bearings and greasing nipples. Lubricating these types of bearings must be carried out after every 5000 running hours or at least once a year. The interval for lubrication are valid for air temperatures of up to +40 C. Reduction of the interval is necessary if the air is of a higher temperature, if the air is polluted or present a high level of humidity, or if the bearings must cope with high loads. Bearing lubrication grease must be of the highest quality and produced using a lithium soap base. Grease which contains additives must not be used. 13

14 Fan Care must be taken not to over grease the bearings. This can result in the bearings becoming overheated and eventually damaged. After lubrication of the bearings the fan should be started as follows: Start the fan and let it run for approximately 2 minutes. The fan must then be stopped and the bearings left to cool down until cold. This process is to be repeated a few times before the fan is allowed to run continuously. V-belt drive The belt drive is to be checked 4 times a year. If one or more of the belts is worn then all belts must be replaced. New and used belts must never be used together as they have different lengths. Check that the pulleys are in line and completely parallel with each other. The belts are to be tightened to a suitably tension. Over tightening can cause unnecessary wear and reduce the life expectancy of the bearings.! NB! Remember to switch off the main power supply Tightening the belts L f kg L mm f mm Profile XPZ XPA XPB Load 1,5 kg 2,7 kg 5,0 kg 14

15 Sound Attenuator and Air Distributor Sound attenuator During operation dust particles can accumulate on the surface of the baffles. Sound attenuators which are designed for dry and wet cleaning are fitted with baffles which can be extracted from the unit casing. Large inspection doors give access to the baffles which can then be easily extracted. Baffles designed for dry cleaning can be cleaned using a soft brush or they can be vacuum cleaned. Baffles designed for wet cleaning can be washed down using a soft brush and soapy water. The detergent used must be non-aggressive. After washing, the baffles must be wiped dry with a cloth. Remember to clean the inside surface of the unit casing before re-fitting the baffles. Air distributor The air distributor, which is fitted on the fan outlet, is to be checked once a year as dust particles can accumulate on the distributor during operation. The dust can be removed using a brush or a vacuum cleaner. Volumeter The measuring probe, which is fitted to the fan inlet opening, is to be checked once a year for dust accumulation. The measuring probe opening must be completely dust free. 15

16 Indholdsfortegnelse Systemair A/S Ved Milepælen 7 DK-8361 Hasselager Denmark Tel.: Fax: mail@systemair.dk GB