...... CI/SfB (57.9) Uniclass L755 September 2005 NATURAL VENTILATION CONTROL SYSTEMS...
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...... Passivent ventilation control systems have been have been specially developed to meet the requirements of natural ventilation and mixed mode (natural/mechanical boost) systems. Systems provide automatic energyefficient ventilation control based on a range of sensor inputs. They complement Passivent natural ventilation products including the Aircool, Airscoop, Litevent and Airstract Roof Terminals. Complete packages can be tailored to individual project requirements as stand alone systems or integrated with building management systems. There are two ranges: Enhanced Thermostatic Controls (Single Zone) The ETC range is designed for local ventilation systems. A simple controller monitors internal room temperature and automatically operates Passivent ventilators or other louvres and dampers to control ventilation. Manual override is also possible via simple push button auto time return switches. Additional options include night cooling, boost fan and dual sensor controls. Enhanced Digital Controls (Multi-Zone) The EDC range provides comprehensive control for larger systems. It can be programmed to meet the demands of different applications, with separate control of several zones. A night cooling strategy is included as standard. In addition to internal and external temperature, sensors can monitor carbon dioxide, air quality, humidity and other factors. Installation and commissioning services Passivent s comprehensive service for control systems includes selection advice, wiring diagrams, installation, commissioning, post-installation inspection at six months, and on-site demonstration or training, all carried out in accordance with CIBSE Guide C. An end user instruction card is provided as a simple guide to operation. Heating systems should be capable of maintaining the minimum air temperatures set down in relevant guidelines for the minimum or background ventilation rate in winter. 3
....... ENHANCED THERMOSTATIC CONTROLS ETC1 230V Two-Position Room Control Unit Room controller with electronic thermostat, suitable for remote location. Wall-mounted combined temperature sensor and rotary switch (open/auto/close) for manual or automatic operation in open or closed positions only. ETC2 24V Two-Position Room Control Unit Room controller with electronic thermostat and low voltage transformer, suitable for remote location. Wall-mounted combined temperature sensor and electronic push button switch (open and close) with LED display. ETC3 24V Modulating Room Control Unit Room controller with electronic thermostat and low voltage transformer, suitable for remote mounting. This controls the ventilation opening proportionately as room temperature increases past a pre-set point within an adjustable 0-6 C band. Wall-mounted combined temperature sensor and electronic push button switch (open and close) with LED display. Electronic Push button override switch This switch is included with ETC2 and ETC3 and is programmed to return to automatic operation after a pre-set time (adjustable between 30 minutes and 3 hours) following any manual operation, as recommended by BSRIA guidance (BG 2/2005). An LED display shows the operating mode and any active manual commands. Pressing the buttons a second time disables the command and returns the unit to automatic control. ETC functions Standard function Description ETC1 ETC2 ETC3 Two-position operation Open or closed only - Modulating operation Auto time return Automatic variable ventilation rate within an adjustable temperature band of 6ºC about the set point. - - Switch returns to automatic operation after a pre-set time following any manual command, adjustable 30mins - 3hrs. - Operating voltage Mains 230V - - Via integral 18VA transformer - 24V 24V Actuator rating Maximum number of actuators that can be connected: standard 16 6 6 upgraded with 75VA transformer - 20 20 Optional functions Intelligent night cooling pack (ETC4) Louvre and boost fan control Dual sensor control for larger spaces Standard function Requires additional control Only available with standard rotary room switch 4.
... 230V supply 230V supply 230V supply ETC settings range room controller combined sensor and rotary override room controller combined sensor and electronic push button override room controller combined sensor and electronic push button override control circuits (230V) control circuits (24V) two position dampers / louvres two position dampers / louvres control circuits (24V) modulating dampers / louvres Controller Parameters Range Typical setting ETC1, ETC2 Two Position Control Unit Day temperature 0 to 35 C 22ºC Night set back 3 to 10 C 5ºC Differential 0.3 to 6 C 0.5ºC ETC3 Modulating Control Unit Day temperature 0 to 40 C 22ºC Night set back 0 to 10 C 5ºC Proportional band 0 to 6 C 4ºC ETC4 Intelligent Night Cooling Pack Minimum external operating temperature -10 to 50 C 16ºC Differential 0 to 6 C 0.5ºC Day setting (on times) 09:00-17:00 (7 days) Night setting (off times) Opposite to day Louvre and Boost Fan Control Fan temperature: Two-position unit 0 to 35 C 24ºC Modulating unit proportional band 0 to 6 C 6ºC Optional functions Intelligent Night Cooling Pack (ETC4) ETC4 allows the ventilation system to take advantage of freely available night cooling during warmer periods. It comprises an external temperature sensor, electronic thermostat, time clock and relays to activate room control units at night in accordance with BSRIA Guidance (TN11/95 and report ref. 11621/4). It can be configured to target night-time room temperatures between 3 C and 10 C below daytime levels. In cold winter periods, the system automatically reverts to daytime temperature settings to prevent discomfort and condensation problems within the occupied space. Louvre and Boost Fan Control This is available for strategies requiring a boost fan to help control temperatures in warmer periods, and can be integrated within any room controller. The controller can be set to activate the fan at a higher temperature than that for the ventilation louvres. The room controller includes a temperature sensor, temperature switch and louvre control, fan controller and manual speed control. A built-in safety interlock prevents operation of the fan until the louvres are open. Night cooling is also possible with modulating systems (ETC3). Dual Sensor Control This controller averages the readings from two temperature sensors, and can be integrated within any room controller. They are ideally suited to larger spaces where temperature differences are possible. A manual override open/auto/close switch can be mounted in a remote location. Additional ventilation controls and actuators All room controllers can be modified to allow simultaneous operation of any volume control dampers, glazed louvres, window actuators etc. Rain sensors Rain sensors can be incorporated to close windows and glazed louvres during wet weather. Specification clause: ETC Control of ventilators/ motorised Passivent ventilators to be by means of: [Select and specify standard unit plus additional option as required, eg ETC1 plus ETC4] ETC1 230V Two-Position Room Control Unit: room controller with electronic thermostat and wallmounted combined temperature sensor and three-position rotary switch. ETC2 24V Two-Position Room Control Unit: room controller with electronic thermostat and low voltage transformer, and wall-mounted combined temperature sensor and electronic push button switch with LED display. ETC3 24V Modulating Room Control Unit: room controller with electronic thermostat and low voltage transformer, and wall-mounted combined temperature sensor and electronic push button switch with LED display. Optional functions: ETC4 Intelligent Night Cooling Pack: external temperature sensor, electronic thermostat, time clock and relays. Louvre and Boost Fan Control: room controller with temperature sensor, temperature switch and louvre control, fan controller and manual speed control. Dual Sensor Control: room controller with two temperature sensors, and manual override switch. Supplied by Passivent Ltd, 2 Brooklands Road, Sale, Cheshire M33 3SS, Telephone: 0161 962 7113, Fax: 0161 905 2085. Email: info@passivent.com 5
....... ENHANCED DIGITAL CONTROLS Central control Room sensor Enhanced Digital Control systems are tailored to each specific ventilation application. They can be designed to meet predetermined performance criteria, and provide separate control of several zones with different requirements. Pre-loaded programmable software will operate a wide range of ventilation strategies. All EDC systems have sensors for internal and external temperature. Additional sensors can monitor carbon dioxide levels, air quality, humidity, external wind and rain etc, enabling them to be tailored to the demands of different applications, for example: CO 2 and temperature for schools and offices, to aid concentration. Air quality and temperature for specific pollutants, eg smoke in pubs and bars. Humidity and temperature for spaces with high moisture content, eg shower or changing rooms. Utilising Invensys Climate Controls, EDC systems operate Passivent ventilators or other louvres and dampers automatically to control ventilation according to sensor levels and pre-set programmable profiles. Control is modulating, ie the ventilation rate is continuously varied according to demand. Central control A touch pad screen provides temperature and sensor readings and enables adjustment of sensor settings within zones, day/night changeover times and other parameters. Remote monitoring and configuration is also possible via an optional modem link which allows engineers or facilities managers to avoid unnecessary visits. Room controls Each occupied zone incorporates a wallmounted combined temperature sensor and manual override push-button switch (open and close). The system is programmed to return to automatic operation after a pre-set time following any manual operation, as recommended by BSRIA guidance. An LED display shows the operating mode of the switch and any active manual commands. Pressing the buttons a second time disables the command and returns the unit to automatic control. Touch pad interface Push button override Touch pad interface Computer control Building Management System Heating interlock signal CENTRAL CONTROL Terminal damper Room controls Zone 1 Fire alarm Smoke extract or ventilation shut down signal Temperature sensor & manual override External temperature sensor Aircool louvre CO 2 / air quality / humidity sensor Weather station Terminal damper Room controls Zone 2 Temperature sensor & manual override Rain sensor Aircool louvre CO 2 / air quality / humidity sensor 6.
... Night cooling Each EDC system software includes a night cooling strategy, operating the natural ventilation at night to purge excess heat and cool the building fabric. This can reduce peak daytime temperatures by 2º to 3º C in a building with sufficient thermal mass. This can minimise or even avoid the use of mechanical cooling and improve the internal conditions in naturally ventilated buildings. Passivent's night cooling program is based on extensive field research and with Brunel University and on BRSIA guidance (TN 11/95 and report ref 11621/4). It provides the control required to achieve maximum free cooling whilst avoiding overcooling and subsequent re-heating or thermal discomfort the following day. An external temperature sensor allows the system to detect when night cooling can be used and also prevent over-cooling; this should be mounted on the north wall of the building for best results. Typical program A typical control program might include: Interlock to heating system or fire and smoke control panels as required. Summer/rapid ventilation rates, typically operating above 16ºC by modulating ventilator openings to vary the ventilation rate. Night cooling to activate between 20:00h and 06:00h, ventilators to open if external temperature is greater than 16ºC and less than the internal temperature reading (full program incorporates BSRIA guidance). Winter shift profile offsets internal temperatures against external temperature during colder periods. This raises the set point to allow the ventilators to open when required and minimise unnecessary heat loss whilst ensuring good air quality. Specific profile to control Airscoop winddriven ventilators that provide both supply and extract air to each space, based on external temperature to operate the ventilator and flush the room of excess heat and pollutants. Manual overrides to open or close ventilators within zones; the system will return to automatic operation after a pre-set time delay. CO 2 sensors override the temperature sensor within a zone. Specification clause: EDC Control of ventilation to be by means of a Passivent Enhanced Digital Control programmable system with Touch Pad Display Unit mounted within a dedicated remote enclosure. System to include night cooling strategy with external temperature sensor. One combined room sensor and manual override switch to be included for each occupied zone. (insert detailed system description by Passivent) Supplied by Passivent Ltd, 2 Brooklands Road, Sale, Cheshire M33 3SS, Telephone: 0161 962 7113 Fax: 0161 905 2085. Email:info@passivent.com Typical summer profile (simplified) Ventilation Rate Internal temperature 24ºC Priority control parameters at different times of day CO 2 Internal temp External temp Internal temp Night cooling 100% 22ºC 50% 20ºC 18ºC 0% 16ºC Time 0800 2000 24hrs CO 2 Internal temperature External temperature Ventilation rate 7
......... FURTHER INFORMATION Quality assurance Passivent products are designed and manufactured under an independently monitored quality assurance scheme to BS EN ISO 9001. Services Passivent offer a comprehensive range of installation and commissioning services for our control systems, see page 3. Other products Passivent market a range of natural ventilation and daylighting products including: Aircool ventilation systems for windows, curtain walling and walls. Airscoop roof-mounted natural ventilation terminals. High capacity ventilation terminals. Natural ventilation systems for commercial and domestic buildings, nursing and care homes. Sunscoop tubular rooflight systems. Separate literature is available for these on request.... PASSIVENT LIMITED 2 Brooklands Road, Sale, Cheshire M33 3SS Tel: 0161-962 7113 Fax: 0161-905 2085 Email: info@passivent.com Web: www.passivent.com Passivent Limited maintains a policy of continuous development and reserves the right to amend product specifications without notice. A member of the Building Product Design Group Produced by Ted Hastings/Rackley Design......