zehnder ComfoAir XL 4400 Central Ventilation Units With Heat Recovery User Manual
- June 13, 2024
- Zehnder
Table of Contents
zehnder ComfoAir XL 4400 Central Ventilation Units With Heat Recovery
Product Information
- Certificate: Certified Passive House Component
- Component-ID: 0468vl03 (valid until 31st December 2022)
- Manufacturer: Zehnder Group Zwolle B.V. (Netherlands)
- Product Name: ComfoAir XL 4400
- Heat Exchanger: Recuperative
- Heat Recovery Rate: 75%
- Leakage: <3%
- Performance Number: 10.5
- Specific Electric Power: 10.5
Product Usage Instructions
- Efficiency Criterion (Heat Recovery Rate): The effective heat recovery rate is measured at a test facility using balanced mass flows of the outdoor and exhaust air. The boundary conditions for the measurement are documented in the testing procedure.
- Airflow Range and External Pressure Difference: The ComfoAir XL 4400 operates within a specified airflow range. The available external pressure difference is 250 Pa when filters, internal electrical preheater, and shut-off dampers are installed. Additional components may decrease the available pressure difference accordingly.
- Efficiency Criterion (Electric Power): The overall electrical power consumption, including controllers, is measured at the test facility as per the requirements for non-residential buildings at an external pressure difference of 294 Pa.
- Performance Number: The performance number is calculated based on the measured values for heat recovery efficiency, power consumption, and climatic data of central Europe (Gt: 84 kKh, heating time: 5400 h/a). The ComfoAir XL 4400 has an average performance number of 10.5 within its airflow range.
- Leakage: The unit’s airtightness is tested for under pressure and over pressure. The leakage airflows must not exceed 3% of the average airflow of the device’s operating range. The internal leakage is measured at 2.10% and the external leakage at 1.20%.
- Settings and Airflow Balance: The ComfoAir XL 4400 allows for adjustment of the balance of airflows at the unit itself. The available operation modes are explained in detail in the operation manual.
- Standby Power Consumption: The device has a standby power consumption of 12.0 W, which exceeds the target value of 1 W. It is recommended to equip the device with an additional external switch for disconnection from the mains, if required. After a power failure, the device will automatically resume operation.
Specification
- Category: Air handling unit with heat recovery
- Manufacturer: Zehnder Group Zwolle B.V Netherlands
- Product name: ComfoAir XL 4400
- Specification: Airflow rate > 600 m³/h
- Heat exchanger: Recuperative
- This certificate was awarded based on the product meeting the following main criteria
- Heat recovery rate ηHR ≥ 75 %
- Specific electric power Pel,spec ≤ 0.45 Wh/m³
- Leakage < 3 %
- Performance number ≥ 10
- Comfort Supply air temperature ≥ 16.5 °C at outdoor air temperature of -10 °C
Airflow range
1500-3200 m³/h
at an external pressure of
294 Pa 1)
Requirements non-residential buildings (Therefore also applic- able for residential buildings)
Heat recovery rate
ηHR = 83 % (at 3200 m³/h) ηHR = 85 % (at 2600 m³/h) ηHR = 87 % (at 2000 m³/h)
Specific electric power
P el,spec = 0.42 Wh/m³
Performance number
10.5
- The real available external pressure with installed filters, internal electrical preheater and shut-off dampers is 250 Pa. Additional components decrease the available pressure difference accordingly.
Passive House comfort criterion
A minimum supply air temperature of 16.5 °C is maintained at an external air
temperature of -5.2 °C. It is assumed that at outdoor air temperatures below
-5.2 °C the frost protection strategy is activated.
Efficiency criterion (heat recovery rate)
The effective heat recovery rate is measured at a test facility using balanced
mass flows of the outdoor and exhaust air. The boundary conditions for the
measurement are documented in the testing procedure.
With
- ηHR Heat recovery rate in %
- θETA Extract air temperature in °C
- θEHA Exhaust air temperature in °C
- θODA Outdoor air temperature in °C
- Pel Electric power in W
- ?̇ Mass flow in kg/h
- cp Specific heat capacity in Wh/(kg.K)
Heat recovery rate
- ηHR = 83 % (at 3200 m³/h)
- ηHR = 85 % (at 2600 m³/h)
- ηHR = 87 % (at 2000 m³/h)
Airflow range and external pressure difference
- The operational range of the device results from the efficiency criterion (see below). As per the certification criteria for ventilation units > 600 m3/h the applicable pressure differences vary with the nominal range of operation (as declared by the producer) and the application (residential or non-residential building).
- The external pressure difference includes all pressure losses of the ventilation system caused by components apart from the tested unit (consisting of casing, heat exchanger and fans). If filters are installed inside of the unit, their pressure losses are to be reduced accordingly. The average filter pressure drop of an operational filter is assumed to be 30 % higher than that of the clean filter.
- According to the certification requirements for non-residential buildings the airflow range achieves 1500-3200 m³/h at an external pressure difference of 294 Pa. The available pressure difference with installed filters, internal electrical preheater and shut-off dampers is about 250 Pa.
Efficiency criterion (electric power)
- The overall electrical power consumption of the device including controllers was measured at the test facility as per the requirements for non-residential buildings at an external pressure difference of 294 Pa.
- Specific electric power
- Pel,spec = 0.42 Wh/m³
Performance number
- Based on the measured values for the calculation of heat recovery efficiency and power consumption and on the climatic data of central Europe (Gt: 84 kKh, heating time: 5400 h/a), an average performance number at the airflow range was determined.
- Performance number 10.5
Leakage
- The airtightness of the unit is tested for under pressure and over pressure before the thermodynamic test is conducted. As per the certification criteria the leakage airflows must not exceed 3 % of the average airflow of the device’s operating range.
| Internal leakage | External leakage |
|---|---|
| 2.10 % | 1.20 % |
Settings and airflow balance
- It must be possible to adjust the balance of airflows at the unit itself (either between the exhaust and the outdoor airflows or between the supply and the extract airflows, if the unit is respectively placed inside or outside of the insulated thermal envelope of the building). Availeable operation modes are explained in detail in the operation manual.
- Balancing of the airflow rates of the unit is possilbe.
- The airflow volumes can be held steady automatically (by measurement of pressure differences at the fan jet nozzle).
- The standby power consumption of this device makes 12.0 W. The target value of 1 W was exceeded. The device should be equipped with an additional external switch so that it can be disconnected from the mains, if required.
- After a power failure, the device will automatically resume operation.
Acoustical testing
- A ventilation unit > 600 m³/h is assumed to be operated in an installation room, for which sound limits are defined in the applicable regulations.
- For this device, the following sound level values have been derived from the measurements at an airflow rate 3200 m³/h:
Duct Casing
| Outdoor| Supply| Extract| Exhaust
67.9 dB(A)| 63.8 dB(A)| 84.3 dB(A)| 72.1 dB(A)| 86.0 dB(A)
- For complying with the required sound level in the supply air and extract air rooms, dimensioning of a suitable silencer is required for the specific project on the basis of the measured sound level.
Indoor air quality
- Instructions for changing of the air filters are documented in the operation manual. This device is equipped with following filter qualities:
| Outdoor air | filter | Extract air | filter |
|---|---|---|---|
| F7 | G4 |
- If the device is not operated during summer, the filter should be replaced before the next operation.
- The producer of the device has to ensure that based on the latest findings, room air hygiene can be maintained by means of integrated or obligatory components.
- For the operation of ventilation systems a strategy for avoiding permanent moisture penetration of the outdoor air filter needs to be considered. The strategies are mentioned in the full report and can be implemented through installation of either an additional component of the ventilation device or on the ventilation site system.
Frosts protection
- Appropriate measures should be taken to prevent the heat exchanger and optional downstream hydraulic heater coil from getting damaged by frost during extreme winter temperatures (−15 °C). It must be ensured that the unit’s ventilation performance is not affected during frost protection cycles.
- Frosts protection of the heat exchanger:
- In order to protect the heat exchanger from freezing, the manufacturer recommends the optional installation of the hot water hydraulic coil W/22/1168/2R/9K/3.0. Depending on the inlet temperature a heating power up to 29.6 kW is available.
- Frost protection of downstream hydraulic heater coils:
- As described in the technical manual this appliance shuts down both the fans if the supply temperature drops below +5 °C behind the heater coil.
- It should be noted that, due to free circulation, cold air can also lead to freezing – even when the fans are stationary.
- This can only be ruled out if the air duct is closed (by means of a shutoff flap).
Bypass of the heat recovery
- A summer bypass of the heat recovery is part of this appliance. Optionally it could be controlled automatically.
- The effectiveness of the bypass for night cooling of buildings has been tested within the scope of the testing to the unit ComfoAir XL 2200.
- www.passivehouse.com
- Zehnder Group Zwolle B.V.
- Postbus 621, 8000 AP Zwolle, Netherlands
- +31 38 429 6911
- info@zehnder-systems.de
- http://www.comfosystems.de
Documents / Resources
|
zehnder ComfoAir XL 4400 Central Ventilation Units With Heat
Recovery
[pdf] User Manual
ComfoAir XL 4400 Central Ventilation Units With Heat Recovery, ComfoAir XL
4400, Central Ventilation Units With Heat Recovery, Ventilation Units With
Heat Recovery, Units With Heat Recovery, With Heat Recovery, Heat Recovery
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References
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