In older homes or buildings where adding new ductwork can be challenging, the CERV2 offers a unique solution by directly interfacing with a central system’s ductwork. In this setup, the CERV effectively functions as an air purifier and fresh air injector within the existing HVAC framework.
CERV2 With Forced Air System:
Dedicated CERV Return, CERV Supply to Forced Air System
The CERV2 seamlessly integrates with central air handlers, offering a seamless solution for homes equipped with existing HVAC systems. In one configuration, the CERV maintains its dedicated return ductwork for extracting air from bathrooms and kitchens while supplying fresh air to the central system. This integration can occur either on the return side, where the CERV feeds air directly into the central system, or on the supply side, utilizing a backdraft damper. This approach allows for the efficient distribution of fresh air throughout the home while leveraging the existing infrastructure of the central HVAC system.
Examples:
newspaperFeatured Article - CERV Retrofit: New Lungs for a 101-Year-Old Home
CERV2 Connected to Forced Air System:
CERV Return from Forced Air System Return, CERV Supply to Forced Air System Return
In many scenarios, such as retrofits or situations where installing new ductwork is impractical, the CERV2 offers a unique solution by pulling air from the central system’s return. In this setup, the CERV effectively functions as an air purifier and fresh air injector within the existing HVAC framework. By extracting pollutants and replenishing with fresh air, the system enhances indoor air quality without the need for extensive modifications or additional ductwork. This configuration is particularly advantageous for older homes or buildings where adding new ductwork can be challenging.
Examples:
newspaperFeatured Article - CERV2 Retrofits in Metropolitan Milwaukee Homes
Tips and Considerations
- To interlock the Forced Air System to run when the CERV2 is running, consider the CERV2’s built-in dry-contact relay output (X0), the I/O Expansion Board Add-on (X1 – X6), or the Low Voltage Wireless Relay option. A powered backdraft damper may require the use of a second output.
- To interlock the CERV2 to run when the Forced Air System is running, consider the CERV2’s built-in dry-contact sensing input (I0), the I/O Expansion Board Add-on (I1-I3), or the Low Voltage Wireless Active Circuit Transmitter option.
CERV Installation General Guidelines
Unit Installation & Ducting
- Avoid operating the CERV2 before construction has been completed, and ensure that ducts are covered to prevent drywall dust and other construction debris from getting into the ductwork.
- It is recommended to install the CERV2 in a plastic appliance basin if location is such that water damage is a concern. A clogged condensate line can cause water to pool around the CERV2. A moisture sensor and alarm can also be used to notify occupants of a problem.
- Fix the CERV into position and ensure stability. Unit must be level. Vibration pads can be placed under CERV to reduce vibration and to keep CERV off of a potentially wet floor surface.
- All ducts except for the Return (from inside) must be insulated. It is recommended to use a minimum of R4.0 insulation for supply to the inside and R8.0 on the ducts to and from the outside. In colder climates, it may be necessary to add additional insulation if it appears that the ducts may be showing signs of sweating.
Fresh Air Inlet & Exhaust Air Outlet Vents
- 8” diameter ductwork is recommended, 6” minimum.
- Exterior wall vents must be sufficiently above ground to avoid blockage from snow or other obstructions. Two feet above ground is recommended. Vents must use a coarse screen or mesh to prevent insects, birds, etc from entering, but fine screens and dampers, and flaps should be removed so as to eliminate any restrictions. Recommended wall vent: Mfr: Imperial, Part #: 6398901
- If possible both inlet and exhaust should be on same side of house to avoid pressure differential, which can impact flow.
- Inlet and exit ducts should be a minimum of 4’ apart in any orientation. Inlet separation from any other possible sources of contamination should be considered and local codes followed.
Bathrooms & Kitchen
- Bathroom vent fans can be used in-line with the ductwork to the CERV to boost airflow. Consider using the Active Circuit Transmitter option to trigger the CERV to vent while the fan is active.
- Do not duct a cooktop vent hood directly in-line with ductwork to the CERV. A recirculating vent hood may be used to remove grease and particulates from the air in combination with a CERV return vent in the kitchen. Any CERV kitchen return vent must be minimum 6ft from cooktop. Consider using the Active Circuit Transmitter option to trigger the CERV to vent when fan active.
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