Last Tuesday, Small Planet Supply’s Albert Rooks met with Shawn Barr of Naikoon Construction to complete the final commissioning of the first Zehnder ComfoAir Q and ComfoPost in North America at the Radcliffe Passive House in West Vancouver.
The installation of the new Q system wasn’t an accident. Radcliffe Passive House owner James Dean was aware that the Q would soon be released in North America and wanted it installed in his new home since it represents a whole new level of heat recovery ventilation.
Dean is also no stranger to this technology, as the ERV enthalpy exchanger and membrane comes from CORE Energy Recover comes from Core Energy Recovery Solutions, a company he founded.
More Sophisticated Technology Makes System Balancing Easier
Albert Rooks expressed excitement about the new unit because of the sophisticated operation of the unit which made installation easier. “It was really exciting because the unit measured the static pressure of the ducting system for the entire house and then confirmed the maximum airflow possible through the ducting, after which it self-balanced the supply and exhaust flows. This allowed me to input my target design flows without having to measure. From there, it prompted me to balance the room to room flows from within the home as the final step in the system’s commissioning wizard.”
This is an improvement from previous Zehnder products. In prior models, all of the balancing had to be done by hand, in a trial and manner fashion. The new version is much easier to commission, especially for remote locations. Another new feature also helps with remote locations. When the Q system is internet enabled, it makes it possible to remotely diagnose system problems.
First ComfoPost in North America Conditions Air
As briefly mentioned previously, the Radcliffe Passive House design didn’t just stop with the Zehnder Q, this system is also equipped with the Zehnder ComfoPost. The system takes heating or cooling from water brought into the home via a heat pump, putting it into the ventilated air. This reduces the amount of refrigerant needed which is better for the environment, while allowing occupants to use the Zehnder system to change the temperature in their home. Dean selected a Daikin heat pump that also produces domestic hot water.
Why did Dean decide to use the ComfoPost in his home? "Once I saw how little heating and cooling we needed from having such a well-insulated and airtight building envelope, I realized that we could really simplify the HVAC system by integrating the heating and cooling with the fresh air ventilation system. We considered using in-floor radiant, but decided it wouldn't feel comfortable when cooling and would rarely be used for heating and we wouldn't feel the warm comfort of the floor because the temperature differential of the floor and air is so small," James Dean noted. "The air quality, temperature and humidity levels from the Zehnder ComfoAir ERV and the ComfoPost is perfect."
Since ComfoPost is new to North America, Albert Rooks has applied to BC housing for a grant to support data collection of the ComfoPost unit. The study would help determine how effective the temperature transfer is on the low-flow ventilation air. The hope to find that due to the coil’s design that the transfer efficiency is quite high since its sized for low air flow and high transfer efficiency.
Custom Grills Made for Trickier Installation
Without a doubt, the decision to make custom grills for the passive house added to the clean lines that the house enjoys. However, the wood grills weren’t sealed tightly to the distribution box causing air to leak, throwing off the readings. This was remedied by removing the grills, getting everything sealed and then putting them back in place.
After one last measurement of the system with the air flow meter in both normal and boost mode, Albert completed the commissioning paperwork, verifying that West Vancouver’s passive house is not only beautiful, but balanced too.