How to Install Zehnder Comfosystems Part 2 - HRV

zehnderamerica.com The second part of ComfoSystems ventilation system installation instructions. Filmed on a real job site, these videos will help new installers understand the simplicity and ease of installing the Zehnder ComfoSystems heat recovery ventilation systems. For more information, contact Zehnder today by calling 888.778.6701 or emailing [e-mail].

[@hanseich]

@homeheatrecovery I guess that's where the Fein tool (high frequency oscillating tool) came in. I was also wondering about the clean cut without damaging the drywall. Would creating a "cutting guide" (piece of plywood, thickness of the drywall) with a hole the size of the supply/extract pipe come in handy? One could cut the metal, then plug it backup with the cover before the drywallers come in.

[@fredjones6065]

nice, complete, system and components...

[@braunzie2]

One of the things I find in most of the HRV videos is the lack of saying what each individual part is for. For example, there is an exhaust fitting mounted to the ceiling with two ports that are ducted. What are the purposes of those ports. If on is in and the other out, how do they not conflict? I saw a wall fitting - is that supply air? The larger box that shows two 8" ducts? (not sure the size) How are those routed through the roof (and what are the proximity rules?). To see an end to end video explained fully would be refreshing.

[@williammackey7243]

I too would appreciate a more precise description of each hole and tube and at what point precisely does the fresh air get introduced etc.

[@Pizzapinedale]

In the first video, Barry says some rooms will require a double supply duct, meaning there will be two 3" supply ducts coming into the register, likely to account for a higher CFM for a larger room. Supply and return are always done thru separate registers spaced sufficiently far apart (>8'), also explained in the first video. The 8" ducts coming through the main HRV are for main supply and return air sources routed outside the house. I imagine weather- and pestproofing these ducts would be no different from other external venting.

[@brownpartnership11]

There is an option to fit the next size up radial piping (I think it is 90mm), as 75mm is the smallest size and can result in unwanted noise, this may mean that just one pipe is required in the receiver to get the same airflow in some circumstances@@Pizzapinedale

[@Homeheatrecovery]

what tool do you use to get a good flush finish without damage to the plaster when cutting off the excess metal duct at diffuser conection