ERV / HRV Details
The more I read both here in discussion forums and in articles, the more I ponder various concepts, and the more perplexed I end up. I’m a homeowner undertaking a gut-renovation on nights/weekends/holidays. I’m trying my best to balance idealism and the realistic necessities of my budget.
~2000 sf house in Southern CT; CCSPF insulation throughout; Hydro-Air HVAC system. I’m pretty well convinced that an ERV is the correct choice.
Everything in life has tradeoffs and I am having a hard time justifying the budget & effort for a fully dedicated system. My current thought is to have a single stale-air return in the kitchen (space also hosts laundry) and duct the fresh-air supply to a point in HVAC return trunk where it is equidistant to most of the return grills.
My rationale is that when the air-handler is NOT running, those rooms (w/ returns noted above) will receive the make-up air. When the air-handler is running, the make-up air will be distributed through the house. This much I like and am comfortable with. I also like the idea that the make-up air will lose velocity as it enters the larger HVAC return ducts and will be tempered that much more prior to entering a given room. Seems like a reasonable concept as my interpretation is with the ERV you are trying to create a slow current of air from high pressure to low; as opposed to HVAC where you are trying to dynamically mix and circulate air from supply to return.
Concern: my biggest concern is with the potential of condensation from the make-up air…
Question: does the make-up air ducting get insulated?
–>The made-up fresh-air is my question (after the ERV)
–>If not insulated it would allow more tempering of the made-up fresh air but (eg, in summer) will have warm moisture laden air entering into a cool metal pipe. Will this be a sweaty mess?
–>In the event that I insulate this fresh-air supply duct to the point where it taps into the HVAC return trunk, once again you have a condensation potential.
Introducing the potential of moisture into the HVAC ducting doesn’t leave me very confident in my “rationalized” plan.
Any commentary would be greatly appreciated. I really enjoy the GBA articles and discussions within these forums.
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