I’m looking for some insight into how I might go about ‘deploying’ HRV units to combat moisture issues in my house. I think I have captured the options through Martin’s ventilation article from 2017, a couple other items on GBA, and searching the web. For my house (~1888 ft2 on three levels (walkout basement, first and second floors)) in Zone 6A (Lubec, ME), it seems to come down to the Micra 60 and 150 and the Lunos e2, eGo, and Nexxt. The Panasonic WhisperComfort Spot can’t handle the low temperatures in 6A; the TwinFresh RA/RW1-50-2 are ERVs (I want to get rid of moisture not recover it); and the Zehnder ComfoAir 70 is no longer distributed in the US.
The Micra 60 and 150 move 18/27/35 and 35/53/71 cfm of air, respectively. The Lunos e2 and eGo move 9/18/22 and 3/12 cfm, respectively, while the Nexxt moves 8.8-53 cfm. My 2 bdrm house appears to be quite tight so if I assume, as a starting point, that I need to supply something on the order of 40-60 cfm then I would need 1 or 2 Micra 60s, a couple pair of Lunos e2, or a single Micra 150 or Lunos Nexxt from strictly a capacity standpoint. The eGo doesn’t seem to be worth considering because of its low capacity.
It isn’t clear to me how to factor in the effects of house geometry (i.e., air mixing/circulation) in selecting suitable units and distributing them throughout the house. About half of the 656 ft2 basement is open, the remainder is divided into a utility room and two other rooms. Doors are usually, or can be, left open. The 656 ft2 first floor is wide open except for a 80 ft2 bathroom. The 576 ft2 second floor has a bathroom and two bedrooms.
The humidity issues (as evidenced by window condensation) are greatest in the bedrooms, esp. if doors are kept closed but even if they are left open (no doubt ‘helped’ along by the fact that I do not actively heat the second floor); condensation lessens but is still quite evident on the first floor and is usually light in the basement. Indoor RHs are never lower than 48-50% anywhere in the house.
I would appreciate hearing ideas people might have about placement strategies of the various units. I want to maximize effectiveness while trying to keep the overall cost in check. If people have experience with the various units listed above I would also appreciate informal reviews of the choices facing me.
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