What’s the best strategy for updating this home’s ventilation systems?
The house we are buying needs quite a few updates. So I am trying to be efficient with our renovation budget. The four bath fans are shot, and I’m thinking about replacing them with Panasonic Whisper Greens. I’ve installed a few of these pricey fans over the years and really like them.
Or I could install an ERV with boost mode for about the same money. I have lots of room to install the ERV inside the condition space. There is easy access in the attic for running dedicated supplies and returns. (It’s vented, so I’ll have to be careful about air sealing and insulating the ducts.) This seems like a better bang for the buck than putting in new bath fans, but maybe I’m missing something.
I’d like to use a Panasonic 10VE2 ERV (around $900). The latest ASHRAE formula suggests 96 CFM is needed, but I tend to agree with the “too much” camp and think the IRC’s 57 CFM (while using my Awair for monitoring) will suffice.
The kitchen is going to get a new exhaust (probably 250-350 CFM) that will be ducted to the outside. There will be no combustion in the kitchen, either.
Will this approach work? Am I missing something that’s likely to come back and bite me later?
PS. After I wrote this question, I came across an article on sizing ERVs by Allison Bailes. (See https://www.jlconline.com/how-to/hvac/how-to-size-an-hrv-or-erv_o.) Bottom line seems to be it’s better to oversize. Panasonic has a new 200 CFM unit, but it is hard to source and overpriced.
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I agree that, especially if you want it for bath ventilation, it's better to have an oversized
ERV and run it on low most of the time.
Thanks, Charlie. If going for more capacity at lower speed, I think I would prefer two Panasonic 10EV2 units over something like a single Broan ERV200TE. Less money and more redundancy.