Heat Recovery Ventilators...what's the story?

[Richard Moore]

Had this today in a small 1985 split entry home.

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Heat source was by unitary wall heaters. I understand the concept behind HRVs, but this was the first time I've actually run across one (unit was functional, albeit noisy, air at all registers, etc). Every other VIAQ system I've seen so far has been a timed fresh air intake at the furnace or an exhaust fan on a "programmable" timer.

Were HRVs a fad that didn't take off? A regional thing and just very rare around here? 80 to 85% efficiency not good enough? Overkill for fresh air?

BTW...anyone recognize the unit or its maker? Completely textured and painted on the outside and interior label not legible.

[charlie]

Hi Richard,

I have never been able to understand why they haven't "taken off"---I installed several in the late 70's early 80's----haven't heard much since. I still think they are a great idea. Search the Nutone site---the one you pictured looks a lot like the Nutones I installed.

Charlie

[Jim Katen]

Originally posted by Richard Moore

BTW...anyone recognize the unit or its maker? Completely textured and painted on the outside and interior label not legible.

Looks like a Honeywell.

If they're of help, here're some pics of a similar one. There's a filter hidden in there that the owners don't usually even know about. It gets really filthy.

The one in my pictures didn't work properly. The core wouldn't turn, so it was pretty useless.

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- Jim Katen, Oregon

[Richard Moore]

Thanks Jim...that's the puppy!

The core turned on mine but something was obviously in contact with the other side as the noise was in time with the revolutions. I didn't find the filters and can't figure out where they are. This house had just been vacated by tenants. Judging by the filth they left behind, I'm guessing a zoo came and got them! I probably didn't want to see the filters!

I tried the Honeywell site for a manual, but there must be a secret code. Every search I attempted on the literature came up "not found".

Oh well...at 18 years old and making a noise, it's time for a service. At least I can tell my client the brand so she can tell the HVAC guy. Maybe he has a manual?

Thanks again (you too Charlie)

[Rob Amaral]

I've got one here.. Those are/or were made in MA for Honeywell by a company called Air Exchange (last I checked). Norwell, MA. Right across the street (practically) where Zildjian cymbals are hammered out! I use mine in summer only. Works great. I bought it off the dock in Norwell.

[carle3]

We started using them quite a bit in our neck of the woods. Needed a means for fresh air and also have the ability to control it. High humidity levels were out of control with all the moisture that we were dumping into the house during construction. We did find that the clients needed to be educated of there use as they do have a tendancy to dry the house out if not careful. We would spec the ones with a humidistat that would run the unit under high humidity conditions. We also would use the models that not only transfered heat but would also recover humidty to the incoming area. Relative humidity of the outside air around here can be in the single digits during the wintertime. When I find one of these during inspection I open them up and check out the filters. I have found most full of leaves and debris with clogged cores.

[Rob Amaral]

Good points. If you don't understand the 'building science' surrounding these things, they can be a heap of trouble. When maintained and operated correctly, they are great. Not, they're potential trouble..