[Greenbuilding] ERV strategy

[Alan Abrams]

**

> aren't we getting caught up in the fallacy that ERV's dehumidify?  they (at
> least mine) don't have a condensate drain to "remove" humidity.
>
> - my understanding (and please correctmr  if wrong) is that the HRV does
> fresh air exchange while maintaining conditioned heat (at about 75%
> efficiency, usually in colder, dryer climates).
> - the ERV does fresh air exchange while maintaining whatever conditioned
> temperatures (heat and cool) AND also doing something with latent heat in
> the humidity differential inside and out.  (i.e. it helps maintain whatever
> humidity you have inside - achieved with separate air conditioners or
> dehumidifiers-- but does not actually change the humidity of the indoor air.
>  just does it's best to make the outside air just as humid as the indoor
> air).
>
> so putting them on a bathroom doesn't make sense to me.  extra humid air in
> there will be equalized with incoming fresh air and tend to KEEP that
> humidity inside the house.  why is it that people use them there?
>


I understand the principles; with regard to the application I was referring
to--bathrooms--the more precise description would be that the ERV functions
primarily as an exhaust fan that removes extremely humid air from the
bathroom where I just took a long hot shower, and replaces it with
relatively less humid air from outside.

In that circumstance, the ERV might actually work in reverse, transferring
some water vapor from the moist exhaust air to the incoming fresh air.

AA
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/greenbuilding_lists.bioenergylists.org/attachments/20101003/63acc714/attachment.html>