[Greenbuilding] ERV strategy

[sat jiwan ikle-khalsa]

> From: Alan Abrams <alan at abramsdesignbuild.com>
> To: ArchiLogic at chaffyahoo.ca


> > Don't know nuttin' about nuttin' about ERVs (because MooseLand is HRV
> > Country but...
> >
> > Assuming that the ERV is functioning similarly to an HRV in MooseLand
> 
> NO MOOSE IN SLIGO CREEK, BUT HERE WHERE THE DEER SWARM LIKE STARLINGS, AND
> SUMMER R/H AND TEMPS EXCEED THE 90'S, THE ERV REMOVES SOME WATER VAPOR FROM
> INCOMING FRESH AIR
> 
> 
> BUT EVEN DURING THE SHOULDER SEASONS YOU WOULD WANT TO MECHANICALLY
> DEHUMIDIFY THE BATHROOMS
> 
> > ie the heating and cooling elements would cycle on and off as heating or
> > cooling demand dictates but wouldn't the ventilation air demand remain
> > somewhat constant (ie except for those times when the fans kick into high
> > speed during a moisture or odour event) ?
> > 
> 
> JUST TO CLARIFY, THE ERV'S UNDER CONSIDERATION ARE TWO STAGE.  DURING TIMES
> WHEN THE MAIN SYSTEMS ARE REQUIRED, THE ERV WOULD RUN AT LOW SPEED, AND
> WOULD BE KICKED UP BY A TIMER SWITCH IN EACH BATHROOM.  DURING SPRING AND
> AUTUMN, THE ERV WOULD BE RESET TO OPERATE MANUALLY ONLY, USING THE TIMER
> SWITCHES.

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?

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