[Greenbuilding] Exhaust Only Passive Inlet Ventilation

[Nick Pine]

Rob wrote:

>If by "simpler exhaust fan" you mean exhaust-only, passive-inlet 
>ventilation strategies (EOPIVS) ... testing done about 10 or 15 years 
>ago here in Canada showed that EOPIVS do not work in all but the most 
>mild Banana Belt locations in Canada, do not work in multi-storey homes 
>and do not work in homes over ~1600 sf.

John wrote:

> The IRC and CMHC have done a number of studies on this. You can do the 
> work to look these up.

Right... :-) "Prove me wrong!"

> The exhaust only passive inlet system can work even in cold climates, 
> BUT, requires more careful design and does not usually offer mixing of 
> the supply air and the interior air. I have this system in my 5 storey 
> apartment building and it works well. Requires a specially designed 
> air inlet in each room that does not have an exhaust fan.

Sounds like each unit should have an exhaust fan, eg a small fan in the 
kitchen or bathroom that runs when the owners turn on a switch or the RH 
exceeds 60%.

> This is still acceptable in code, but that does not mean it is the 
> best system and many code approved things may not work if they are 
> done correctly.

If done INcorrectly?

> HRVs often cost more electric fan energy and do no better for air 
> quality than the return side air inlet with controller but they cost a 
> lot more and demand better maintainance.

At 15 cfm per occupant, the energy penalty seems small, compared to the 
cost of an HRV.

Nick