[Strawbale] Distributed ventilation

[Rob Tom]

On Fri, 13 Apr 2007 10:06:19 -0400, Corwyn <corwyn at midcoast.com> wrote:

>
> On Apr 12, 2007, at 13:43, David Neeley wrote:
>
>> Don,
>>
>> I live in a climate which is fairly brutal in the Summer--quite the
>> opposite of what many of your readers face in Canada. (I am in Texas).
>>
>> What is the drawback, if any, to integrating an ERV into the ductwork
>> for a forced air system?
>
> ERVs are designed to stay balanced; that is input flow equaling output
> flow.  Piping the input directly to your HVAC system might mess with
> that.  It probably can be done, but would need careful thought and
> installation.

I'm guessing that Don's busy outside harassing porcupines or something.  
Again.

In any case, I don't know the specifics concerning integration of ERVs but  
for HRVs,
when using the ductwork of a forced air heating system, the fresh air  
outlet from the HRV is best dumped near an intake grill cut into the  
return air plenum at the air handler unit.

Obviously it would be best if the space where this interchange takes place  
is isolated so as to avoid crud getting into the ventilation air stream.

I recall Don telling me once long ago that about 75% of HRV installations  
were done improperly, in that the inlets and outlets to and from the HRVs  
were connected directly to the return air plenum , and from what I've seen  
of such, with minimal separation between the two (ie 18 inches).

Moral of the story is that it is important to have the system designed and  
installed by people who know what they are doing as opposed to just going  
through the motions. ie Don't leave the "design" of the system up to  
furnace or duct installer.

-- 
=== * ===
Rob Tom
Kanata, Ontario, Canada
<A r c h i L o g i c   at  c h a f f y a h o o   dot   c a >
winnow the chaff from my edress in your reply