[Greenbuilding] CONDITIONED crawlspace ventilation

[Rob Tom]

Someone wrote:

> I am designing an addition to be built on a crawlspace foundation.
> I'd like to seal and insulate the crawlspace for energy
> conservation,but I think codes require some kind of mechanical  
> ventilation of
> the crawlspace.  Since my addition has no mechanical ventilation, I
> don't want to add a fan just for the crawlspace.


If this addition is still at the design stage, I'd look real hard at  
getting rid of the wood framed floor, fill the crawlspace up with stone  
and top it off with a 3" thick concrete slab or earthen floor.

If the crawlspace was in place initially to provide some space for  
mechanical equipment, maybe you just make a mechanical pit in a convenient  
location with access flooring over.

Similarly if there is underfloor plumbing, provide accessible-from-above  
chases.

With the persnickety problem of "crawlspace ventilation" eliminated, then  
the only real question is whether or not to take advantage of the thermal  
mass that the stone fill would provide. If "not" then I would insulate  
directly under the floor slab.
If "yes" then I'd insulate the stem wall and the earth before the stone  
fill is placed.

===* ===
Rob Tom
Kanata, Ontario, Canada
<archilogic at chaffyahoo dot ca>
winnow the chaff from my edress in your reply