Re: New home, conditioned attic/crawl space
Yep -- this is the modern thinking in the building science communit -- although I'm surprised they aren't pouring a concrete slab for the crawl space ( likely saving a few dollars )
Originally Posted by PaulLo
. Including both the crawl space and the attic to the conditioned space greatly improves the heating/cooling of the home. Especially for you folks in the States that have the HVAC located in the attic , insulating the entire attic maintains a more even temperature within that space and lessens the load on the HVAC.
You mentioned there will be vents in both the crawl space and the attic -- so -- there will be air circulation.
As long as there is no water infiltration and the foam is properly apllied, you shouldn't have any issues with mold.
This sounds very strange to me.
An HVAC technique they are using is to install a 3x3 solar panel grid on the roof in a way that allows air to flow under the panels, and enter the return line of the air handling unit. The top row of panels is actually only used to preheat the air before it enters the duct (via an intake fan to a "heat transfer" module built into the duct line). This preheated air is used to maintain the water temperature of the hot water tank and to supplement the heating of the forced air heat pump system. My concern here also is the growth of mold due to the higher humidity levels in the Southeast. Is there a comparison that can be made of this method between the southwest and southeast?
Unless , an ERV ( Energy Recovery Ventilator ) is being used ---
The HVAC system is a closed system and shouldn't have any outside unconditioned air directly introduced to the conditioning air system.
In the summer months this would introduce hot humid air from outside into the air conditioning air stream --- in the winter this would introduce colder outside air into the heated air stream --- greatly reducing the performance and creating condensation within the ducting and air handler.
Being in your location open cell foam will likely be fine , otherwise if you were in a colder region I would definately recommend closed cell foam.
"" an ounce of perception -- a pound of obscure "