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Crawl Space, COMCheck and 2006 Energy Code Requirements

Mule

Platinum Member
Joined
Oct 19, 2009
Messages
1,520
Location
Texas
Okay, I have a middle school going in. There is approximately 100,000 square feet of crawl space, ranging from around 3.5 feet tall to 7 feet tall (don't know if has anything to do with anything).

The building passed COMCheck without showing any insulation between the crawl space and concrete building floor. The 2006 energy code technically says insulate the floor being that it is part of the building envelope.

What say you???? Insulate or not? Of course the owners and contractors say they would prefer not too....money thing!
 
Re: Crawl Space, COMCheck and 2006 Energy Code Requirements

IMO the "perimeter" envelope must comply typically by using insulation.....so if the OP is to install insulation between the underside of the first floor and what is the ceiling of the crawl space....would say NOT required (NOT perimeter envelope).

insulation under the crawl space floor (at least) along the perimeter and at the perimeter crawl space walls is where I would expect it...
 
Re: Crawl Space, COMCheck and 2006 Energy Code Requirements

Mule said:
The building passed COMCheck without showing any insulation between the crawl space and concrete building floor.
The code does not require "insulation", it requires it to pass, I am not familiar wiht COMCheck since we have our own Title 24 regulations, but all is predicated on trade-offs. A concrete floor not only providers some insulatetive properties, but also acts as a heat reservoir, heat or cold is stored in the concrete for release later. I'd guess that whatever COMCheck losses in R-Value it gains back in spades in it's ability to act like a Trombe Wall. Go with whatever COMCheck says, there are so many problems with all kinds of insulation from a health perspective that look for lots of it to be banned in the future, we are building new homes with higher formaldehyde levels than the infamous FEMA trailers now, and much of that formaldehyde is coming from the insulation in the floors and walls, although much is also coming from particleboard cabinets, caulking, and Flakeboard sheathing.
 
Re: Crawl Space, COMCheck and 2006 Energy Code Requirements

Thanks for your responses.
 
Re: Crawl Space, COMCheck and 2006 Energy Code Requirements

If the perimeter wall is insulated down to the grade, and the crawlspace can be considered "conditioned", then the thermal envelope is complete, and no insulation is required between the crawlspace and the occupied space. From an energy standpoint, this is no different than a floor between two above grade occupied floors. This is a good set-up because then the floor is kept close to the occupied space temperature, and the crawlspace is suitable for running pipe. But, they can't ventilate it with outside air unless it is pre-heated.

If the perimeter wall insulation stops at the occupied floor, and the crawlspace is "unconditioned", then insulation is required between the crawlspace and the occupied space. Of course in that scenario, the floor will be cold, and they will need to be concerned with freezing pipes in the crawlspace, but it can be ventilated with unconditioned outside air.

There are a couple of issue with ComCHECK - it can be "gamed", and it actually does not show compliance with the IECC. It is an alternative method that requires approval from the AHJ per section 103. Straight IECC does not allow trade offs.
 
Re: Crawl Space, COMCheck and 2006 Energy Code Requirements

At that size (100,000 sf), I'm guessing it is a concrete floor (panels or poured doesn't make much difference on this one). The mass, as noted above, will absorb and slowly release heat or cold. Not unlike a mass wall of concrete.
 
If the ComCheck perameters were put in correctly, and the building passed without crawl space insulation.. what's the question? It passed with an IBC approved alternate method.
 
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