Is my crawl space considered non-vented??

Mr Blotto

I live in the Chicago area in a house built in the 60s. It is a tri-level with a crawl space under the living room/kitchen. The access to the crawl space is from the lower level of the house. It is about 5' tall. There are no vents from the crawl space to the outside. There are uninsulated water/waste lines and HVAC ducts running in the crawl space. There is no insulation anywhere in the crawl space (under the livingroom/kitchen floor, on the exterior walls, or on interior walls). In the winter, the main floor floors are COLD and I know I am loosing heat where there are interior walls on the lower level that face the crawl space. The crawl space is not heated per-se but I am sure it gets heat from the unisulated heating ducts running in it.

So I know I need to insulate, but am not sure if I should treat it as a vented or unvented. What if I just insulated the heating ducts, the ceiling and against the intenal walls of the crawlspace? Or should I just do the external and internal walls of the crawlspace?

Thanks for any input!

ionized

By your description is seems like it was designed as an unvented space. That does not mean that it is well-sealed, as you probably know. What is the floor of the space consisted of?

If you are going to be living in your house for some time, I'd consider hiring an energy rater to identify the low-hanging fruit for improvements in efficiency and comfort. Local government and utilities often have rebate programs to help pay for the service. Find info at Resnet or Building Science corp.

Mr Blotto

The floor of the crawl is very thin concrete or slurry mix (not hard concrete, but not dirt).

Windows on Wash

Kind of sealed and kind of not insulated.

Insulated the walls and seal up the leaks.

A vapor barrier is probably still a good idea across the floor to control any smell or radon.

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