Re: Proper Crawl Space Insulation
First thing is get rid of the white plastic stuff and use rigid metal ducting for your dryer exhaust and don't forget to cover that duct boot with insulation that's exposed in your picture.
There is a couple of methods I would probably use for that space.
If you are going to use the vents then I would add insulation to the joist bays filling the entire space and either use a house warp or attach 1 inch sheets of foam insulation attached to the under side of the joists .
The house wrap material will provide an air barrier for the insulation and the foam would prevent any air infiltration as well provide a thermo break to the joists and inprove the insulation.
You definately want the fiberglass batts in contact to the underside of the sub floor .
The sample of insulation in your picture is just a waste of material with the large air gap between the insulation and the floor .... it isn't doing much of anything.
If you decide to not use the vents then I would insulate the walls with sheets of foam and apply batts to the joist bays ( though you likely wouldn't need to fill the whole cavity ).
In my opinion .... I would close off the vents to the outside at least for the winter.
Hopefully this helps.
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