I agree 100% about insulating the duct work in the crawlspace. I hesitated to do that this Fall because of the water supply pipes running in there as well. (old galvanized pipe) I bought the tools and most of the supplies to change all the supply plumbing to PEX, I just have to get 2 manifolds and the PEX tubing itself.
I really noticed the difference in heating the house when I ran the blower on the furnace to suck the hot air from the living/dining room that was accumulating there from the insert to circulate it thru the rest of the house. The Master bedroom is the furthest room away from the living room, and it's 20*F cooler than the living room without running the blower on the furnace. With the fan running, the temp only climbs 4*F, but the temp in the living/dining room will drop 10 to 12*F.
The floors are cold as well, and after I switch to PEX I want to get the bottom side of the floors covered with foam insulation. If the PEX pipes do freeze, at least they won't break. I'm planning the piping so that there won't be any fittings in the crawlspace, with the exception of where the well supply line transitions to PEX from beneath the ground. (the bladder tanks are in an old underground milk room that is insulated and heated). I'll make sure that I have heat tape on the copper pipe.
I upgraded the windows in the house 3 years ago, and before last Winter I blew 18" of cellulose insulation in the ceiling. This Summer/Fall I ripped two layers of siding off of the house and covered the outside with OSB, calking all of the seams. Old Man Winter caught me before I could get the Tyvek vapor barrier up.
Every wall cavity that I checked had fiberglass insulation in it, and I couldn't get hardly any more cellulose insulation in the walls. There was the origional shiplap siding, a layer of clapboard siding over that, a layer of fiberboard/asphalt granular siding with the exposed siding being aluminum. I ripped all the siding off down to the clapboard. When I replaced the roof 2 years ago I added a temp/humidity controlled power vent.
The duct work is the older galvanized tin. What insulation works better, the bubble/foil wrap or the fiberglass/plastic faced?
