AC Insulates Under Floor of 120 Year Old Crawlspace

[AC_Hacker]

Originally Posted by Daox

Did you see anything interesting when you had the thermal imaging camera?

Good question... I've been kicking myself that I didn't examine the floor, from under the crawlspace. I think that could have been useful.

The thermal imaging camera did show up some heat (infiltration) leaks I hadn't counted on:

This one that is clearly visible at the peak of the roof...

...and also this one, which is harder to see (it is behind the "3" in the upper left:

This second one may actually be the worst.

Originally Posted by Daox

I know it hasn't been real long, but have you been able to notice a difference in energy consumption? I know you previously didn't really heat the kitchen directly, and now you do.

Until I fix those spots, it doesn't seem like a good idea to try to heat the kitchen full time.

The weather is really pretty mild right now, so when a good chill hits, I'll have some better data.

However, In all my previous measurements of the kitchen floor, it has always been about two degrees above the temperature of the crawlspace.

But now it measures at about two degrees below the temperature of the kitchen.

I'd say that's an improvement.

Come chillier weather, and I'll measure it again.

-AC

[Elcam84]

Good progress. Funny your house is way older than ours (1960) but the lumber looks identical as ours was built using lumber from a much older deconstructed house. Royal pain to drill through or drive screws into.

Question about one of your pics in the first post. What is the purpose of the ac blower motor in the crawlspace?


I have over half our crawlspace covered in plastic. A pain with all the piers. 7' on center... When done will either use 4" poly iso on the walls or have it sprayed. Depends on if I can get a load of used foam sheets cheap. 15 sheets iirc. Will wait till spring before finishing under there. Still need to dig out the sewer pipe as it is going to be replaced with pvc and re routed due to remodeling I hate cast iron pipe.

Also need to design a sealed crawlspace door as well. Very little on the market and nothing that will fit.

[Mikesolar]

One place you can look for foam is to the insulated door makers. They often cut windows out of the doors and toss the cutout. I know a HP manufacturer who did all their underfloor insulation with them for basically free.
It's a bit of labour but it works.

[AC_Hacker]

Originally Posted by Elcam84

...Question about one of your pics in the first post. What is the purpose of the ac blower motor in the crawlspace?...

The blower motor was there temporarily.

There was a lot off debris to be removed before the film went down, so for that, the blower motor exhausted the dust and also drew in fresh air.

Then we kept the blower motor during the phase where the edges of the styrofoam were sealed with foam-in-a-can. My son was doing that part, and he was concerned about breathing any fumes.

Now, the job is done and the blower is removed.

Yeah, as to crawl space doors, I need to do that, also. The entrance to my crawlspace is through my unheated basement. The opening was originally intended as a basement window (the kitchen is an addition). My plan is to make a frame around that opening, seal it with foam-in-a-can, and making an insulated-sandwich door. I will probably make the door removable, rather than hinged, since it is used so seldom. A removable door will allow a larger aperture for entering.

Best,

-AC

[Elcam84]

That was what I figured the fan was for. I run a fan when under the house as well. Lots of debris under ours too as well as piles of sand from the original excavation for the foundation walls. A number of pieces of the 1" t&g fir sub flooring down there. All the pieces on the ground were like brand new after 55 years. Very little moisture as it drains away fast due to the sand.

My crawlspace hole is on the back of the house. Concrete foundation with a brick house on top. Concrete is about 2' from ground to brick and about that width. Not a clue what to do that will look good. Has never had a real door that I can tell. So far my only thought is to furr the inside with treated 2x4 and make an insulated and sealed hatch that screwed to it. Rarely ever need access there.
Probably a sandwich panel for the hatch as well.

[AC_Hacker]

Originally Posted by Elcam84

Probably a sandwich panel for the hatch as well.

You never know what you may want to do with your crawlspace in the future.

I have a cousin in L.A. that put in a second gas-fired tank-type water heater in the far end of his house, so he dug out a hole in the crawlspace to set up the water heater in.

Sounded like a dreadful job to me, and not very economical either, in term of energy wasted from standing losses.

But it does suggest that a crawlspace might be useful.

-AC

[where2]

Originally Posted by AC_Hacker

I have a cousin in L.A. that put in a second gas-fired tank-type water heater in the far end of his house, so he dug out a hole in the crawlspace to set up the water heater in.

Hope there's no path for leaves to blow into that space. My wife's family has a place with a gas water heater under the structure, plumbed in and standing in a low spot. Whenever we stay there, I always go under the building and make absolutely certain the maple leaves haven't accumulated in the low spot around the base of the water heater.

[Elcam84]

Shouldn't be any way to get leaves in a sealed crawlspace. I would never put the waterheater in there especially not gas. Main problem being all the heat the hheater looses warms the crawlspace and heats the house. We do everything we can to eliminate heat going into the house. Our WH is in the middle of the house. When I remodel that part it will be moved to the garage where it belongs and go back to gas.

[AC_Hacker]

Originally Posted by Elcam84

Shouldn't be any way to get leaves in a sealed crawlspace. I would never put the waterheater in there especially not gas. Main problem being all the heat the hheater looses warms the crawlspace and heats the house. We do everything we can to eliminate heat going into the house. Our WH is in the middle of the house. When I remodel that part it will be moved to the garage where it belongs and go back to gas.

Sounds like heat is a big problem for you, living in the Lone Star state.

You might want to check out heat pump water heaters. They remove the heat from the air and their out put is hot water and cold air.

They also de-humidify.

You could leave the water heater right where it is...

-AC

[Elcam84]

If we were staying I would go with a heat pump. I just missed out on one at lowes last year. Was walking down the aisle towards the water heaters. From a distance I saw the yellow sticker and the $400 price then as I got closer i saw the sold tag on it. Arghhhh.

I can't leave the waterheater where is is as it would be smack in the middle of the master bathroom. The Hvac is in a closet next to it and it will be moving as well to an existing closet in what will be left of the hallway. Actually it won't be moved but a new system installed there. 90% furnace ac won't be any higher than 16 seer probably 13 or 14. No benefit for resale on higher seer.
And no minisplits won't do much for us as they provide no circulation for bathrooms and other small rooms and areas. However I may put one in the kitchen as it is the biggest heat producer. A mini would pull the heat out more efficiently than the main system playing catchup. Proper sized house systems can't cope with the actual summer heat loads Here as the design numbers aren't right. Imo all kitchens should have their own systems just like commercial kitchens do.