I've been told that insulating my basement would save between 20k to 27k BTU of heat loss. My initial response was doubtful, since the basement isn't heated anyway. When I thought about it, since the basement is cooler than the 1st floor above it, it would tend to cool off the first floor faster then it should. I know that 20k BTU is just a rough estimate, but is there a formula I could apply to figure out what my actual BTU heat loss currently is. I would think that a 10 x 20 foot uninsulated basement would have the same heat loss per sq foot as a 20 x 50 uninsulated basement. And number two, how much can I expect to save per 1k BTU heat loss if I insulated the basement. This would give me a cost / benifit ratio I can use to justify the expense of insulating.

Attached are two heat loss calculations from a house.  The first has no insulation in the floor.  The second has R 30 in the floor.

As you can see the difference is about  20k BTUh.

This is for total floor footage of 2700sqft.

1 kw is about 3400 BTU.  If your heat pump has a COP of 3 then you get about 10k BTUh for each kw you buy.  So based on your kw rate,  you can figure your savings.

Hope this helps.

Thanks for the PDF files! Over what period of time are these figures for? Daily Averages?

Thanks!

 

These are BTU's per hour at the design conditions listed at the top of each report.

This particluar house was designed for an outside temp of -10° F.   So when it is -10  the heat loss will be what is listed on the report.