Hi all,

I recently moved into a 25 year old ranch-style house in the high mountain desert in central Arizona, at about 6000 feet elevation. It is a well-built house with 2x6 construction, full cavity of wall insulation, but the floor is not insulated at all. Below the floor is a 3-4 foot tall vented crawl space with a poured concrete floor.

The summers here are warm, but not "Phoenix hot." The warmest it got here this past summer was 95. I was amazed at how cool the house stayed all summer (we kept the window blinds closed during the day). It never got above 84 in the house, so we only cranked up the heat pump in cooling mode a few times on the very hottest days.

Winters here are relatively mild. It rarely gets below 25 at night, and during the day it is usually in the 50-60s. A large wood stove provides more than enough heat for the living room/dining room/kitchen, but the bedrooms at the other end of the house do get chilly.

My question is, how much of the house's ability to stay cool in the summer is due to the floors not being insulated? Is there a way to measure this? If we insulate the floors to add extra warmth in the winter. how much will the house lose in its ability to stay cool in the summer?

Thanks for any insight into this situation.