What makes the biggest difference in comfort and $ - new ac system, energy efficent windows or . .?

Question

insulation under the house or a radiant barrier in the attic?

We can't afford to do everything, but we do want our house cooler and our bill lower. Right now, with the thermostat set to 70, the actualy temp can be 80 when it's 100 outside.

Our A/C system is about 12 years old (one system for upstairs and one for down). Our house was built in the 1920's and the windows (presumably) are original.

We added insulation to the outside walls as it had none. Floors are hardwood over pier and beam. We have installed ceiling fans everywhere we could put one.

The upstairs is better than downstairs, but the upstairs is a later addition also. we did add insulation to the attic too.

Winter time is just as bad, but in reverse. Thermostat on 80 to heat the house to 68 if it's 30 or below outside. Gas is (or was last season) cheaper than electricity but our gas bill was still pretty high.

What would make the biggest impact on our bill and the comfort level?

Answer 1

insulation first then the windows and the doors then the ac unit. the better the insulation the easier the ac and heating plant will work(saving you some money) first insulate the ceiling and crawl space then the walls.If your windows and doors are 1920's vintage then all need to be replaced (you will see and feel and difference, see a drop in heating and cooling costs and a more uniform temp around the house). the AC and heating plant replacement will yeid the least savings of the three.  have fun!!

Answer 2

40% of heat loss is through the windows