We purchased our new 1950 sq ft home in Feb. 2009. We just got our power bill for May and June that has really gone up. I had the power company pull the past 9 years and the our bill has increased $200 from the previous years.

I had the power company do a energy test and they said we had a problem with the HVAC unit because the charts show the high use at the middle of the day (up to 14 kwh).

I had a company come out and check the unit inside and out and could find nothing wrong except they said our ductwork is to small and needs to be replaced. They also said our 3 ton unit was undersized for our house. They also said that dirty filters could cause the high bill.

The unit is a carrier 3 ton that is 9 years old the rating when new was a 10. We have changed nothing from the previous owners and have set the temp on 80 degrees inside to save money and the bill went up from $411 in May to $505 in June.

We do not know what else to do?

Could the dirty filters have this much of a impact on the bill? Should we have another company come out to check the unit?

Thanks for all your help. We are broke and very hot in South Carolina!