I'm looking at buying a 1,900 sq ft two story home with Central Air, but I've only had gas or baseboard electric. I would only run it during the winter, but I'm not sure what to expect to pay keeping it around 60 degrees. I'm in Philadelphia so it usually doesn't get brutally cold.Please Log In to view this link! for temperature trends. How much do you think it would cost? Is there any way for me to calculate this?