We are in the process of purchasing a home. There is a strange smell that appears to get worse when we use the air conditioner. I have NEVER smelled anything like this before. We have tried everything we can think of. We have had a plumber check the drains and he found nothing. This is an OLD home - 90 years. There is a chimney that is not used and there have been bats getting in the home. We are closing the chimney but wonder if the smell could be from the bats? We are at a total loss as what to try or what part of the house to start with. Any suggestions?

Something could be dead in the air ducts,rat,or a bat.The only way to know is check it out yourself or hire someone to do it.:eek:

Pompano is correct. When the air runs it will circulate air through the house. If you have something in the chimney it will pull that through the house through the return air and back through the vents. You need to find the source to elminate it. Try getting one of those freshners that you put on your air filter. Can find in the air filter section at Lowes/Home Depot.It won't elminate but will help.