Just installed a new Waterfurnace geo unit as a replacement for a worn out LP gas furnace and AC. Home is a single story ranch with full finished basement. During the new install we zoned off the basement using the intellizone 2 system and added a return air register in the basement. We have 2 zones (main floor and basement) Everything working as it should except I am finding that unless we close the door leading to the basement most of my cool air upstairs drops down the stairway into the basement. I think adding the return air in the basement has made it worse. With the door open AC run time increases.
Any suggestions besides leaving the door closed? When the door is closed it functions great. With it open we get a loop of cold air into the basement. Since the install was finished the basement zone has never called for AC. I was wondering if a zone damper was installed on the return air in the basement which would open with an AC call for that zone.
I would appreciate any help so that we could leave the basement door open and have the 2 zones close to the same comfort level.