I put the backer rod on both the a/c units in the kitchen n the living room ones and its holding the cool air inside longer during the night i had only one a/c going in the kitchen and its holding it at 75" befoire i had to have both a/c's units running to maintain the cool air inside.. i love it if only i have known about this back rod.. a long time ago.. -- My Twitter: »www.twitter.com/hdtvtechno
