We service the Glendale Ca area and provide maintenance service, new installation of furnaces and air conditioning units. The following are some tips to troubleshoot problems. Improper operation is a very common problem with home and business air conditioning. It sounds obvious but is often overlooked, all windows in a home or business need to be closed while the air conditioning system is running. If room air conditioners are used then it is vital to keep the room(s) you are cooling closed off from the rest of the home or building for the best efficiency.