Question: I change my furnace air filter in the winter and the summer because I have air conditioning. Is there a filter on my air conditioner outside that needs cleaned or replaced? Answer: There is no filter to change out by your air conditioner, but your condenser coil does need washed or back flushed with a hose. The condenser coil, which is similar to a car radiator, can get blocked with grass clippings or cottonwood from the trees. This is very detrimental to your air conditioner. We recommend a precision tune up and professional cleaning in the spring before you use the system for the hot summer months.