Air Conditioning - Odor

Hi, I have 2 window units (both under 3 years old) that seem to have the same problem that started the end of last year. They smell. The best way to describe the smell - similar to cat pee. I took off the fronts of the units and cleaned the vents, I also cleaned the filters with soap and water but the smell is still there and is especially bad when its on low cool setting. I did have a smoker living her last summer - could that have something to do with it? I don’t know what to do.

The rule of thumb for cleaning window units is to clean the filter, vacuum the fins of the evaporator coil, and clean the condenser coil to make the air condition run better. Take unit out of window and take outside. Wash filter with soap and water. Vacuum fins behind filter to remove dirt and debris. Then, you have to clean the condenser coil. Cover the electric motor with a plastic bag to keep it and the wiring dry. Some recommend just tilting in such away that water does not get to the motor and wiring. Then take a hose-end nozzle and spray water from the outside inward. Wipe off the unit to dry. Let air dry for a couple of days before storing or returning to window. If you have an air compressor, it’s a good idea to blow air through the fins to speed drying and reduce the risk of rust setting in. Do not use the unit until it's completely dry.

Mold and mildew in units have been reported by forum posters to produce a urine odor. You may want to spray condensor coils with enzyme digester cleaner and let set before rinsing with water hose.

If you are a landlord, you should know that renters will not properly maintain units. Annual cleaning of units should be on your to-do list and document all cleaning and maintenance of units. We live in litigious times with many people who suffer from allergies.