If you have noticed that your house smells like an old gym locker while your heat pump is operating, your system may have "dirty sock syndrome. If you suspect this could be the issue, use the following three-step guide for diagnosing and treating your heat pump to minimize the odors and clean up your air quality.
Step 1: Test To See If Your Heat Pump Has Dirty Sock Syndrome
Before you treat your heat pump, test to see if it has dirty sock syndrome. The best tool for this is your nose, since it has a distinct odor.
Just as the name implies, the air coming from your vents will smell like old, filthy socks. This smell comes from the bacteria and fungi that grow on the pump's coil and inside the drip pan. You will smell this stench the strongest as soon as the heat pump kicks on.
After the coil cools once it switches off, the microbes release gasses that accumulate inside the compressor. When the system comes back on, this is then circulated throughout your house.
If this describes the odor you are smelling, go on to the next step to treat the inside of your heat pump. If not, you may need to call an HVAC technician so they can diagnose the problem.
Step 2: Treat The Coil With A Homemade Cleaner
If you strongly suspect your pump has dirty sock syndrome, a homemade cleaner made from bleach and tea tree oil will kill the bacteria and fungi living inside your unit. The bleach kills most of the bacteria and viruses, while the tea tree oil kills the fungi because of its natural anti-fungal properties.
You will also need a bucket and a pair of disposable, plastic gloves to protect your hands from the bleach's chlorine. Lint-free rags, such as cloth diapers or mechanics cloths, are also needed.
Turn off your HVAC system to let the coil cool while you are mixing the cleaner. Then, in the gallon bucket, mix together two cups of warm water, a cup of bleach, and 15 drops of tea tree oil.
Once the coil has cooled, use a rag to apply the treatment to the coils. Let the cleaner remain for a few minutes, then apply a second application. Let the coils air dry for about an hour before turning on the unit. While you are waiting, go on to the third step.
Step 3: Clean And Soak The Unit's Drip Pan
Your heat pump's drip pan is another place the microbes like to call home inside your unit, thanks to the constant moisture and warmth. While you are letting the coils dry, remove the pan and clean it with a mild dish detergent. You may need a scrub brush to remove the slimy film.
Once you have scrubbed the pan, mix the same cleaner you used in step two. Pour the cleaner into the drip pan and let it soak for about an hour. After the time is up, empty the pan. Do not rinse it, because the residual cleaner will provide a protective coating to prevent future growth.
Let it air dry for a few minutes before placing it back inside your heat pump. Then, start up your HVAC system. You may smell the bleach and tea tree oil strongly for the first couple of cycles, but the odor should dissipate.
After performing the above treatment, you may still detect strong odors when your heat pump is running. If so, it is possible there is another issue causing the smell. You may want to contact an HVAC contractor so they can diagnose the problem and offer possible solutions. You can also visit http://www.capefearair.com for more information.