AC Units – the same mold story?

More and more, residents of the Northeast are learning what those in warmer states have learned over time – air conditioning makes life more comfortable but also adds an element of risk from mold. For that small percentage of people who are hyper-sensitive to mold spores, prevention can mean fewer doctor bills and greater comfort. With warm weather upon us, it makes sense to look carefully at your air conditioners to be sure they are clean and running efficiently.

Last fall when you took out your window air conditioners for the winter, you may have noticed they still had some moisture sloshing around inside. Without thinking about it, though, you may have put the unit in the cellar or up in the attic or some other storage area that had little air circulation – places that mold loves to grow.

For some of us, even a hint of mold can trigger mild to severe symptoms. Sudden onset of stuffy noses to all out asthma attacks can be mold-induced. Even your car can harbor those nasty little spores. What should you do to get your AC units and cars in shape?

First, take the unit into your garage or outside so as not to spread any mold spores around the house. Open up the unit and remove the air filter. With a stiff brush, remove as much lint as possible. If the filter is washable, cleanse it in warm soapy water and let it dry thoroughly. With the unit open (and not plugged in!) use rags, cotton swabs and other cleaning devices to reach into all the nooks and crannies that can hide dust and mold. Your hardware store likely has an air conditioner cleaning fluid you can buy that kills or inhibits mold. Use the cleaner according to the directions. Clean everything that is visible including any accessible fan blades as they can accumulate dust and mold on both sides.

The inside and outside metal fins that help disperse the hot air and cool the interior also need cleaning. Again, a mildly stiff brush can be used to clean the spaces between the fins. Spraying some cleaner on the brush will get the solution into those hard to reach areas. If there is a removable pan at the base of the unit, take it off and give it a good cleaning, as well.

More homes in Maine and New Hampshire are relying on year-round central heating, ventilation and air conditioning (HVAC) systems which makes this more than just a seasonal task. Attending to the system should be at the beginning and end of every heating and cooling season. Also, in the summer months, it may be worthwhile cleaning air conditioning filters at least once a month depending on how quickly dust, pollen and mold accumulate. A thorough cleaning may also reduce your energy bill.

Ultimately, you may want to have a repair and maintenance person undertake the cleaning particularly if you or members of your family experience an unhealthy reaction when the AC kicks in.

If you have an old unit or one that simply is not functioning properly, you may want to buy a newer or more efficient model. When buying a new unit, be sure it is sized correctly for the space you intend to cool as a unit that can never remove enough humidity or heat will simply run constantly using large amounts of electricity.

Finally, if you are not at home, try to set the units on a timer so they are not running all day but will have just enough time for your home or bedroom to be comfortable when you return or head for bed. If the forecast calls for overnight cooling, switch the unit to fan or completely off and save on your electrical bill as well as ease the burden on the power generation facilities.

Don’t make summer the same mold story. Take an extra hour or so to be safe and healthy.

P.S. A reader also suggests the following (for which we are very grateful).

The duct work in your home or auto a/c is going to be cold when you shut it off. Moisture from warmer air will condense on those colder surfaces. If you run the fan for a period after the compressor stops you will warm up that duct work and moisture will not condense as much and the moving air will also help keep the ducts dry.