Spring is in the air, and as temperatures increase, you'll soon need to turn your air conditioner on for the first time. During that first yearly run, things can get a bit... smelly. Some of these smells are worrisome, and others are just normal consequences that you'll have to deal with (maybe by getting a good air freshener.) Do you know the difference? Here's a look.
Musty, Dusty Smells
If you're like most people in a temperate climate, you turned your heat off a few months ago and your HVAC ducts have not seen any action since then. As such, dust has had a chance to build up in those ducts, so when the AC kicks on, all of that dust blows out through the vents and gives off a dusty, musty odor. This odor should dissipate within a day or two. If you want to ensure it goes away, change your air filter after the AC unit has been operating for a day. The filter will have trapped a lot of the circulating dust, so removing it helps to remove the odors from your home.
If you smell an odor that reminds you of plastic or chemicals, this is not a good sign. There may actually be a refrigerant leak in your air conditioner. As refrigerant leaks out, the remaining refrigerant tends to get too cool, which causes the coil to freeze over. Keep an eye on the coil for the next day or two. If you see ice on the coil and that plastic smell does not go away, you need to call your HVAC contractor and have them check for and repair the refrigerant leak.
A mild musty odor is one thing; a serious musty odor that reminds you of sweaty gym shorts is quite another. Such odors can point to mold growth inside your ducts. This can occur when your home's humidity levels are too high or when there is a leak in the walls or foundation that allows water to drip down into a duct. You may notice some sneezing and itching as a result of mold spores being propelled through your home.
Luckily, most HVAC repair companies have duct cleaning equipment and can remove the mold from within your ducts, rendering a cleaner home. Then, you will need to install a dehumidifier or repair leaks to keep the same mold from growing back again.