Why Your A/c Might Be Kicking Dust Into Your House And How To Stop It

Dusting your home regularly can be chore enough, but if your house stays dusty no matter how much you clean, then it's just plain frustrating. You'll be even more surprised to find that the culprit could be your air conditioner. Yup, the same system meant to filter your air could contribute to all that dust buildup in your home. Now, you should know that your faulty air conditioner doesn't actually produce dust. If it has certain defects, it just moves it around your home via airflow instead of filtering it out. These faults include leaky or dirty ductwork, dusty or low-grade air filters, and clogged intake vents.

Dust in your air conditioning should be dealt with quickly because it can be harmful to both you and your HVAC system. For you and your family, there are many hidden hazards of built-up dust in your home, including exposure to toxic chemicals and allergens. You may also find that the HVAC system itself could suffer from reduced efficiency because of excess dust in the system. Additionally, the reduced airflow could result in frozen evaporator coils and make the condenser coils less efficient. Eventually, all these issues could increase your energy costs and possibly damage the entire HVAC system, so you should make it a priority to find the dust-causing fault in your A/C and fix it ASAP.

The first place to check is the air filter. Filters are there to trap dust in the air the air conditioner circulates. If one gets too clogged up with dirt, it won't be able to perform this function effectively. It's best to change your filter every three months, but if you have a pet, the changes should be more frequent, about once every two months. That ideal interval between filter replacement shortens to under 45 days if a home has multiple pets or people with respiratory issues. Even between changes, you should make sure to clean the filters when they get dirty.

A filter with a low Minimum Efficiency Reporting Value (MERV) rating could be another reason behind your dust problem. The higher the MERV rating of a filter, the smaller the particles it can trap. So, if your filter has a low rating that ranges from MERV 1 to 4, it might not be catching some of the smaller dust particles, and they continue circulating the air in your house. Installing a filter with a higher rating of at least MERV 5 would solve this issue. Consider getting a polyester filter, as filters of this type are better at purifying air than the common fiberglass ones.

If the filter isn't a problem, finding excess dust in your home could point to an issue with the ductwork. Your ductwork is usually found in wall cavities and under the floor, so penetrations in the ducts can draw dust from these areas into the air circulating your home. How you address this problem depends on the configuration of your HVAC system. If you can access your ductwork without damaging it or hurting yourself, then you could be able to fix small leaks with duct tape. However, if the ducts are in hard-to-reach places, we recommend you call an expert HVAC technician instead. With the ducts repaired, you'll still need to make sure that they're clean; you can DIY clean your air ducts or hire a professional.

Finally, clogged intake vents could be another culprit. Intake vents (also known as air returns) draw your indoor air into the HVAC system for cooling or heating. Air returns tend to get particularly dirty because they pull unfiltered air along with dust, pet hair, and other debris into the ducts. When you use your air conditioner, the HVAC system spews out this dusty air back into your living spaces. 

To remedy this problem, start by finding the air returns. You'll typically see these vents in the hallway or on the ceiling of the living room or bedroom. To clean a vent, first unscrew the cover and give it a good wipe with a wet microfiber cloth. Then, clean the inside of the air return thoroughly with a vacuum. Finally, reattach the vent cover and restart your air conditioner to see if the dust problem persists. If it does, call an HVAC professional for help.