Renovation & Design

ASK THE INSPECTOR: House too dusty? This may be the cause

QUESTION: I have a problem with house dust. We have a 15-year-old home with a gas forced-air furnace. About 10 years ago, we installed a Kenmore electronic air cleaner on our furnace. We get a lot of dust in our house. We do have the furnace fan running continuously. I clean the filter elements frequently, have had the ducts cleaned and have talked to a technician about the problem. They tell me I have one of the best methods for filtering the air in my house.

Can you advise if there are better methods to keep the air clean and dust down?

Thanks, Mark Neskar.

ANSWER: I receive several inquiries about excessive dust in homes several times a year. While I am never sure what people like you consider "a lot" of dust, I will offer some general suggestions for things that may help and one very likely culprit.

Dust in homes can come from several sources and contain unusual items such as dead skin flakes and pet hair. While it may be impossible to prevent dust inside our domiciles, there may be a few common items you can address to help reduce the circulation throughout your home.

One observation about homes your age is that you have drywall on your ceilings and walls, which are not prone to deterioration like old plaster walls, which can lead to increased dust. Also common to homes as old as yours are interior finishes with dark wood. If that is the situation, especially with dark wood cabinets and flooring, it may appear you have a higher than normal amount of dust, but in reality it is only more visible due to the dark surfaces. If you don't have dark floors or finishes, ignore the previous point and keep reading.

Running your furnace fan continuously may be a mixed blessing. While this ensures good air movement in the home, preventing condensation and damp areas, it may allow airborne dust to circulate more frequently than intermittent fan usage. Conversely, having continuous airflow through the furnace will allow more constant filtering of the air, which should theoretically cut down on dust if the filter is cleaned regularly. While I often recommend continuous furnace-fan use, you must ensure your filter is clean and in proper operational condition at all times to prevent excessive movement of dust.

One common area of concern for newer homes such as yours is whether there is something external to the living space that may be contributing to the dust. This may be caused because you have a fresh-air intake, which normally brings unfiltered air from outside the home directly into the return-air ducting for your furnace. If the vent hood for this intake is too close to grade, dryer-vent outlets or other dusty areas, this could be a source of excessive airborne particles.

While this intake should enter the ducting upstream of the air filter, it may still add significant debris to the air if you are in an area prone to high levels of airborne dust or debris from exterior sources. You should regularly check and clean any dirt off this vent hood and possibly install a small, homemade filter if it is excessively dirty.

Household activities and habits may contribute to your dusty observations. If you have any pets, especially more than a single long-haired dog or cat, higher than normal dust levels should be expected. Not only fur or hair is the issue, dust from cat litter boxes, rabbit or hamster cages, or debris from pet beds may be a significant contributor.

Large numbers of plants, particularly cacti or other plants with sandy soil, can add to air pollutants. If you do any woodwork inside the home, it is very difficult to prevent sawdust from travelling through the living space. Hobbies such as pottery or sewing can add to dust collection in the living space.

Though all these factors should be considered, there is one main area that should be double-checked, as it is the most likely cause of your dusty home.

You stated you installed an electronic air cleaner on your furnace about a decade ago. Depending on the style and maintenance, this filter may not be effectively preventing circulation of dust throughout your heating system. If this device is the wide-bodied type, with removable metallic elements and pre-filters, it may be fine if you clean it regularly and hear frequent crackling when it is dirty.

If it is the simple, thin model that replaced the original paper filter, with a small, low-voltage wire that unplugs, it may be the main problem. Many of this second type of filter can be ineffective, especially after several years of use. Even if you clean this type regularly, they are little more than a foam filter with a slight electronic charge passing through. Over time, the electronic wiring may become deteriorated, corroded or damaged and offer little to no additional dust protection.

If, as I suspect, you have a one-inch-thick, electronically charged, cleanable filter, pull it out and try throwaway filters for a few months to see if there is improvement. Purchase higher-quality pleated filters, which will catch more dirt and debris and help clean the air. If this solves the problem, recycle or discard the old unit and change your filters every month or two for a cleaner house. If this does not solve the problem, check the other possible causes or continue to dust your furniture more frequently.

Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and president of the Canadian Association of Home & Property Inspectors-Manitoba ( Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at


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