Are you thinking of getting an air purifier, but don’t want another big clunky thing sitting in the rooms of your home? Some people think that maybe they can put a purifier right into their furnace instead of having it take up space in the house. But there are pros and cons to this idea that you should be aware of before you take the leap into this option.

The underlying idea of putting the air purifier into the furnace system is that it will help keep the entire house free of airborne contaminants, rather than relying on a piecemeal, room-by-room solution. It would clean almost all the incoming air as well as air that is recirculated through the house. As well as saving on space, it could also save the homeowner the inconvenience and expense of having to find a place for the purifiers in each room. It couldn’t go directly into the furnace, but it could be set in a utility room or a closet that’s out of the way.

Additionally it would reduce the noise levels that come from running these appliances in all those rooms. And it would be safer from young children or pets that might damage appliances that are sitting out in the open.

All of this sounds like a great solution. So why would anyone think it’s not such a good idea?

First of all, you would have to have your central furnace fan running all the time, day and night. You could find your electrical bills shooting up. Some would argue, though, that you’re probably going to have a similar increase in electrical costs by running several smaller air purifiers in all your rooms. But if you don’t use an air purifier in every room the house – placing it just in one or two rooms where you spend the most amount of time (say, a home office and your bedroom) – the cost won’t come anywhere close to what you would pay to run the furnace and try to purify the air in the entire house.

And remember that in many parts of North America, people turn their furnaces right off for long stretches of the year. So having the air purifier run through the furnace would definitely be an added expense in these cases.

You would also need to hire a trained technician to install the system, and probably to maintain it along the way. Another extra cost.

Perhaps there’s an alternative to having a complete air purifier system attached to a furnace. What about just putting the same filters into the furnace system that would be used in a purifier?

This is possible, though still a bit complicated, yet even in this case there can be problems. For one thing, the filters in a furnace aren’t really intended to clean the air, but are mainly there to keep all the duct work clean. So you’d need much stronger filters. You might even need an extra filter system added to the furnace, since the standard filters aren’t designed to handle the requirements you’d be placing on them. There are now HEPA filters designed to work with furnaces, but they would need constant monitoring. They filter out even the smallest contaminated particles, but they can also severely restrict the air flow. You’d have to watch that your furnace wasn’t overworking and damaging the motors of its fans. You could use an electrostatic cleaner instead, but you’d be trading efficiency for a lower cost, and the air would be less clean.

Furnace air purifiers might be an option if you can afford them. You need to be aware, though, that using a purifier with your furnace could end up not just being more costly than using individual appliances, but could become quite complicated.