Indoor Air Quality and Your HVAC System

While thinking about air quality is common to Utahns, this summer has made it particularly relevant. Utah, and the greater Salt Lake area in particular, has made headlines lately by earning the unenviable title of having the worst air quality in the world for many days. (Sources: KUER, ABC4, Fox13, saltlaketrib.com, KSL) In the wake of the bad air alerts caused by California and Oregon wildfires, Governor Cox issued statements urging Utah residents to stay indoors.

However, this has brought up many questions from homeowners regarding just how safe it is to be inside their own homes. Here are a few questions to help you understand your HVAC system’s role in indoor air quality and what you can do to make your indoor air safer.

1. IS SMOKE GETTING INTO OUR HOMES THROUGH THE HVAC SYSTEM?

Most likely, the answer to this question is yes. If your home has a large, gas-burning appliance like a water heater or furnace, then you need combustion air from outside. Wherever these appliances are located, you’ll have an air vent, bringing outside air into your home.

The outdoor AC unit is circulating outside air to cool refrigerant in the condenser but that outdoor unit is not pumping outside air into the house. So, while your air conditioner is circulating that air through the home, it is not technically how the air got in the house. It came in through the vent in your furnace room.

2. DOES THE TYPICAL AIR-CONDITIONED HOME FILTER OUT 2.5 MICRON SMOKE PARTICLES?

Not from what we see. Filters are measured by their MERV rating, 1 to 16. The higher the number, the smaller the particle it will filter out of the air.

To filter all smoke out of the air in your home, you need at least a MERV 13 filter. However, when you bump your standard filter to a MERV 13, you reduce the amount of air you’re able to pass through that filter at one time. And not enough air flow means your air conditioner could freeze up or motors can burn out.

If you want to improve the filtration in your home, I’d talk to someone who knows HVAC and can evaluate your system and tell you what your options are.

3. DO ROOM AIR CONDITIONERS FILTER OUT SMOKE PARTICLES?

No, but they do make room air cleaners or filtration systems.

4. WHAT ABOUT SWAMP COOLERS?

On poor air quality days, the Salt Lake County Outdoor Health Department recommends not running swamp coolers at all, as these bring outside air directly into the home without filtration. So, even though your furnace does bring some air into the home through vents, you’re still better off with an HVAC system than any other method.

5. IF WE TOOK A POLLUTION TEST IN THE HOME, WOULD IT BE BETTER THAN OUTSIDE?

Under normal circumstances, the EPA says that the air in our homes can be 3 to 5 times worse than outside. But with this sudden change in air quality, it’s likely not as bad. However, the longer the air quality stays bad, the worse the air quality in our homes will get. The Salt Lake County Health Department offers some additional suggestions for keeping your indoor air cleaner:

- They suggest postponing indoor cleaning. Vacuuming, dusting, and other cleaning activities can kick up additional dust and small particles.
- They also suggest keeping all windows and doors closed. This one may seem obvious, but it will help keep the smoke out. If you need to circulate air, use an indoor fan rather than opening windows or doors.
- They also recommend purchasing an indoor air purifier and using it on the highest setting during poor air quality days--especially during wildfires. These would be especially useful in bedrooms or other rooms where occupants spend long periods of time.

6. IS THERE FILTRATION EQUIPMENT FOR MY HVAC SYSTEM THAT GUARANTEES TO GET THE SMOKE OUT?

Yes. Improving the filtration is the easiest way. It doesn’t require you to replace your system; you may just need to reconfigure the duct work where the filter is.

They also make polarized electrostatic air filters that remove all the smoke from any air that crosses over the charged filter material. Those come in standard filter sizes and can usually go where your existing filter is, with a little bit of wiring.

7. HOW MUCH IS THIS HVAC FILTRATION EQUIPMENT?

$500 to $1,000 plus or minus, depending on your home and your HVAC setup.

If you have any additional questions about your HVAC system and how to improve your indoor air quality, talk to a licensed HVAC technician. They can help you clean your indoor air more efficiently and effectively to keep you and your family safe during poor air quality days.

Other helpful articles:

🛠️ DIY videos from Any Hour Services
🎙️ Listen to Our Podcast - In the House
🎥 Watch our VLOG - Along For The Ride

Aug 27th 2021

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