Block dangerous air from your home with a roll of weatherization tape

September 15, 2020

A full week has passed since wildfire smoke began pouring into the Willamette Valley, seeping into homes, saturating clothes and hair and lungs.

Air purifiers sold out first. Then people struggled to find furnace filters and box fans they could use to make their own purifiers.

And after days of air quality at hazardous levels, residents in the Portland Metro area were warned Monday they must hunker down for a few more days of dangerous air.

“Part of the reality is we don’t have a ton of tools at our disposal,” said Elliott Gall, an engineering professor at Portland State University who studies indoor air quality. “One thing I have been doing is trying to create a safe air refuge in my home and trying to prevent smoke from getting into that room.”

Outside Gall’s home on Saturday, an air quality monitor registered particulate matter at 450 micrograms per cubic meter (Hazardous air is considered anything above 250).

So Gall and his wife set about creating a “clean room” where the air inside was as healthy as possible. They started with the room where their 18-month-old son sleeps. 

They were already running an air purifier — if you have it, run it! — in the nursery, and Gall installed an air monitor, which showed pollutants between 30 and 40 micrograms per cubic meter.

It was significantly better than the dangerous air outside, but still well above the healthy range of up to 12. 

That’s when they picked up a few rolls of weatherization tape and set about sealing the windows. The next night the measure of pollutants in the air had dropped to 5, well within a healthy range. 

“I am an air quality scientist so I have air cleaners. I am probably more attuned to air quality issues than the average person,” Gall said. “I probably also worry more than the average person.”

Most residents likely didn’t or weren’t able to invest early in an air purifier or assemble a DIY purifier, two of the most protective steps to clean indoor air, in addition to installing a higher MERV rated filter in your furnace. 

But any measures to seal off your home from outdoor air will keep the air from getting much worse, until conditions improve. So pick up a roll of weatherization tape. You can also try painters tape if that’s what you have on hand.

But don’t forget to open your home back up again when the air clears, Gall said. 

“Generally indoor air is more polluted than outdoor air. But not right now,” Gall said. 

And when conditions improve, the skies clear, and filters and fans return to store shelves, consider investing in supplies for the next wildfire season. Gall also recommends talking to a weatherization professional to fix unwanted leaks at your home.

“This is the new seasonal normal,” he said. “This is something we need to plan for and think about long term.”

Here’s your guide for protecting indoor air:

  • Close all doors and windows, including internal doors.

  • Set your air conditioner to recirculate.

  • Use an air purifier with a HEPA filter, or make your own.

  • Tape windows and unused doors where outdoor air seeps in.

  • Create a clean air room within your home.

  • Don’t vacuum. Use a damp mop. Dust with a damp cloth. 

  • Do not burn anything: including candles, incense, sage, cigarettes or gas stoves.

  • Avoid frying or broiling food.