Wildfire smoke now reaches Brooklyn most summers. The good news: a closed‑up room with a right‑sized HEPA purifier can hold fine particles near clean‑day levels even when it's 150+ outside. Here's the whole playbook — calm, specific, and free.
No sign‑up required to read it. That's the point.
The Air Quality Index is the outdoor number in every headline. Your job on a smoke day is to make your indoor number tell a different story.
A well‑sealed room with adequate filtration should hold indoor PM2.5 in the single digits (µg/m³) even during an outdoor advisory. If you own a monitor, that's the number to watch — not the one on the news.
If you have central air or a unit that takes a real filter, check the rating. MERV 13 captures smoke particles well — confirm your system can handle it (most can; older motors sometimes can't). Write the size on your phone so reordering is one tap.
The quick rule: the purifier's smoke CADR (in cfm, on the box) should be at least two‑thirds of the room's square footage. A 12×15 bedroom is 180 sq ft — look for CADR 120 or higher. Bigger is quieter, because you can run it on low.
A box fan with a MERV‑13 furnace filter strapped to the back (or the four‑filter “Corsi–Rosenthal” cube) moves serious clean air for about $60. Ugly, effective, beloved by scientists.
Window units, PTACs, and central systems all have a mode that cools the air you already have instead of pulling from outside. Know where it is before you need it.
They work on smoke the way they work on everything else — when worn snug, outdoors, for the errands you can't skip.
Windows shut, including the ones you forget — bathroom, stairwell‑facing, the kid's room. If your building hallway smells smoky, a rolled towel at the door helps more than you'd think.
Cooling and filtration beat fresh‑air intake on a smoke day. Heat guidance still wins overall: if your home gets dangerously hot, prioritize getting cool.
Purifiers clean rooms, not apartments. Put them where people actually are — the room with the kids beats the hallway with the outlet.
Skip frying, broiling, candles, and vacuuming (it stirs up settled particles). Tonight is a lid‑on‑the‑pot kind of night.
If you have a monitor, indoor PM2.5 is your scoreboard. Rising indoors? Find the open window or the gap — the number will lead you to it.
When the outdoor AQI drops back under ~100, open up and air the place out — cross‑ventilation for 20–30 minutes clears what seeped in.
After a heavy event or a heavy season, inspect purifier and HVAC filters. A loaded filter is a filter that did its job — and one that's ready to retire early.
That's literally what the audit measures — how your rooms perform with the windows closed and the filtration running, plus the exact sizing your home needs. September founding cohort: eight Brooklyn homes, $395, payment after.
One email with this playbook to keep, plus a short heads‑up when a smoke advisory hits the city and when September booking opens. No newsletter, no noise.
Tap below and your email app will open with the request pre‑filled — just hit send, and the playbook comes back to you.
Prefer to type? Email hello@brownstoneair.com with the subject “playbook.”