Woke up to the smell of smoke and a hazy view over Lake Sammamish? You are not alone. Wildfire smoke now reaches our area more often, and it can make indoor air feel uncomfortable and unsafe. In this guide, you will learn simple steps to keep your home’s air cleaner during smoke days, plus smart upgrades that can add comfort and appeal when you sell. Let’s dive in.

Why wildfire smoke hits Sammamish

Sammamish sits in east King County where smoke can drift in from eastern Washington, Oregon, California, or Canada. Washington’s fire season is generally tied to spring through fall, and smoke episodes often peak from mid summer into autumn. To understand timing and statewide context, review the Washington Department of Natural Resources’ smoke resources and seasonal guidance at the DNR wildfire and smoke resources page.

Wildfire smoke contains very small particles called PM2.5 that can irritate eyes and lungs. Young children, older adults, pregnant people, and anyone with heart or lung conditions are more sensitive. Reducing your time in smoky air and improving indoor filtration can lower exposure.

Check air quality fast

Before you decide what to do, check the air quality for Sammamish. Use the official NowCast AQI and fire map summarized by the EPA at Preparing for smoke and heat. Many residents also view neighborhood sensors for street-level context, then confirm trends with official sources.

• If AQI is over 100, limit outdoor time. If it rises over 150, take stronger precautions and focus on indoor air.
• Recheck AQI in the afternoon and evening, since smoke often shifts with wind and temperature.

What to do today when smoke rolls in

Small changes add up. Use this quick checklist when AQI turns unhealthy.

• Close windows and exterior doors. Keep latches engaged and wait to ventilate until AQI improves. See practical steps from the Washington Department of Health.
• Set your system to recirculate. If your HVAC or heat pump allows it, close the fresh-air intake to avoid pulling smoky air inside. Switch back when outdoor air improves.
• Run a HEPA air purifier in the rooms you use most, such as your living area and bedroom. The EPA’s guide explains what to look for at the Guide to Air Cleaners in the Home.
• Use a well-fitted N95 or P100 if you must go outside. Fit matters more than brand. See proper use guidance in this NIOSH respirator overview.
• Create a simple clean room. Pick an interior room with few windows, run a HEPA purifier, and seal door gaps with towels if needed.
• Avoid indoor smoke sources. Skip frying and broiling, candles, incense, vacuuming with a non‑HEPA vacuum, and wood-burning until air improves.

For people or pets who are more sensitive to smoke, keep activity light indoors and follow your health care provider’s plan. The CDC explains health risks and precautions in its wildfire smoke safety guidance.

Set up a clean room

A clean room gives you a safe space when air is worst.

• Choose a room on the interior of your home with minimal windows and doors.
• Close windows, seal door gaps with a towel, and run a HEPA purifier sized for the room.
• Keep pets and kids in this room during peak smoke hours so everyone breathes cleaner air.

Choose the right air purifier

Sizing matters. Look for the “smoke” Clean Air Delivery Rate, often listed as CADR in cubic feet per minute.

• As a rule of thumb, aim for a smoke CADR that is at least two thirds of the room’s square footage with typical 8 foot ceilings. For example, about 133 CFM for 200 square feet, 200 CFM for 300 square feet, and 267 CFM for 400 square feet. See state guidance on selecting units at WA DOH: Choosing a portable air cleaner.
• Run purifiers on high during smoky periods and place them where airflow is not blocked.
• Avoid devices that generate ozone. Public health agencies advise against ozone for smoke.

DIY on a budget: the Corsi‑Rosenthal box

A Corsi‑Rosenthal box uses a box fan plus MERV‑13 filters to create an effective, low cost purifier. It can be a great backup if store units are sold out. Learn how it works and what to consider in this overview of the DIY purifier.

Longer term upgrades that help

Looking beyond a single smoke day, a few home improvements can make a real difference.

Filtration and your HVAC

If your system allows, using MERV‑13 filters can reduce fine particles. Some older furnaces cannot handle higher resistance filters, so check with an HVAC pro before upgrading. HEPA portable units plus better HVAC filtration are a strong combination supported by public guidance and field research.

Ventilation and fresh‑air intakes

During heavy smoke, close outside air intakes and run systems on recirculate if your equipment allows. Resume bringing in fresh air when outdoor conditions improve. If you pause mechanical ventilation for long periods, watch comfort and CO2 levels.

Seal drafts and reduce leaks

Weatherstripping, caulking, window film, and door sweeps reduce smoke infiltration and can lower energy costs. Repair leaky fireplace dampers and confirm windows latch tightly.

Monitor and learn

An indoor PM2.5 monitor helps you see what works in your home. Use it to decide when to run purifiers on high and when it is safe to crack a window.

Maintenance matters

Stock spare filters before summer. Expect to replace filters more often during prolonged smoke. Keep user manuals handy so you can change settings quickly when AQI shifts.

Buyer and seller checklist in Sammamish

These features offer everyday comfort and can stand out in listings during smoke season.

If you are buying

• A central system that can run on recirculate and documentation of filter type, ideally MERV‑13 if compatible.
• Portable HEPA units sized for main living areas and bedrooms.
• Well-sealed windows and doors, plus door sweeps and a tight fireplace damper.
• Indoor air monitors that show PM2.5 levels and trends.

Industry groups are highlighting indoor air quality in building guidance, which signals growing attention in real estate. See context from ASHRAE’s smoke mitigation guidance.

If you are selling

• Replace or document recent HVAC filter service and list the filter rating.
• Note any weatherization, upgraded windows, or added door sweeps.
• Leave user guides for HEPA purifiers and a small “smoke day” kit with spare filters and a couple of N95s. This shows care and preparedness that buyers appreciate.

Local burn bans and rules

During poor air quality, the Puget Sound Clean Air Agency can issue Stage 1 or Stage 2 burn bans that limit fireplace and wood stove use. Check current rules and sign up for alerts at the Puget Sound Clean Air Agency burn ban page.

Ready to prep your Sammamish home for a cleaner air season and make smart updates that buyers will notice? Reach out to the Six Degrees Team for practical, design‑savvy guidance and a plan that fits your goals.

FAQs

When is wildfire smoke most common in Sammamish?

• Smoke events often occur mid summer through fall, and the state tracks fire season during warmer months, so start preparing early.

How do I know if it is safe to open windows again?

• Wait until AQI returns to good or moderate for your area, then ventilate during the cleanest part of the day and keep filtration running.

What if I do not have central AC?

• Use portable HEPA purifiers, create a clean room, and cool the house during cleaner air periods so you can keep windows closed when smoke is heavy.

What size air purifier should I buy for a bedroom?

• Multiply the room’s square footage by two thirds to estimate the smoke CADR you need, then choose a unit that meets or exceeds that number.

Can I run my HRV or ERV during smoke?

• If your unit brings in outside air without high efficiency filtration, pause or reduce ventilation during heavy smoke and return to normal when air improves.

Are DIY Corsi‑Rosenthal boxes safe to use at home?

• Build with a stable frame, secure filters and cords, and do not leave it running unattended around small children or pets.

Do indoor air upgrades help resale value?

• Buyers increasingly ask about comfort and air quality, so clear documentation of filtration, maintenance, and weatherization can help your home stand out.