When smoky days roll into Moraga, it can feel like there’s no escape. You want to keep your home comfortable and safe, especially if anyone in your household is sensitive to smoke. The good news is you can make a big difference indoors with the right filters, portable HEPA purifiers, and a few sealing strategies. This guide gives you clear steps you can use right away, plus local tips to help you plan ahead. Let’s dive in.
Why indoor air matters in Moraga
Wildfire smoke raises PM2.5 levels, which are tiny particles that can travel deep into your lungs. Moraga sits within the Bay Area airshed, so even distant fires can impact your air. Children, older adults, and people with heart or lung conditions may feel the effects first.
During smoke events, check local air quality updates and public health notices from regional and county sources. If conditions worsen or evacuation orders are issued, follow official guidance immediately.
Upgrade filtration: HVAC filters that work
Your central HVAC can pull a significant amount of smoke particles out of the air if you use the right filter. For most homes, a MERV 13 or higher filter is the recommended target for capturing fine particles like PM2.5. It is a major improvement over standard MERV 8 filters.
Before upgrading, confirm your furnace or air handler can handle a higher-MERV filter. Some older systems may lose airflow with higher resistance. If your system cannot support MERV 13, install the highest MERV rating it allows and add portable HEPA units in the rooms you use most.
During smoky periods, set your HVAC fan to ON so the air recirculates through the filter continuously. If your system has a recirculation setting, use that instead of pulling outdoor air in. Expect to replace filters more often during smoke season. Check them frequently and swap them when they look loaded or if airflow drops.
Portable HEPA air cleaners: sizing and placement
Portable true HEPA air cleaners are one of the most effective tools you can use room-by-room. They remove fine particles and are easy to move where you need them.
- Aim for at least 4 to 6 air changes per hour (ACH) in the rooms you occupy most. Higher-risk individuals may prefer more ACH if noise and energy use are acceptable.
- Use the CADR (Clean Air Delivery Rate) for smoke to size a unit. A quick formula: CADR (CFM) = Room volume (ft³) × Desired ACH ÷ 60.
- Example: A 12 ft × 12 ft × 8 ft bedroom is 1,152 ft³. For 5 ACH, you need about 96 CFM.
Place the purifier where you spend time. For a bedroom, near the head of the bed works well but avoid blowing air directly on you. Keep several inches of clearance around the unit so it can move air freely. If you have a multi-room home, using more than one purifier often beats one big unit in a single location.
Run units on the highest practical speed during smoke events. If noise is an issue at night, step down a speed but try to maintain at least two-thirds of the maximum if you can. Replace prefilters and HEPA filters as recommended by the manufacturer, and expect faster wear during heavy smoke.
Avoid ionizers or ozone-generating devices. Ozone can irritate your lungs and does not help with PM2.5.
DIY option: Corsi-Rosenthal box
You can make a low-cost purifier by taping a high-quality box fan to a MERV 13 or higher filter and sealing the edges well. Place it on a stable, non-flammable surface and avoid leaving it running unattended if you are concerned about heat buildup.
Check your progress with a sensor
A simple PM2.5 monitor can show how well your setup is working. Compare indoor readings to outdoor levels and adjust purifier speeds, filter changes, or sealing steps to improve results.
Seal and manage ventilation on smoky days
Keeping smoke out is as important as filtering the air already inside.
- Close and lock all windows and exterior doors for a tighter seal.
- Close fireplace dampers and turn off whole-house or attic fans that pull outdoor air in.
- Seal obvious gaps under doors with a sweep or even a rolled towel for the day.
- Temporarily seal problem spots, like leaky pet doors, with clear plastic and painter’s tape. Label anything you tape for easy removal later.
For a longer-term upgrade, add weatherstripping, caulk gaps, and install door sweeps and threshold seals. Consider air sealing larger penetrations and insulating or sealing ductwork. A blower-door test or home energy audit can help you find the biggest leak points.
If you cook during a smoke event, keep doors to other rooms closed and use a vented range hood if it does not worsen smoke infiltration. Avoid burning candles and using unvented combustion appliances. Make sure carbon monoxide detectors are working on every level of your home.
Room-by-room setup in a Moraga home
Bedroom
- Use a HEPA purifier sized for the room. Place it near the head of the bed with 6 to 12 inches of clearance.
- Keep the HVAC fan set to ON and use a MERV 13 filter if compatible.
- Close windows and seal gaps around the frame.
Living room
- Place a high-CADR HEPA unit in a central spot or near the main seating area.
- For larger or open layouts, consider two units or one per frequently used zone.
Kitchen
- Limit long cooking sessions during heavy smoke. Consider microwave or no-cook meals.
- If the hood vents outdoors and does not draw smoke in, use it to remove cooking pollutants.
Garage and entry
- Keep the garage door closed.
- Add a tight door sweep and weatherstripping between the garage and the house.
Quick smoky-day checklist
- Close and lock windows and exterior doors.
- Set the HVAC fan to ON; use recirculation and close outside-air intakes.
- Install or upgrade to MERV 13 or the highest your system supports.
- Run portable HEPA purifiers in key rooms and size by CADR.
- Seal gaps under doors and around windows as needed.
- Turn off whole-house fans and attic fans.
- Avoid indoor combustion sources like candles and unvented gas appliances.
- Test carbon monoxide detectors and smoke alarms.
- Track indoor PM2.5 with a monitor and compare to outdoor conditions.
- If symptoms become severe or indoor air stays hazardous, seek a cleaner-air location following public health guidance.
Plan ahead with local resources
In Moraga, the Moraga-Orinda Fire District provides seasonal updates on defensible space, mitigation projects, and evacuation planning. Bay Area Air Quality Management District issues local air quality advisories and guidance for smoke days. Contra Costa Health Services, California Air Resources Board, and federal agencies like the EPA and CDC publish practical steps for indoor air protection.
Stock up on HVAC filters and HEPA replacement filters ahead of peak season. During major smoke events, supplies can run low in local stores. Schedule HVAC service before summer and fall to confirm your system is ready for a MERV 13 filter if it can handle it.
Thinking about selling or buying in Moraga?
Simple upgrades like better sealing, a compatible MERV 13 filter, and a few well-placed HEPA purifiers can make your home more comfortable during showings and everyday living. These steps also signal care and upkeep to buyers.
If you are planning a move, I am here to help you navigate Moraga and nearby neighborhoods with a calm, step-by-step approach. Have questions about preparing your home or timing your sale around the season? Let’s talk. Request Your Free Home Valuation with Kailani Kimoto.
FAQs
What’s the best HVAC filter for wildfire smoke in Moraga?
- For most homes, a MERV 13 filter offers strong PM2.5 removal, if your system can handle it; otherwise use the highest MERV your system supports and add portable HEPA units.
How do I size a HEPA purifier for my room?
- Use CADR for smoke and target 4 to 6 air changes per hour: CADR (CFM) = Room volume (ft³) × Desired ACH ÷ 60; adjust for noise and comfort.
Where should I place a HEPA unit for sleeping?
- Put it in the bedroom with some clearance, near the head of the bed but not blowing directly on you; run it on the highest comfortable speed.
Are ionizers or ozone air cleaners good for wildfire smoke?
- Avoid them; they can create ozone and byproducts that may irritate your lungs and do not effectively remove PM2.5 like a true HEPA.
What should I seal first on a smoky day?
- Close and lock windows and exterior doors, shut fireplace dampers, turn off attic or whole-house fans, and seal door gaps with sweeps or a rolled towel.
How often should I replace filters during wildfire season?
- Check HVAC and HEPA prefilters frequently; replace them sooner if you see heavy loading or airflow drops, sometimes every few weeks during extreme smoke.
