Haze Season Survival Guide: How to Keep Your Home's Air Clean

Singapore's 24-hour PSI crossed into the unhealthy range for the first time since 2023 on 4 September, prompting NEA to start issuing daily haze advisories. If your eyes have been stinging on the commute or the view from your window has turned a hazy grey, you're not imagining it. 

The instinctive move during haze season is to shut every window and door. That's the right call for keeping PM2.5 particles out, but it creates a second problem most people don't plan for: a sealed-up home traps heat, humidity, and stale air. In Singapore's climate that turns "haze-proof" into "stuffy and damp" within a day or two. 

Why closing your windows isn't the whole answer

Sealing your home is effective at keeping outdoor pollution out. The trade-off is that Singapore homes rely on cross-ventilation to manage heat and humidity. Cut that off and you get:

• Warmer, more stagnant rooms, since the airflow that would normally carry heat outside is gone

• Higher indoor humidity, especially in kitchens, bathrooms, and laundry areas

• A slow build-up of indoor pollutants, cooking fumes, dust, and everyday particulate matter, that normally gets flushed out through open windows

None of this means you should crack a window during a bad haze day. It means indoor air now needs active help instead of passive ventilation.

Fix 1: Let an air purifier do the job your windows used to do

With natural airflow off the table, an air purifier becomes the thing doing the work of clearing dust, haze particles that do sneak in, and everyday indoor pollutants. A few things matter more than others when you're picking one for haze season specifically:

• A true HEPA filter (H13 or better) — this is the grade that captures PM2.5-sized particles, which is exactly what haze is made of. PRISM+'s Air Purifiers run true HEPA H13 filtration for this reason.

  Don't know what's HEPA? Read this guide: What Is a HEPA Filter And Does the Grade Actually Matter?

• Coverage area matched to your room size — an undersized purifier running at max fan speed all day is less effective than a correctly sized one running comfortably.

• Running it continuously, not just when it smells smoky — PM2.5 is often invisible and odourless, so "the air seems fine" isn't a reliable signal to switch it off.

• Filter replacement on schedule — a saturated filter stops filtering. PRISM+ offers filter subscription plans so that your filter change comes just in time.

Fix 2: Stop fighting stuffiness by cracking a window

Since opening windows defeats the point, the stuffiness itself needs a different fix:

• Sealed un-cooled rooms build heat and humidity the fastest. Run PRISM+ Ceiling Fans or PRISM+ Air Conditioners in rooms you use. PRISM+ Connect App allows you to switch on and off your appliances from anywhere.
  
  

• If you do want to open your windows to ventilate briefly (clearing cooking smoke, for instance), do it during the parts of the day when PSI readings are lower, then seal up again — NEA's hourly PSI readings make this easy to time

Fix 3: Solve the "my clothes won't dry" problem properly

Air-drying laundry depends on airflow and low humidity, exactly the two things a sealed, haze-season home doesn't have. Clothes left on an ordinary rack indoors during haze season often take longer to dry, and half-dry fabric left too long is a fast track to that musty smell (and mould, if it sits in a corner without airflow).

A dryer is the most direct fix, but if you'd rather keep laundry on a rack, a rack with its own built-in drying function solves the same problem.

PRISM+'s Solaris Pro is built around exactly this: four brushless DC turbine fans (six on the Pro XL) pushing 9 m/s airflow through the full width of the rack, plus 12 built-in heater elements that warm the air up to 75°C, so clothes dry from active airflow and heat rather than waiting on ambient humidity to drop.

It also runs an ioniser and anti-dust-mite cycle to cut down odour and airborne bacteria while it dries, with UV sterilisation added on the Pro XL.These features are useful when the air in the room is already carrying more haze-related particulate than usual. 

Everything's controlled by voice ("Hi PRISM"), the PRISM+ app, or the included remote, with auto-timer scheduling so you can set it going and forget it, and it's rated to carry up to 50kg of laundry.

The bottom line

Haze season means running two systems at once: keep the outdoor air out, and actively manage what happens to the indoor air as a result. An air purifier with true HEPA H13 filtration covers the air quality half; better airflow management and getting laundry off drying racks covers the stuffiness and humidity half. Do both, and a sealed-up home doesn't have to be an unpleasant one.

Check today's PSI readings on the NEA website or the myENV app before deciding whether it's safe to air out your home, and keep an eye on NEA's daily haze advisories for the latest guidance.

Sources: NEA haze advisories (nea.gov.sg), reporting on Singapore's 4 September 2026 PSI reading via Mothership.sg.