Air purifier Singapore: choose by CADR and room size

For an air purifier in Singapore during haze, NEA’s air pollution FAQs say a highly efficient filter such as HEPA is preferred, and that an appropriate purifier should have a smoke CADR (Clean Air Delivery Rate) of at least 3 times the room’s volume in cubic metres, or 1/12 of its volume in cubic feet. NEA does not state a unit for the CADR figure. For an illustrative 3.2 m × 3.0 m bedroom with a 2.6 m ceiling (24.96 m³), the metric rule gives about 75.

The timing is real. The 24-hour PSI entered the Unhealthy range due to haze on 4 September 2026, and at 8pm on 16 October NEA reported 159 to 222 (Unhealthy to Very Unhealthy); the environment minister said that day that improvement is expected towards the end of October or early November. A label that says only “covers 30 sq m” cannot be checked against NEA’s rule, so this guide shows how to work out your number and what to ask when the label does not give one.

This is desk research from NEA, ministry and CCS pages read on 3 October 2026 and rechecked on 17 October. No purifier was tested and no brand or model is rated here.

What does NEA say to look for in a haze air purifier?

The “How to choose an air purifier” section of NEA’s air pollution FAQs gives two criteria and a caution.

• Suitable cleaning technology. For removing fine particles, NEA says highly efficient filters, such as HEPA filters, are preferred.
• Appropriate size. The unit should be sized appropriately for the intended room. NEA names the effective floor area and the flow rate of the purifier as factors to consider, and gives the smoke CADR rule below as what an appropriate purifier should have.
• Maker’s evidence. NEA says there are many effective air purifiers without a CADR rating, and that users should obtain from the manufacturer information that backs any claim about how efficiently the unit removes fine particles.

NEA’s air cleaning devices page (last updated 31 May 2023) defines CADR as the amount of clean air a device can produce for a room; a higher CADR indicates greater ability to return clean air to the room. On the FAQs page, NEA says a CADR label has three numbers, one each for smoke, dust and pollen, and that the smoke CADR is the most appropriate for haze pollutants. A larger CADR number means faster cleaning in an enclosed room.

How do I work out the CADR my room needs?

Use this worksheet for the room where the unit will run. NEA’s wording is about an enclosed room, so the worksheet assumes the door is closed; it says nothing about an open-plan living and dining area (our reading).

1. Measure the length, the width and the floor-to-ceiling height, all in metres.
2. Multiply the three: length × width × height = volume in m³.
3. Multiply the volume by 3. That is the minimum smoke CADR on NEA’s metric rule.
4. Cross-check with NEA’s cubic-feet rule: convert the volume to cubic feet (1 m³ is about 35.3 ft³) and divide by 12. It should land within about 2% of step 3.
5. Find the smoke CADR on the label or spec sheet and note the unit printed beside it. It should be at or above your number from step 3, but only if the label’s unit is the one NEA’s rule assumes, which NEA does not say (see the note on units below).

Two illustrative rooms (the dimensions are made up; measure your own):

• Bedroom: 3.2 m × 3.0 m × 2.6 m = 24.96 m³. Times 3 is 74.88, so at least about 75. In cubic feet the room is about 881.5 ft³, and 881.5 ÷ 12 is about 73.5.
• Living room: 5.0 m × 4.0 m × 2.6 m = 52 m³. Times 3 is 156; the cubic-feet rule gives 153.

Ceiling height counts, because the rule uses volume: the same bedroom with a 3.0 m ceiling is 28.8 m³ and needs about 86. NEA says “at least”, so treat your number as a floor; it does not say how far above it to go.

NEA names no unit for the rule. Its two forms agree to within about 2% for any room (35.3 ÷ 12 is 2.94, against 3), so they appear to describe one CADR figure; that is our reading, not NEA’s statement. A label figure can only be compared with your number if it is in the same unit, so if you cannot tell, ask the supplier rather than converting it yourself.

TBYB’s air purifier room size calculator does the volume sum for a room in metres or feet and shows both of NEA’s forms. It is arithmetic on NEA’s stated rule, not a recommendation.

What should I ask when the label says only “covers X sq m”?

NEA lists floor area as a factor, but its rule uses the smoke CADR, so a floor-area figure alone cannot be put through that rule, and it hides the ceiling height and other assumptions behind it (our reading). The Competition and Consumer Commission of Singapore (CCS) published a media release on its guide to product claims on 6 October 2025. The release says claims should clearly state any assumptions, limits or conditions underlying them, and be backed by evidence that is valid, specific and up to date. It is a general release about product claims and does not mention air purifiers; we did not read the guide itself.

Questions to put to the seller, in writing if you can:

• Does this exact model have a smoke CADR? What is the number, which unit is it in, and who measured it?
• If there is no CADR, what evidence backs the claim that it removes fine particles? (NEA’s advice is to ask the manufacturer.)
• Does it use a HEPA or other highly efficient filter? (NEA’s preferred technology for fine particles.)
• If the label gives a coverage figure, what ceiling height and fan setting does it assume?
• Can I see the spec sheet, test report or maker’s page for this exact model and variant?

NEA’s FAQs point to a haze.gov.sg list of portable air purifiers and suppliers “for reference”, and its air cleaning devices page mentions a list of portable air cleaners against COVID-19 aerosols that is based on data provided by suppliers. We could not open the haze.gov.sg list and did not check the COVID-19 list; treat any such list as a source of questions rather than a ranking (our reading). Keep the answers with your order record, as the checkout record guide suggests. If a claim looks misleading, the CCS release says consumers can approach the Consumers Association of Singapore (CASE) on 6277 5100.

Do I need to buy an air purifier for haze at all?

NEA presents the purifier as one item on a household list, not a requirement. The practical tips for households include:

• Close doors and windows when the outdoor air quality appears to be worsening, and re-open them when it improves.
• Stay indoors and reduce physical activities.
• Reduce indoor sources such as cigarettes and candles, and wet-clean (mop or wipe), which unlike dry-dusting or vacuuming generally does not stir up dust particles.
• Use fans or air-conditioners for circulation and cooling. If an air-conditioner draws in unfiltered air from outside (NEA’s example is window units), close the outdoor air intake.
• Portable air purifiers “can be used to further reduce the indoor particle level”.

The word “further” suggests the purifier is an addition to the other steps rather than a replacement for them (our reading). NEA does not say the other steps are enough on their own, or that a purifier is required. The Haze Task Force release of 4 September 2026 also says N95 masks are not required for short exposure, such as commuting from home to school or work, or in an indoor environment. Our N95 mask guide covers who can collect a mask from the Government’s distribution and when one helps.

A decision rule of our own, not NEA’s:

1. Do the no-purchase steps first.
2. Think about who is at home. NEA says the health impact depends on health status, the PSI level, and the duration and intensity of outdoor activity. This guide gives no health advice; NEA advises people who develop breathing difficulties to consult their doctor.
3. Buy only when you can name the room, measure it and get a smoke CADR, or the maker’s evidence, that clears your minimum. NEA notes that Singapore is not affected by haze throughout the year, and the minister expects improvement from late October or early November, so also ask whether you would use a purifier outside haze periods. That is a household judgement, not an NEA finding.

What should I check before I pay?

Copy this list and fill it in for each model:

• Room measured in metres, volume and minimum smoke CADR written down, with both NEA forms checked.
• Exact model and variant, with its smoke CADR, the unit beside it and who measured it, or the maker’s evidence if there is none.
• Filter type confirmed as HEPA or another highly efficient filter, plus replacement filter price and availability and the unit’s rated power in watts. The energy label guide shows how to turn kWh into your own running cost; it is written for labelled appliances such as air-conditioners, and we have not checked whether purifiers carry that label.
• Return terms in writing. A change-of-mind return depends on the seller’s own terms, as the home trial and return window plan explains.
• The total payable at checkout, not the headline price: see the year-end sales total price check.
• Your minimum smoke CADR in the must-work row of a simple product brief.

More guides are under comparing. Next action: measure the room, write down the minimum number, and check NEA’s latest haze update for current readings before you decide.

Common questions