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, since 22 October 2026, that a portable air cleaner’s filters should provide a smoke CADR (Clean Air Delivery Rate) of at least 5 times the room’s volume in cubic metres, in m³/h. Where ventilation cannot be easily improved, where there are high-risk activities, or if the unit contains electronic air-cleaning technologies, NEA recommends an overall smoke CADR of at least 7 times the volume. For an illustrative 3.2 m × 3.0 m bedroom with a 2.6 m ceiling (24.96 m³), that is at least about 125 m³/h, or 175 m³/h in those cases.

The timing is real. The 24-hour PSI entered the Unhealthy range due to haze on 4 September 2026, and NEA was still issuing daily haze updates on 25 October, when it forecast a 24-hour PSI of 70 to 100 (Moderate) for 26 October; at 8am on 26 October NEA’s website showed 68 to 75, in the Moderate band. The environment minister said on 16 October that improvement is expected towards the end of October or early November, and that, depending on the weather, air quality could fluctuate. 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 and 19 October; NEA’s purifier advice was reread on 23 October 2026, after NEA changed its sizing rule, and every page was reopened on 26 October 2026. 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 points to a list.

• Suitable cleaning technology. For removing fine particles, NEA says highly efficient filters, such as HEPA filters, are preferred.
• Appropriate size. NEA says to select a unit that is appropriately sized for the space, and gives the minimum smoke CADR, in m³/h (which it also writes as cmh), as a multiple of the room size in m³: the two rules are below.
• A list for reference. NEA links to a list of portable air cleaners suitable for use in household and/or commercial settings for reducing airborne particulates.

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. NEA’s sizing rules are written in smoke CADR, so that is the figure to compare.

How do I work out the CADR my room needs?

Use this worksheet for the room where the unit will run. It assumes one enclosed room with the door closed; NEA’s FAQs size the unit for “the space” and do not discuss 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 5. That is NEA’s minimum smoke CADR effected by the unit’s air filters, in m³/h: “Smoke CADR (cmh) effected by air filters ≥ room size (m3) × 5”.
4. If ventilation cannot be easily improved (NEA’s example is no operable windows), if the room is used for high-risk activities, or if the unit contains electronic air-cleaning technologies, multiply the volume by 7 instead: “Overall smoke CADR (cmh) ≥ room size (m3) × 7”.
5. Find the smoke CADR on the label or spec sheet and check that it is given in m³/h. It should be at or above your number from step 3 or step 4. A figure in cubic feet per minute (CFM) is in a different unit: 1 CFM is about 1.7 m³/h (our conversion, from 0.3048 m per foot and 60 minutes per hour).

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 5 is 124.8, so at least about 125 m³/h; times 7 is 174.72, so about 175 m³/h where NEA’s higher rule applies.
• Living room: 5.0 m × 4.0 m × 2.6 m = 52 m³. Times 5 is 260 m³/h; times 7 is 364 m³/h.

NEA gives its own examples for a 4-room HDB flat: for a typical bedroom (10–12 m²), a smoke CADR of approximately 130–156 m³/h or higher, and for a typical living room (20–25 m²), approximately 260–325 m³/h or higher, depending on room size. Those room sizes are floor areas. Our reading, not NEA’s statement: the figures match the standard rule with a 2.6 m ceiling (10 m² × 2.6 m × 5 = 130; 25 m² × 2.6 m × 5 = 325). NEA does not say what ceiling height it assumed.

Ceiling height counts, because the rule uses volume: the same bedroom with a 3.0 m ceiling is 28.8 m³ and needs about 144 m³/h, or about 202 m³/h on NEA’s higher rule. NEA’s formulas are minimums and its examples say “or higher”, so treat your number as a floor; NEA does not say how far above it to go.

Until 22 October 2026, NEA’s FAQs gave a different rule: a smoke CADR of at least 3 times the room’s volume in cubic metres, or 1/12 of the volume in cubic feet, with no unit stated. That wording is no longer on the page, so a figure worked out from it, such as about 75 for the bedroom above, falls short of NEA’s current minimum.

TBYB’s air purifier room size calculator does the volume sum for a room in metres or feet and shows NEA’s standard and higher minimums in m³/h. 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’s rule uses the smoke CADR and the room’s volume, so a floor-area figure alone cannot be put through it, and it hides the ceiling height and other assumptions behind it (our reading). NEA’s own HDB examples start from floor area, but each pairs it with a smoke CADR in m³/h. 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, is it in m³/h, and who measured it?
• Is that figure from the air filters alone, or overall, including any other technology? (NEA’s two rules use those two terms.)
• Does it contain any electronic air-cleaning technology? (If so, NEA recommends the higher figure, 7 times the room volume.)
• If there is no CADR, what evidence backs the claim that it removes fine particles? (NEA’s air cleaning devices page advises buyers to speak with suppliers to obtain detailed product information.)
• 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 now link to “a list of portable air cleaners suitable for use in household and/or commercial settings for reducing airborne particulates”; our saved copy of the page does not record where the link goes, and we did not open the list. NEA’s air cleaning devices page describes its List of Portable Air Cleaners Against COVID-19 Virus Aerosols in the same words and says it is based on data provided by suppliers; we did not check that list either, and the haze.gov.sg list the FAQs named before 22 October could not be opened. 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 worked out, and both of NEA’s minimums (5 and 7 times the volume, in m³/h) written down, with a note of which one applies to your room.
• Exact model and variant, with its smoke CADR in m³/h, whether that figure is from the filters or overall, 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