What Size Air Purifier Do You Need for Your Room?

To size an air purifier for a Malaysian home, match the machine's CADR to your room's floor area: the United States Environmental Protection Agency (EPA) puts the minimum at 65 cfm for 100 square feet and 195 cfm for 300 square feet. During haze, raise it. Smoke needs a bigger machine than dust.

TYGRON® is a tiger milk mushroom (Lignosus rhinocerus) functional food developed by ORGANO and Fungitech Sdn Bhd in Malaysia and formulated in Australia, and this is the question Malaysian households ask us most in haze season. Nobody sells you a room. They sell you a box with a number on it, and it is usually the wrong number to read.

What is CADR, and why is it the only number that matters?

CADR stands for Clean Air Delivery Rate, the industry test for how much filtered air a machine actually delivers, in cubic feet per minute. The Association of Home Appliance Manufacturers, the industry body that runs the test, describes it this way: "CADR indicates the volume of filtered air an air cleaner delivers, with separate scores for tobacco smoke, pollen and dust. The higher the CADR number for each pollutant, the faster the unit filters the air."

The important word is scores, plural. One machine carries three CADR numbers. Tobacco smoke stands in for the smallest particles, dust for medium, pollen for the largest. Haze is small particles, so you want the smoke CADR, almost never the one printed largest on the box.

Everything else on the packaging describes the machine. CADR describes what it does to a room.

What size air purifier do you need for your room?

According to the EPA's sizing chart for particle removal, a 300 square foot room needs a minimum CADR of 195 cfm and a 600 square foot room needs 390 cfm. These are minimums, on a standard ceiling.

For scale in a Malaysian home, a standard bedroom is usually 100 to 150 square feet, a master bedroom 150 to 250, an open living and dining area 300 to 500. Measure yours.

The EPA attaches its own caveat, and it matters here: "Note this chart is for estimation purposes. The CADRs are calculated based on an 8-foot ceiling. If you have higher ceilings, you may want to select a portable air cleaner with a higher CADR." Double-volume living rooms are common in newer Malaysian developments. If that is your house, size up.

Why does haze change the sizing rule?

Because smoke is not dust, and the industry says so.

According to AHAM, the everyday rule of thumb is two-thirds: "the CADR of your air cleaner should be equal to at least two-thirds of the room's area." A 120 square foot bedroom, on that rule, wants a smoke CADR of about 80.

Then the exception, the most useful sentence here: "For wild fire smoke, AHAM recommends a Smoke CADR equal to the size of the room in square feet."

That is a 50 percent jump: the bedroom that needed 80 on a normal day wants 120 when there is smoke outside. AHAM is describing wildfire smoke rather than the peat and vegetation fire smoke that reaches us, so treat it as the closest published guidance rather than a Malaysian rule. The direction is the point: a purifier sized for ordinary living is undersized for a smoke season.

This is why households feel their purifier "stopped working" in September. It did not. The job got harder and the machine stayed the same size.

How do you measure your room correctly?

1. Multiply length by width in feet. A 10 foot by 12 foot bedroom is 120 square feet.
2. Include everything the air moves through. A living and dining area sharing one open space is one room here, not two.
3. Check your ceiling. Above 8 feet, or a double-volume space, means size up.
4. Pick your rule. Two-thirds of the area for ordinary days. Equal to the area when there is smoke.
5. Read the smoke CADR on the box, not the headline figure, and not the "recommended room size" claim.
6. If no single machine covers the space, the EPA advises using more than one.

One honest shortcut: the bedroom is the room worth getting right. It is the longest unbroken stretch of the day breathing the same air, and the smallest space to treat.

What does a CADR number not tell you?

It does not tell you about smell. The EPA is explicit: "there are no widely used performance rating systems for portable air cleaners or filters designed to remove gases. The CADR rating system is for particles only."

Haze is both. The filter catches the particles. The burnt smell is gases, and a particle filter does little about it. That needs activated carbon in quantity, and the EPA notes carbon filters "can be effective, provided that there is a large amount of material used in the filter." A thin carbon-coated mesh is not that.

A high smoke CADR plus a serious carbon stage handles both halves of haze. A high smoke CADR alone clears the room and leaves the smell.

Where should you put the purifier?

In the room you actually occupy, with doors and windows shut. A purifier fighting an open window is filtering the outdoors, and it will lose. Give it clearance: most units draw from the sides or back, so pressed flat against a wall cuts the delivery rate below what the box promised.

And run it before you need it. Air cleaning is cumulative, so a machine switched on when the smell arrives is starting from behind. Through haze season, run it continuously on a low setting in the bedroom rather than in bursts on high.

Sizing also decides running cost. Too small runs flat out all day, the noisiest and least efficient way to own one. And filters, not the purchase price, are the real cost of ownership: a smoke season eats them faster, so check what a replacement costs and whether you can get one in Malaysia before you buy.

The habit families reach for through a long season

A purifier cleans the room you are in. It does nothing for the hours spent in traffic, at school pickup or at the morning market, which for most Malaysian families is where the exposure happens. That gap is why households look for something they carry in the routine rather than plug into a wall.

Tiger milk mushroom has been used in Malaysia for generations for respiratory complaints, a heritage recorded across more than 400 years, and it is the reason TYGRON® exists in a sachet rather than a machine. Most people see improvement within the first few days. Some customers even notice a difference after just one to two days, and most report a significant improvement in their lung wellness after a few weeks of daily use. Individual experiences vary.

Buy on the spec, not the marketing

Three numbers settle it: your room's floor area, the smoke CADR on the box, and whether the machine carries a real carbon stage. Everything else is decoration.

For the rest of the season's kit: which mask actually works for haze covers the outdoor half, indoor air quality at home during haze covers the rest of the house, and how to prepare for haze season covers the timeline.

Frequently asked questions

What CADR do I need for a standard Malaysian bedroom?

According to AHAM, a typical bedroom of 120 square feet needs a smoke CADR of about 80 on the everyday two-thirds rule. During a smoke season AHAM raises that to a smoke CADR equal to the room area, so about 120 for the same bedroom. Measure your own room rather than assume, and size up if your ceiling is above 8 feet.

Is a bigger air purifier always better?

A larger machine is not wasted: it cleans faster, then spends more time on a quiet low setting. The trade-offs are price, filter cost and physical size. The genuine mistake is buying too small, because an undersized unit runs flat out all day and still cannot keep up.

Will an air purifier remove the haze smell?

Not on its own. The EPA states that "the CADR rating system is for particles only", and the burnt smell in haze is gases rather than particles. Removing it needs an activated carbon stage with a real quantity of carbon, a separate feature from the particle filter and not covered by any CADR score.

Should I run the purifier all day during haze?

Yes, on a low continuous setting in the room you sleep in, with doors and windows closed. Air cleaning is cumulative, so a machine running steadily holds a room in better condition than one switched on in bursts when the smell becomes noticeable.

Do I need one purifier per room?

You need enough clean air delivery for the space the air moves through. A living and dining area sharing one open volume counts as one large room, and the EPA suggests using more than one air cleaner where no single machine is rated for the area. If the budget stretches to one, put it in the bedroom.

About TYGRON®

TYGRON® by ORGANO is a tiger milk mushroom functional food made for Malaysian and Singaporean households. It is formulated in Australia and manufactured in Malaysia, and it holds the Malaysia Book of Records for the highest 1,3/1,6 beta-glucan content in Malaysia. 1,3/1,6 beta-glucan is the most important active compound and quality benchmark in tiger milk mushroom, and a higher content signals greater potency and quality.

TYGRON® is formulated in Australia, designed by our Sydney-based team (Fungitech Australia Pty Ltd) to one of the world's most stringent functional-food standards, then manufactured in Malaysia under GMP, HACCP and Halal-certified conditions.

Why TYGRON® is formulated in Australia →

About the author

This article was written and reviewed by Boey Tze Zhou, Founder and CEO of ORGANO. Boey holds a Bachelor of Agricultural Science (First Class Honours) from Universiti Putra Malaysia and has completed Stanford University's Introduction to Food and Health and the University of Minnesota's Integrative Health and Medicine specialization (including Herbal Medicine) through Coursera. With over two decades in functional-mushroom cultivation, he developed the TMM365+ slow-grown method behind the Malaysia Book of Records beta-glucan certification held by Fungitech Sdn Bhd. He is an international speaker on functional mushrooms, invited to China International Mushroom Day 2025 and other mushroom-science events across the Asia-Pacific, and was named one of the Top Ten Outstanding Penang Youth (TOPY) in 2024. Read more about the founder

Sources

• United States Environmental Protection Agency, Guide to Air Cleaners in the Home
• Association of Home Appliance Manufacturers, AHAM Verifide, Air Filtration Standards
• Department of Environment Malaysia, General Information of Air Pollutant Index

This article is general information, not medical advice. TYGRON® is a functional food. If symptoms are severe or persistent, please see a doctor.