Two running costs, one of which matters
Electricity is minor. A purifier is essentially a fan behind a filter, and at the 30 to 50 watt ratings common in this class, running it around the clock adds roughly 22 to 36 kilowatt-hours a month, a few ringgit at domestic tariff rates.
The filter is not minor. HEPA and activated-carbon filters load up and need replacing, typically every six to twelve months in a household that runs the unit through haze season and beyond. Replacement filters are priced by the manufacturer for a customer who has already bought the unit and has nowhere else to go. Across three years, the filter bill can exceed the unit’s price several times over.
Why the cheap unit is often the expensive one
Entry-level units frequently pair a low sticker price with proportionally expensive filters and shorter replacement intervals. Mid-range units often do the opposite. Run the three-year number, unit plus filters plus electricity, and the ranking frequently reverses. The sub-RM1,000 bracket in Malaysia currently runs from about RM369 to RM959 for the unit alone, and manufacturers such as Xiaomi rate their combined filters at six to twelve months, a figure to treat as a ceiling in Malaysian humidity. The rental alternative makes the same point from the other side: at RM70 to RM77 a month with servicing and filters included, renting overtakes the cost of buying a sub-RM1,000 unit outright by month 13 or 14.1
This is the same pattern as a printer sold cheap with expensive ink, and the same defence applies: price the consumable before the machine.
The mismatch most people buy
Every unit carries a rated room size or a clean-air delivery rate. A unit rated for a 15 square metre bedroom placed in a 40 square metre living room does not fail. It runs continuously without catching up, its filter loads faster, and the cost rises again. Match the rating to the room it will actually sit in, and if in doubt, size up rather than down.
What it does not fix
A purifier cleans the air in a closed room. It does nothing for outdoor exposure, nothing if the windows are open, and it is not a substitute for a mask on bad days or for keeping children indoors when the reading is high. It is one layer of a response, not the response. An honest article says so, and so does an honest salesperson.
If you already own one
The decision this season is not whether to buy but whether the filter is due. Check the indicator or the date you last changed it. A purifier running on a saturated filter is drawing electricity to move dirty air.
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THE MOVEFilter price, filter interval, room rating. Three numbers before the sticker price means anything.
Sources: Xiaomi Malaysia filter specifications (6 to 12 month rating); Cravings in Malaysia guides to sub-RM1,000 purifiers and haze units, Aug 2026, for unit and rental pricing; Department of Environment API readings for the seasonal context.
The post Haze season: what an air purifier actually costs to run, and what it does not fix appeared first on iMoney Malaysia.
