Sizing by room type

Quick answer

There are 14 room types here and 112 pages sized to a specific floor area. Each room type carries its own ceiling assumption and air change target, because a basement at seven feet and an open plan kitchen at nine feet need different arithmetic even at the same floor area.

A machine that suits most rooms

GermGuardian HEPA Air Purifier - Large Room Air Purifier for Bedroom, Office, Dorm, and Home - Filters Pet Dander, Dust, Pollen, Smoke, Scents - AC4825E - 22" Tower - Gray

Enough airflow for a bedroom or a medium living space at four and a half air changes an hour, with a published specification to check against the room.

$80.74Check pricePrices change often

Check the noise at the speed that delivers the airflow, not the figure quoted for the lowest setting.

Every room type

  • 8 sizes

    Air purifier sizing for a bedroom

    What clean air delivery rate a bedroom needs, from 100 to 250 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a master bedroom

    What clean air delivery rate a master bedroom needs, from 200 to 450 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a nursery

    What clean air delivery rate a nursery needs, from 80 to 200 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a kids bedroom

    What clean air delivery rate a kids bedroom needs, from 100 to 250 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a living room

    What clean air delivery rate a living room needs, from 200 to 600 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a open plan living and kitchen

    What clean air delivery rate a open plan living and kitchen needs, from 400 to 1200 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a home office

    What clean air delivery rate a home office needs, from 80 to 250 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a kitchen

    What clean air delivery rate a kitchen needs, from 100 to 350 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a basement

    What clean air delivery rate a basement needs, from 300 to 1000 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a garage

    What clean air delivery rate a garage needs, from 200 to 800 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a dorm room

    What clean air delivery rate a dorm room needs, from 90 to 225 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a studio apartment

    What clean air delivery rate a studio apartment needs, from 250 to 600 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a home gym

    What clean air delivery rate a home gym needs, from 150 to 500 sq ft, with the ceiling height and air change target this room actually calls for.

  • 8 sizes

    Air purifier sizing for a classroom

    What clean air delivery rate a classroom needs, from 400 to 1200 sq ft, with the ceiling height and air change target this room actually calls for.

Machines that come up most often

Common questions

Why does the room type change the answer?

Three reasons: ceiling height, what is producing particles, and whether the room is genuinely closed. A basement usually has a low ceiling and a moisture problem, an open plan kitchen has a high ceiling and the largest particle source in the house, and a bedroom is the one room that is reliably shut for eight hours at a time.

Which room should I do first?

The bedroom, in almost every household. Eight hours a night in one closed room is the largest single block of time anybody spends breathing indoor air, and a closed room is also the easiest space for a machine to actually hold at the rate you calculated.

What if my room is not on the list?

Use the room closest in shape and purpose, or go straight to the CADR pages, which work purely from floor area and ceiling height. The room type pages add the ceiling assumption, the usual sources and the caveat that matters for that space, but the arithmetic underneath is identical.

Does an open door really change things?

Substantially. An open door connects the room to a hallway and often to a stairwell, so the machine is serving a much larger volume than the floor plan says and delivers fewer air changes an hour to it. Either size for the connected volume or close the door during the hours that matter.

Do I need a purifier in every room?

No. Rooms nobody occupies for hours at a time are not where the benefit is, and the budget is better spent doing the occupied rooms properly. Air does not move between rooms fast enough for one machine to serve a house, which is the honest reason whole home means one machine per room rather than one big one.