Dehumidifier, Air Purifier & Lighting Size Calculator
Size appliances for a room: dehumidifier capacity (pints/day), air purifier CADR for its square footage, and the lumens of light the room needs.
How to use
- 1Enter the room's area and ceiling height.
- 2Choose how damp the room is and what the room is used for.
How it's calculated
Dehumidifier (AHAM chart, 2019 test standard): roughly 22–50 pints/day depending on area and dampness. Air purifier: CADR (cfm) ≥ ⅔ of floor area for 8 ft ceilings (AHAM 2/3 rule). Lighting: lumens = area × recommended foot-candles.
Frequently asked questions
What's CADR?
Clean Air Delivery Rate — how many cubic feet per minute of filtered air a purifier delivers, measured by AHAM for smoke, dust and pollen.
Why did dehumidifier ratings change?
The US Department of Energy's 2019 test procedure uses cooler conditions, so a 70-pint unit from before 2019 is about a 50-pint unit today.
How many lumens does a kitchen need?
About 50–75 foot-candles for work areas — a 150 ft² kitchen needs roughly 7,500–11,000 lumens across ambient and task lighting.