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Ignore the square feet. Count the pints
One 50-pint dehumidifier is sold as "7,000 sq ft". A 53-pint crawl space unit is sold as "1,200 sq ft". Both can be fair, because coverage depends on how wet the space is. The number that lets you compare machines is pints per day at the standard 65°F test. Pick that from your area and dampness, and the rest gets simple.
Dehumidifier size calculator
This is an estimate based on the commonly published AHAM and Energy Star sizing guidance. That table ends at 2,500 sq ft. Past that, I extend the same steps, so treat the answer as a rough guide.
See the 7 dehumidifiers I'd shortlist
Three things the listings skip
- The test changed in 2019. Units are now rated in a 65°F room instead of an 80°F room. Cool air holds less water, so the same machine scores lower. An old 70-pint is a 50-pint today. More on the claims.
- Some pint numbers come from a 95°F room. "80 pints" or "120 pints" at 95°F and 90% humidity is not the number your basement will see.
- Where the water goes matters as much as capacity. A 50-pint unit can fill its bucket in about 6 hours at full output. Plan the drain before you buy.
Guides
- The 7 best dehumidifiers, sorted by what they really remove
Seven dehumidifiers for basements, crawl spaces, bedrooms and bathrooms, compared by pints per day and drain type instead of square foot claims.
- What size dehumidifier do you need?
Enter your square feet and how damp the space is. Get pints per day on today's 2019 rating scale, and the size class to shop for.
- "Covers 4,500 sq ft" tells you almost nothing
Why a 50-pint dehumidifier is sold as 4,500 or 7,000 sq ft, why old 70-pint units are 50-pint now, and what '80 pints at 95°F' means.
- Pump, gravity hose or bucket: decide before you buy
A 50-pint dehumidifier can fill its bucket in hours. When a gravity hose works, when you need a built-in pump, and how to set up the hose.
- Cool basement? Compressor vs desiccant
Compressor dehumidifiers lose output and frost up in cool air. When a compressor unit is still right, and when a desiccant unit makes sense.
- What a dehumidifier costs to run
How much power a dehumidifier uses per month, from listed watts. Enter your own electric rate. Plus what Energy Star means for dehumidifiers.
- Recalls, humidistats, noise and upkeep
Millions of dehumidifiers have been recalled for fire risk. How to check yours, why the humidity readout is often off, and what noise to expect.