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"Covers 4,500 sq ft" tells you almost nothing
Updated
There is no single rule that turns pints into square feet, so every brand picks its own number. Coverage depends on how wet the space is. The rating you can compare across brands is pints per day at the standard test: 65°F and 60% humidity. Find that number and ignore the rest of the title.
What the listings claim
I divided each listing's square feet by its pints per day. If square foot claims followed one rule, the last column would be about the same on every row. It is not even close.
| Model | Claimed area | Pints per day on the listing | Sq ft claimed per pint |
|---|---|---|---|
| hOmeLabs 50 Pint with Pump | 7,500 sq ft | 50 | 150 |
| hOmeLabs 50 Pint | 7,000 sq ft | 50 | 140 |
| Midea Cube 20 Pint | 1,500 sq ft | 20 | 75 |
| Waykar | 5,000 sq ft | 80, measured at 95°F | 62 |
| AlorAir Sentinel HD55 | 1,200 sq ft | 53 | 23 |
| Ivation Desiccant | 270 sq ft | 13 | 21 |
The two machines with nearly the same capacity, 50 and 53 pints, claim 7,500 sq ft and 1,200 sq ft. Neither is lying. The crawl space maker assumes a wet space. The home brand assumes a barely damp one. Many other 50-pint listings say 4,500 sq ft. Same class of machine, third number.
Why old 70-pint units are 50-pint units now
Before mid 2019, the Department of Energy test ran in an 80°F room at 60% humidity. Now it runs at 65°F and 60%, which is closer to a real basement. Cooler air holds less water, so every machine pulls less in the new test.
| Old label (80°F test) | Today's label (65°F test) |
|---|---|
| 70 pint | 50 pint |
| 50 pint | 35 pint |
| 30 pint | 20 to 22 pint |
Midea says so right on its listing: the Cube 20 Pint is "similar to" a 30-pint unit under the 2012 test. If you are replacing an old 70-pint unit, a new 50-pint is the same size machine. You did not downgrade.
Watch for pints measured in a hot room
Some listings lead with pints at 95°F and 90% humidity. That is a steam room, not a basement. The numbers are big because hot, soaked air gives up water easily.
- The Waykar title says 80 pints. The bullet under it says that is at 95°F and 90% humidity. I did not find a 65°F number on the listing.
- The hOmeLabs 50 Pint title says "max 120 pint" at 95°F and 90%. Its everyday number is 50. One more wrinkle: the listing quotes that 50 at 80°F, which is the old test temperature. I could not confirm a 65°F figure from the listing.
- The AlorAir HD55 shows both: 113 pints at saturation and 53 at the AHAM condition. That is how every listing should do it.
When you see two pint numbers, the smaller one is the one to shop by. When you see only one, look for the test condition next to it. When a big number has no condition at all, assume it is the hot-room number.
What the sizing table says a unit can cover
This uses the same math as the size calculator. The published table stops at 2,500 sq ft, and I would not count on one portable unit past that, because the air has to reach it.
| Unit size today | Moderately damp | Very damp | Wet | Extremely wet |
|---|---|---|---|---|
| 20 pint | 2,500 or more sq ft | 2,100 sq ft | 1,700 sq ft | 1,300 sq ft |
The same 20-pint machine fits 1,300 sq ft or 2,500, depending on how wet the space is. That spread is why a single square foot number on a box cannot be right for everyone. By the same math, a 35-pint or a 50-pint unit reaches the 2,500 sq ft end of the table at every dampness level. The bigger unit just gets there faster and rests more.
And the mini units? The Pro Breeze Mini claims 215 sq ft on about half a pint a day. That works out to 382 sq ft per pint, the most stretched claim on this page. It suits a closet. See the full list of picks for where each one fits.