What happened in 2019
Dehumidifier capacity is measured in pints of water removed per day. Until mid-2019, the standard test ran at 80°F and 60% relative humidity. The Department of Energy then switched the required test for portable dehumidifiers to 65°F at 60% RH — cooler air, which holds less water, which is much closer to what an actual basement feels like. Honest change, real consequence: the same physical machine pulls fewer pints from 65° air, so ratings dropped roughly a third overnight. Nothing about the hardware changed. Only the label.
The conversion table
Official ENERGY STAR guidance for portable units:
| Old label (pre-2019) | 2019 standard | What it handles |
|---|---|---|
| 30 pints | 20 pints | Small rooms, mild damp |
| 40 pints | 25 pints | Large room / small basement |
| 50 pints | 30 pints | Average basement |
| 60 pints | 35 pints | Large or damper basement |
| 70 pints | 40–45 pints | The old "basement workhorse" |
| 90 pints | 55 pints | Big, wet spaces |
Seven years later, Amazon listings, old reviews, and a startling share of "what size dehumidifier" articles still mix both eras freely. When a 2018 blog post tells you to buy "a 70-pint unit" for your basement, it means what today's boxes call 40–45 pints. Buy a literal modern 70-pint unit on that advice and you've bought commercial-grade overkill.
It's actually three numbers, not two
Spec sheets in the crawl-space world carry up to three pint figures:
- 2019 DOE standard (65°F/60%): what retail portable boxes must use now. The honest small number.
- AHAM 80°F/60% ("the old test"): still the standard rating for commercial and crawl-space units, which are a different product class. When AlorAir says the Sentinel HD55 is "55 PPD," that's this test.
- Saturation (90°F/90%): the machine's absolute maximum in sauna conditions. This is the big number in Amazon listing titles — "145 pints!" — and it describes an environment your crawl space will hopefully never be.
How to not get fooled
- Reading a retail box or a post-2020 review? You're looking at 2019-standard pints. Use them directly with our sizing calculator.
- Reading an old article or an Amazon title with a huge number? Assume old-standard or saturation. Divide the hype number by ~2.5 to guess the 2019 rating, or find the spec PDF.
- Comparing a crawl-space unit to a portable? Don't compare pints at all — the tests differ. Compare manufacturer coverage claims (sq ft), which is exactly what our calculator does.
The part nobody says out loud
The rating change was good policy — the new test reflects reality. The problem is purely informational: the market never cleaned up the old numbers, and confusion favors whoever prints the biggest figure. That's the entire reason this site is named what it's named. Pints per day only means something when you know which pints.