Sizing a dehumidifier: pint ratings, the 2019 test change and why a '50-pint' may equal an old '70-pint'
Pint-per-day ratings depend on the test conditions. Since 2019, DOE's test procedure (10 CFR 430 Subpart B, Appendix X1) rates portable dehumidifiers at 65 °F and 60% RH and whole-home units at 73 °F and 60% RH. Older portable ratings were taken in warmer air (80 °F, 60% RH), where a coil pulls out more water, so the same machine shows a smaller number today. Size from the space's real condition (measured RH, water entry, temperature) and compare ratings only on the same basis.
Before you start
- A dehumidifier is not a fix for standing water, active leaks or seepage. Find and stop the water source first.
- Use a grounded outlet; in a damp basement or crawlspace the receptacle should be GFCI protected.
Diagnostic steps
Unlock all 5 steps with expected values
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