Dehumidifier Sizing

14 pints for 500 sq ft basement — Very damp

Modeled from DOE/ENERGY STAR guidance; see methodology.

Recommendation: 14 pints/day (22–35‑pint class)

  • Space type: Basement
  • Size: 500 sq ft
  • Moisture condition: Very damp

When to size up

If the space often stays below ~68°F, connects to other damp rooms, or you see frequent condensation, consider sizing up from 22–35‑pint class to the next class.

Portable dehumidifiers are rated at 65°F under DOE 2019/2020. Cooler air reduces capacity; basements and crawls often benefit from moving up one class.

What 14 pints/day means for this basement

  • Old-label equivalent: about 20 pints on a pre-2019 (80°F AHAM) box. Ratings shrank when DOE moved testing to 65°F, so ignore old charts that list bigger numbers (why).
  • Water removed at rated output: about 1.8 gallons a day. Most bucket units need emptying at least daily at that rate, so a drain hose or condensate pump is worth it here.
  • Capacity density: 28.0 pints per 1,000 sq ft, versus 12 pints/day for a above-grade room and 16 pints/day for a crawl of the same size and dampness.
  • If the space is larger: 1,000 sq ft at the same dampness needs 22 pints/day (35‑pint class).
  • If it gets wetter: wet conditions push this to 16 pints/day (35‑pint class).

Compare nearby sizes

FAQ

What size dehumidifier for a 500 sq ft basement that is very damp?

About 14 pints/day under current DOE (65°F) ratings, which puts you in the 22–35-pint class. On older pre-2019 labels that is roughly 20 pints.

How much water will it pull out each day?

At rated output about 1.8 gallons (14 pints) per day; real output is lower once humidity drops toward your setpoint.