Dehumidifiers

How to Size a Commercial Dehumidifier

Dehumidifiers are rated by pints of water removed per day at standard conditions. Sizing depends on the cubic footage of the space, current relative humidity, the source of moisture and how fast the air must dry. Restoration crews and contractors typically over size by 20 to 30 percent so the unit can keep up with active water sources.

Pints Per Day vs AHAM Rating

Some manufacturers list AHAM ratings (60 percent RH at 80 degrees Fahrenheit) and others list saturation ratings (90 percent RH at 90 degrees). Saturation ratings look bigger but apply only in flood conditions. Compare AHAM numbers when shopping for warehouse, basement or office work, and saturation numbers when shopping for active water restoration.

Refrigerant LGR vs Desiccant

• Standard refrigerant. Best in mid temperature spaces between 65 and 90 degrees Fahrenheit. Lowest cost per pint.
• Low Grain Refrigerant (LGR). Removes more water at low humidity below 40 grains per pound. The standard for water damage restoration.
• Desiccant. Works in cold spaces and below freezing. Used for crawlspaces, cold storage and ice damage drying.

Stand Alone vs Wall Mounted vs Ductable

Stand alone units are wheeled in for restoration jobs and basements. Wall mounted units sit out of the way in finished basements and pool rooms. Ductable models tie into HVAC for warehouses and grow rooms where a single fixed installation handles the whole space.

On any restoration job, run a dehumidifier together with an air scrubber for HEPA filtered air, and a carpet extractor to pull free water out of soft surfaces first. Add mobile containment when isolating a work area from occupied space.

Browse 70 pint dehumidifiers for residential basements, 90 pint dehumidifiers for small commercial spaces, or LGR dehumidifiers for restoration grade output.

Frequently Asked Questions

How many pints per day do I need for a basement?

An average 1500 square foot basement at moderate humidity needs 50 to 70 pints per day. Wet basements with active seepage need 90 pints or more, plus a sump pump and waterproofing fix.

What is an LGR dehumidifier?

A Low Grain Refrigerant dehumidifier uses a heat exchanger to pre cool the incoming air before the cold coil, which lets it pull water out of low humidity environments below 40 grains per pound. Standard refrigerant units stop working efficiently in those conditions.

Can I run a dehumidifier all the time?

Yes. Most commercial dehumidifiers are built for continuous duty. Use a hose drain to a floor drain or condensate pump so the tank does not need to be emptied. Set a target humidity of 45 to 55 percent for occupied spaces.

How long does water damage take to dry?

With proper LGR dehumidifiers and air movers, most water damage dries in 3 to 5 days. The IICRC S500 standard expects daily monitoring and adjustment until moisture readings match unaffected materials.