Moisture Removed by Grain Depression

Water a dehumidifier removes per hour and over the run, from its grain depression and airflow.

Run the calculator

Example

You enter

Process airflow (CFM) 250
Inlet grains-per-pound (GPP) 90
Outlet grains-per-pound (GPP) 50
Run hours 24

You get

Water removal rate 6.43
Total water over run 18.5 gal

Checked against published worked examples from: Psychrometric mass balance + IICRC S500 grain-depression method.

Details, formula, and sources

ScopeWater-removal rate (lb/hr, pints/hr) and total water over the run from a dehumidifier's measured inlet/outlet grain depression and process airflow - an in-situ performance check.

Formula or tabledG = inlet_GPP - outlet_GPP; mass-air = CFM*60/13.33 lb-dry-air/hr; water lb/hr = mass-air * dG / 7000 (7000 grains/lb); gal = lb/hr * hours / 8.345.

Source and editionFirst-principles psychrometric mass balance (7000 grains/lb; ~13.33 ft3/lb dry air); IICRC S500 grain-depression field method, by name.

Free accessPublic psychrometric constants; IICRC S500 governs the drying plan.

What governsEstimate. AHJ and licensed professional govern.

API field namescfm, inlet_gpp, outlet_gpp, hours, water_lb_hr, water_gal

Humid volume ~13.33 ft3/lb dry air at standard conditionspsychrometric chart