Sources of Moisture in Homes


Household Moisture Sources

Moisture Source Estimated Amount of Moisture (Pints)
Aquariums Replacement of evaporative loss
Tub bath (excludes towels and spillage) 0.1/standard size bath
Shower (excludes towels and spillage) 0.5/5-minute shower
Combustion (unvented kerosene space heater) 7.6/gallon of kerosene burned
Clothes drying (dryer not vented outdoors, or indoor drying line) 4.7-6.2/load
Cooking dinner (family of 4, average) 1.2 (plus 1.6 if gas oven/range)
Dishwashing by hand (dinner, family of 4) 0.68
Firewood stored indoors 400-800/6 months
Gas range pilot light (each) 0.37/day
House plants (5 to 7 plants) 0.86-0.96/day
Humidifier 2.08/hour
Respiration and perspiration (family of 4) 0.44/hour
Refrigerator defrost 1.03/day
Saunas, steam baths, and whirlpools 2.7/hour
Combustion exhaust gas backdrafting or spillage 0-6,720/year
Desorption of building materials and furnishings (seasonal) 6.33-16.91/average day
Desorption of building materials and furnishings (new construction) 10/average day
Ground moisture migration 0-105/day
Seasonal high outdoor absolute humidity 64-249/day

Source: Moisture Sources Associated with Potential Damage in Cold Climate Housing (1988)