breathing,+naturally+ventilated+building

//Heating and Ventilating// magazine indicates that the modern life of a family of four can easily generate 70 litres of water per week into the household air. The following chart is from "Builders' Guide to Energy Efficiency in New Housing, 2nd Edition" published by Canadian Homebuilders Association/Ontario Ministry of Energy/HUDAC:


 * **Source** || **Amount of Water Vapor Generated** ||
 * Cooking (3 meals) || 1 kg per day ||
 * Dishwashing (3 meals) || 0.5 kg/day ||
 * People (family of 4) || 5 kg/day ||
 * Bathing (shower) || 0.25 kg each time ||
 * Bathing (tub) || 0.05 kg each time ||
 * Clothes Washing || 2 kg each time ||
 * Clothes Drying || <span class="seventy" style="font-family: Verdana,Geneva,Arial,Helvetica,sans-serif; font-size: 10px;">12 kg each time ||

<span class="hundred" style="font-family: Verdana,Geneva,Arial,Helvetica,sans-serif; font-size: 13px;">This publication also indicates that a very small break in the Air Barrier System can allow a startling amount of moisture to find its way into the walls. Under typical Canadian winter temperature and humidity conditions, assuming an interior temperature of 21C and 40% relative humidity, in a 10-square-meter room with 9mm ceiling board painted with two coats of enamel paint, the water vapor moved by diffusion over the course of 100 days would be 3 kilograms, or 6.6 pounds. If, however, there were a crack in that ceiling 1.5 millimeters wide and 1.2 meters long, the water vapor moved by air leakage over the same 100 days would be 20 kilograms, or 40.4 pounds. That one tiny crack creates a six-fold increase in water vapor intrusion.

[[[] indoor air quality]

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