The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
First Aid For The Ailing Houses
CONDENSATION
AIR ALWAYS CONTAINS an amount of water in the form of an invisible vapor; it will continue to absorb water vapor until saturated. The quantity of water vapor that air can hold will depend on temperature; warm air can hold more water than cold air. For example, air at 50 degrees cannot hold as much water vapor as air at 70 degrees. Thus, if air that is saturated at 70 degrees is cooled to 50 degrees, the part of the water vapor that can no longer be held will return to liquid form and collect in drops on the cold surfaces that have chilled the air. The appearance of this water in liquid form indoors is called "condensation, sweating, and steaming"; outdoors it is called "dew."
On a warm and damp day the air in a house will become saturated with water vapor. Should the outdoor temperature drop, the window glass will be cooled; indoor air in contact with the glass will also be cooled, and, no longer being able to hold so much water vapor, the part that cannot be here will collect drops on the glass.
One of the sources of high humidity indoors during the summer is the activity of the inhabitants of the house. Cocking can produce a great deal of moisture, both from the evaporation of liquids in the pan or oven and from the formation of water in the combustion of gas. A shower bath can raise the relative humidity as much as 10 per cent. Drying laundry in the house, the use of an unvented clothdryer (either gas or electric), or the operation of a dishwasher can raise relative humidity to an uncomfortable and often unbearable point in the summer.
Condensation is likely to be especially heavy in a new house that is finished and occupied during the summer, because of the drying out of the quantity of water in plaster, concrete, and other parts. Even when apparently dry, new plaster may contain water that will not disappear until after some weeks of artificial heat. During this period of drying, condensation on window glass is to be expected.
Condensation on window glass is especially noticed in the autumn. During the summer, plaster and other inside parts of a house will have absorbed moisture, which will then be drawn into the house air as this is wanned with the starting of the heater. Condensation will occur as the air is chilled by contact with cold window glass. It will continue until the plaster and other parts have given up their moisture to the air and until there is no more moisture in the air than will be held at house temperatures. Much of this condensation can be avoided by thoroughly airing the house on dry autumn days.
