Do identical houses have the same condensation problems?
Generally not Just as heating and hydro biils vary between identical houses, with the same number of occupants, so will the level of humidity. Much of this will depend on the life-style and activities of the household and although appearing identical one house may have a slightly lower air infiltration rate, or other factors, that could influence the humidity level. Recommended Humidity Levels Medical authorities indicate that the level of humidity indoors should not be below 15%. It is generally acknowledged that the level of humidity in houses with a good vapour barrier should not exceed 40%, or, in older homes without a vapour barrier, 35%. Table 1, below, shows suggested levels of relative humidity for inside the home for varying outside temperatures. Table 1 Relative Humidity with inside Temperature of 20 C (68 F) Outside air Temperature C -30 or below not over 15% -30 to -24 not over 20% -24 to -18 not over 25% -18 to -12 not over 30% -12 to – 6 not over 35% -6 to 0 not over 40%
