It’s not the heat (or cold), it’s the humidity
Although there can be humidity-related problems year-round, they’re typically worse during winter in the North and during summer in the South.
While there is not one ideal indoor humidity level, a target of 40% to 45% relative humidity is usually ideal for personal comfort. Most people can be reasonably comfortable with a relative humidity ranging from 30% to 50% and can tolerate 20% to 60%. You can purchase an inexpensive hygrometer at most hardware stores to measure to indoor relative humidity.
The keys to maintaining a comfortable and efficient indoor humidity level are controlling the sources of moisture and ventilating them efficiently. For example, cooking for a family of four produces five cups of moisture per day.
Exterior moisture sources include leaky roofs, plumbing, windows and doors. Once you take care of these problem areas, check the slope of the ground around your home. It should slope slightly downward away from the house walls. Soggy soil around your home lets excess moisture indoors year-round.
Humidity fixes
Installing new efficient replacement windows or exterior storm windows is the best method to control a humidity-caused window condensation problem. This also saves energy during the summer cooling season.
New bathroom vent fans with humidity sensors that come on automatically and run until the humidity level drops can help there. Check the seal around the clothes dryer duct leading to the outdoor vent.
You can also install a new furnace/heat pump with a variable-speed blower and compatible thermostat to enable it to run in an efficient dehumidification mode during summer. Make sure the damper handle on the central humidifier is set for the proper season.
HUMIDITY AND HEALTH
When the relative humidity level is too high, it may create serious health problems related to allergies, dust mites, mold, mildew and other harmful microbes. At the other extreme, with relative humidity too low, a person’s mucous membranes may dry out, increasing the susceptibility to cold and respiratory illness. Some nasty microbes also prefer excessively dry air.
JAMES DULLEY is a nationally syndicated columnist who writes on energy efficiency and do-it-yourself energy topics
