Home energy efficiency is often dominated by discussions about cooling and heating. After all, heating and cooling (including water heating) account for about 60% of energy expenses in the average single-family home. Yet the discussion often neglects an important factor in home comfort and in heating and cooling usage: moisture.
For example, most people will feel cooler in a room at 75˚F and 25-percent relative humidity than in a room at the same temperature with 40-percent relative humidity. Rooms with higher relative humidities feel warmer, so occupants are less likely to raise their thermostat setting in winter when they have a healthier level of humidity.
Optimal moisture levels depend on many factors: time of year, regional climate, ventilation, vapor barriers, home-heating type, and more. During the summer, optimal indoor moisture levels are between 30 and 40 percent.
There are many problems associated with high or low levels of moisture in a home. Homes that are too “tight” (that is, homes that trap moisture inside without accounting for humidity) can lead to costly mold and indoor air quality issues. Homes that are air-tight, like Passive Homes, employ a vapor barrier and a mechanical, balanced ventilation system with heat recovery that addresses both air-quality and comfort issues by continually exchanging indoor air.
Remember, some humidity is important. Contact a home energy professional to best understand your home’s humidity levels and what you could do to improve them.
By David Zussman, Marketing Coordinator, Elysian Energy, a Montgomery County Certified Green Business