Build Tight, Ventilate Right!

The dew point is the temperature at which air becomes saturated with moisture and water vapor begins to condense into liquid water (dew). In simpler terms, it's the temperature at which the air can no longer hold all the moisture in the form of vapor, and it turns into water droplets.

The dew point is an important indicator of humidity. The higher the dew point, the more moisture there is in the air. If the dew point is close to the current air temperature, the air feels humid, and the likelihood of dew or fog forming is high. If the dew point is much lower than the air temperature, the air feels dry.

When insulating a new home, or retrofitting an older home, it is important to understand how humidity can affect both the comfort of the inhabitants as well as the health of the home itself. Adding insulation will often cause humidity levels to rise within the home as warm humid air resulting from activities such as showering and running a dishwasher is contained within the building envelope. To ensure there is good airflow in a well-insulated home, an HRV (heat recovery ventilator) should be used to keep moisture levels ideal.