Friday, December 13th, 2013 

Stack effect refers to the way pressures and air movement occurs in a house work.  Most people do not realize that homes have varying pressures from level to level, and even room to room.  These pressures play a huge role in heat and energy loss and also in overall comfort inside the home.

Balanced ventilation is the key to a comfortable home

These pressure changes occur because of air movement in the home.  Warm air rises through the house to the attic where it escapes through vents. If your attic is properly air-sealed and insulated less of the warm air will escape.  If you have poor attic insulation, the air that is lost must be replaced, so cold air is sucked into the house at the lower levels where there is less pressure, oftentimes through sill plates in the basement.  This constant air movement is referred to as ventilation, which is vital for a healthy home.  Not enough ventilation can make the home unhealthy and unsafe, while too much results in heat and energy loss.