Don’t Be Surprised By The Stack Attack

Written by: Bobby Veit on Jun 12th 2012
Don’t Be Surprised By The Stack Attack

Summer is the perfect time to get your home "Energized" so you can save on those air conditioning costs. Air sealing and proper insulation are essential defenses to safeguard your home from the 'stack attack.'

The stack attack, known technically as “The Stack Effect,” takes place when warm air rises to the top of the house, leaking through holes between the living space and the attic. In the winter, this results in wasted heating dollars, since the warm air can easily exit the living space and move into the attic through hidden holes in your home’s framing called thermal bypasses. The stack effect occurs 24 hours a day, 7 days a week, anytime the interior of the house is warmer than the outside.

One clear sign of the stack effect is the formation of icicles along the roof of your home, which are created as the warm air in your attic warms up the roof, causing snow to melt and refreeze along the bottom of the roof. Have you wondered why you had icicles on your roof even though your attic was insulated? It was probably due to air leaks from stack effect.

Proper insulation is a critical tool that home performance contractors use to keep heat inside in the winter and outside in the summer. But insulation alone does not provide the necessary defense against the stack attack. Insulation acts more like a “wool sweater” for your home, which keeps you warm on mild cold days but performs less effectively on days when there is a strong wind. Your house needs a “windbreaker” to prevent airflow out of your house, and air sealing is this extra protection. The “wind” from stack effect is greatest at the top and bottom of your house so the most effective air sealing should be done first at the top of your house between your living space and your attic and then at the bottom of your house around the foundation.

Air sealing stitches up the holes in the wool sweater of home insulation that allow heat to escape your home in the winter and enter your home in the summer and leads to a more effective defense against the stack attack.

Home performance contractors who visit homes as part of Energize New York’s home energy assessment program are trained to locate and shut off the air leaks through the thermal bypasses caused by the stack effect. Professional analyses such as the blower door test help the contractor and his trained crews find, seal and insulate the areas that are leaking both heating and cooling dollars.

So before the temperatures force you to turn on the air conditioner this summer, have a contractor come out to assess your home to prevent the sneak stack attack of high-cost energy bills. Summer is the perfect time to get your home "Energized". The plus side is that you'll then be ready for winter heating expenses, with a home that has been made more energy efficient!