How “Stack Effect” Could Be Reducing Your Home’s Heating Efficiency

March 16, 2017


This effect occurs when the outdoor temperature is significantly lower than the indoor temperature.

Your furnace fills your home with warm air, however, more needs to be done to ensure that this warm air stays inside the home. This can generally be achieved by ensuring that the home is well-insulated. However, when it comes to multi-story homes, there are other challenges to be met, and an important among them is stack effect. In this post, our St. Louis HVAC experts will discuss this phenomenon in detail.

What is Stack Effect?

Stack effect is a major challenge faced by skyscrapers, however, it can also be a factor in houses with two or more floors. It is a condition in which the building acts like a huge chimney, and funnels warm air upwards until it eventually escapes the structure completely.

This effect occurs when the outdoor temperature is significantly lower than the indoor temperature. Cold air, being denser than warm air, pushes the warm air higher, and creates an airflow that pulls in more cold air. This airflow is stronger in taller structures.

This is why revolving doors were designed shortly after the first skyscrapers were developed. The force of suction used to be so strong during the winter months that pulling the doors open would become a challenge.

How does stack effect impact your home’s heating?

The biggest problem posed by stack effect is that your home loses conditioned air, and you therefore end up wasting energy and will likely see your heating costs increase. However, another factor is that this problem tends to become worse over time. If the airflow is particularly strong, it can put pressure on crumbling masonry, cracking weather stripping, fine cracks and other vulnerable areas. Constant pressure can widen these gaps and make them expand, which can further intensify the airflow and accelerate energy loss.

Overcoming stack effect

The best way to overcome this problem is through proper insulation. Stack effect occurs when warm air has a place to go once it reaches the top level of the home. It may escape into the attic through leaky air ducts, cracked ceilings, recessed light fixtures, or through improper insulation on the attic floor. When it reaches the attic, it can escape to the outdoors through any escape point it finds.

If you believe that your insulation may have degraded, or that there are some air leaks, which you cannot locate, don’t hesitate to contact the experienced heating and cooling technicians at Scott-Lee Heating Company. Our technicians will assess the whole situation and try to figure the exact nature and source of problem. Give us a call today at (314) 200-0788!