Where does the majority of airflow come from in my house?

Warm air rises, pushing through cracks at the top of your house, pulling in cold air from below.Airflow is Your Home’s Stack Effect

It may sound like the name of the hottest new boy band to hit the scene. But it’s really just an airflow fact that could be hitting your wallet hard on energy costs.  “The Department of Energy estimates that just by reducing air leaks in your home, you can save 10% on heating and cooling bills. The savings can be much higher—as much as 30% of conditioned air may be escaping through cracks, holes, and gaps. All that air movement costs you money and makes your home more uncomfortable. “

You’ve always heard that heat rises

And that’s the truth. But it’s not the WHOLE truth. Heat also moves in other directions, going from areas of higher temperatures to lower ones. So no matter where cooler air resides, heat will follow.

Density has an effect on airflow too

As air heats up, the molecules spread out and take up more room, resulting in lower density. Cold air is more dense than warm; hence, warm air, being less dense, rises. Voila. That’s the stack effect, and it may be the reason that your home “leaks” when internal and external temperatures are way different.

That means that in winter, your nice warm inside air can leak outside, and in summer, the warmer outside air can push its way inside. To make matters worse, poorly insulated or uninsulated subfloors can team up with the stack effect, compounding energy leaks in both winter and summer.

But don’t fear the stack effect

Spray polyurethane foam insulation is here to help you “attack the stack” and defeat its crawl space “partner in crime,” air sealing your home to keep heat in its place, both winter (inside) and summer (outside). Not only will spray polyurethane foam reduce your utility bill while increasing your home’s year-round comfort, but it can also protect your home against rot, mold, mildew and even insect infestation.


The highly trained, certified professionals at Sunlight Contractors know just what to do to protect your home against uncomfortable and costly airflow leaks. Call Sunlight Contractors to schedule a free home energy audit. They’ll  root out any problems caused by poor insulation and/or the stack effect and offer solutions to keep your conditioned air exactly where you want it to be.

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