The Stack Effect: How Air Leaks Drive Up Energy Costs

The stack effect occurs when warm air inside your home rises and leaks out through the attic, while cooler outside air gets pulled in through cracks and gaps at the lower levels. This continuous cycle creates drafts, uneven temperatures, and forces your heating and cooling systems to work harder. In winter, for example, cold air seeps in from the bottom while valuable heated air escapes above, quietly driving up energy bills as the conditioned air you pay for is lost.

Why the Stack Effect Matters

This overlooked culprit can be invisible but most homeowners can feel the stack effect by its symptoms or signs. Drafty rooms, cold floors, that room in your home that never seems to stay comfortable and high energy bills are some signs that can be contributed to the stack effect.

• Winter: Cold air seeps in at the lower levels while the warm, conditioned air you’ve already paid to heat rises and escapes through the attic. As a result, your furnace or boiler runs longer to compensate, driving up your energy costs.
• Summer: In summer, the stack effect is less noticeable due to smaller indoor-outdoor temperature differences, but cooler indoor air still escapes through lower openings, pulling in warm, humid air from higher ones, which can raise cooling costs.

In any case, your home is losing both air and money through these leaks.

Locating Common Leaks

The stack effect creates multiple points where air can leak in or out of your home. The most common areas include:

• Basement or crawl space rim joists and sill plates
• Gaps around windows and doors
• Unsealed plumbing and wiring penetrations
• Attic hatches or access points, recessed lights, gaps around chimneys, top plates, and any other cracks or openings in the attic

Even small leaks can add up, creating the same effect as leaving a window open all year long.

The Solution: Air Sealing and Insulation

We can stop the stack effect by sealing hidden air leaks. Our professionals pinpoint the areas where air enters and escapes, using spray foam and foam sealant to air seal the leaks. Paired with proper insulation, this results in a tighter, more energy-efficient home.

• Air Sealing blocks the paths air uses to escape and enter.
• Insulation slows heat transfer, keeping temperatures consistent.

Together, these upgrades reduce drafts, balance indoor temperatures, and ease the burden on your HVAC system.

The Payoff

By addressing the stack effect, homeowners can expect:

• Lower monthly energy bills
• Improved comfort in every room
• Reduced wear and tear on heating and cooling equipment
• A quieter, healthier indoor environment with fewer drafts and pollutants sneaking in

Take Control of Your Home’s Comfort

The stack effect may be invisible, but its impact is anything but. Uneven temperatures, drafts, and rising energy bills are signs that your home is losing conditioned air. By sealing air leaks and upgrading insulation, you can stop the stack effect in its tracks—keeping warm or cool air inside, improving comfort, and reducing energy costs.

Schedule a free home evaluation with Dave Hoh’s Home Comfort & Energy Experts to see how much you could save. Our team can help lower your energy bills, enhance comfort, and create a healthier home all year long.