The Science Behind Air Sealing & Insulation

When people talk about making their homes more energy-efficient, the focus is often on insulation — but the real magic happens when insulation and air sealing work together. If you’ve ever wondered why your home still feels drafty even though you have “good insulation,” this post is for you!

Let’s break down what’s really going on behind your walls — and why spray foam insulation is one of the best solutions for stopping energy loss in its tracks.

What Is Air Sealing (and Why Does It Matter)?

Every home has small cracks, gaps, and joints — around windows, doors, outlets, attic hatches, basement rim joists, and even where walls meet floors. These tiny leaks allow unconditioned air to sneak in and heated or cooled air to escape.

That constant exchange of air makes your heating and cooling system work overtime, driving up energy bills and making it nearly impossible to maintain a comfortable temperature.

Air sealing is simply the process of closing off those leaks — creating a tight “envelope” around your home.

When your home is properly sealed, you:

• Keep warm air inside during winter and cool air in during summer

• Reduce drafts and temperature swings

• Lower your energy bills

• Improve indoor air quality by keeping out dust, pollen, and moisture

How Insulation and Air Sealing Work Together

Insulation slows down heat transfer, while air sealing stops the movement of air. Think of insulation as a cozy sweater — and air sealing as the windbreaker that goes over top.

Without air sealing, insulation alone can’t perform at its best. Air can still move through gaps, carrying heat (and moisture) with it. That’s where spray foam insulation stands out — it insulates and air seals at the same time, expanding into every crack and crevice for a continuous barrier.

The Science in Simple Terms

Here’s the short version of the science:

• Air leakage increases heat loss through convection.

• Spray foam eliminates that air movement, reducing convective heat transfer.

• With both air and thermal barriers in place, your home stays at a stable temperature longer, using less energy to do it.

That means your furnace or heat pump runs less often — and you stay more comfortable all year round.

Real-World Benefits for Nova Scotia Homes

Nova Scotia homes deal with unique weather challenges — salty coastal air, cold winters, and humid summers. Spray foam helps in all of these:

• Cold drafts? Gone.

• Moisture creeping into the basement or crawl space? Sealed out.

• High energy bills? Lowered — often significantly.

Plus, spray foam helps prevent ice dams on roofs (a common East Coast issue) by keeping attic temperatures more consistent.

How to Tell If Your Home Needs Better Air Sealing

Here are a few red flags:

• You feel drafts even when windows are closed

• Rooms never stay the same temperature

• Your furnace or AC runs constantly

• You notice condensation or frost around windows

• Your energy bills are climbing each year

If that sounds familiar, it’s worth having a professional perform a blower door test or energy audit — Efficiency Nova Scotia even offers incentives to help with this.

Why Spray Foam Is the MVP of Air Sealing

Unlike batt or blown-in insulation, spray foam expands to fill every little gap and seals tight against framing, plumbing, and electrical. It’s like wrapping your home in a custom-fitted blanket — one that doesn’t leave any cold spots behind.

It’s also durable, long-lasting, and doesn’t sag or settle over time. Once installed, it stays put and keeps performing for decades.

The Bottom Line

Air sealing and insulation go hand in hand — you really can’t have one without the other if you want true energy efficiency. Spray foam insulation does both in a single step, keeping your home comfortable, efficient, and protected year-round.

So, if your house feels drafty or your energy bills are creeping up, it might be time to seal the deal — literally.

Want to Learn More or Get a Quote?

If you’re ready to make your home airtight and energy-efficient, reach out to our team today. We’re proud partners with Efficiency Nova Scotia and can help you take advantage of available rebates while getting your home sealed up right.