Does Spray Foam Really Make A Home More Comfortable?

You’ve heard some great things about spray foam insulation, like how spray foam can lower your energy bills or reduce the strain on your HVAC system. You’ve also heard people claim that spray foam makes homes more comfortable. What does that mean, and is it true? Or is the comfort argument just something that salespeople say?

South Central Services has insulated hundreds of new and existing homes with spray foam. We choose to install spray foam because of the numerous benefits it can offer homeowners, including increased comfort. This article will break down what it means for a home to be more comfortable and how spray foam can offer that.

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Comfort Cannot Be Measured.

Before we jump into the science behind spray foam, we have to discuss quantitative and qualitative data. For example, if you wanted to prove that spray foam lowered your energy bills, you could look at your energy bills before and after spray foam. That hard data can give you quantitative information about the benefit of spray foam.

If you want to prove that spray foam made your home more comfortable, there is no data to support your claim. Comfort is an experience. Someone saying that their home is more comfortable is anecdotal evidence. There are no numbers. Instead, there are statements like these.

“Our rooms used to be cold. After spray foam, they were instantly warm and they’ve stayed warm.”

“Our house used to be so drafty. But even when the temperatures dipped below freezing, our home was nice and toasty.”

We can’t measure comfort. What we can do is understand how spray foam works and why many homes are uncomfortable to live in.

Without Spray Foam Insulation, Homes Are Often Leaky.

Most home construction does not account for air leakage. Making a house airtight is not the concern of the average homebuilder. In fact, some homeowners bristle at the idea of an airtight home.

It used to be commonly accepted that homes needed to breathe. Air needed to circulate through the house and between the inside and outside. It’s a simple concept: we cannot breathe the same air forever.

As innovations were made in HVAC equipment and mechanical ventilation, homes no longer needed to be leaky in order to facilitate air exchange. Rather than air passing through the house on a whim, a machine could control how much air and what type of air was entering and exiting.

These HVAC advancements can only do so much if the home is still leaky. Traditional insulations do not create an airtight seal. Fiberglass, for example, allows air to infiltrate the home. What does air infiltration practically mean for a home?

Think about your house in the height of summer. In southern Pennsylvania, some of those hot summer days are over 100 degrees Fahrenheit and muggy. In an attempt to keep cool, you might eat some popsicles and crank the air conditioning.

If your home is leaky, the air that you pay to condition is exchanged with the hot and humid air outside. The uncontrolled air exchange leads to unwanted heat exchange, as well.

The same concept applies to your home in the winter. Winters in our service area can have bitterly cold days and the occasional snowstorm. When it is so snowy outside that you don’t plan on leaving your house, you might burrow under some blankets and drink hot cocoa. But you’ll also turn up the thermostat.

If your house is leaky, you are literally paying to heat the world. The heat that you are paying for freely exchanges with the below-freezing temperatures outside. While these examples indicate an impact on your energy bills, they also relate to your comfort.

Cold drafts, cold floors, and not being able to keep your home at a livable temperature are all “comfort symptoms” of a leaky house.

Spray Foam Insulation Creates An Airtight Seal.

If most houses are leaky, how can we fix the leaks? The answer is an airtight seal in your thermal envelope.

The thermal envelope is like the outline of your house. Any surface that creates a barrier between the outside world and the home you live in is a part of the thermal envelope. Your attic, exterior walls, basement, and crawl space are all examples.

An airtight seal in these key areas prevents uncontrolled air exchange. In the summer, the hot air cannot get into your attic or press down into your living space. In the winter, cold from the ground cannot seep into your floors.

The best product available to create this airtight seal is spray foam insulation. Spray foam not only creates this airtight seal, stopping convection heat transfer, but also matches traditional insulation performance. Spray foam has a high R-value and prevents conductive heat transfer like other insulation products.

Since these areas of your thermal envelope already need insulation to meet building codes, you can kill two birds with one stone and make sure your insulation is as effective as possible.

Let’s return to our hypotheticals about summer and winter. How does an airtight seal make a difference?

What Does An Airtight Seal Do In The Summertime?

Summers in southern PA usually come with humidity. When it’s muggy outside, it can feel hotter and more uncomfortable than it would with dry heat. Installing spray foam insulation in your attic can keep the humidity and heat outside.

On a summer day when you feel like you’re melting, attic spray foam insulation keeps the heat out. If the foam is installed on the floor, it doesn’t matter how hot your attic gets–the rest of your home will not exchange any hot air with the air from the AC.

If the foam is installed on the roof and walls of your attic, the attic space itself is at a livable temperature. None of the hot air surrounding your roof can exchange with the air inside. As a bonus, if your attic has any HVAC ductwork running through it, it can deliver conditioned air better. Since the HVAC doesn’t have to counterbalance the heat load it would absorb in the attic, it doesn’t have to work as hard to keep your home at that comfortable temperature.

The airtight seal will lower your energy bills. If you don’t crank your AC, keeping your home cool will take less energy. But from a comfort perspective, you should not feel sweaty, sticky, or irritable when inside.

What Does An Airtight Seal Do In The Wintertime?

The ground in our service area is always cool, but it gets colder during winter. Your basement may already be an unpleasant place to visit, but it could be frigid in the winter. Installing spray foam insulation in your basement band boards or your crawl space can prevent that cold air from invading your living space.

Heat is attracted to the cold. In the wintertime, heat can leak from a house incessantly. With an airtight seal, the heat stays within the walls of your home.

Spray foam in a crawl space can help prevent drafts and cold floors. Similarly, basement band boards (or rim joists) are vital areas where heat can escape. The location where wood and porous masonry meet is vulnerable to air exchange.

Even attic insulation is helpful in the winter. As heat rises in your home, it reaches a stopping point. Attic insulation is like a lid that prevents the heat from escaping.

Again, spray foam will reduce your energy bills. If you don’t have to crank the heat to stay warm, it will cost less to keep your house comfortable. Not having to dress in layers inside, wrap yourself in a blanket, or wear something on your feet are all examples of increased comfort.

Spray Foam Insulation Can Make A Home More Comfortable.

These comfort improvements are possible because of spray foam insulation’s airtight seal. However, it is vital to understand that the results of spray foam will vary based on what is insulated.

Different spray foam applications offer different results. Arguably, one of the best applications is spray foam insulation in your attic. With attic spray foam, energy bills can be lowered by anywhere from 30% to 70%.

Crawl space encapsulation is another excellent application of spray foam. However, crawl spaces are more likely to offer 20% to 40% lower energy bills.

How comfortable your home becomes also depends on the areas of your home that are not insulated with spray foam. If we think back to the thermal envelope, there can be areas of major leakage that are not addressed. Your spray foam contractor may not insulate these areas, or may have no control over them.

Spray foam is an excellent insulation material with numerous benefits, but it isn’t a miracle product. Spray foam must be applied correctly and in the right areas of a home to make an impact on comfort.

The Bottom Line About Home Comfort And Spray Foam

While home comfort cannot be measured like your energy bills, spray foam insulation can make a home more comfortable. Once you understand the building science behind your home and how heat travels, the idea of spray foam comfort becomes more tangible.

If you live in an uncomfortable house, upgrading to spray foam insulation could be the first step in making your house feel more like home. Consider insulating your attic or encapsulating your crawl space. The next time summer or winter roll around, you may be able to give your own anecdotal evidence about the comfort of spray foam.

Use these resources to determine which spray foam upgrade is right for you:

• Learn about all the benefits of insulating an attic with spray foam
• Discover why you should encapsulate your crawl space