Heating and cooling are the two biggest costs when it comes to electrical use in your home. Together, they account for 51% of the annual energy consumption of a home.
Properly insulating your home during the construction phase will make a huge difference in the long run. Knowing the type to use and understanding how it works are key points to making a smart decision about insulation.
Let’s look at how heat flow works in a home and what makes for good insulation to understand how it can effectively save homeowners money in the long run.
HEAT FLOW
Understanding heat flow is important for understanding how to make your home more energy efficient through insulation.
There are three types of heat flow that happen in homes. Let’s briefly look at what they are, how they work, and how your insulation interacts with them.
Conduction
Conduction is how heat travels from one material to another. An excellent example is a hot cup of coffee. When you pour hot coffee into a cup, heat will flow from the liquid into the cup and make the cup hot.
In your home, the insulation in your walls acts as a barrier to slow and prevent the transfer of heat between your home and the outside world.
Convection
Convection is the transfer of heat through liquids and gasses (that includes air). Most people know that hot air rises and cool air sinks. Convection is the principle that causes it to happen.
We can see this happening in a pot of boiling water, too. As the water at the bottom of the pot is heated by the burner, it rises to the top. It cools at the top of the pot and moves back down to the bottom of the pot — this is what causes the circular action we see during a rolling boil.
In your home, insulation in the ceiling, attic, and floors helps control the transfer of heat as it tries to rise upward and out of your home.
Radiation
Radiant heat is most easily understood as the type of heat that’s given off by the sun or a campfire. Heat energy from radiation travels in a straight line. It heats people and objects directly.
In your home, radiant heat can be kept inside your home through the use of reflective material. However, a radiant barrier is only effective at reflecting radiant heat if the surface material is in contact with an air space.
R-VALUE
Choosing the correct R-value of insulation for your home is the most important decision you can make when it comes to making sure your home efficiently prevents the flow of heat into and out of your home.
A material’s R-value is a measure of its thermal resistance. In other words, the higher the R-value, the better insulating effect the material will have. Because of variations in temperatures through the year, different zones in the United States have different requirements for a home’s recommended insulation R-value.
The R-value of insulation in your walls will increase proportionally to each value of insulation (if you place R5 over R13, the R-value of your insulation is R18). However, if your insulation becomes compressed as it ages — or if it’s too tight of a fit — you will lose the benefits of adding additional insulation.
New Energy Homes uses 6 inches of R19 Textrafine insulation for exterior walls and R38 Textrafine in ceilings. That’s because the insulation bounces back from compression to its regular thickness and doesn’t compress over the life of your home. That means it will give you the same insulation R-value on day one as it does when you pay off your mortgage.
PROPER INSULATION INSTALLATION
Insulation can only perform at its rated R-value if it fills an entire cavity. If you have gaps from improperly cut material, the R-value drops drastically.
If insulation is cut too narrow or too short then air gaps appear, which allows air to flow into and out of a home. This creates drafts as well as reduces the R-value. If it’s too long or too wide — not cut to fit a cavity — it will also lose its R-value by being compressed to fit.
Regardless of how high the R-value, improper installation will instantly negate the effectiveness of insulation.
Imperfections in materials and construction in stick frame homes often results in stud placement that requires insulation to be cut to be more narrow. Every cut increases the chance of creating a gap for air leakage.
At New Energy Homes, we are able to effectively install more insulation in a home because the homes we build are post-frame and not stick frame. By using post-frame construction, we don’t have to have studs in the walls every 16 to 24 inches. That means we can evenly install insulation with less thermal bridging and less air gaps than a stick frame home.
Properly installing the correct R-value and type of insulation can affect your home for the rest of its life. Great insulation is just one of the ways that New Energy Homes ensures all of our homes are high performance. If you’re planning to build a home and want to maximize the performance of your home for decades to come, contact us today.