How Does Insulation in a House Work?
House insulation is one of the most important elements of a home, yet many people don’t know how it works. Insulation is simply a mechanism of trapping heat inside the house during winter and keeping cool air inside during summer. This helps to keep your home at a comfortable temperature year-round without having to use as much energy from heating and cooling systems.
If you want your home to be energy-efficient and comfortable, you need to make sure it’s well-insulated. In this article, we’ll explain everything you need to know about how insulation works and other related questions.
How Does It Work?
First, you must understand how heat is lost or gained in a house to know how insulation works. Heat transfer takes place in three ways, including:
The most common form of heat transfer is conduction. It occurs when a warm object comes into contact with a colder object, and the heat transfers from one to the other. Conductive heat transfer is also known as thermal conductivity.
You can stop conduction by placing an insulator between two objects conducting heat to slow down or stop transfer heat. The heat can move through solid materials like walls and ceilings, as well as gaps around doors and windows. These are the main areas that you should consider insulating.
Convection is the heat transfer in liquids and air. Air is warmed when it rises and cools as it falls—the same as liquids. Warm air is less dense than cool air, so it rises, and cool air sinks to take its place.
Heat loss through convection occurs when warm air escapes through cracks in the house. You can reduce this by using insulation to balance temperature differences between inside and outside surfaces.
Radiation is the transfer of energy as waves or particles move from one place to another through a vacuum. It is simply the transfer of thermal energy by electromagnetic waves. Radiation accounts for most of the heat loss from houses during winter and gains during summer.
All these methods of heat transfer can be reduced by insulation. Different types of insulation are better at stopping different kinds of heat loss, so it’s important to choose the right type of insulation for your home.
The Insulation Process
Now that you understand the three modes of heat transfer in your house, you can start to understand how insulation works.
Heat always moves from warmer objects to cooler objects. So, in the winter, heat will move from the inside of your home to the outside. And in the summer, heat will move from the outside of your home to the inside.
Insulation works by slowing down the transfer of heat. The more insulation you have, the slower the transfer of heat will be. That’s why homes in colder climates tend to have more insulation than homes in warmer climates.
Different Types of House Insulation
There are many types of insulation available for houses. Some are safer and more effective at keeping your home at a comfortable temperature. Here’s a rundown of the most common types of insulation:
1. Loose Fill (Cellulose)
Cellulose insulation is made from recycled paper products that are treated with fire retardants. It is often used in attics and walls. Cellulose insulation can be found in loose fill, batts, or rolls. It has a high R-value. R-value is the capacity for an insulating material to resist heat flow. The higher the value, the greater the insulating power. These values range from 1.5–7. Cellulose insulation is typically 3.5–4.0.
Cellulose insulation is also good at absorbing sound. Apart from ease of installation, it is also cost-effective. It even has a chemical that prevents bugs and pests from digging through and making it their habitat.
2. Rigid Foam Panels or Foam Board
Foam board insulation is the most common type of house insulation. It comes in different densities and thicknesses, so you can choose the type that works best for your home.
Foam board panels are made with polyurethane, polystyrene, or polyisocyanurate. They come with different R-values. You can use foam board on ceilings, unfinished walls, and floors.
3. Spray Insulation
Spray foam insulation is sprayed into the walls as they’re being constructed. It will expand to fill cracks, leaks, and gaps in existing walls to prevent air leaks. It is best for hard-to-reach and irregularly-shaped spaces.
Spray foam insulation can be found in two forms: closed-cell and open-cell. Closed-cell spray foam insulation has a higher R-value than open-cell spray foam insulation. Its R-value is 6–7 per inch. Open-cell spray foam insulation typically has an R-value of 3–4 per inch.
Spray insulation has several advantages over other forms of insulation. It includes reduced air infiltration and improved energy efficiency. Besides, spray foam offers better soundproofing than other types of insulation.
Find an insulation specialist in your area, and get free, no-commitment estimates for your project.
Consult an insulation expert
Find an insulation specialist in your area, and get free, no-commitment estimates for your project.
4. Blanket Batts and Rolls/Fiberglass
Fiberglass insulation is made from recycled glass that is melted down and spun into fibers. It is among the most common types of insulation used in homes. It is typically found in rolls or batts. It is easy to install and is available in a variety of R-values of 2.5–4 per inch. You can use them for insulation on ceilings, unfinished walls, and floors.
5. Rockwool (Mineral Wool)
Rockwool is similar to fiberglass but with better fire resistance and sound absorption. However, it’s more expensive than fiberglass. You can install it in areas with plumbing pipes or wires present. It won’t break down like fiberglass does over time.
Also, you can use it in commercial buildings, such as warehouses, because it offers a higher R-value than other types of insulations. It is ideal for use on floors, ceilings, and walls.
Related Read: Guide to Insulating Homes With Sheep Wool
6. Blown-In Insulation
Blown-in insulation is made from glass fibers, rock wool, or reclaimed cellulose. It is perfect for hard-to-reach or irregularly-shaped spaces. The material is sprayed into wall cavities or attics through specialized equipment. It expands as it fills the space, then hardens to create an airtight seal.
Factors to Consider when Choosing Insulation for your House
When you need to insulate your house, you need to look at the different types of insulation available and figure out what will work best for your home. Here are some crucial factors to consider:
Parts of the House Should You Insulate More Than Others
Many parts of your house may need insulation, but some will need it more than others. They include:
Barriers That Can Boost Your Insulation’s Effectiveness
Some types of insulation must be used with a barrier to mitigate the moisture content getting in through the walls and reduce heat transfer into the house. You can use a barrier without house insulation, but you cannot use it in place of house insulation. Here are some you can use:
Vapor barriers are used with insulation to keep moisture out of the walls and prevent mold growth. They work by preventing water vapor in the air from reaching the wall surface, where it can condense into a liquid.
These vapor barriers are installed between the home’s exterior and interior walls. You can also install them between your flooring and subfloor.
You’ll often find vapor barriers in new construction projects. They prevent moisture damage caused by leaks in plumbing pipes or roofing materials.
Radiant or Reflective Barriers
Radiant barriers are an excellent addition to your insulation system. They reflect radiant heat into the room, thus reducing heat transfer through the walls, floors, and ceilings. They also allow air to pass through.
Usually, radiant barriers are made of thin aluminum sheets, foil, or plastic films. They are effective in houses with high ceilings and large windows, which allow more radiant heat to enter the house.
Signs Your House Needs Insulation
Your home is probably the biggest investment you will ever make. It can also be your source of comfort and enjoyment, but only if it is well-insulated. Here are several tell-tale signs that your house needs insulation:
Frequently Asked Questions
1. What Insulation Is the Best for the Exterior Walls of Your House?
The best insulation for the exterior walls is fiberglass batt insulation. It’s made from glass fibers compressed together into batts or rolls.
Fiberglass batt has a high R-value. It lasts longer than other types of insulation because it doesn’t absorb water or lose its effectiveness over time. This insulation is usually installed between the studs on an exterior wall. There’s no vapor barrier needed.
2. Is Installing House Insulation a Do-It-Yourself Project?
Installing insulation can be a DIY project but check with your local building department before starting. Some municipalities have specific guidelines about house insulation.
Usually, insulation is installed with other home improvement projects. In this case, it’s best to hire a professional contractor with experience working with these materials.
3. How Long Does Insulation Last?
The lifespan of an insulation product depends on the quality of the installation and the materials used. Usually, insulation can last for 15–20 years.
While you may not think much about house insulation, it’s crucial to understand what it does, how it works, and why you need it. House insulation is a great way to reduce energy bills and improve comfort. But it’s important to choose the right type of insulation for your climate and budget. Regardless, be sure to hire a professional installer, especially if you choose spray foam insulation.
Featured Image Credit: Bilanol, Shutterstock
- 1 How Does It Work?
- 2 The Insulation Process
- 3 Different Types of House Insulation
- 4 Consult an insulation expert
- 5 Factors to Consider when Choosing Insulation for your House
- 6 Parts of the House Should You Insulate More Than Others
- 7 Barriers That Can Boost Your Insulation’s Effectiveness
- 8 Signs Your House Needs Insulation
- 9 Frequently Asked Questions
- 10 Conclusion