Finding the right insulation for your home can be difficult. There are different material types, installations and areas in your home to put insulation to make your home more energy efficient and save you money in the long run. The insulating material’s R-Value is the most used criteria to measure the material’s efficiency. R-Value matters, but it isn’t the only thing to look for when searching to upgrade your home insulation. Learning what R-Value means and what those other factors are can help you choose the right insulation for your home.
What is R-Value?
First and foremost, insulation is meant to stop the movement of heat, which flows from hot to cool until there is no more temperature difference. An insulating material’s resistance to conductive heat flow is measured by its R-Value, also known as thermal resistance. In theory, the higher the R-Value, the more effective the material is at slowing the transfer of conductive heat. R-Value depends on the type of material, its density and thickness, as well as moisture levels and how old the material is. In reality, R-Value isn’t the only factor that determines how well the insulation will perform in a system, such as a house.
Heat moves in four different ways: by conduction – measured by R-Value -, convection and radiation – none of which are measured. Conduction is the transfer of heat through materials, such as the heat you feel through the cup when grabbing a hot cup of coffee. Convection is the way heat flows through liquids and gases, which is why hot air rises and cooler, denser air sinks. Radiation passes through any material that will allow radiative heat to pass, like the warmth of the sun on your skin or the heat transmitted by incandescent light bulbs.
Other Factors to Consider
Wind, humidity, air infiltration and outside temperature changes are other important factors to keep in mind when choosing insulation. These factors create pressure differences between the interior and exterior of your home, forcing air to travel through any opening – big or small -, including to the unconditioned areas like attics, basements and crawl spaces. Having proper air sealing to avoid air infiltration while maintaining proper ventilation through HVAC systems also matter.
Proper installation also affects the efficiency of the insulating material. When insulation densely fills wall cavities – the space between the studs and other building materials -, it reduces airflow and can also reduce convective heat loss. Insulation materials that are compressed do not provide its fully measured R-Value. When installing blown-in or loose-fill insulation in your attic, compression of the material under its own weight causes its settled density increases, which reduces R-Value. Therefore, R-Value does not increase in proportion to the material thickness in every application.
Heat Loss in Your Home
In winter, heat flows directly from all heated living spaces of your home to adjacent unheated attics, garages, basements, and even to the outdoors. Heat flow can also move indirectly through interior ceilings, walls, and floors – wherever there is a difference in temperature. During summer, heat flows from the hot outdoors to the interior of a house.
In the winter, the lost heat must be replaced by your heating system and the heat gained in the summer must be removed by your cooling system. Properly insulating your home will decrease the heat transfer, maintain a comfortable temperature and humidity levels, and save money on energy bills throughout the year.
Choosing the Right Insulation for Your Home
Properly insulating your home depends on the climate where you live in. The International Energy Conservation Codes (IECC) ensures that buildings are constructed as efficiently as possible to suit the climate they’re in. They divided the United States map into eight different climate zones. Here in Houston, we’re in Zone 2A, which means we have a hot and humid climate – in case you didn’t notice already by going outside. Based on the IECC, the most efficient R-Value for an attic is R-38.
We know this can be a lot of information for just a single home improvement project, so we always recommend consulting your local insulation contractor. As an insulation company, we provide free estimates – no commitment necessary! Give us a call or drop us a message and our insulation consultants will gladly to assist you.
Our Recommendation
The ideal insulation system will cover all of the factors mentioned above: prevent heat loss through conduction, convection, radiation and air infiltration. A high performing insulation material has a high R-Value, can fully fill any cavities, be pneumatically or spray applied and be packed densely. Cellulose insulation – blown-in, pressure-filled in call cavities, or spray applied to roof decks -, meets all of these criteria.
In addition to insulating, cellulose insulation can prevent the spread of flames in the event of a fire. Because of its high density, it also reduces sound transmission and noise. which is why we choose to install it over any other insulating material. This is why we choose to install cellulose over any other insulating material.
