When it gets cold outside, we bundle up when heading outdoors. You might wear a jacket that may be stuffed with feathers, put on wool mittens and a hat to keep warm. It’s no secret that the more bundled up you are, the warmer you are. Also, what you wear and what it is made of can have a big impact. Insulation in homes and buildings is very similar. While we can’t put a scarf and hat on our house and trade those in for shorts when the weather warms up, we can do the home-improvement-world equivalence through insulation. The best way to understand how insulation works is to first understand heat flow.
Heat can be transferred from one place to another through three methods: conduction, convection, and radiation. Conduction is the way heat moves through solids and is the transfer of heat from one material to another. Convection is the way that heat circulates through liquids and gases, such as air. Radiation is when radiant heat is transferred through electromagnetic waves and heats anything solid in its path that absorbs energy.
Heat is always going to travel to cooler areas until there is no longer a temperature difference through one of the three methods. Your home is always going to try to reach equilibrium inside while at the same time battling the outdoor temperature. In the winter, the heat in your home is going to try to move to cooler areas, which could be an attic or garage. This causes your heating system to work harder in order to maintain the desired temperature. Insulation is designed to slow down conduction and convection- keeping the temperature inside consistent. This makes your heating or cooling system not have to work as hard, and creates real energy savings.
The purpose of insulation is to slow down temperature changes, just like an insulated mug keeps your beverages hot or cold. So just like your puffy winter jacket helps trap your body heat, insulation traps your home’s warm air from escaping. At the same time, in the summer, it will help keep cool inside air from escaping. Browse through the tabs of the insulation page to learn more about the different types of insulation available today, as well as answers to many questions you may have about insulation.
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Types of Insulation
Insulation comes in a variety of forms and materials, each with their own strengths and weakness. Learn more about the different types of insulation here on Energize Connecticut and for more information, please visit the Department of Energy (DOE).
Blanket - Batts and Rolls:
The most common and widely available type of insulation is blanket insulation. It comes in the form of batts (pre-cut) or rolls and is available in widths appropriate for the standard spacing of wall studs, attic trusses or rafters, and floor joints, but can be hand-cut or trimmed to fit any area. Blanket insulation is also available with or without facings. Facings are a type of material such as kraft paper, foil-kraft paper, or vinyl, that acts as a vapor barrier and/or air barrier. Flame-resistant facing is available and is good for areas where the insulation may be left exposed, such as a basement. Unfaced batts are a good choice when adding insulation over existing insulation.
Blanket insulation consists of flexible fibers such as fiberglass (most common), mineral (rock and slag) wool, plastic fibers, and natural fibers (such as cotton and sheep’s wool). The R-value (measurement of the resistance of heat flow through the insulation) for blanket insulation depends on the type and thickness of insulation you are buying. Standard fiberglass blankets and batts have an R-value between R-2.9 and R-3.8 per inch of thickness, whereas high-performance fiberglass blankets and batts have R-values between R-3.7 and R-4.3 per inch of thickness. Check with the manufacturer and/or local building supplier to determine actual thickness, R-value, and cost.
When working with fiberglass batts, make sure to wear a mask, safety glasses, and cover your skin as it contains very small fibers that can cause irritation.
Concrete Block Insulation:
Foam Board or Rigid Foam:
Insulating Concrete Forms (ICFs):
Loose-fill and Blown-in:
The most common materials used for loose-fill insulation are produced using recycled waste materials. The most common materials used include: cellulose (primarily made from recycled newspaper), fiberglass (most contains 20%-30% recycled glass), and mineral wood (usually produced from 75% post-industrial recycled content). These materials are usually blown in by experienced installers, while less common materials are usually poured. Other, less common, materials include polystyrene beans and vermiculite and perlite.
For more information on Loose-fill and blown-in insulation, including R-values, please visit the Types of Insulation page on Energy.gov.
Radiant Barriers and Reflective Insulation System:
For more information, please visit the Radiant Barriers page on Energy.gov.
Rigid Fiber Board Insulation:
Liquid Foam Insulation:
Liquid foam insulation combined with a foaming agent expands and hardens as it cures. It can be applied using small spray containers, or as a foamed-in-place product for larger quantities. The mixture will conform to the shape of the cavity and will thoroughly fill and seal. There is also slow-curing liquid foam available that will flow over obstructions before expanding and curing. This type is often used for empty wall cavities in existing buildings. You can also buy small spray cans of insulating foam sealant that is great for windows and doors. The foam is minimal-expanding so it will not bow or bend window frames, but provides an airtight, water-resistant seal to help keep warm air in during the winter and hot air out in the summer.
Structural Insulated Panels (SIPs):
SIPs are made in a factory and shipped to job sites where builders connect them together to build a house or other structure. They can be produced in various sizes or dimensions and the interior and exterior materials can be customized to fit customer requirements. Many manufacturers accept design plans and will build SIPs systems based on your plans.
For more information on SIPs, please visit the Structural Insulated Panel Association.
What is an R-Value?
For more details as well as a helpful graphic, please visit the Department of Energy’s page on Where to Insulate in a Home.
|Recommended R-Values for Connecticut (Zone 5)|
|Type of Heat/Area|| Gas, Heat Pump |
or Fuel Oil
|Attic||R38 to R60||R38 to R60|
|Cathedral Ceiling||R30 to R38||R30 to R60|
|Cavity||R13 to R15||R13 to R21|
|Insulation Sheathing||R2.5 to R6||R5 to R6|
|Floor||R25 - R30||R25 - R30|
Insulation in Connecticut
Connecticut is no stranger to below freezing temperatures in the winter and heat waves in the summer, so take action to make sure your home is well insulated. Not only will it help make your house more energy efficient, but it will also make it more comfortable.
Check out the Department of Energy’s Zip Code Insulation Calculator to find the best level of insulation for your home.
A home energy assessment (audit) is also a good idea to help assess the type of insulation you have in your attic, walls, and basements. Professionals will come to your house and offer advice on what kind of insulation and amount is best for your home, as well perform on-the-spot air sealing and other services to increase energy efficiency. There are also rebates available through the Home Energy Solutions Programs.
Smart-E Loans, as well as the Connecticut Housing Investment Fund, Inc., offer long-term, low-interest financing for projects that help you upgrade your home’s energy performance, including insulation.