What is Insulation? – Insulation is a material designed to prevent heat from being transmitted from one area to another. It’s normally used to keep heat in or out of your home. Insulation can work in a number of different ways, but it generally incorporates materials that consist of their high thermal resistance.
Heat flow, involves three basic mechanisms — conduction, convection, and radiation. Conduction is the way heat moves through materials, such as when you place a pot on the burner or an iron in the fire. Convection is the way heat circulates through liquids and gases, and is why lighter, warmer air rises, and cooler, denser air sinks in your home. Radiant heat travels in a straight line and heats anything solid in its path that absorbs its energy. Insulating materials work by slowing the conductive heat flow from one area to another.
Properly Insulating the Attic (25% heat loss), Floors (15% heat loss) and Walls (35% heat loss) with the right type and R-Value of insulation you can have an impact on energy consumption and in turn save money…$. (all heat loss values are approx.)
What is Thermal Resistance or R-Value? – An insulating material’s resistance to conductive heat flow is measured or rated in terms of its thermal resistance or R-value, the higher the R-value, the greater the insulating effectiveness. The R-value depends on the type of insulation, its thickness, and its density. Generally you can increase the R-Value by adding additional insulating materials which increases it’s thickness.
R values and their metric equivalent, RSI values, are a way of labelling the effectiveness of insulating materials. The higher the R value or RSI value, the more resistance the material has to the movement of heat. Insulation products sold in Canada are labelled with R and RSI values.
How much Insulation Do I need? – The amount of insulation required will be based on where you live (zone), your heating equipments efficiency rating (AFUE) and what your trying to insulate. Home Depot has a basic matrix on their website which may help or you can also check out the OBC Energy Efficiency Standard. This (OBC) Ontario Building Code and Energy Star will require more reading and understanding of codes. ENERGY STAR® for New Homes Standard – Version 12.6 Effective: 22 April 2015 may also provide information on new home construction and energy savings – Insulation levels for Ontario can be found starting at 6.9.4.
At the end I highly recommend you contact a qualified contractor who can assess your current condition and or project and can provide the necessary type and amount of insulation…you may also be entitled to rebates.
One last thought – You may benefit with additional insulation, but please keep in mind that insulation alone may not be enough. How old are your windows and doors? Have you properly weather stripped your doors and windows? Air sealing around protrusions such as electrical sockets, recessed lights etc can be a major loss in conditioned air. Properly maintained furnaces and A/C. Depending on how old your house is, your walls may have very little to no insulation value. All of these may play a part in conditioned air loss or lack of energy efficiency (heat or A/C).
Also, will you actually benefit with more attic insulation. What if you already have an R-Value of 32-40 in your attic, will you actually benefit by adding more insulation based on a cost to savings aspect?. Sooner or later somebody may knock on your door and push you into spending money…just make sure it’s something you actually need.
Insulation Materials – Insulating materials can come in a variety of products which some can be sprayed, blown and or placed onto a surface. Such as;
1.Batt Insulation which comes in rolls and can be rolled out onto the surface and cut to fit easily between joists.
2.Loose-fill or blown In insulation which can insulate hard to reach places. But may require more professional installation.
3.Foam boards or ridged foam boards which may need to be cut to fit around pipes and may need to be covered for fire safety.
4. Spray Applied Insulation which combines chemicals to form a spray which expands as it fills and dries which may contain Chemicals and or VOC’s which are released during the application stage and may require the house to be vacant for several days as it cures, see the spray foam section below. Professional Installation is highly recommended.
All of which have different R or RSI Values and one type may benefit more than others depending on the insulation project.
Some of the most common types of materials are:
- Fiberglass – R-Value 3.0 – 3.7, very popular – good for walls, floors, ceiling.
- Mineral Wool – R-Value 2.8 – 3.7, same as fiberglass, better fire resistance than fiberglass
- Fiberglass – R-Value 3.0-3.7, very light, usually a pink or yellow
- Mineral Fiber – R-Value 2.8-3.7, very light, usually a brown color
- Cellulose Fiber – R-Value 3.0-3.7, fine particles, usually grey
- Type I and II (expanded) polystyrene or EPS – R-Value 3.6-4.4, white in color
- Type III and IV (extruded) polystyrene or XPS – R- Value 4.5-5, blue or pick color, works well in wet conditions.
- Open-cell light density polyurethane, R-Value 3.6, can act as air barrier
- Closed cell medium density polyurethane, R-Value 5.5-6, can act as air and moisture barrier
For a more comprehensive list click Energy.gov – Types of Insulation.
SPRAY FOAM INSULATION
Is Spray Foam Insulation Safe? – Spray polyurethane foam (SPF) is an effective insulation and air sealant material; however, exposure to its key ingredient, isocyanates and other SPF chemicals that may be found in vapours, aerosols, dust, or on surfaces during and for a period of time after installation can cause adverse health effects.
If you stay out of your home during and after spray foam installation, and if the spray foam has “cured” properly, then spray polyurethane foam insulation (SPF) is generally considered to be safe.
However, some of the chemicals used to make spray foam insulation are known to be hazards to human health, according to the Environmental Protection Agency (EPA). Spray foam installers must wear protective gear while spraying. And residence are asked to leave the residence for at least 24 hours during and after spray foam installation. Spray polyyurethane foam insulation is manufactured in your home, and not in a factory. Two liquids chemicals, called Side A and Side B are combined together and mixed on site during installation. Side A consists mostly of highly reactive chemicals called isocyanates.
Exposure to isocyanate’s is know to cause severe breathing and skin problems. These chemicals are reported to be a leading cause of work related asthma, and in severe cases, fatal reactions have occurred, according to the EPA.
Spray Foam Insulation – TERMITES? – Spray foam insulation is a popular construction material, but some exterminators are warning that the puffy stuff lining your walls could be a speedway for hungry termites seeking out wood.
The foam insulation creates a dense, sponge like environment that can save energy and lower utility bills, but also allows termites to tunnel their way to wooden beams and frames that could be holding up your house. According to a recent CBC news article posted online July 16, 2013. I recommend you read the article and watch the video.