Insulation is a great way to reduce heating and cooling bills. However, it’s important to choose the right product for your climate zone.
An insulation’s ability to resist heat flow is known as its R value. The higher the R value, the better it is.
Spray foam insulation creates a strong barrier, helping to prevent the transfer of heat. It also helps to keep moisture and humidity away from wall and ceiling cavities.
Temperate Climates
Insulation for temperate climates needs to balance the need to limit heat loss with keeping the home cool. Insulation should generally be rated between R-30 and R-60. Fiberglass and cellulose are suitable materials for this type of insulation. For new construction, a vapour permeable barrier (sarking) should be added below the insulation to prevent moisture build-up and mould growth.
For existing homes, foam boards or cavity fill (loose-fill fiberglass) may be used in brick cavity walls. It is important that the air gap is large enough for the insulation to operate properly. Solid wall construction (brick, concrete block, stone, mud brick or rammed earth) and cladded timber frames with no cavities require a combination of bulk and reflective insulation such as foil backed batts. The orientation of the foil should be carefully considered to ensure that it performs as designed without adding to condensation risks.
Attics and ceilings in this climate zone need high levels of insulation but wall and slab insulation is not as critical. It is still recommended that you insulate walls to reduce energy bills.
Moist Climates
If you live in a moist climate, such as a coastal state or the Pacific Northwest, you need insulation that does more than just slow down the transfer of heat. You also need insulation that helps with moisture and humidity control, since both of these factors can negatively impact your home’s energy efficiency.
Insulation materials like cellulose, recycled denim, sheep’s wool, and cork work well in damp climates because of their natural moisture-absorbing properties. However, if you’re looking for an eco-friendly option, there are plenty of synthetic options available, too, such as urethane foam, polystyrene, and Aerogel (a material made of more than 90% air).
When selecting insulation for a moist climate, it is important to look at the R-value. The higher the R-value, the more effective the insulation will be. In addition, it is critical to ensure that the insulation is installed correctly, ensuring that no air gaps are present. This will prevent cool, moist air from rising in the walls, which can lead to condensation and mold growth.
In the past, builders weren’t as concerned with the movement of moisture vapor because they assumed that materials like brick and concrete masonry would be impermeable to it. However, new innovations have led to the widespread use of vapor retarders, which are now an essential part of a building’s construction in most humid climates.
Extreme Temperatures
The extreme temperatures experienced in many parts of the world make insulation a must. High-performance insulation reduces the transfer of thermal energy between hot components and the surrounding area, extending their service life and reducing significant risks. In addition, it is also highly resistant to fire and smoke.
Cold climates require more insulation than warm ones, and it is important to use the correct materials for maximum efficiency. For example, using a water-resistant covering on the outside cover of an insulating jacket will help to prevent moisture buildup that can damage the material and promote condensation in wall cavities.
To meet the building codes for this type of climate, homeowners will need to opt for an R-value around 30 or more. Fiberglass and cellulose are popular choices that fit within this range, as well as spray foam options. Polyurethane foams offer an excellent option for those who want to stay away from products that contain CFC gases, as they use a non-CFC gas in their blowing agent.
Adding the right insulation during construction will provide maximum benefit, but retrofitting older homes can also be effective with the right products. To ensure the best results, professional installers should be used to eliminate air gaps that can reduce the R-value and lead to condensation. The use of a vapor retarder will also help to protect the structure from moisture that could cause mold growth.
Dry Climates
Dry climates are dominated by evaporation, where water molecules escape from the Earth’s surface, and transpiration by plants. These processes are much more than the amount of rain, snow or hail in the atmosphere. As a result, these regions are very dry and sparsely vegetated. Dry climates have high temperatures throughout the year and large daily and seasonal temperature variations. These environments are often characterized by deserts and semi-arid regions like the Sahara, Arabia, Thar and South-western USA and Australia.
In these climates, insulation must be able to resist radiant heat. The required R value of insulation for a home in a dry climate depends on its design and climate zone.
Ideally, homes should use a combination of thermal and acoustic insulation to achieve the required R values. In some cases, it is a good idea to use reflective insulation to help keep the house cooler in summer and warmer in winter. However, reflective insulation must be installed with a vapour permeable barrier (sarking) below to prevent condensation.
If you live in a dry climate, consider using rockwool batts or other thermal insulation that offers high levels of fire resistance and moisture control. Insulation must be a minimum of 30mm thick in external walls to reach the recommended R values for your home. If your home uses concrete cladding, consider adding a vapor retarder under the cladding. This will help reduce condensation, which can damage and degrade your wall.