Higher thermal performance in buildings is being called up by the National Construction Code (NCC) and industry associations across the country are welcoming the focus on energy efficient buildings and costs savings increases.
In the past, building professionals have had to think outside the box when selecting insulation for their walls, floors and roofs. Advances in insulation technology have led to a number of solutions entering the market that can accommodate the changing requirements and expectations within the industry.
Continuous insulation has become a hot topic and the benefits of using continuous insulation are being realised. Thermal bridging in buildings is an important factor that needs to be addressed when designing or building an energy efficient building with a high thermal performance.
It is important to understand thermal bridging, know how to identify areas that are prone to it and be able to adequately combat it with the use of your insulation.
How can continuous insulation help?
Continuous insulation is: “Insulation that runs continuously over structural members and is free of significant thermal bridging.” - Building Energy Codes (USA)
Continuous insulation has become a phrase that has gained traction in the industry in recent years, and for those who have implemented it, it has returned some great results.
Continuous insulation is an effective way of combatting most forms of thermal bridging. It has the ability to limit the amount of heat transfer through thermal bridges and increases the overall thermal performance of the building.
Heat will naturally follow the paths of least resistance and travel to cooler temperatures often using thermal bridges as their path and without addressing thermal bridges, heat loss in winter and heat gain in summer can be a big problem.
Where continuous insulation is not able to be achieved (such as around windows and doors) other methods should be used to limit the amount of thermal transfer occurring at these points, in order to deliver a performing building.
A high performance building can provide huge benefits to the occupants including saving energy costs that could be incurred by the use of heating or cooling systems, and a more comfortable and healthy environment.
What happens without continuous insulation?
Thermal bridging compromises the thermal performance of your building and in wall constructions can account for a total R-Value decrease of 10% - 25% if it is not properly addressed.
Wall framing is one of the biggest contributors to thermal bridging and in some cases can account for 12% - 15% of the surface area, resulting in up to 15% of your walls being subject to thermal bridging.
Without the application of continuous insulation, thermal bridges remain unencumbered and promote heat transfer through the walls, floors and roofs of your building letting the summer heat in and the winter warmth out.
The effects of this can result in less thermal comfort for building occupants. In turn, this results in increased energy costs as the use of heating and cooling systems is increased in an attempt to counteract the uncomfortable environment within the building.
What does it look like?
When it comes to heat transfer it is often hard to determine the weak spots in a building where heat is being transferred. With the use of a thermal imaging camera it is easy to see where thermal bridges occur and the effect they are having on the thermal environment within your building.
When looking at a regular bedroom wall from the outside, it is not always obvious that heat is escaping through the framing of the house. Once a thermal camera is used however, the thermal bridges created by the framing of the building become obvious.
In Figure 1 you can see the framing of the walls clearly, thanks to the difference in temperature of the insulated walls. It is clear the wall of this family home is not consistently insulated and the thermal bridges are clearly visible.
When continuous insulation is applied, it is easy to the see to difference it makes when it comes to reducing thermal bridges. In Figure 3 a ceiling installed with non-continuous insulation. Again, the thermal bridges in the ceiling are clear and the temperature of the roof is inconsistent, promoting thermal seasonal gains or losses.
Figure 4 shows the same ceiling after continuous insulation had been installed. The ceiling becomes thermally consistent and the thermal bridges that appeared in the first images, have disappeared. The continuous insulation has aided in creating a more thermally stable environment within the building by blocking the transfer of heat through the ceiling.
When continuous insulation is applied throughout a building the overall thermal performance increases and the results can be easily spotted with a thermal imaging camera.
Providing for continuous insulation and removing thermal bridges in your building can result in a number of benefits. Not only does provide a higher thermal performance, it also lowers energy costs and provides a more stable, comfortable environment for its occupants.
Technology in insulation has come a long way and there are now a number of continuous insulation solutions that can provide high thermal performance whilst reducing the occurrence of thermal bridging.
To learn how to properly insulate your building envelope check out our Technical Services FAQs page or contact our Technical Services team on 1300 247 235, technical@kingspaninsulation.com.au.
