The Present and Future of Building Envelope Thermal Insulation
Thermal insulation is a frequently used technology for reducing a building’s energy consumption by preventing the loss or gain of heat through the building envelope. This objective is accomplished by using materials that have low thermal conductivity. Building envelope thermal insulation is done using several industrial insulation products as well as certain natural elements.
Insulation Products: Three different categories of insulation products are used in building envelopes.
- Mineral fibre products such as glass wool, slag wool, and rock wool are frequently used for building envelope insulation. Most importantly, it is possible to source all these materials from recycled waste. Insulation batts and sheets can be created from these materials by high temperature melting, spinning them into a fibre, and adding a binding agent.
- Oil-derived cellular plastic products such as extruded polystyrene, expanded polystyrene and rigid polyurethane are also used to insulate building facades. All these products are available in the form of foam, rigid sheets, and loose fill. The production of these insulating materials involved the use of ozone depleting agents in the past. However, at present, the production process uses neutral hydrocarbons instead of HCFCs.
- These days, an increasing number of building envelope projects make use of animal or plant derived products such as flax, cotton, sheep wool, and cellulose fibre for insulation purpose. The embodied energy of all these materials is low, and can be used in different forms such as batts, fibre, and compressed board. The production process involves chemical treatment to make sure that the material has the desired properties such as resistance to fire and vermin infestation.
New Trends: Thermal insulation of building envelopes is a proven technology that has contributed significantly to thousands of energy efficient building all over the world. As far as the development of insulating materials is concerned, some new trends have been observed recently.
- Use of phase change materials or PCM is a popular trend, based on the principle of latent heat storage. The advantage of using PCMs for insulation is that they can store large amounts of heat within small ranges of temperature. These materials must be encapsulated because they undergo a change of phase between liquid and solid. In hot weather conditions, paraffin-based PCMs with melting points between 24 and 26°C are frequently used for heat gain prevention. This emerging technology is extremely promising because the materials are easy to apply, lightweight, and compatible with the conventional methods of construction.
- Application of raw natural materials is another development trend for insulation materials. For example, untreated straw bales can be used as the insulating material to overcome a fire hazard. This is done by using layers of glass panels or metal-based cladding, and sandwiching the straw bales between two layers. Air is also used commonly these days as the insulating material to enhance thermal insulation performance in cavity walls.
Technological Feasibility & Operational Necessities: In most of the industrialised and developed countries, there are minimum acceptable levels of insulation for building envelopes, included in building codes. However, this is not the scenario in many developing countries. In these countries, there is a need for supporting policies for large scale implementation of thermal insulation.
Please note that quality thermal insulation demands appropriate product selection, good workmanship, detailed design, and correct installation methods. Therefore, investing adequately in training the construction work force as well as design professionals is a requirement.
Thermal insulation of all building envelopes require proper detailing and workmanship in order to prevent any type of air leakage. Therefore additional attention must be paid during the installation of insulation materials within the wall frame, electrical outlets, and internal wirings.
Future Potential: In temperate climates, thermal insulation products are extensively used in building envelopes. In many developed countries, this is a regulatory requirement for occupant health as well as energy efficiency. With a growing trend all over the world to make buildings more energy efficient, the global market for thermal insulation is undoubtedly set for a great future ahead.
If you still have any questions about thermal insulation related to your next building envelope project, please feel free to contact the experts in CGS Façade Group. Since our inception in 2005, we have been involved in creating building envelopes that are not only energy efficient, but also enhance a building’s unique aesthetic appeal. We offer end-to-end façade solutions starting from the initial stage to the installation of fabricated products to envelop the building.