Insulation Perth is a critical building material that resists heat flow, lowering heating and cooling costs and improving comfort. There is a wide variety of insulation methods, styles and materials.
Some are eco-friendly, such as Aerogel and fiberglass, and others can be made from recycled materials. All insulation saves energy, which reduces emissions and helps the planet.
Insulation is designed to slow the transfer of heat into and out of buildings. This is achieved by blocking all three types of heat transfer: conduction, convection and radiation. The best insulators are not only good at preventing conduction and convection but also have high radiant barrier properties to block the transmission of solar radiation.
The most common way that heat moves through a construction is through direct contact with materials of different temperatures, referred to as conduction. This is the process by which cold air from outside transfers into a home’s walls, windows and roof in winter. Insulation can prevent this transfer by being a poor conductor of heat, thereby keeping the surface of the insulation at a lower temperature than the surrounding material.
A good insulator has low thermal conductivity and a high specific heat capacity. The higher the specific heat capacity, the more time it takes for an insulator to warm up and transfer heat into the surrounding air. This characteristic can help reduce the amount of energy needed to keep a home or commercial building warm and comfortable.
Insulators must meet demanding physical requirements in addition to their insulating properties. For example, they must be strong enough to withstand extreme mechanical stresses such as those placed on spacecraft during launch and re-entry into the atmosphere at extremely high speeds. They must also be fire-resistant, water-resistant and capable of resisting chemical degradation.
Other important properties of a good insulator include its thickness, R-value and the ability to resist condensation and mold growth. The R-value of a material is determined by measuring the resistance to the flow of radiant heat through it and is determined by dividing its thermal conductivity by its specific heat capacity at a given temperature. The higher the R-value, the better the insulator. It is also important for insulators to be moisture-resistant because moisture can decrease their R-values and cause them to fail. It is also important to air-seal a building prior to adding insulation to avoid the transfer of moisture from outside into the home and vice versa.
Convection
The transfer of heat into and out of your home occurs through conduction, convection and radiation. Effective insulation should prevent all three of these types of heat transfer.
Conduction is the transmission of heat through direct contact between materials, usually a metal surface and a non-metal material such as concrete or wood. Insulation that reduces conduction is essential in preventing hot surfaces from being in direct contact with cold ones.
The type of insulation that is most effective at reducing conduction is typically made with small, closed-cell foam like rock wool and cellulose. These are able to trap air within its cell structure, which reduces the flow of warm air from the warmer to the cooler areas and slowing the transfer of heat. This insulating principle is also employed by natural insulators such as down feathers and fleece.
Heat can also be transferred through convection when warm air comes into contact with cooler surfaces, which causes it to rise. This process can be sped up by wind or artificial means such as forced convection, and can be controlled by using air conditioning. Insulation that impedes this process is often designed to have very little air flow within its cells and/or to use foil facing that has low emissivity.
Indirectly, heat can also be transferred by radiation between surfaces. This type of heat transfer is aided by gaps or joints in a construction and can be minimised by ensuring that any fasteners are not in direct contact with the insulation.
The ability of a material to absorb or release thermal energy is often measured by its Specific Heat Capacity and Thermal Mass. A higher SHC/TM allows a material to store more heat and slows its transfer. Insulation with a high SHC/TM is often made from fibrous materials such as fibreglass and cellulose.
An insulating material’s resistance to the flow of conductive heat is rated by its R-value. The higher the R-value, the better the insulating performance. R-values depend on the thickness, density and thermal conductivity of a material as well as its temperature, aging and moisture accumulation. When calculating R-values for multilayered constructions, it is important to add the R-values of all the individual layers.
Vapor Barrier
Vapor barriers are important building components to help control moisture and humidity levels, which can damage insulation. These thin, flexible materials stop water vapor from permeating walls, attics, crawl spaces or roofs, where it can cause building materials to rot or grow mold. This type of damage is costly to repair and can significantly reduce the performance of insulation, lowering energy efficiency and comfort.
A vapor barrier can be made of paper, polyethylene or a synthetic material. The material’s performance is measured in a unit called “water vapor permeance,” which measures how quickly water vapor moves through it under standard atmospheric pressure conditions.
The higher the permeability, the more water vapor that can pass through the material. A vapor barrier is typically installed underneath drywall or behind insulation to prevent conditioned air from reaching the wall’s surface, where it may condense. When a vapor barrier is installed, it’s ideally placed on the warm side of a wall in cold climate zones and on the exterior of the structure in hot/wet climate zones.
While a vapor barrier is a vital component of insulation, many Bay Area homeowners ask whether they need one with their RetroFoam insulation installation. It all depends on the climate, as a vapor barrier is a requirement in colder North American regions.
In climate zones where winter temperatures are lower than the interior humidity level, a vapor barrier is essential to preventing condensation within the wall cavity, which can destroy insulation’s R-value and lead to mold and mildew issues.
When a vapor barrier is installed with insulation, it ensures that the material stays dry and helps the system operate at peak performance. This helps to keep a home or commercial building warm in winter and cool in summer, which can save on energy costs.
Vapor barriers are required by building codes in most colder regions of North America and are a part of the insulation installation process for new construction projects. For existing homes or commercial buildings, a vapor barrier can be a great way to add life to old insulation and improve the thermal performance of the building envelope.
Foam
Foam insulation offers a high level of thermal and acoustic protection. It is also fire-retardant and chemical resistant. Foam insulation products are also often lightweight. They are also easy to install, can fit in nooks and crannies of your home (including the attic, which is usually difficult to reach) and help to lower your energy costs.
Polyurethane foam is made of billions of gas bubbles that are uniformly distributed throughout the material. These bubbles are not only responsible for its soft, comfortable feel, but for its thermal and acoustic performance as well. Foam insulation products can be manufactured in several ways including injection molding, slabstock, spraying and lamination.
Rigid PU foam is an excellent choice for insulation because it has high levels of closed cell structures, which means it can’t easily allow air to pass through it. This also gives it excellent load-bearing properties, water resistance and low thermal conductivity. It is a very effective thermal and sound insulator, as well as a cushioning material for furniture, mattresses, and automobile seats.
There are two main types of insulating foams: open- and closed-cell. The difference lies in how the bubbles are arranged within the structure of the foam. Closed-cell foams don’t let air escape, which makes them firmer and more durable, while open-cell foams have a looser, less rigid structure.
In general, open-cell insulating foams are less expensive than closed-cell insulation. However, they do not act as a moisture or vapor barrier, so they can’t be used in areas where humidity or moisture are likely to be present, such as in basements and foundations.
Closed-cell insulating foams, which are denser than open-cell insulators and act as a vapor barrier, are more expensive but offer better performance. They can save you 10 to 15 percent on your energy bills, making them a smart investment. If you want to increase your savings, choose a high-rvalue foam that uses low GWP blowing agents. This will also reduce your home’s environmental impact.