Building Facade Material Suggestions and Insulation Material Ideas
Polystyrene is a waterproof thermoplastic foam thatis an excellent sound and temperature sheathing material. There are two types, expanded (EPS) and extruded (XPS), also known as Styrofoam. The two types differ in performance values and cost. Polystyrene sheathing has a uniquely smooth surface that no other type of insulation has.
Typically, the foamis formed or cut into blocks, which is ideal for wall insulation .
The most important aspect of an insulating material is its performance – providing a consistently designed resistance to the passage of heat throughout the life of the building. Published performance expectations of the sheathing manufacturerAlthough an important guide , other factors associated with the "real life" installation of the material need to be considered as part of the design process:
- Ease of installation - ultimate performance will be determined by how effectively a builder can install a material using traditional skills. For example, thermal insulation boards should be installed in such a way that there are no gaps between adjacent boards or between the boards and other building components that form part of the overall exterior sheathing , such as beams or beams . The remaining gaps will allow the passage of air and cause a decrease in performance.
- Shrinkage, compression, settlement - Some insulation materials are likely to undergo some degree of dimensional instability during their installed life. In many cases, this is anticipated and can be overcome with careful design and installation methods. In all other cases, the specifier should provide guidance on the associated risks of the sheathing material , particularly where there is no recorded record of the installed performance of the cladding materials .
- Moisture protection - some insulation materials degrade in performance when damp or wet. The designer must ensure, through careful detailing, that the sensitive insulation is protected from moisture . If humidity is a high risk (intake or above 95% RH), a material with suitable resistance should be specified. Below we'll take a look at the performances exhibited by a range of common and increasingly common construction sealants .
Facade cladding materials , especially when it comes to the "green" specification, are divided into " natural thermal insulation materials " and " factory manufactured sheathing materials ".
When considering how to specify an insulating material in terms of environmental impact, it is often the case where the natural material is most beneficial in terms of environmental properties. However, in some cases, the inherent efficiencies of man-made materials can be factored into the environmental equation, for example where space for isolation is at a premium, such as reinforcement, to provide a wider environmental benefit.
What are Facade Cladding Performance Requirements and What Does It Mean?
Thermal Conductivity / λ (lambda)
Thermal conductivity measures the ease with which heat can pass through a material by conduction. Conduction is the main form of heat transfer through insulation (read more about heat transfer). It is often referred to as the λ (lambda) value. The lower the number, the better the performance.
Thermal Resistance (R)
Thermal Resistance is a figure that connects the Thermal Conductivity of a material to its Width - providing a figure expressed as resistance per unit area (m²K/W) A larger thickness means less heat flow and a lower conductivity. These parameters together form the thermal resistance of the structure. A High Thermal Resistance building layer is a good insulator; One with a low Thermal Resistance is a bad insulator.
Equation Thermal Resistance (m²K / W) = Thickness (m) / Conductivity (W / mK)
Specific Heat Capacity
of a material The Specific Heat Capacity of a material is the amount of heat required to raise the temperature of 1 kg of material by 1K (or 1oC). A good insulator has a higher Specific Heat Capacity because it takes time to absorb more heat before it actually gets hot (temperature rise) to transfer heat. High Specific Heat Capacity is a property of materials that provide Thermal Mass or Thermal Buffering (Reduction Delay).
Density refers to the mass (or 'weight') per unit volume of a substance and is measured in kilograms per m 3 . A high density material maximizes overall weight and is a feature of 'low' thermal spread and 'high' thermal mass.
Thermal Diffusivity measures the ability of a material to transmit thermal energy relative to its ability to store thermal energy. For example, metals transmit thermal energy quickly (cold to the touch), whereas wood is a slow transmitter. Insulators have low Thermal Diffusion. Copper = 98.8 mm 2 / s; Wood = 0.082 mm 2 / h.
Equation: Thermal Diffusion (mm 2 / s) = Thermal Conductivity / Density x Specific Heat Capacity
Although not an aspect of the thermal performance of an insulating material, Embodied Carbon is a key concept in the manufacture of the material, balancing global warming gases with what is retained over the life of the insulation. Embedded Carbon is generally considered to be the amount of gas used to generate energy, usually released from fossil fuels and spent between raw material extraction to factory doors through the manufacturing process. In reality, of course, transportation to the construction site goes much further than including the energy used for demolition and disposal in installation. Embodied carbon science is still evolving – as a result, solid and reliable data are difficult to obtain.
- Vapor Permeability is the measure of how a material allows water to pass through it. It is measured by the rate of vapor transmission through one unit area of unit thickness flat material induced by a unit vapor pressure difference between two specific surfaces, under specified temperature and humidity conditions.
- thermal insulation is generally characterized as Permeable to Vapor or Permeable to Non-Vapor. Often referred to as 'Breathing construction', walls and roofs are characterized by their capacity to transfer water vapor from inside the building to the outside – thus reducing the risk of condensation.
How Does Insulation Work?
Insulation, usually with a combination of two properties:
- The capacity of the thermal insulation material to prevent heat conduction
- Using pockets of trapped gases, which are natural insulators.
Gases have poor thermal conduction properties compared to liquids and solids and thus make a good insulating material if they can be compressed . To further increase the effectiveness of a gas (such as air), it can be divided by natural convection into small cells that cannot transfer heat effectively. Convection involves a larger flow of gas driven by buoyancy and temperature differences and does not work well in small cells where there is little density difference to drive it. In foam materials , small gas cells or bubbles form within the structure; In fabric insulation such as wool, small variable air pockets naturally form to form gas cells.