Thermal insulation in buildings is an important factor to achieving thermal comfort for its occupants. Insulation reduces unwanted heat loss or gain and can decrease the energy demands of heating and cooling systems. The effectiveness of insulation is commonly evaluated by its R-value (thermal resistance). Saint-Gobain Gyproc India through its Gyproc range of products and systems provides excellent solutions for thermal insulation. The solutions range from providing wall lining insulation solutions for external masonry wall facade systems to complete false ceiling and drywall solutions.
Key terms used in thermal insulation.
1) K Value (Thermal Conductivity) – Is for a product
K, is the property of a material that indicates its ability to conduct heat.
K = ΔQ/AΔt * x/T
A is the total cross sectional area of conducting surface, ΔT is temperature difference, and x is the thickness of conducting surface separating the two temperatures.
In other words, it is defined as the quantity of heat, ΔQ, transmitted during time ΔT through a thickness x, in a direction normal to a surface of area A, due to a temperature difference ΔT, under steady state conditions and when the heat transfer is dependent only on the temperature gradient.
2) U Value (Thermal Transmittance) – Is for a system
A U-value is simply a measure of the rate of heat loss through a material. The lower the U-value, the less heat that escapes, so it's ideal to have low U-values.
3) R Value (Thermal Resistance) – Is for a system
R-value is a measure of thermal resistance used in the building and construction industry. Under uniform conditions it is the ratio of the temperature difference across an insulator and the heat flux (heat flow per unit area) through it. The bigger the number, the better the building insulation's effectiveness. R-value is the reciprocal of U-value. R-values are given square-metre Kelvin per watt or m²*K/W (or equivalently to m²*°C/W).
Systems associated with thermal resistance are: