Assessment of insulation products are reviewed in 3 ways;
- The efficiency measurement of an actual material is called the Lambda. The higher the Lambda rating the more efficient it is and as a result will require less energy or heat to feel warm an cosy. This rating is measures in Watts / Meter x Kelvin.
- Another aspect id the thermal resistance (R) a measurement of how well a material resists the transfer of heat, this takes into account the thickness and the material's ingredients. The higher the rating the more resilient the material is, retaining the heat rather than allowing it to waste away. The measurement units are meters squared x Kelvin/Watts.
- Thermal transmittance (U) is the exact opposite of thermal resistance. This measurement is how easily a material conducts heat, so the lower the number the smaller of amount of energy or heat will be lost. This is measure in Watts/mtr2 x Kelvin
- Reviewing The Thermal Liner Energy Savings
With these 3 measurements the energy savings can be worked out once the room is up to a constant steady temperature. The advantage of using thermal liner is that its heat saving properties will allow a room to get to a steady working temperature as it retains more heat. So in real life the savings will be greater, precisely how much will depend on the outside temperature, wall thickness and construction plus how many times the heating is switched on and off.
- A typical U value of a plastered solid brick wall is 2.1 Watts/mtr2 K
- Therefore the R value is 1/2.1 = 0.476m2 K/W
- The BBA certificate for Thermal liner states an R value of 0.0821 mtr2 K/W
- The total R value for the wall with thermal liner is 0.476 + 0.0821 = 0.5581mtr2 K/W
- This can be converted back to a U value; 1/ 0.5581 = l.79 W/mtr2K
- As a result by applying Wallrock Thermal Liner to solid walls the U value is reduced from 2.1 to 1.79 W/mtr2 K