| |
 |
Why Insulate?
- Poor standard of insulation in buildings causes increases in power use and pressure on the electricity grid.
- Buildings should meet Professor Fanger’s thermal comfort theory. This theory relates to levels of comfort. For thermal insulated, naturally ventilated buildings the range should be 7°C around the thermal neutral zone, which is approximately 23°C (where 90% of people are comfortable) dropping to a range of between 10°C and 32°C (where 20% of people are comfortable)
The goal is achieve 80% of the above.
- Well designed buildings, with good quality insulation, improve health, productivity, reduce electricity costs and reduce the effects on the environment namely green house gases.
- Upon implementation of the new regulations regarding thermal insulation, up to 4500MW of electricity will be saved.
- Minimum thermal values will be legislated these will vary from region to region the proposed R-Values;
- Roofs equate to 50 – 60% of heat load, and will need R-values of between 2.70m²K/W to 3.70m²K/W, which equates to insulation of between 80 – 150mm thick depending on the roof type. The insulation levels can also be made up of various layers of insulation such as foil, fiber and insulated ceiling.
- Walls, which make up between 10 -15%of the heat load, and will need R-values of between 1.90m²K/W to 2.20m²K/W.
- Floors which loose approximately 10%, will need R-values of between 1.00m²K/W and 1.50m²K/W.
Thermal Principles
- Heat is energy!
-
- Heat is a form of kinetic energy that moves from a hot area to a cold area.
- For insulation the flow of heat is broken down into Thermal Values:
- Thermal conductivity (K-Value) co-efficient of a material is the amount of heat energy conducted by the specific material under standard conditions.
- The thermal conductivity is measured in Watts conducted per meter degree temperature difference.
- The units of K-Value (thermal conductivity) are: W/m°C (Celcius or centigrade) or W/mK (Kelvin).
- The lower the K- Value, the better the insulation.
- Thermal resistance (R)
- The thermal resistance that a specific thickness of material will provide is given by: R = t/k mK/W, where t = thickness.
- The higher the better the Thermal resistance.
- Thermal transmittance (U-value)
- The U-value of a building system is the heat flow through the system per square meter for each degree Kelvin temperature difference across the system. It includes the co-efficient of thermal resistance of all surfaces of the system and the thermal resistance of the individual layers (i.e. external air space, roof sheets, ceilings etc) and can be calculated as follows:
- Ut = ________1___________ where R is the resistance of each layer or surface. R1 + R2 + R3 …. Rn
- System R-Value
- Is the combination of all the R-Values (including all air gaps, materials etc)
- The lower the R- Value the better the insulation.
- Fire Legislation
- SANS 428 Fire Standard, a new standard that ensures that all insulation products are correctly classified to adhere to the new fire standards.
- All ThermocousTex and Romatherm products comply with SANS 428.
- TIASA
- TIASA is the Thermal Insulation Association of South Africa. Datlink, the owner of the ThermocousTex and Romatherm brands, is a member. All members have signed a code of conduct to act ethically, giving correct information and adhering to legislation whilst selling insulation products.
- Acoustic Principles:
- Acoustic design is generally overlooked when designing a building.
- Internal Acoustic design; sound absorption within a building, which improves working or living conditions, assists school children to concentrate etc.
- Roof Acoustic design; for sound transmission loss, from rain and wind noise. NRC value also assists.
- Two types of values that make acoustics important;
- NRC, Noise Reduction Co-efficient which is the absorption of noise, the worst value is 0 and the best is 1, if the value is 0,5 it means that 50% of the noise is absorbed.
- STL, Sound Transmission Loss is measured in Decibels (Db).
- The higher the Db the better the product
|
| |
|
