24 Aug 2012
Environmental Living and Building Insulation – Revisited
Presented by Mr Winston Lam, Envirobuilding Solutions
3 ft ?
20 ft ?
200 ft?
Average emission factor of CO2 : 0.7kg CO2e per KWh
Each tree can absorb 23kg of C02 throughout its life
Building Energy Efficiency Ordinance (Cap. 610, Laws of Hong Kong SAR), will be enforced on 21 September 2012.
1. Total annual electricity consumption of HK in 2009: b t 41 5 billi 2009 about 41.5 billion kWh ( (equivalent t th i l t to the consumption by 9 millions of families annually) 2. About 90% of the electricity consumed by buildings g
Overall Thermal Transfer Value
Cool Roofing is technology th t according t th C l R f C l R fi i a t h l that, di to the Cool Roof Rating Council and US Department of Energy, can reduce utility costs by 7-15% SRI (Solar Reflective Index) is a way to estimate how hot something will get in the sun. It’s the combination of two measurements: how reflective the item is (SR) plus its (SR), emissivity – or how effectively it rejects heat (TE). Higher numbers mean materials that heat up less in the sun. SRI is given on a scale of 1 to 100
Rating Systems (such as the Cool Roof Rating Council, and LEED®) call for 78 and above for low slope roofing. A standard black (reflectance 0.05, emittance 0.90) is 0 and a standard white (reflectance 0.80, emittance 0.90) is 100.
Comparison: NIR against standard i t t d d
Ambient conditions: Outside temperature: 10,4 °C Humidity: 45 % Radiation R di ti on plates: 560 W/m ² l t W/
~ 65 ° C
~ 52 ° C
K= 0.37 W/(m2.K)
Concrete:λ= 2.1W/mK
EPS:λ= 0.04W/mK
1300
Solar Intens [W/m² sity
Near infrared Near infrared
∼ 58 % ultraviolet lt i l t
∼3%
0 350 750
2500 Wavelength [n/m]
Total Solar Energy Rejected (TSER) = percentage of incident solar energy rejected. t f i id t l j t d Typical Range: