- To match existing (Budget Windows)
o Sliding window - aluminium 2 lite – Single Glaze – 5mm Clear - brick veneer / cladding or double brick / Masonry – Size to suit brick coursing (coursing chart available here) - U-Value: 6.3 (R-Value 0.158) - SHGC: 0.72 - Air Infiltration: 0.74 L/s m2 o East and West Facing Window Upgrade - tinting film - solar high performance window film – Low E (3M™ Thinsulate™ TCC 40 Window Film) – - U-Value (Glass upgrade only): Approx. 4.0 (R-Value 0.25) - SHGC (Glass upgrade only): Approx. 0.31 - Air Infiltration: 0.74 L/s m2
Conduction: U-value U-value (expressed as Uw in windows) measures how readily a window system conducts heat. It is a measure of the rate of non-solar heat loss or gain through it. The rate of heat is indicated in the terms of the U-value of a window assembly which includes the effect of the frame, glass, seals and any spacers. The lower the U-value, the greater a window’s resistance to heat flow and the better its insulating value. A simple formula can help quantify the impact of improved U-value:• the amount of heat conducted through a glazed unit (in watts) equals the U-value (Uw)• multiplied by the number of degrees difference in air temperature on each side (T)• multiplied by the area of the glazing unit (A)Uw x T x A = watts (W) If your home has 70m2 of windows and glazed doors with aluminium frames and clear glass (i.e. U-value of 6.2), on a winter’s night when it’s 15°C colder outside, the heat loss would be about:6.2 x 15 x 70 = 6,510WThat’s equivalent to the total heat output of a large gas heater or a 2hp air conditioner running at full capacity. If you roughly halve the U-value of the window by selecting double glazing, you can halve the heat loss — in this example avoiding about 3,000W of heat loss, equivalent to the energy use of fifty 60W incandescent light bulbs. Solar heat gain coefficient The SHGC for windows (expressed as SHGCw) measures how readily heat from direct sunlight flows through a window system. The SHGC is the fraction of incident solar radiation admitted through a window, directly transmitted as well as absorbed and subsequently released inward. SHGC is expressed as a number between 0 and 1. The lower a window’s SHGC, the less solar heat it transmits.