The Scorecard Made Easy

SARIERA Accredited Manufacturer of Energy Efficient Windows The Scorecard Made Easy We have acquired some useful experience in quoting and supplying our clients with energy efficient windows so I can share a few helpful tips that may save you time when preparing plans for new buildings, additions and alterations so that they comply with SANS 204 in climatic zones 1 and 2 Windows in naturally ventilated buildings must comply for conductance, solar heat gain and the SANS 613 SAFIERA tests for air tightness An assessment must be made for each floor level separately 1. SANS 204 applies when the total of the windows area m² exceeds 15% of the habitable net floor area m² Assessments must not exceed the constants listed in SANS 204 2. For assessment of Conductance: List: a) Window sizes, the type of glass in each window and the U Value of each window b) Area m² of each window c) Net habitable floor area m².of building Here are some examples of glass U Values and SHGC in Timber window frames. TIMBER TIMBER Glass Description frame U Value SHGC Glass Description frame U Value SHGC Single Clear 5.6 0.77 Clear Double 3. 0.68 Single Tinted 5.6 0.65 Clear Double LowE 2.41 0.62 Single LowE 4.06 0.63 Clear Double Tinted 2.41 0.51 d) You can now calculate the conductance: Am² (glazing) x U Value (glass + frame) for each window to get a total) e) You can then compare the result with the Conductance constant in SANS 204 f) A(net floor area m² ) x C (zone 1 = 1.2 zone 2 = 1.4) How to calculate shading. P is measured horizontally from top of glass to the edge of the projection. H is measured vertically from the base of the glass to the edge of the projection. The P Value is calculated by dividing P with H. G is measured vertically from top of glass to the edge of the projection. Example: P = 500mm H = 2000mm P/H = 0.25 How to calculate P/H when G exceeds 500mm. The H is halved. 3. For assessment of Solar Heat Gain List: a) Area of each window m² = A b) The SHGC = S for the type of glass in each window c) Orientation (8 possible sectors) N, NE, E, SE, S, SW, W, NW., d) Shading – see graphic above (from unshaded to total shading by adjustable means) e) Get the P/H value and convert to E (Solar Exposure Factor) (see Table C1 and C2 in SANS 204) f) You can now calculate the solar heat gain. A(glazing) x S x E (for each window to get a total) g) You can then compare the result with the SHGC constant in SANS 204 A(net floor area) x SHGC (zone1 = 0.15 zone 2 = 0.12) 4 Air Tightness of windows per SANS 613. I have a compliance certificate for windows from SAFIERA SANS 613 KPJ windows are air tight