Hi All,
We're building our own house and needed to investigate the window properties as we were looking at ComfortPlus, standard Double Glazing as well as Low E glass. We had always planned to go Double Glazing but looked at ComfortPlus as were told its sometimes better in cold environments (in all cases bar SHGC, it turns out its not)
Here's the breakdown on the stats from one of our suppliers - figuired it might help others. These are for standard residential aluminium windows with air filling:
Sliding Window (ComfortPlus) - Cooling Stars (2), Cool% (35%), Heating Stars (3.5), Heat% (34%), SHGC (0.59)
Sliding Window (Double Glazing) - Cooling Stars (2), Cool% (37%), Heating Stars (4), Heat% (37%), SHGC (0.58)
Sliding Window (LowE) - Cooling Stars (2.5), Cool% (43%), Heating Stars (4.5), Heat% (42%), SHGC (0.54)
Awning Window (ComfortPlus) - Cooling Stars (2), Cool% (38%), Heating Stars (4.5), Heat% (48%), SHGC (0.53)
Awning Window (Double Glazing) - Cooling Stars (2.5), Cool% (40%), Heating Stars (5.5), Heat% (57%), SHGC (0.55)
Awning Window (LowE) - Cooling Stars (3), Cool% (45%), Heating Stars (6), Heat% (61%), SHGC (0.51)
Stacker Door (ComfortPlus) - Cooling Stars (2), Cool% (38%), Heating Stars (4), Heat% (38%), SHGC (0.59)
Stacker Door (Double Glazing) - Cooling Stars (2), Cool% (36%), Heating Stars (4.5), Heat% (42%), SHGC (0.61)
Stacker Door (LowE) - Cooling Stars (2.5), Cool% (42%), Heating Stars (4.5), Heat% (47%), SHGC (0.57)
Some general observations:
- Awning windows perform significantly better than sliding windows. They're also more expensive
- we live in Canberra so Heating is far more important than cooling - find out for yourselves what they key is for your area and then base your decision around that
- we plan to cater for summer heat gain through use of external awnings, decent curtains, eaves, decidious trees and a pateo. These are all incorporated into the house design
- we compared the above (standard residential grade) windows against the top of the line (magnum) option - the only improvement (bar the looks) was that the SHGC was slightly (generally 0.01) less (meaning you gain more sunlight), the cooling stars were on average 0.5 better for comfort plus (only). In general, it was sigificantly worst for heat%, especially for awning and sliding windows
- Push your suppliers for the WERS information, or at least the model numbers so that you can compare your options - you'll be suprised at the results - we certainly were
In the end, we're going with the LowE to maximise our heat retention. The price difference was as follows (note, these were trade prices so things may get marked up for retail):
- Comfort Plus = $X
- Double Glazing = 0.98 * $X
- LowE (with Double Glazing) = 1.09 * $X
Posted Sunday 17 Jul 2011 @ 6:46:54 am from IP
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