 rheather
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| Joined: 14 Dec 2004 |
| Total Posts: 1 |
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Plastic skylight u factors
Posted: 14 Dec 2004 04:45 PM |
| When lookin thru the certified products directory, I notice that there are several plastic dome skylights using thermalized aluminum frames that have very different u-factors. When I look at the details of these different units they do not appear to be very dissimilar yet the u-factors are extremely different. Can anyone give an explanation of this? |
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Re: Plastic skylight u factors
Posted: 15 Dec 2004 11:31 AM |
Without more information this is difficult but are you possibly seeing the difference between NFRC 100-97 ( simulated vertically) and NFRC 100-2001 (Simulated at a 20 degree slope)? The difference is roughly 20%.
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Re: Plastic skylight u factors
Posted: 15 Dec 2004 02:27 PM |
| It is possible for the units to differ significantly depending upon the material properties of the dome and curb/mounting. can you be more specific? how variable? |
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Re: Plastic skylight u factors
Posted: 21 Dec 2004 10:29 AM |
| I would say it's both the curb materials and the mounting of the skylight. All else equal, a curb-mount (atop the hole)skylight will have a higher U-factor than a flush-mount (within the hole) as some of the curb would be within the mount. I don't believe the NFRC database records or displays how a skylight is typically mounted so you would have to go back to the manufacturer to find out. |
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