have aluminum frames and/or thermally improved
aluminum frames may qualify per the Energy Star
Windows program for the Central and Northern Climate
Zones.
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Thermal transmittance for thermally broken aluminum windows with insulating
glass shall not exceed a U-factor of [4.3 W/m2K (0.75 Btu/hr-ft2-F) 0.75
Btu/hr-ft2-F determined according to NFRC 100, and a solar heat gain
coefficient (SHGC) of 2.3 W/m2K (0.40 Btu/hr-ft2-F) 0.40 Btu/hr-ft2-F
determined according to NFRC 200. Window units shall comply with the U.S.
Department of Energy, Energy Star Window Program for the Southern Climate
Zone.].[2.3 W/m2K (0.40 Btu/hr-ft2-F) 0.40 Btu/hr-ft2-F determined
according to NFRC 100, and a solar heat gain coefficient (SHGC) of 3.1 W/m2
K (0.55 Bth/hr-ft2-F 0.55 Btu/hr-ft2-F determined according to NFRC 200.
Window units shall comply with the U.S. Department of Energy, Energy Star
Window Program for the Central Climate Zone.].[2.0 W/m2K (0.35 Btu/hr-ft2
-F) 0.35 Btu/hr-ft2-F determined according to NFRC 100. Window units shall
comply with the U.S. Department of Energy, Energy Star Window Program for
the Northern Climate Zone.]
1.3.5
Condensation Index Rating
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NOTE: Determination of the resistance of the window
unit to the formation of condensation in any form,
referred to as the Condensation Index, shall be
accomplished using the NFRC-approved software tool,
THERM. The following criteria shall be used to
evaluate and determine compliance with the
condensation specifications:
a. Interior environmental temperature of 21.1
C (+0.25 C) (70.0 F (+ 0.5 F)).
b. Exterior environmental temperature of
-17.8C (+0.25 C) (0.0 F (+0.5F)).
c. A 35% RH providing a dew point temperature
of approximately 5.0 C (41 F).
Others for consideration:
a.
30% RH = dew point of 2.8 C (37 F).
b.
40% RH = dew point of 7.2 C (45 F).
The Condensation Index shall be determined as
follows:
a. calculate the average interior ambient
surface temperature for each individual thermocouple
location.
b. Calculate the wetted area assigned to each
individual surface thermocouple sensor as described
(proposed from NFRC Test Procedure).
SECTION 08520A
Page 8
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