[bldg-sim] EQuest handling of window conductance?

[John Weale]

Hello,

I am doing some modeling with EQuest 3.55 and am trying to understand two
things: How to input an NFRC window U-value, and how the DOE2.2 engine deals
with window conductance.

For inputting an NFRC window U-value, the help file offers Table 2.5 under
Glass Conductance to convert between "manufacturer's U-Value and DOE-2 glass
conductance." However, the conversion is different between summer and
winter, and conductance is a single input, not a seasonal one. Is it really
a matter of doing a weighted average of the converted Summer and Winter
U-values? I am leaving the emissivity at its default 0.84.

Once the conductance is fed in (1), the resultant window U-value in the LV-D
report does not match the conductance. I assume that Table 2.5 is intended
to add the air film, and I am not modeling any frame (2). Does DOE2.2/EQuest
assume a frame of some sort by default?

Thank you for any insights,

John Weale


(1) "GLASS-0.470-0.563" = GLASS-TYPE
TYPE = SHADING-COEF
SHADING-COEF = 0.5635
GLASS-CONDUCT = 0.531

(2) A typical window definition:
"WINDOW3" = WINDOW
GLASS-TYPE = "GLASS-0.470-0.563"
SHADING-SCHEDULE = "DEFAULT-SHADE"
MULTIPLIER = 1
HEIGHT = 13.86
WIDTH = 13.86
MAX-SOLAR-SCH = "SHADE-CTRL"
..


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