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Design Criteria for Manual J Calculations

Clear Creek County Design Criteria as needed for Manual J entries:

 Elevation:                                                          Below 7400 Ft                         Above 7400 Ft

Latitude:                                                           39 degrees North                     39 degrees North

Winter Heating 99% Dry Bulb:                                  -7°                                           -11°

Summer Cooling 1% Dry Bulb:                                 95°                                           90°

Coincident Wet Bulb:                                              59°                                           59°

Design Grains difference at 50% RH:                -39° to -45°                             -39° to -45°

Daily Range:                                                     High (H)                                  High (H)

Relative Humidity:                                 50% winter and summer             50% winter and summer

Indoor Design Temperatures:

            Heating:                                                     72°                                           72°

            Cooling:                                                     75°                                           75°

Heating Temperature Difference:                               79°                                           83°

Cooling Temperature Difference:                              20°                                           15°

Solar Heat Gain Coefficient (SHGC): While not required for windows in Climate Zone 7, the SHGC is still required data for Manual J calculations. SHGC should be taken directly from sticker on glass. If not known, either use default as per Table 102.1.3(3) of the 2009 IECC or equation SHGC = .87 x SC(Shading Coefficient) under19-23 of Manual J.

Altitude Correction Factor (ACF):        Site specific to elevation

Wind Velocity Values:  15 mph for Heating and 7.5 mph for Cooling