Distributed Renewable Energy Operating Impacts and Valuation Study

APPENDIX H — DAYLIGHTING PROGRAM AND MODEL PARAMETERS
Equipment Qualifications
(APS Renewable Energy Incentive Program) eQuest Building Simulation Method (version 3-61)
A roof mounted skylight assembly with a dome having a
minimum of 70% solar transmittance
A reflective light well to the interior ceiling or a minimum
of 12" below roof deck in open bay areas
An interior diffusion lens
A minimum of one thermal break/dead air space in the
system between the skylight dome and the interior diffuser
If artificial lighting systems remain part of the installation,
the system shall include automated lighting control(s) that
are programmed to keep electric lights off during daylight
hours
The system must provide a minimum of 70% of the light
output of the artificial lighting system that would
otherwise be used for all of the claimed period of energy
savings, as measured in foot-candles
“Skylight Glazing Type” the “Domed” box is checked
See “Skylight Glazing Type” specifications to meet the
70% solar transmittance requirement
“Skylight Light Well”- specify % inside reflectance (70%
default) and depth
“Skylight Glazing Type” the “Skylight is diffusing” box is
checked
Specified in the “Frame Type” within the “Skylight
Glazing Type”
Lighting control inputs defined below.
This qualification was assumed to hold true for the
building models; however, it was not tested on all
models.
Other Simulation Inputs
Skylit Rooftop Zones
Amount of skylights (% coverage)
Typical skylight dimensions (width 1, width 2)
Skylight Glazing Type
All zones
3.5% (default)
4 feet x 4 feet (Source: Natural Lighting Co., Inc. Model
NL-SM 5252)
User specified skylight properties
Conductance: U-value
Solar transmit: Shading coefficient
Product Type: Acrylic/Polycarbonate w/ curb (Source:
Natural Lighting Co., Passive Daylighting TM System)
Number of Panes: Single (Source: Natural Lighting Co.
products)
Frame Type: Aluminum w/ thermal break (Source:
Natural Lighting Co. products; based on APS’s
requirement for a thermal break )
Glass Tint: Clear (Source: Natural Lighting Co. products)
U-Value: 0.43 Btu/h*ft2*°F (Source: Stein, B., J.S.
Reynolds, W.T. Grondzik, and A.G. Kwok, Mechanical and
Electrical Equipment for Buildings, 10 th edition, Appendix
E, Table E.17, 2006)
Arizona Public Service | Distributed Renewable Energy Operating Impacts & Valuation Study
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