SUMMARY OF RESULTS FROM SKYLIGHT STUDIES:
HMG Study:
With code compliance skylight :
1. Minimum SDR: With Skylight to Daylight area ratio (SDR) of 3% - Ware house (Heating and cooling), Warehouse (Heating only) and Big Box Retail (with Fluorescent lighting) in climate zones 1,2 and 3 has benefit to cost ratio (energy savings/cost of skylight, control and increased tonnage) above 1.5 for almost all the building types while the benefit to cost ratio in the rest of the climate zones is less than 1 thus not making the skylight cost effective. There are many unresolved questions on this part of the study, e.g. The trend of cost increase doesn't seem to make sense.
2. Maximum SRR: With a minimally compliant skylight and Skylight to Roof Ratio (SRR) of 6%, there are positive energy savings for all climate zones across all building types.
Note: There is a conflict between the report and the values given in Spreadsheet. The spreadsheet values are calculated for 3% SRR not for 6% SRR as per John McHugh. Clarification requested and waiting for response
As per spreadsheet, all the skylights in all the climatic zones for the building types show positive energy savings in all the climate zones for 3% SRR. Example graphs are attached here.
Simulation summary:
Cities : 21 cities across all the climate zones
Skylight area : 0% to 10% (Current code case: 3% skylight and no lighting controls.) Skylight size : 8 ft x 4 ft (max) – Warehouse (area per skylight 23.04 sf), Grocery BB (area per skylight 12.96 sf), Grocery with Drop ceiling (area per skylight 4.41sf ) - mainly used for skylight cost
Skylight types: 12 Aluminum and TB Aluminum with both Glass and Plastic (Table 5 and 6 show 13 glass type and 11 plastic types) : U values ranges from: 0.4 to 1.33 : SHGC ranges from : 0.27-0.80 : Tvis ranges from : 0.29-0.83 Note: Whole list is in the report. These values may need update. Compare Skycalc listing with NFRC listing of products .
Building models:
Lighting : 1.5 W/sf Number of Control types : 5
HACS systems: Heating only – Gas unit heaters Heating and cooling – Air cooled roof top units
Ware house – 82,944 sf with 32 ft ceiling ht (wall/floor/ceiling reflectance – 50,20,60%), stack?? (not sure what stack means) 15ft
2 HVAC - 2 LPD (lighting power density) – 10 controls (5 control types per lighting type)– 10 SRR (from 0% to 10% in increment of 1%) + current code
Big Box Retail : Area 46,656 sf with 24 ft ceiling hight – 82,944 sf with 32 ft ceiling ht , stacks 15ft
Grocery Store: 46,656 sf with 24 ft ceiling ht. Stacks 7 ft : Modeled with 2 light wells (2’ and 8’ deep)
Note: Plug loads were not mentioned in the report.
Economic analysis:
Utility rate: High and low costs of both natural gas and electricity were considered as per NBI’s data. (average from high and low was reported in the final analysis)
Skylight cost: depending on size (Manufacturer’s cost obtained from Joe Derringer ASHRAE 90,1 ev Sc Chair)
Note: Check the costs of skylights with Skylight collaborative
Lighting control: 4 control zones in Warehouse and BB Retail and 2 control zones for Grocery store
Modeling needs: To develop new prescriptive criterion use generic U and SHGC How to include Haze – May need to run Radiance or Skyvision
Note: Requested DOE 2 input files from HMG Carli Study:
Study 1: Skylight area increase from 3% to 5% and with and without daylight controls Aluminum and thermally broken skylights with 4 different glazing options (clr, tint, HC lowE and SC lowE) were analyzed for Zones 4,5,6 and 7 (one city each). The area of skylight was varied from 3% to 5% and both the cases were considered with and without skylights. With daylighting controls, positive energy savings were obtained for all the climate zones for the case of increased skylight area (5%) in comparison to base case of 3%.
Study 2: Trade off between U factor and SHGC Dome skylights (generics) were analyzed for Retail, School and Gym building for climate zones 2,3,4 and 5 with 3% SRR. The results were compared with current code U factor and SHGC and variations were made to find the optimum U and SHGC. U, SHGC combinations of [1.05, 0.52], [0,90, 0.52], [0.90, 0.62], and [0.90, 0.62] respectively in climate zones 2,3,4 and 5 showed net energy savings in all the climatic zones except one city in Zone 3 (Fresno, CA) which showed slight increase (less than 1%) in energy consumption. It is to be noted that daylighting control was not assumed in this study (if we consider daylighting controls, the energy savings will be positive in all the climate zones).
Modeling needs: To do generic SHGC, U factors to determine prescription criteria, if not available RETAIL: ON/OFF Control
Glass Skylights - Annual Energy Costs by Skylight Area Plastic Skylights - Annual Energy Costs by Skylight Area Miami, FL: HID, Daylight Control = On/Off mWHTNfla Miami, FL: HID, Daylight Control = On/Off 90000 mCLRNfla+PRM 85000 mPRMdom mEVGNfla+PRM mWHTdom 80000 bCLRNairWHTNfla bCLRairMWHTdom ) ) r
r 80000
y 70000 bCLRNairCLRNfla+PRM y bLWHTairCLRdom / / $ $ ( (
bEVGNairWHTNfla bCLRairHWHTdom s s
t 60000 t s bCLRLairWHTNfla s
o bPRMairPRMdom o 75000 C C
50000 bCLRLairCLRNfla+PRM y bCLRairCLRairMWHTdom y g g r r
e bEVGLairWHTNfla 40000 e bLWHTairCLRairCLRdom n n
E 70000 E
bCLRLargWHTNfla bCLRairCLRairHWHTdom l l a 30000 a u bCLRLargCLRNfla+PRM u bPRMairPRMairPRMdom n n n bEVGLargWHTNfla n bCLRairCLRairCLRairCLRdom
A 20000 A 65000 bCLRLairCLRNfla No Skylights 10000 No Skylights Code Skylight - No Ctrl 0 Code Skylight - No Ctrl 60000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area % Skylight / Floor Area % Zone 1 – Miami, FL
Glass Skylights - Annual Energy Costs by Skylight Area Plastic Skylights - Annual Energy Costs by Skylight Area Houston, TX: HID, Daylight Control = On/Off mWHTNfla Houston, TX: HID, Daylight Control = On/Off 90000 mCLRNfla+PRM 90000 mPRMdom mEVGNfla+PRM mWHTdom 85000 bCLRNairWHTNfla bCLRairMWHTdom ) )
r 85000 r y
bCLRNairCLRNfla+PRM y bLWHTairCLRdom / / $ $ ( (
bEVGNairWHTNfla bCLRairHWHTdom s s
t 80000 t s bCLRLairWHTNfla s bPRMairPRMdom o o 80000 C C
bCLRLairCLRNfla+PRM bCLRairCLRairMWHTdom y y g 75000 g r r
e bLWHTairCLRairCLRdom
bEVGLairWHTNfla e n n 75000 E E
bCLRairCLRairHWHTdom bCLRLargWHTNfla l l a 70000 a u bCLRLargCLRNfla+PRM u bPRMairPRMairPRMdom n n n bEVGLargWHTNfla n bCLRairCLRairCLRairCLRdom A A 70000 65000 bCLRLairCLRNfla No Skylights No Skylights Code Skylight - No Ctrl 60000 Code Skylight - No Ctrl 65000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area % Skylight / Floor Area %
Zone 2 – Houston, TX
Glass Skylights - Annual Energy Costs by Skylight Area Plastic Skylights - Annual Energy Costs by Skylight Area Memphis, TN: HID, Daylight Control = On/Off mWHTNfla Memphis, TN: HID, Daylight Control = On/Off 85000 mCLRNfla+PRM 84000 mPRMdom mEVGNfla+PRM 82000 mWHTdom bCLRNairWHTNfla bCLRairMWHTdom
) 80000 )
r 80000 r y
bCLRNairCLRNfla+PRM y bLWHTairCLRdom / / $
$ 78000 ( (
bEVGNairWHTNfla bCLRairHWHTdom s s t t s bCLRLairWHTNfla s 76000 bPRMairPRMdom o 75000 o C C
bCLRLairCLRNfla+PRM 74000 bCLRairCLRairMWHTdom y y g g r r
e bLWHTairCLRairCLRdom bEVGLairWHTNfla e 72000 n n E
70000 E
bCLRairCLRairHWHTdom bCLRLargWHTNfla l l 70000 a a u bCLRLargCLRNfla+PRM u bPRMairPRMairPRMdom n n 68000 n bEVGLargWHTNfla n bCLRairCLRairCLRairCLRdom A 65000 A 66000 bCLRLairCLRNfla No Skylights No Skylights 64000 Code Skylight - No Ctrl 60000 Code Skylight - No Ctrl 62000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area % Skylight / Floor Area % Zone 3 – Memphis, TN Glass Skylights - Annual Energy Costs by Skylight Area Plastic Skylights - Annual Energy Costs by Skylight Area Baltimore, MD: HID, Daylight Control = On/Off Baltimore, MD: HID, Daylight Control = On/Off mWHTNfla 80000 mCLRNfla+PRM 82000 mPRMdom mWHTdom 78000 mEVGNfla+PRM 80000 bCLRairMWHTdom bCLRNairWHTNfla 78000 ) ) r
r 76000
y bLWHTairCLRdom y bCLRNairCLRNfla+PRM / /
$ 76000 $ ( (
74000 bEVGNairWHTNfla bCLRairHWHTdom s s t t 74000 s s bCLRLairWHTNfla bPRMairPRMdom o o 72000 C C
72000 bCLRairCLRairMWHTdom
bCLRLairCLRNfla+PRM y y g g 70000 r r bLWHTairCLRairCLRdom e
e bEVGLairWHTNfla 70000 n n E E 68000 bCLRairCLRairHWHTdom
bCLRLargWHTNfla l
l 68000 a a u u 66000 bCLRLargCLRNfla+PRM bPRMairPRMairPRMdom n n 66000 n n bEVGLargWHTNfla bCLRairCLRairCLRairCLRdom A A 64000 64000 bCLRLairCLRNfla No Skylights 62000 No Skylights 62000 Code Skylight - No Ctrl 60000 Code Skylight - No Ctrl 60000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area % Skylight / Floor Area % Zone 4: Baltimore
Glass Skylights - Annual Energy Costs by Skylight Area Plastic Skylights - Annual Energy Costs by Skylight Area Chicago, IL: HID, Daylight Control = On/Off Chicago, IL: HID, Daylight Control = On/Off mWHTNfla 72000 mCLRNfla+PRM 74000 mPRMdom mWHTdom mEVGNfla+PRM 72000 70000 bCLRNairWHTNfla bCLRairMWHTdom ) ) r r 70000 y y bCLRNairCLRNfla+PRM bLWHTairCLRdom / / $ $ ( ( 68000
bEVGNairWHTNfla bCLRairHWHTdom s s 68000 t t s s bCLRLairWHTNfla bPRMairPRMdom o o C C 66000
66000 bCLRairCLRairMWHTdom
bCLRLairCLRNfla+PRM y y g g r r bLWHTairCLRairCLRdom e e bEVGLairWHTNfla 64000 n n 64000 E E bCLRairCLRairHWHTdom
bCLRLargWHTNfla l l a a 62000 u u bCLRLargCLRNfla+PRM bPRMairPRMairPRMdom n n 62000 n n bEVGLargWHTNfla 60000 bCLRairCLRairCLRairCLRdom A A 60000 bCLRLairCLRNfla No Skylights 58000 No Skylights Code Skylight - No Ctrl 58000 Code Skylight - No Ctrl 56000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area % Skylight / Floor Area % Zone 5: Chicago
Glass Skylights - Annual Energy Costs by Skylight Area Plastic Skylights - Annual Energy Costs by Skylight Area Burlington, VT: HID, Daylight Control = On/Off Burlington, VT: HID, Daylight Control = On/Off mWHTNfla 72000 mCLRNfla+PRM 72000 mPRMdom mEVGNfla+PRM mWHTdom 70000 70000 bCLRNairWHTNfla bCLRairMWHTdom ) ) r r
y bLWHTairCLRdom y bCLRNairCLRNfla+PRM / / $ $ 68000 ( (
bEVGNairWHTNfla bCLRairHWHTdom s s
68000 t t s s bCLRLairWHTNfla bPRMairPRMdom o o 66000 C C
bCLRairCLRairMWHTdom
bCLRLairCLRNfla+PRM y y g g 66000 r r bLWHTairCLRairCLRdom e
e bEVGLairWHTNfla n
n 64000 E E bCLRairCLRairHWHTdom
bCLRLargWHTNfla l l a a 64000 u u bCLRLargCLRNfla+PRM 62000 bPRMairPRMairPRMdom n n n n bEVGLargWHTNfla bCLRairCLRairCLRairCLRdom A A 62000 bCLRLairCLRNfla 60000 No Skylights No Skylights Code Skylight - No Ctrl 60000 Code Skylight - No Ctrl 58000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area % Skylight / Floor Area % Zone 6: Burlington, VT Glass Skylights - Annual Energy Costs by Skylight Area Plastic Skylights - Annual Energy Costs by Skylight Area Duluth, MN: HID, Daylight Control = On/Off mWHTNfla Duluth, MN: HID, Daylight Control = On/Off 78000 mCLRNfla+PRM 78000 mPRMdom mEVGNfla+PRM mWHTdom 76000 76000 bCLRNairWHTNfla bCLRairMWHTdom ) ) r r y
bCLRNairCLRNfla+PRM y bLWHTairCLRdom / / 74000 $ $ ( 74000 (
bEVGNairWHTNfla bCLRairHWHTdom s s t t s bCLRLairWHTNfla s 72000 bPRMairPRMdom o o C 72000 C
bCLRLairCLRNfla+PRM bCLRairCLRairMWHTdom y y g g 70000 r r
e bLWHTairCLRairCLRdom
bEVGLairWHTNfla e n 70000 n E E
bCLRairCLRairHWHTdom bCLRLargWHTNfla 68000 l l a a u bCLRLargCLRNfla+PRM u bPRMairPRMairPRMdom n
68000 n n bEVGLargWHTNfla n 66000 bCLRairCLRairCLRairCLRdom A A bCLRLairCLRNfla No Skylights 66000 64000 No Skylights Code Skylight - No Ctrl 64000 Code Skylight - No Ctrl 62000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area % Skylight / Floor Area % Zone 7: Duluth, MN
Glass Skylights - Annual Energy Costs by Skylight Area Plastic Skylights - Annual Energy Costs by Skylight Area Fairbanks, AK: HID, Daylight Control = On/Off Fairbanks, AK: HID, Daylight Control = On/Off mWHTNfla 76000 mCLRNfla+PRM 76000 mPRMdom mWHTdom 74000 mEVGNfla+PRM 74000 bCLRNairWHTNfla bCLRairMWHTdom ) ) 72000 r
r 72000
y bLWHTairCLRdom y bCLRNairCLRNfla+PRM / / $ $ ( ( 70000
70000 bEVGNairWHTNfla bCLRairHWHTdom s s t t s s bCLRLairWHTNfla bPRMairPRMdom o o 68000 68000 C C
bCLRairCLRairMWHTdom
bCLRLairCLRNfla+PRM y y g g 66000 66000 r r bLWHTairCLRairCLRdom e
e bEVGLairWHTNfla n n 64000 E E 64000 bCLRairCLRairHWHTdom
bCLRLargWHTNfla l l a a u u 62000 bCLRLargCLRNfla+PRM 62000 bPRMairPRMairPRMdom n n n n bEVGLargWHTNfla bCLRairCLRairCLRairCLRdom A A 60000 60000 bCLRLairCLRNfla No Skylights 58000 58000 No Skylights Code Skylight - No Ctrl 56000 Code Skylight - No Ctrl 56000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area % Skylight / Floor Area % Zone 7: Fairbanks, AK Grocery BB
Glass Skylights - Annual Energy Costs by Skylight Area Miami, FL: Daylight Control = On/Off mWHTNfla 220000 mCLRNfla+PRM mEVGNfla+PRM 215000 bCLRNairWHTNfla ) r
y bCLRNairCLRNfla+PRM / $
( 210000 bEVGNairWHTNfla s t
s bCLRLairWHTNfla o
C 205000 bCLRLairCLRNfla+PRM y g r
e bEVGLairWHTNfla
n 200000 E
bCLRLargWHTNfla l a
u bCLRLargCLRNfla+PRM
n 195000 n bEVGLargWHTNfla A 190000 bCLRLairCLRNfla No Skylights 185000 Code Skylight - No Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl Skylight / Floor Area %
Plastic Skylights - Annual Energy Costs by Skylight Area Miami, FL: Daylight Control = On/Off
220000 mPRMdom mWHTdom 215000 bCLRairMWHTdom ) r
y bLWHTairCLRdom / $ (
bCLRairHWHTdom
s 210000 t
s bPRMairPRMdom o C bCLRairCLRairMWHTdom y
g 205000 r bLWHTairCLRairCLRdom e n
E bCLRairCLRairHWHTdom
l
a 200000
u bPRMairPRMairPRMdom n
n bCLRairCLRairCLRairCLRdom A 195000 No Skylights Code Skylight - No Ctrl 190000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area %
Zone 1 – Miami Glass Skylights - Annual Energy Costs by Skylight Area Houston, TX: Daylight Control = On/Off mWHTNfla 240000 mCLRNfla+PRM mEVGNfla+PRM 235000 bCLRNairWHTNfla ) r
y bCLRNairCLRNfla+PRM / $ (
bEVGNairWHTNfla s 230000 t
s bCLRLairWHTNfla o C bCLRLairCLRNfla+PRM y
g 225000 r
e bEVGLairWHTNfla n E
bCLRLargWHTNfla l
a 220000
u bCLRLargCLRNfla+PRM n
n bEVGLargWHTNfla A 215000 bCLRLairCLRNfla No Skylights 210000 Code Skylight - No Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl Skylight / Floor Area %
Plastic Skylights - Annual Energy Costs by Skylight Area Houston, TX: Daylight Control = On/Off 240000 mPRMdom mWHTdom 235000 bCLRairMWHTdom ) r
y bLWHTairCLRdom / $ (
bCLRairHWHTdom
s 230000 t
s bPRMairPRMdom o C bCLRairCLRairMWHTdom y
g 225000 r bLWHTairCLRairCLRdom e n
E bCLRairCLRairHWHTdom
l
a 220000
u bPRMairPRMairPRMdom n
n bCLRairCLRairCLRairCLRdom A 215000 No Skylights Code Skylight - No Ctrl 210000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area %
Zone 2 : Houston, TX Glass Skylights - Annual Energy Costs by Skylight Area Memphis, TN: Daylight Control = On/Off mWHTNfla 240000 mCLRNfla+PRM mEVGNfla+PRM 235000 bCLRNairWHTNfla ) r
y bCLRNairCLRNfla+PRM / $ (
bEVGNairWHTNfla s 230000 t
s bCLRLairWHTNfla o C bCLRLairCLRNfla+PRM y
g 225000 r
e bEVGLairWHTNfla n E
bCLRLargWHTNfla l
a 220000
u bCLRLargCLRNfla+PRM n
n bEVGLargWHTNfla A 215000 bCLRLairCLRNfla No Skylights 210000 Code Skylight - No Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl Skylight / Floor Area %
Plastic Skylights - Annual Energy Costs by Skylight Area Memphis, TN: Daylight Control = On/Off 240000 mPRMdom mWHTdom 235000 bCLRairMWHTdom ) r
y bLWHTairCLRdom / $ (
bCLRairHWHTdom
s 230000 t
s bPRMairPRMdom o C bCLRairCLRairMWHTdom y
g 225000 r bLWHTairCLRairCLRdom e n
E bCLRairCLRairHWHTdom
l
a 220000
u bPRMairPRMairPRMdom n
n bCLRairCLRairCLRairCLRdom A 215000 No Skylights Code Skylight - No Ctrl 210000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area %
Zone 3: Memphis, TN Glass Skylights - Annual Energy Costs by Skylight Area Baltimore, MD: Daylight Control = On/Off mWHTNfla 245000 mCLRNfla+PRM mEVGNfla+PRM 240000 bCLRNairWHTNfla ) r
y bCLRNairCLRNfla+PRM / $ (
bEVGNairWHTNfla s 235000 t
s bCLRLairWHTNfla o C bCLRLairCLRNfla+PRM y
g 230000 r
e bEVGLairWHTNfla n E
bCLRLargWHTNfla l
a 225000
u bCLRLargCLRNfla+PRM n
n bEVGLargWHTNfla A 220000 bCLRLairCLRNfla No Skylights 215000 Code Skylight - No Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl Skylight / Floor Area %
Plastic Skylights - Annual Energy Costs by Skylight Area Baltimore, MD: Daylight Control = On/Off 245000 mPRMdom mWHTdom 240000 bCLRairMWHTdom ) r
y bLWHTairCLRdom / $ (
bCLRairHWHTdom
s 235000 t
s bPRMairPRMdom o C bCLRairCLRairMWHTdom y
g 230000 r bLWHTairCLRairCLRdom e n
E bCLRairCLRairHWHTdom
l
a 225000
u bPRMairPRMairPRMdom n
n bCLRairCLRairCLRairCLRdom A 220000 No Skylights Code Skylight - No Ctrl 215000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area %
Zone 4: Baltimore, MD Glass Skylights - Annual Energy Costs by Skylight Area Chicago, IL: Daylight Control = On/Off mWHTNfla 208000 mCLRNfla+PRM mEVGNfla+PRM 206000 bCLRNairWHTNfla ) r
y bCLRNairCLRNfla+PRM / 204000 $ (
bEVGNairWHTNfla s t
s 202000 bCLRLairWHTNfla o C bCLRLairCLRNfla+PRM y
g 200000 r
e bEVGLairWHTNfla n E
198000 bCLRLargWHTNfla l a
u bCLRLargCLRNfla+PRM n
n 196000 bEVGLargWHTNfla A 194000 bCLRLairCLRNfla No Skylights 192000 Code Skylight - No Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl Skylight / Floor Area %
Plastic Skylights - Annual Energy Costs by Skylight Area Chicago, IL: Daylight Control = On/Off 210000 mPRMdom 208000 mWHTdom bCLRairMWHTdom
) 206000 r
y bLWHTairCLRdom / $
( 204000 bCLRairHWHTdom s t
s bPRMairPRMdom
o 202000 C bCLRairCLRairMWHTdom y
g 200000 r bLWHTairCLRairCLRdom e
n 198000 E bCLRairCLRairHWHTdom
l a
u 196000 bPRMairPRMairPRMdom n
n bCLRairCLRairCLRairCLRdom A 194000 No Skylights 192000 Code Skylight - No Ctrl 190000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area %
Zone 5: Chicago, IL Glass Skylights - Annual Energy Costs by Skylight Area Burlington, VT: Daylight Control = On/Off mWHTNfla 208000 mCLRNfla+PRM mEVGNfla+PRM 206000 bCLRNairWHTNfla ) r
y bCLRNairCLRNfla+PRM / $
( 204000 bEVGNairWHTNfla s t
s bCLRLairWHTNfla o
C 202000 bCLRLairCLRNfla+PRM y g r
e bEVGLairWHTNfla
n 200000 E
bCLRLargWHTNfla l a
u bCLRLargCLRNfla+PRM
n 198000 n bEVGLargWHTNfla A 196000 bCLRLairCLRNfla No Skylights 194000 Code Skylight - No Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl Skylight / Floor Area %
Plastic Skylights - Annual Energy Costs by Skylight Area Burlington, VT: Daylight Control = On/Off 208000 mPRMdom mWHTdom 206000 bCLRairMWHTdom ) r
y bLWHTairCLRdom
/ 204000 $ (
bCLRairHWHTdom s t
s 202000 bPRMairPRMdom o C bCLRairCLRairMWHTdom y
g 200000 r bLWHTairCLRairCLRdom e n
E bCLRairCLRairHWHTdom 198000 l a
u bPRMairPRMairPRMdom n
n 196000 bCLRairCLRairCLRairCLRdom A No Skylights 194000 Code Skylight - No Ctrl 192000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area %
Zone 6: Burlington, VT Glass Skylights - Annual Energy Costs by Skylight Area Duluth, MN: Daylight Control = On/Off mWHTNfla 222000 mCLRNfla+PRM mEVGNfla+PRM 220000 bCLRNairWHTNfla ) r
y bCLRNairCLRNfla+PRM / 218000 $ (
bEVGNairWHTNfla s t
s 216000 bCLRLairWHTNfla o C bCLRLairCLRNfla+PRM y
g 214000 r
e bEVGLairWHTNfla n E
212000 bCLRLargWHTNfla l a
u bCLRLargCLRNfla+PRM n
n 210000 bEVGLargWHTNfla A 208000 bCLRLairCLRNfla No Skylights 206000 Code Skylight - No Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl Skylight / Floor Area %
Plastic Skylights - Annual Energy Costs by Skylight Area Duluth, MN: Daylight Control = On/Off 220000 mPRMdom mWHTdom 218000 bCLRairMWHTdom ) r
y bLWHTairCLRdom
/ 216000 $ (
bCLRairHWHTdom s t
s 214000 bPRMairPRMdom o C bCLRairCLRairMWHTdom y
g 212000 r bLWHTairCLRairCLRdom e n
E bCLRairCLRairHWHTdom 210000 l a
u bPRMairPRMairPRMdom n
n 208000 bCLRairCLRairCLRairCLRdom A No Skylights 206000 Code Skylight - No Ctrl 204000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area %
Zone 7: Duluth, MN Glass Skylights - Annual Energy Costs by Skylight Area Fairbanks, AK: Daylight Control = On/Off mWHTNfla 268000 mCLRNfla+PRM 266000 mEVGNfla+PRM bCLRNairWHTNfla
) 264000 r
y bCLRNairCLRNfla+PRM /
$ 262000 (
bEVGNairWHTNfla s t
s 260000 bCLRLairWHTNfla o C 258000 bCLRLairCLRNfla+PRM y g r
e 256000 bEVGLairWHTNfla n E
bCLRLargWHTNfla
l 254000 a
u bCLRLargCLRNfla+PRM
n 252000 n bEVGLargWHTNfla A 250000 bCLRLairCLRNfla 248000 No Skylights 246000 Code Skylight - No Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Code Skylight - Ctrl Skylight / Floor Area %
Plastic Skylights - Annual Energy Costs by Skylight Area Fairbanks, AK: Daylight Control = On/Off 270000 mPRMdom mWHTdom bCLRairMWHTdom
) 265000 r
y bLWHTairCLRdom / $ (
bCLRairHWHTdom s t
s bPRMairPRMdom
o 260000 C bCLRairCLRairMWHTdom y g r bLWHTairCLRairCLRdom e
n 255000 E bCLRairCLRairHWHTdom
l a
u bPRMairPRMairPRMdom n
n bCLRairCLRairCLRairCLRdom A 250000 No Skylights Code Skylight - No Ctrl 245000 Code Skylight - Ctrl 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% Skylight / Floor Area %
Zone 8: Fairbanks, AK