CPI_Design_Case by ENlight Design LLC

EN ENlig EN ENlig Supermarket Design Case Date: July.09.2010 Prepared by: Nick Hubof Jacob Dunn

ENlight ENlight design design ngised th gilN energy and

lighting solutions

LLC

ENlight ENlight design design ngised th gilN This document, its designs, ideas, and graphics are intellectual property rights of Enlight Design LLC.

Table of Contents

N N

Project Narrative Design Case 1 Luminance Renderings Illumination Data Cloudy Sky Conditions Daylight Autonomy LEED Analysis Comparison

1 2 3 4 5 6 7

SFAR 2.6% Size 4’ x 4’

Design Case 2 Luminance Renderings Illumination Data Cloudy Sky Conditions Daylight Autonomy LEED Analysis Comparison

8 9 10 11 12 13

Design Case 3 Luminance Renderings Illumination Data Cloudy Sky Conditions Daylight Autonomy LEED Analysis Comparison

14 15 16 17 18 19

20 21 22

SFAR 2.6% Size 4’ x 4’

Energy and Cost Analysis Comparative Slide Recommendations

Project Narrative

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The following design case is a fictitious building situation designed and produced to showcase the energy and daylight modeling services that Enlight Design can offer.

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Design Question: What size and quantity of intelligent CPI Solaquad skylights are necessary to daylight a 200’ x 200’ x 24’ grocery retail space without it negatively impacting heating and cooling performance? Software: Autodesk Ecotect 2010, Radiance V3.9, and Daysim was used for dayilghting simulation and analysis while Open Studio V5 and Energy Plus V5 handled the energy modeling. Methodology: Three different design cases with 4’ x 4’ skylights and 5’ x 14’ skylights were simulated with Skylight to Floor Area Ratios (SFAR) between 2.6 and 5.6%. Horizontal Illumination data was extracted from the models at different times of the year under different sky conditions. LEED V3 analysis was also conducted to ascertain compliance with the rating systems daylight credit. Daylight autonomy was then measured to understand annual daylight availability difference between the different designs. Luminance based renderings and false color images were created to visualize the space and any potential glare issues. Working in an iterative process, the daylight simulations were run parallel with energy simulations, which informed and directed each study. Energy performance was simulated using standards from both Ashrae 90.1 and the International Code Council (IECC 2009) documents to create a baseline case with zero top lighting. Our three different design cases were then simulated against this base case to understand how adding skylights impacted the heating and cooling performance of the envelope. Additionally, three different photocontrols were simulated for each case to calculate both energy and cost savings.

Project Name: Supermarket Design Location: Chicago, IL Building Type Grocery Square Footage: 40,000 SF Daylighting Criteria: 50 fc Skylighting System: CPI Solaquad

Case

CPI Solaquad Skylight CPI’s unique Solaquad Skylight utilizes a glazing composition where intelligent Solablades are sandwiched in between two layers of Quadwall polycarbonate panels. The Solablades are internal louvers that intelligently adjust light transmittance, solar heat gain coefficient, and u-value. Daylight modeling only specified one Visable Light Transmission (VLT) to represent the ideal condition to achieve maximum amount of daylight possible. The u-value difference between “open” and “closed” was only one R-Value and had little effect on the overall energy consumption.

Design Case 1 SFAR 2.6% SIZE 4â&#x20AC;&#x2122;x4â&#x20AC;&#x2122;

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Luminance Rendering SEP 21/NOON - SUNNY Casework and furniture was added for luminance rendering purposes only. Grid data on the following pages does not reflect interior furnishings and represents a completely open floor plan. The type of casework, furniture, and interior furnishings could potentially affect light levels significantly.

cd/m2

Design Case 1

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SFAR 2.6% SIZE 4’x4’

N % Floor Area above 50 fc

Equipment Equipment

Lighting

1.6%

45 40

scale: footcandles

kBtus/SF kBtu/SF--yr YR

35 30

+11%

25 20

-23%

10 5

-69%

BASE BASE CASE CASE

Illumination Data SEP 21/NOON - SUNNY This illumination data measures the amount of light falling on a workplane 30 inches tall. The different contours represent varying steps of footcandles, while values falling above our daylighting criteria are highlighted by a black dashed line. The energy data shows the architectural heating, cooling, equipment, and lighting energy loads imposed onto the building by a base case (no toplighting) and the different design cases modeled with photocontrol systems.

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SFAR 2.6% SFAR 2.6% SIZE SIZE 4' 4’x4’ x4'

Energy Data SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 3 Vent/Inf: Ashrae 90.1

Design Case 1

SFAR 2.6% SIZE 4’x4’

N % Floor Area above 50% DA

Equipment Equipment

Lighting

45 40

scale: percentage

kBtus/SF kBtu/SF--yr YR

35 30

+11%

25 20

-23%

10 5

-69%

BASE BASE CASE CASE

Daylight Autonomy ANNUAL SIMULATION Daylight autonomy refers to the percentage of annual daylight hours where the illumination values are above a specified threshold. This simulation was run with a 50 footcandle threshold while the scale highlights the range of daylight autonomy above 50% availability throughout the year. * simulated VLT does not change as in the Solaquad Product.

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SFAR 2.6% SFAR 2.6% SIZE SIZE 4' 4’x4’ x4'

Energy Data SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 4 Vent/Inf: Ashrae 90.1

Design Case 1 SFAR 2.6% SIZE 4’x4’

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Jun 21

Sep 21

Dec 21

scale: footcandles

TYP Monthly Sky Cover (Chicago) jan

feb

mar

apr

may

jun

0% clear skies 100% total cloud cover jul aug sep oct nov dec

63%

59%

62%

66%

53%

51%

53%

51%

53%

75%

63%

Illumination Data CLOUDY SKY CONDITIONS Simulations were ran during cloudy sky conditions to test the skylights performance during a less than ideal sky condition. High ceiling height, translucent material, and less available exterior lux all combine to lower the skylight’s performance values. The sky cover data was obtained using Climate Consultant 5 software and represents the typical amount of cloudiness during each month throughout the year.

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 5 Vent/Inf: Ashrae 90.1

Design Case 1 SFAR 2.6% SIZE 4’x4’

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Sep 21 - 9 am = 69% between 25 -500 fc

N Sep 21 - 3 pm = 21% between 25 -500 fc

LEED Analysis LEED V3 EQ Credit 8.1 requires that a range of 25-500 footcandles must be achieved in at least 75% of all regularly occupied spaces. Simulation must be ran on September 21st at both 9.00 am and 3.00 pm and meet the 75% requirment for both timeframes.

scale: footcandles VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 6 Vent/Inf: Ashrae 90.1

Comparison SFAR 2.6% SIZE 4’x4’

Luminance Rendering Sunny Sep 21

Illumination Sunny Sep 21

Base Case VS. Design Case 1 Daylight Autonomy Annual w/cont. dimming Heating Heating Equipment

Equipment

Cooling Cooling Lighting Lighting

50 45 40

kBtus/SF kBtu/SF--yr YR

35 30

+11%

25 20

-23%

10 5

-69%

Illumination Cloudy Sep 21

LEED Sunny Sep 21 9.00 AM

LEED Sunny Sep 21 Noon

BASE BASE CASE CASE

SFAR 2.6% SFAR 2.6% SIZE SIZE 4' 4’x4’ x4'

Energy Base vs DC 1

Worst Case Scenario This case performs badly in every condition due to its low skylight to floor area ratio (SFAR) and small unit skylights. The translucent, diffuse nature of the glazing, combined with the 24’ foot tall ceilings, creates a condition where the light transmitted does not reach the occupied areas of the building. However, this case does have the smallest penalty in heating due to there being more opaque envelope in the roof.

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 7 Vent/Inf: Ashrae 90.1

Design Case 2 SFAR 2.8% SIZE 5â&#x20AC;&#x2122;x14â&#x20AC;&#x2122;

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N cd/m2

Design Case 2 SFAR 2.8% SIZE 5’x14’

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N % Floor Area above 50 fc

Equipment

Lighting

91%

45 40

scale: footcandles

kBtus/SF - yr kBtu/SF - YR

35 30

+11%

25 20

-22%

10 5

-70%

BASE BASE CASE CASE

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SFAR 2.8% SFAR 2.6% SIZE 5'4’x4’ x14' SIZE

Energy Data SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 9 Vent/Inf: Ashrae 90.1

Design Case 2

SFAR 2.8% SIZE 5’x14’

N % Floor Area above 50% DA

Equipment

Lighting

45 40

scale: percentage

kBtus/SF - yr kBtu/SF - YR

35 30

+11%

25 20

-22%

10 5

-70%

BASE BASE CASE CASE

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SFAR 2.8% SFAR 2.6% SIZE 5'4’x4’ x14' SIZE

Energy Data SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 10 Vent/Inf: Ashrae 90.1

Design Case 2 SFAR 2.8% SIZE 5’x14’

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Jun 21

Sep 21

Dec 21

scale: footcandles

TYP Monthly Sky Cover (Chicago) jan

feb

mar

apr

may

jun

0% clear skies 100% total cloud cover jul aug sep oct nov dec

63%

59%

62%

66%

53%

51%

53%

51%

53%

75%

63%

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 11 Vent/Inf: Ashrae 90.1

Design Case 2 SFAR 2.8% SIZE 5’x14’

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Sep 21 - 9 am = 94% between 25 -500 fc

LEED Analysis

LEED V3 EQ Credit 8.1 requires that a range of 25-500 footcandles must be achieved in at least 75% of all regularly occupied spaces. Simulation must be ran on September 21st at both 9.00 am and 3.00 pm and meet the 75% requirment for both timeframes.

Sep 21 - 3 pm = 87% between 25 -500 fc scale: footcandles VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 12 Vent/Inf: Ashrae 90.1

Comparison SFAR 2.8% SIZE 5’x14’

Luminance Rendering Sunny Sep 21

Illumination Sunny Sep 21

Base Case VS.

DesignAnnual Case 2 Daylight Autonomy

w/cont. dimming Heating Heating Equipment Equipment

Cooling Cooling Lighting Lighting

50 45 40

kBtus/SF - yr kBtu/SF - YR

35 30

+11%

25 20

-22%

10 5

-70%

BASE

Illumination Cloudy Sep 21

LEED Sunny Sep 21 9.00 AM

LEED Sunny Sep 21 Noon

CASE BASE CASE

SFAR 2.8%

SIZE 5' 2.6% x14' SFAR SIZE 4’x4’

Energy Base vs DC 1

Size Matters Even with the similar skylight to floor area ratios (SFARS) this design case performs significantly better than the previous case. The larger 5’ x 14’ east-west oriented skylights distribute the luminance much deeper into the space. This case has the better energy performance of the two through its increased lighting savings and thereby more efficient cooling performance.

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 13 Vent/Inf: Ashrae 90.1

Design Case 3 SFAR 5.6% SIZE 5â&#x20AC;&#x2122;x14â&#x20AC;&#x2122;

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N cd/m2

Design Case 3 SFAR 5.6% SIZE 5’x14’

ENlight ENlight ENlight ENlight de ndesign gdesign ised de ENlight design ENlight design ENlight ENlight de ngised de Base Case Vs. Base Case VS. design ENlight ENlight design Design DesignCase Case 32 w/cont. w/cont.Dimming dimming ENlight ENlight dd ngised Heating Cooling Heating Cooling

N % Floor Area above 50 fc

Equipment Equipment

Lighting Lighting

99%

45 40

scale: footcandles

kBtus/SF - yr kBtu/SF - YR

35 30

+13%

25 20

-12%

10 5

-78%

BASE BASE CASE CASE

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SFAR 5.6% SFAR 2.6% SIZE 5' x14' SIZE 4’x4’

Energy Data SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 15 Vent/Inf: Ashrae 90.1

Design Case 3

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SFAR 5.6% SIZE 4’x4’

N % Floor Area above 50% DA

Equipment Equipment

Lighting Lighting

30%

45 40

scale: percentage

kBtus/SF - yr kBtu/SF - YR

35 30

+13%

25 20

-12%

10 5

-78%

BASE BASE CASE CASE

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SFAR 5.6% SFAR 2.6% SIZE 5' x14' SIZE 4’x4’

Energy Data SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 16 Vent/Inf: Ashrae 90.1

Design Case 3 SFAR 5.6% SIZE 5’x14’

ENlight ENlight ENlight ENlight de ndesign gdesign ised de ENlight design ENlight design ENlight ENlight de ngised de ENlight design ENlight design

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Jun 21

Sep 21

Dec 21

scale: footcandles

TYP Monthly Sky Cover (Chicago) jan

feb

mar

apr

may

jun

0% clear skies 100% total cloud cover jul aug sep oct nov dec

63%

59%

62%

66%

53%

51%

53%

51%

53%

75%

63%

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 17 Vent/Inf: Ashrae 90.1

Design Case 3 SFAR 5.6% SIZE 5’x14’

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Sep 21 - 9 am = 99.6% between 25-500 fc

LEED Analysis

N Sep 21 - 3 pm = 99.4% between 25-500 fc scale: footcandles VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 18 Vent/Inf: Ashrae 90.1

Comparison SFAR 5.6% SIZE 5’x14’

Luminance Rendering Sunny Sep 21

Illumination Sunny Sep 21

Base Case VS. DesignAnnual Case 3 Daylight Autonomy w/cont. dimming Heating Heating Equipment Equipment

Cooling Cooling Lighting Lighting

50 45 40

kBtus/SF - yr kBtu/SF - YR

35 30

+13%

25 20

-12%

10 5

-78%

Illumination Cloudy Sep 21

LEED Sunny Sep 21 9.00 AM

LEED Sunny Sep 21 Noon

BASE BASE CASE CASE

SFAR SFAR2.6% 5.6% SIZE 4’x4’ 5' x14' SIZE

Energy Base vs DC 1

Balance This design case’s increased skylight to floor area ratio (SFAR) facilitates an optimum daylit environment in all sky conditions. Additionally, the 5.6% ratio balances the cooling energy bonus with the increased heating penalty due to conductive losses in the wintertime. With a continuous dimming system, this design case has the most lighting savings while providing great indoor quality and occupant comfort through a well-daylit environment.

VLT: .50 Ceiling Reflectance: .85 Structure Reflectance: .92 Light Well Reflectance: .91 Floor: Reflectance: .5-.95 Wall Reflectance: .6-.9

SHGC: .418 U Value: .23 Weather Data: TMW 3 Roof R-Value: IECC 09 Wall R-Value: IECC 09 Floor R-Value: IECC 09

HVAC: Ideal 100% Eff LPD: 1.7 w/sf (Ashrae 90.1) EPD: .8 w/sf (Ashrae 90.1) Daylght ctrl: Cont. Dimming Schedules: Sales Retail 19 Vent/Inf: Ashrae 90.1

Energy and Cost Analysis Combined Combined EUIEUI With With Continuous Continuous Dimming Dimming

-55% BASEBASE CASECASE

SFARSFAR 2.6% 2.6% SIZE 4' SIZE x4'4' x4'

0% -70% SFARSFAR 2.8% 2.8% SIZE 5'x14' SIZE 5'x14'

0% -78%

SFAR 5.6% SIZE 5’x14’

35 39

Energy Use Index Data

Modeled photocontrol systems included continuous, 3 step, and 2 step dimming. Continuous dimming does not have a minimum input power fraction or light output fraction for zero usage. Both step dimming systems reduce lighting and power density proportionally to their specified number of steps. All systems were controlled by two input sensors distributed centrally in the space and set at 50 footcandles each. The system represents a closed loop photocontrol system where electric feedback from the lights is accounted for in the space.

100000

80000

60000

40000

20000

3 STEP DIMMING

2 STEP DIMMING

3 STEP DIMMING

2 STEP DIMMING

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CONT. DIMMING

3 STEP DIMMING

CONT. DIMMING

2 STEP DIMMING

Monthly Kilowattt Hour Consumption Photocontrols Savings

Monthly Kilowattt Hour Consumption

kWh kWh

Methodology This simulation focused on the building’s lighting system and how it impacted the architectural loads of the project. Heating and cooling energy usage does not represent the actual consumption data from a grocery store or supermarket, in reality it should be much larger. This simulation modeled an ideal HVAC system that is 100 percent efficient for both heating and cooling loads without refridgeration cases. Thus the consumption statistics represent the architectural loads of the building and not the loads imposed by the HVAC system itself or specialized equipment, which in this case would contribute to the majority of a grocery store’s energy use. Percentages, not neccessarily overall magnitude, should be used for comparison and analysis to understand skylighting’s impact on lighting and energy consumption.

120000

80000

CONT. DIMMING

SFARSFAR 5.6% 5.6% SIZE 5'x14' SIZE 5'x14'

100000

140000

$ 11,452 / yr

SFAR 2.8% SIZE 5’x14’

100000

120000

160000

$ 11,597 / yr

-12%

140000

180000

$ 11,881 / yr

-22%

SFAR 2.6% SIZE 4’x4’

120000

160000

$ 9,451 / yr

-23% 0%

+13%

140000

180000

kWh

+11%

160000

$ 9,854 / yr

+11%

180000

200000

$10,653 / yr

BASE CASE

200000

$ 7,841 / yr

kBtu/SF - YR

35 30

kbtu/SF - YR

200000

kWh

SFAR 2.6% SIZE 4'x4'

$ 8,373 / yr

Design Case 1

EUI

kWh

kBtu/SF - YR

$ 9,110 / yr

Heating Heating Cooling Cooling Equipment Equipment Lighting Lighting 50

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BASE CASE BASE CASE 18000 18000 16000 16000 14000 14000 12000 12000 10000 10000 8000 8000 6000 6000 4000 4000 2000 2000 0 feb 0 jan

SFAR 2.6% SIZE 4'x4' SFAR 2.6% SIZE 4'x4'

mar

apr

may

SFAR 2.8% SIZE 5'x14' SFAR 2.8% SIZE 5'x14'

jun

july

aug

sep

SFAR 5.6% SIZE 5'x14' SFAR 5.6% SIZE 5'x14'

oct

nov

dec

Monthly kWh Usage Date: Annual Sim Sensor setpoint: 50 fc Opaque Envelope:

IECC 2009

Skylight U-Value: .23 Skylight SHGC: .41

HVAC System: Ideal 100% Eff Lighting Pwr Den: 1.7 w/sf (Ashrae 90.1) Equip Pwr Den: .8 w/sf (Ashrae 90.1) Daylight Controls: CD, 3 Step, 2 Step Schedules: Sales Retail - Ashrae 90.1 20 Ventilation/Infiltration: Ashrae 90.1

Daylight Comparison

ENlight ENlight ENlight ENlight de ndesign gdesign ised de ENlight design ENlight design ENlight ENlight de ngised de ENlight design ENlight design

Case 1 2.6%

ENlight ENlight ngised thdd 1.6%

91%

Case 2 2.8%

Case 3 5.6%

Sep 21-12 Sunny

Sep 21 - 12Sunny

scale: footcandles

99%

Sep 21-12 Cloudy scale: footcandles

Daylight Autonomy

30%

scale: percentage

Recommendations

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ENlight design ENlight design ENlight design ENlight design

ENlight ENlight ngised thdd

Skylight Size: Between the 4’ x 4’ and 5’ x 14’ skylight at the same Skylight to Floor Area Ratio, the rectangular larger skylight performs significantly better in all sky conditions. This skylight’s longer east-west exposure allows more uninterrupted light transmittance through the skylight opening which creates less interference for daylight entering the space. Additionally, the larger elongated orientation harvests more of the available lumens and pushes light deeper into the 24’ tall space than the 4’ x 4’ skylights. Skylight to Floor Area Ratio: In terms of lighting performance, the higher the SFAR the better the lighting performance. Although both 2.8% and 5.6% SFAR achieve a well daylit space during sunny sky conditions, only the latter also performs well under overcast sky conditions. With the CPI Solaquad product’s unique ability to shade itself, the system should be designed for cloudy sky conditions under the assumption that the skylight can shade itself to avoid too much light transmittance under other sky conditions. However, as you increase the amount glazing in the ceiling of a building, adverse heating and cooling effects will happen. By reducing electric lighting consumption, peak cooling is lowered, however less opaque envelope in the ceiling equates to increased heat loss through conduction and potentially more heat gain in the summer. Consequently, our energy model concluded that a 5.6% SFAR ratio achieved significant lighting energy savings while achieving a balance between heating and cooling performance. The 5.6% SFAR showed a 12% decrease in cooling consumption with a 13% increase in heating energy and a 78% savings in lighting energy. The increase in heating is also due to there being less waste heat in the

space from electric lighting, which increases opportunity for more efficient use of energy by using the HVAC system to heat versus heating through lighting.

Photocontrol System: While continuous dimming with full shutoff capabilities achieves the most annual cost savings, 3 step switching will still give you about 90%+ of the same savings with less upfront cost. Additionally the data trend from the energy models suggests that this discrepancy between the two systems gets smaller and smaller as the space gets more and more daylit. However with a grocery store program, constant uniform lighting and occupant satisfaction might be a top priority, thereby justifying the continuous dimming system. Whatever the case, typically a photocontrol system needs to be implemented to realize savings from a daylighting strategy mostly due to occupant override of the lights. Signed,

Jacob Dunn - LEED AP ENlight Design

Nick Hubof - LEED AP ENlight Design

All analyses and predictions included in this report are for feasibility purposes only. The numbers provided are preliminary in nature and should be used to determine if a more detailed and careful study should be conducted.