The Cool Daylighting Design Approach Workbook Volume 1 ...€¦ · Simple math is used to compare the net differences in first cost ... Cool Daylighting Design Approach Worksheet

The Cool Daylighting Design Approach Workbook

Volume 1 – Offices

Copyright 2000 LightForms, Santa Barbara, CA, All rights reserved Energy Center of Wisconsin

Notice of Disclaimer

This Daylighting Goes Mainstream: How to Daylight Every Office Building training has been prepared by the Daylighting Collaborative. Neither the Daylighting Collaborative or any of its partners, nor any person acting on behalf of them, make any representation or warranty whatsoever, whether express or implied, or assume any legal liability, regarding the completeness or accuracy of the information contained herein, with respect to the use of any information, apparatus, method, process, or similar item disclosed in this training manual, including merchantability and fitness for a particular purpose; or that any such use does not infringe on or interfere with privately owned rights, including any party’s intellectual property. Copyright 1999 Daylighting Collaborative. All rights reserved. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or means: electronic, mechanical, photocopying, recording, or otherwise, without written permission from the Daylighting Collaborative, 595 Science Drive, Madison, WI 53711, 608-238-8276, ext. 122 (Abby Vogen). For information on reproduction, purchase or borrowing of this material, please contact the Daylighting Collaborative at the above address. Cool Daylighting is a trademark of Steven E Ternoey of LightForms: Architectural Daylighting, Lighting, Energy & Training Consultants, Santa Barbara, CA (805) 560-6055 www.CoolDaylighting.com

The Cool Daylighting Design Approach

Workbook: Volume 1 – Office Buildings

Draft Dated

November 16, 2000

Prepared by: Steven E Ternoey, AIA, IES

LightForms: Architectural Daylighting, Lighting & Energy Consultants Phone: (805) 560-6055

E-mail: [email protected]

Prepared for: Daylighting Collaborative

A program administered by The Energy Center of Wisconsin Abby Vogen, Program Director

Phone: (608) 238-8276 extension 122 E-mail: [email protected]

2

Table of Contents

A. Overview p.3

B. Worksheets p.4

C. Series 1 Base Case & Prototypical Designs p.9

• Overview

• 8’ x 12’ Perimeter Office

• 10’ x 15’ Perimeter Office

• 20’ x 22.5’ Perimeter Open Office

• 20’ x 22.5’ Core Open Office

3

A. Overview Welcome to the Cool Daylighting Design Approach Workbook Volume 1: Office Buildings. The purpose of this Workbook is to facilitate quick economic and performance assessments of simple, yet very effective Cool Daylighting design strategies for office buildings. The goal is to empower architects, engineers, building owners, etc., with concise information that suggests how no-cost and low-cost Cool Daylighting strategies can be included in all office buildings. This goal supports the Daylighting Collaborative’s vision of making daylighting a mainstream building technology. For a detailed definition of the Cool Daylighting design approach, or further information on the Daylighting Collaborative’s other products and resources, please visit our web site at www.daylighting.org. The technique utilized in this Workbook is called Comparative Analysis. Comparative Analysis is based on the integrated whole-building environmental design approach developed by Steve Ternoey, et al, in The Design of Energy Responsive Commercial Buildings, John Wiley & Sons, 1985. In this workbook, comparative analysis documents the cost and performance of standard or “Base Case” office solutions, then compares the cost and performance of “Prototypical” daylighting solutions. Easy-to-use worksheets are provided to facilitate simple comparisons and choices by building designers and owners. The Workbook summarizes the daylighting means and methodologies taught at the Daylighting Collaborative’s Office Building training seminar. Please review the Training Manual if you have questions about the design of the Solution Prototypes documented in this Workbook. The Workbook is also intended to compliment the Daylighting Collaborative Copy Rooms. While the Base Case offices presented here will be very familiar to everyone, the Prototypical Daylighting Solutions are beyond the experience of most people. Therefore, the Daylighting Collaborative has (will) scattered mock-ups of the Prototypes around the region for personal inspection and experience. We call these mock-ups “Copy Rooms”, since the intent is to allow building designers and owners to review a “catalog” of real solutions, select the one(s) they desire, and “copy” those basic systems into their office project. Granted, not every possibility can be demonstrated, so there are limits to this approach. However, copying simple mock-ups is an excellent place to begin daylighting every building. The approach cuts risk and insures a specific level of success from the very first project. For a list of Copy Room sites, please refer to the Daylighting Collaborative web site. (Note: This version of the Workbook is being released before Copy Room sites are in place in the State of Wisconsin. Therefore, the prototypes listed in this current draft workbook version are standard offices utilized by the author in his consulting practice. Watch our web site for Copy Room grand openings, and updated Prototype documentation for this workbook.) As with the Copy Rooms, the Workbook Base Cases and Prototypes are presented on a per room basis. Typical office areas, such as perimeter and core offices, are presented. Quite simply, one uses a “worksheet” to first document the number (or area) of typical offices included in your proposed building, and key performance and cost data. Next, select the Prototypical solutions you want to evaluate for use on your project. As with the Base Case, a worksheet is used to record performance and cost factors for the Prototype alternative. Simple math is used to compare the net differences in first cost, HVAC CFM & tons, peak kW, ductwork, etc., between the two solutions.

4

Two “Levels” of solutions are shown for each Prototype. Level 1 solutions hold the cost of lights, glass and window treatments to the same approximate total as the Base Case, without taking credits for HVAC downsizing. Level 1 solutions represent no cost alternatives that can be used on most building, new or retrofit, without any cost premium over standard construction or HVAC sizing calculations. Level 2 solutions generally represent higher quality Cool Daylighting systems where first cost is higher, but where partial to full first cost savings can be derived from HVAC downsizing and other cost reallocation methods. While we generally recommend Level 2 solutions where possible, both prototype solution levels increase human, environmental and economic performance compared to standard or Base Case office solutions. Cost data for each Base Case and Prototype are based on the author’s experience designing Cool Daylighting solutions over the last decade, and on widely available construction cost references, where noted. Refer to the Training Manual for additional data. Energy and HVAC capacity data is derived from calibrated Energy 10 simulations using an hourly Minneapolis TMY weather file. The Minneapolis weather file is used since it is representational for the region, while remaining relatively conservative in predicting the benefits of cooling load avoidance strategies. All simulated loads are based on typical conditions, NOT PEAK CONDITIONS. In other words, absolute values are not to be used alone; only the difference between two numbers is a valid estimate of improvement or benefit. Do not use this data to design or size HVAC equipment. Workbook data must only be used to approximate the differences between the Base Cases and Prototypes in values such as air-conditioning tonnage, CFM, peak kW, cost, etc. Additional modeling technique discussions will be eventually published on the Daylighting Collaborative web site. Use this workbook as a simple design tool to point out potentially useful design alternatives. Once options are selected, use your own design team to define cost and performance for your particular situation and circumstances. While this Workbook can be a useful tool, it is never intended to replace the need for a competent design team! Good luck, and remember to daylight every building! B. Worksheets For easy comparison, Base Cases and Prototypes are always presented as pairs. Likewise, Worksheets are divided into two sections. The front of each Worksheet is for the Base Case layout, while the back is for the Prototype solution. Each side of the Worksheet has an area to sketch the building layout, and a place to create a data table summarizing areas, cost and performance factors. Simple math is used to calculate overall results for the proposed layouts The data tables can be used in two ways. First, one can literally count the number of offices by orientation and type, and complete the form on a “per office” basis (as shown in the attached example). Alternately, one can use square foot data to approximate the same general answers. This is strictly a matter of choice. Base Case and Prototypical data is provided in Section C in both square foot and per office format. Open office core zones are used to approximate all core functions (circulation, elevators, rest rooms, etc.). This is sufficient since our only desire is to approximate the benefits of daylighting and solar shading, factors that vary little by the exact space use. Blank and sample Worksheets are attached. Photocopy the blanks for future use.

5

Cool Daylighting Design Approach Worksheet Page 1 Base Case Project Name:

Sketch

Description: Space/ID Number Tons Ea. Tons Total CFM Ea. CFM Total kW Each kW Total $/yr (or Area) (or Tons/sf) (or CFM/sf) (or kW/sf)

Summary/Conclusions: www.daylighting.org

6

Cool Daylighting Design Approach Worksheet Page 2 Proposed Solution Name:

Sketch

Description: Space/ID Number Tons Ea. Tons Total CFM Ea. CFM Total kW Each kW Total $/yr (or Area) (or Tons/sf) (or CFM/sf) (or kW/sf)

Summary/Conclusions: www.daylighting.org

7

Cool Daylighting Design Approach Worksheet Page 1 Base Case Project Name: Santa Rosa Office Building Scheme A

Sketch

Description: 3-Story, 20,400 square foot gross.

Space/ID Number Tons Ea. Tons Total CFM Ea. CFM Total kW Ea. kW Total $/yr $/yr Total (or Area) (orTons/sf) (or CFM/sf) (or kW/sf) (or $/sf)

B1.1 South 36 .367 13.21 141 5076 .70 25.2 3770 B1.1 North 36 .250 9 83 2988 .55 19.8 3297 B1.3 East 6 1.77 10.62 731 4386 3.07 18.4 2570 B1.3 West 6 1.76 10.56 682 4092 3.01 18.1 2587 B1.4 Core 18 1.02 18.36 325 5850 2.3 41.4 5962 61.75 22,392 122.9 18,186

Summary/Conclusions:

www.daylighting.org

Core Open Offices

8’x12’ South Perimeter Enclosed Offices

8’x12’ North Perimeter Enclosed Offices

West Open Offices 20’x22.5’

East Open Offices 20’x22.5’

N

65 Ton Unit

8

Cool Daylighting Design Approach Worksheet Page 2 Proposed Solution Name: Santa Rosa Office Building Scheme B

Sketch

Description: Use Level 1 Prototypes for each perimeter space. Use Window Pattern 1 to keep first cost from increasing without the reallocation of Mechanical funds.

Space/ID Number Tons Ea. Tons Total CFM Ea. CFM Total kW Ea. kW Total $/yr $/yr Total (or Area) (orTons/sf) (or CFM/sf) (or kW/sf) (or $/sf)

P1.1L1.WP1 So 36 .233 8.39 78 2808 .47 16.9 2568 P1.1L1 WP1 No 36 .192 6.91 58 2088 .42 15.1 2436 P1.3L1 WP1East 6 1.06 6.36 379 2274 2.07 12.4 1828 P1.3L1 WP1West 6 1.08 6.48 350 2100 2.17 13.0 1858 B1.4 Core 18 1.02 18.36 325 5850 2.3 41.4 5962 46.50 15,120 98.8 14,652

15 ton reduction, for a multizone system, is worth about $2300 x 15 = $34,500 A 32% reduction in fan power is worth about .32/.50 x .33 x $1.15 x 20,400 sf = $6,463 (see training manual)

Summary/Conclusions: The above results are achieved without increasing first cost (potentially reducing first cost) and greatly improving the quality of the luminous environment. www.daylighting.org

(-32%)

Core Open Offices

8’x12’ South Perimeter Enclosed Offices

8’x12’ North Perimeter Enclosed Offices

West Open Offices 20’x22.5’

East Open Offices 20’x22.5’

N

50 ton unit (-23%)

(-20%) (-19%)

9

C. Series 1 Base Case & Prototypical Designs The Series 1 Base Case and Prototypical Designs presented here mirror the basic Cool Daylighting solutions recommended by the author at the Daylighting Collaborative Office Building Training. Series 2 and beyond, to be added later to this Workbook, will document additional solutions demonstrated at Daylighting Collaborative Copy Room sites. It is highly recommended that both building owners and the design team visit Copy Room sites before implementing any solutions represented in this Workbook. Many of these solutions push existing design standards and, therefore, require owner approval before construction.

As illustrated below, Series 1 designs include 1) 8’ x 12’ Enclosed Perimeter Offices, 2) 10’ x 15’ Enclosed Perimeter Offices, 3) 20’ x 22.5’ Perimeter Open Offices, and 4) 20’ x 22.5’ Core Open Offices (no windows in Base Case, clerestory added to Daylighting Prototype). For each of these configurations, one Base Case Design is included, and one or more Prototypical Designs. Multiple Prototypical Designs are presented to bracket key cost and performance factors, and to provide choice. Designers are encouraged to interpolate between solutions, and create variants not documented in this Workbook. 8’ x 12’ Enclosed Perimeter Office: Base Case has (2) 2x4 3” Parabolic 2-lamp Troffers (1.42 W/sf) and 32.5 sf of tinted glass (S.C. = 0.51). The Prototypical Design shown below (Level 2, Window Pattern 1) uses a 4’ long 2-lamp indirect and a 16W task light (0.77 W/sf connected, with photosensor control), 11.4 sf of view glass (S.C. = 0.18) and 13.5 sf of clerestory (S.C. = 0.38, plus overhang provided). Variants document Prototype performance without the overhang or lighting controls (Level 1) and with different view glass patterns (WP 2 = double view glass windows, WP 3 = half a view glass window). Figure D1: 8’ x 12’ Perimeter Office Base Case & Prototype Copyright 1997 LightForms, All Rights Reserved

2x4 troffer

2x4 troffer

2-lamp Indirect

Overhang or Exterior Sun Shade

10

10’ x 15’ Enclosed Perimeter Offices: As shown below, Base Case has (3) 2x4 3” Parabolic 2- lamp Troffers (1.36 W/sf) and 40 sf of tinted glass (S.C. = 0.51). The Prototypical Design shown below (Level 2, Window Pattern 1) uses a 8’ long 2-lamp indirect and a 16W task light (0.88 W/sf connected, with photosensor control of half the ambient lights), 15.2 sf of view glass (S.C. = 0.18) and 18 sf of clerestory (S.C. = 0.38, plus overhang provided). Variants document Prototype performance without the overhang or lighting controls (Level 1) and with different view glass patterns (WP 2 = double view glass windows, WP 3 = half a view glass window). Figure D2: 10’ x 15’ Office Base Case & Prototype Copyright 1997 LightForms, All Rights Reserved

20’ x 22.5’ Perimeter Open Offices: As illustrated on the next page, Base Case has (6) 2x4 3” Parabolic 3- lamp Troffers (1.36 W/sf) and 97.5 sf of tinted glass (S.C. = 0.51). The Prototypical Design shown below (Level 2, Window Pattern 1) uses a 20’ long 2-lamp indirect and (6) 16W task light (0.86 W/sf connected, with photosensor control of half the ambient lights), 34.2 sf of view glass (S.C. = 0.18) and 40.5 sf of clerestory (S.C. = 0.38, plus overhang provided). Variants document Prototype performance without the overhang or lighting controls (Level 1) and with different view glass patterns (WP 2 = double view glass windows, WP 3 = half a view glass window).

2x4 troffer

2x4 troffer

2x4 troffer

8’ 2-lamp Indirect

Overhang or Exterior Sun Shade

11

Figure D-3: 20’ x 22.5’ Perimeter Open Office - Base Case & Prototype Copyright 1997 LightForms, All Rights Reserved

Overhang or

Exterior Sun

Shade

12

Figure D-4: 20’ x 22.5’ Core Open Office – Base Case & Prototype Copyright 1997 LightForms, All Rights Reserved

Overhang or

Exterior Sun

Shade

13

20’ x 22.5’ Core Open Offices: As illustratede on the previous page, Base Case has (6) 2x4 3” Parabolic 3- lamp Troffers (1.36 W/sf) and no windows. The Prototypical Design raises the ceiling to 16.5’ in height, and inserts a 2.8’ high clerestory across one side. It uses a 20’ long 2-lamp direct/indirect and (6) 16W task light (0.86 W/sf connected, with photosensor control of half the ambient lights), no view glass and 50.4 sf of clerestory (S.C. = 0.38, plus overhang provided). With the exception of removing the lighting controls, no additional variants are recommended for this configuration. All cost values cited in the Base and Prototypical data are as presented in the Office Building Training. The lone exception is the cost for the above core open office roof pop-up. Past experience suggests the minimum added cost is about $250/linear foot of pop-up for a small (less than 3’-0” high) clerestory. This number assumes exposed structure above, with an exposed acoustical deck, with the pop-up ocurring at the normal column line. Refer to the Training Manual for cost factors concerning glass, window treatments, overhangs and sun shades, electric lighting trade-offs, HVAC downsizing, etc. Each of the designs will now be presented in data sheet format. Performance factors will be tabulated for each Base Case and Prototype for the four cardinal directions for each variant. Variants include multiple levels of completeness for the Prototypes (to show performance with the most limited of construction budgets), and with different window patterns.

14

Base Case #1.1 8’x12’ Office

Description: Base Case has (2) 2x4 3” Parabolic 2-lamp Troffers (1.42 W/sf) and 32.5 sf of tinted glass (S.C. = 0.51) and mini-blinds. Nighttime illuminance = 47.5 fc. Surface reflectances are 0.8 ceiling, 0.5 walls and 0.2 floor. Ceiling height is 9’– 0”.

Copyright 1997 LightForms, All Rights Reserved


15

Base Case #1.1 8’x12’ Office Performance Factors

Description North Glass Orientation

South Glass Orientation

West Glass Orientation

East Glass Orientation1

CFMpeak

83

141

209

215

CFM/Sq. Ft.

0.87

1.47

2.18

2.24

AC Tons

.250

.367

.500

.492

Sq. Ft./Ton

384

262

192

195

Tons/Sq. Ft.

.0026

.0038

.0052

.0051

kWpeak

2

.55

.70

.77

.80

kWpeak/Sq. Ft.

.0057

.0073

.0080

.0083

$/Office - Yr3

91.54

104.74

113.86

111.65

$/Sq. Ft.-Yr3

.954

1.091

1.186

1.163

1 Typically, one would expect capacities to be higher for the West orientation than for the East. However, the TMY used for these simulations has a very warm and sunny morning in May which makes the East-side capacities slightly higher than the West-side. 2 Room peak may not be same as building peak. 3 Based on $0.025/kWh, and $9.50/kW, autosized equipment with average loads

16

Prototype #1.1 8’x12’ Office Description: Ceiling height is raised to 9’-6” for better daylight distribution. This 6” increase is achieved by reducing ductwork and plenum sizes, not by increasing floor to floor height. Using a picture mold, with wall reflectance above this line being 0.80 to match the ceiling, increases wall reflectance. Electric lighting converts to a 4’ long 2-lamp indirect and a 16W task light (Nighttime: 0.77 W/sf; 26.1 fc). View glass is held to 11.4 sf (S.C. = 0.18). Clerestory glass is emphasized at 13.5 sf (S.C. = 0.38 with an overhang; 0.24 without). Variants are as follows: Level 1 - As above, without overhang and without photosensor based lighting controls. Two miniblinds are installed, one at the clerestory, and one at the view window. Since electric lighting revision is a deduct, and since window and window treatment areas have decreased over the base case, no significant 1st cost increase is expected for this upgrade of the Base Case. Level 2 – To Level 1 solution, add East, South and West-side exterior solar shading to provide a cut-off angle at the bottom of the clerestory of 30o or less (cost: about $100/Lin. Ft. for overhang, or $150/Lin. Ft. for applied sunshade). Level 2 solution includes simple photosensor controls at $100/office (see training materials). With the overhang, window treatments are not necessary for the clerestory window. To increase transparency, a perforated roller screen is used at the view window. While perforated roller screens are about $3.75/Sq. Ft. more expensive than mini-blinds, no cost increase is expected since only 11.4 Sq. Ft. are required, compared to 32.5 Sq. Ft. of mini-blinds in the Base Case. Three window patterns (WP) are appraised for both solution levels. WP1 is as above. WP2 uses two view windows, the addition of 11.4 Sq. Ft. of glass. In WP 3, the original view window above is cut in half with the top part eliminated, a deduct of 5.7 Sq. Ft of glass (Sturm Window – to be used to control glare on East & West elevations only– see Training Material).


17

Prototype #1.1 – WP 1 8’x12’ Office Performance Factors





CFMpeak Level 1 Level 2

58 55

78 59

93 96

100 103

CFM/Sq. Ft. Level 1 Level 2

.60 .57

.82 .62

.96

1.00

1.04 1.07

AC Tons Level 1 Level 2

.192 .183

.233 .192

.267 .267

.267 .258

Sq. Ft./Ton Level 1 Level 2

500 525

412 500

360 360

360 372

Tons/Sq. Ft. Level 1 Level 2

.0020 .0019

.0024 .0020

.0028 .0028

.0028 .0027

kWpeak2

Level 1 Level 2

.42 .39

.47 .40

.49 .43

.47 .43

kWpeak/S.F. Level 1 Level 2

.0044 .0041

.0049 .0042

.0051 .0045

.0049 .0045

$/Office – Yr3

Level 1 Level2

67.68 62.50

71.33 61.82

73.73 67.49

72.29 66.62

$/Sq. Ft.-Yr3 Level 1 Level 2

.705 .651

.743 .644

.768 .703

.753 .694

1 Typically, one would expect capacities to be higher for the West orientation than for the East. However, the TMY used for these simulations has a very warm and sunny morning in May which makes the East-side capacities slightly higher than the West-side. 2 Room peak may not be same as building peak. 3 Based on $0.025/kWh, $9.50/kW, autosized equipment with average loads

18

Prototype #1.1 – WP 2 (Double View Glass)

8’x12’ Office Performance Factors






62 60

90 64

115 118

121 123


.65 .62

.94 .66

1.19 1.23

1.26 1.28


.200 .200

.258 .200

.308 .308

.308 .300


480 480

372 480

312 312

312 320


.0021 .0021

.0027 .0021

.0032 .0032

.0032 .0031

kWpeak2

Level 1 Level 2

.43 .40

.51 .41

.53 .46

.52 .48


.0045 .0042

.0053 .0043

.0055 .0048

.0054 .0050

$/Office – Yr3

Level 1 Level2

72.86 67.69

77.57 66.43

81.50 75.07

79.58 73.92


.759 .705

.808 .692

.849 .782

.829 .770


19

Prototype #1.1 – WP 3 (Half View Glass) 8’x12’ Office Performance Factors






83 85

89 92


.86 .89

.93 .96


.250 .242

.242 .233


384 397

397 412


.0026 .0025

.0025 .0024

kWpeak2

Level 1 Level 2

.47 .41

.45 .41


.0049 .0043

.0047 .0043

$/Office – Yr3

Level 1 Level2

70.08 63.94

68.83 63.26


.730 .666

.717 .659


20

Base Case #1.2 10’x15’ Office Description: Base Case has (3) 2x4 3” Parabolic 2-lamp Troffers (1.36 W/sf) and 40 sf of tinted glass (S.C. = 0.51) and mini-blinds. Nighttime illuminance = 49.9 fc. Surface reflectances are 0.8 ceiling, 0.5 walls and 0.2 floor. Ceiling height is 9’– 0”.



21

Base Case #1.2 10’x15’ Office Performance Factors





CFMpeak

113

178

268

278

CFM/Sq. Ft.

0.75

1.19

1.78

1.86

AC Tons

.342

.475

.650

.642

Sq. Ft./Ton

439

316

231

234

Tons/Sq. Ft.

.0023

.0032

.0043

.0036

kWpeak

2

.79

.96

1.05

1.10

kWpeak/Sq. Ft.

.0053

.0064

.0070

.0073

$/Office - Yr3

128.55

139.50

154.50

153.00

$/Sq. Ft.-Yr3

.857

0.93

1.03

1.02


22

Prototype #1.2 10’x15’ Office Description: Ceiling height is raised to 9’-6” for better daylight distribution. This 6” increase is achieved by reducing ductwork and plenum sizes, not by increasing floor to floor height. Using a picture mold, with wall reflectance above this line being 0.80 to match the ceiling, increases wall reflectance. Electric lighting converts to a 8’ long 2-lamp indirect and a 16W task light (Nighttime: 0.88 W/sf; 32.7 fc). View glass is held to 15.2 sf (S.C. = 0.18). Clerestory glass is emphasized at 18 sf (S.C. = 0.38 with an overhang; 0.24 without). Variants are as follows: Level 1 - As above, without overhang and without photosensor based lighting controls. Two miniblinds are installed, one at the clerestory, and one at the view window. Since electric lighting revision is a deduct, and since window and window treatment areas have decreased over the base case, no significant 1st cost increase is expected for this upgrade of the Base Case. Level 2 – To Level 1 solution, add East, South and West-side exterior solar shading to provide a cut-off angle at the bottom of the clerestory of 30o or less (cost: about $100/Lin. Ft. for overhang, or $150/Lin. Ft. for applied sunshade). Level 2 solution includes simple photosensor controls at $100/office (see training materials). With the overhang, window treatments are not necessary for the clerestory window. To increase transparency, a perforated roller screen is used at the view window. While perforated roller screens are about $3.75/Sq. Ft. more expensive than mini-blinds, no cost increase is expected since only 15.2 Sq. Ft. are required, compared to 40 Sq. Ft. of mini-blinds in the Base Case. Three window patterns (WP) are appraised for both solution levels. WP1 is as above. WP2 uses two view windows, the addition of 15.2 Sq. Ft. of glass. In WP 3, the original view window above is cut in half with the top part eliminated, a deduct of 7.6 Sq. Ft of glass (Sturm Window – to be used to control glare on East & West elevations only– see Training Material).


23

Prototype #1.2 – WP 1 10’x15’ Office Performance Factors






82 76

109 81

128 134

138 138


.54 .50

.73 .54

.85 .89

.92 .92


.275 .258

.333 .267

.375 .367

.367 .350


545 581

450 562

400 409

409 429


.0018 .0017

.0022 .0018

.0025 .0024

.0024 .0023

kWpeak2

Level 1 Level 2

.63 .56

.70 .58

.73 .62

.71 .62


.0042 .0037

.0047 .0039

.0049 .0041

.0047 .0041

$/Office – Yr3

Level 1 Level2

100.95 89.70

106.05 88.95

108.75 96.30

107.25 95.40


.673 .598

.707 .593

.725 .642

.715 .636


24


10’x15’ Office Performance Factors






88 82

120 86

157 158

167 166


.59 .55

.8 .57

1.05 1.06

1.11 1.11


.283 .275

.358 .283

.433 .417

.425 .408


530 545

419 530

346 360

353 368


.0019 .0018

.0024 .0019

.0029 .0028

.0028 .0027

kWpeak2

Level 1 Level 2

.65 .58

.73 .60

.78 .65

.77 .69


.0043 .0039

.0049 .0040

.0052 .0043

.0051 .0046

$/Office – Yr3

Level 1 Level2

107.40 96.30

109.65 94.35

118.35 105.45

116.55 104.25


.716 .642

.731 .629

.789 .703

.777 .695


25

Prototype #1.2 – WP 3 (Half View Glass) 10’x15’ Office Performance Factors






115 114

123 123


.76 .76

.82 .82


.342 .325

.333 .317


439 462

450 473


.0023 .0022

.0022 .0021

kWpeak2

Level 1 Level 2

.70 .60

.67 .60


.0047 .0040

.0045 .0040

$/Office – Yr3

Level 1 Level2

103.65 92.10

102.15 91.65


.691 .614

.681 .611


26

Base Case #1.3 20’x 22.5’ Perimeter Open Office Description: Base Case has (6) 2x4 3” Parabolic 3-lamp Troffers (1.36 W/sf) and 97.5 sf of tinted glass (S.C. = 0.51) and mini-blinds. Nighttime illuminance = 47.5 fc. Surface reflectances are 0.8 ceiling, 0.5 walls and 0.2 floor. Ceiling height is 9’– 0”.

9’



27

Base Case #1.3 20’x 22.5’ Perimeter Open Office Performance Factors





CFMpeak

342

510

682

731

CFM/Sq. Ft.

0.76

1.13

1.52

1.62

AC Tons

1.058

1.417

1.76

1.77

Sq. Ft./Ton

425

318

256

254

Tons/Sq. Ft.

.0024

.0031

.0039

.0039

kWpeak

2

2.41

2.84

3.01

3.07

kWpeak/Sq. Ft.

.0054

.0063

.0067

.0068

$/Office - Yr3

370.80

411.75

431.10

428.40

$/Sq. Ft.-Yr3

.824

.915

.958

.952


28

Prototype #1.3 20’x 22.5’ Perimeter Open Office Description: Ceiling height is raised to 9’-6” for better daylight distribution. This 6” increase is achieved by reducing ductwork and plenum sizes, not by increasing floor to floor height. Using a picture mold, with wall reflectance above this line being 0.80 to match the ceiling, increases wall reflectance. Electric lighting converts to a 20’ long 2-lamp indirect and (6) 16W task lights (Nighttime: 0.86 W/sf; 30.8 fc). View glass is held to 34.2 sf (S.C. = 0.18). Clerestory glass is emphasized at 40.5 sf (S.C. = 0.38 with an overhang; 0.24 without). Variants are as follows: Level 1 - As above, without overhang and without photosensor based lighting controls. Two miniblinds are installed, one at the clerestory, and one at the view window. Since electric lighting revision is a deduct, and since window and window treatment areas have decreased over the base case, no significant 1st cost increase is expected for this upgrade of the Base Case. Level 2 – To Level 1 solution, add East, west and South exterior solar shading to provide a cut-off angle at the bottom of the clerestory of 30o or less (cost: about $100/Lin. Ft. for overhang, or $150/Lin. Ft. for applied sunshade). Level 2 solution includes simple photosensor controls at $100/office (see training materials). With the overhang, window treatments are not necessary for the clerestory window. To increase transparency, a perforated roller screen is used at the view window. While perforated roller screens are about $3.75/Sq. Ft. more expensive than mini-blinds, no cost increase is expected since only 34.2 Sq. Ft. are required, compared to 97.5 Sq. Ft. of mini-blinds in the Base Case. Two window patterns (WP) are appraised for both solution levels. WP1 is as above. WP2 uses two view windows, the addition of 34.2 Sq. Ft. of glass. WP 3 is not recommended for this space since transparency outward is critical for the people seated along the wall opposite the windows.

9.5’


29

Prototype #1.3 – WP 1 20’x 22.5’ Perimeter Open Office Performance Factors






237 257

317 254

350 339

379 378


.57 .54

.71 .56

.77 .75

.84 .84


.875 .842

1.008 .858

1.075 1.050

1.058 1.050


514 534

446 524

419 429

425 429


.0019 .0019

.0022 .0019

.0024 .0023

.0024 .0023

kWpeak2

Level 1 Level 2

1.96 1.79

2.10 1.83

2.17 1.93

2.07 1.91


.0044 .0040

.0047 .0041

.0048 .0043

.0046 .0042

$/Office – Yr3

Level 1 Level2

292.50 264.60

302.85 264.15

309.60 279.45

304.65 277.20


.650 .588

.673 .587

.688 .621

.677 .616


30


20’x 22.5’ Perimeter Open Office Performance Factors






271 256

352 267

407 402

441 440


.60 .57

.78 .59

.90 .89

.98 .98


.908 .875

1.083 .892

1.200 1.192

1.183 1.183


496 514

416 504

375 378

380 380


.0020 .0019

.0024 .0020

.0027 .0026

.0026 .0026

kWpeak2

Level 1 Level 2

2.00 1.84

2.21 1.87

2.30 2.01

2.20 2.02


.0044 .0041

.0049 .0042

.0051 .0045

.0049 .0045

$/Office – Yr3

Level 1 Level2

306.00 279.45

320.85 276.75

331.20 299.25

324.90 297.00


.680 .621

.713 .615

.736 .665

.722 .660


31

Base Case #1.4 20’x 22.5’ Core Open Office

Description: Base Case has (6) 2x4 3” Parabolic 3-lamp Troffers (1.36 W/sf) and no windows or mini-blinds. Nighttime illuminance = 48.9 fc. Surface reflectances are 0.8 ceiling, 0.5 walls and 0.2 floor. Ceiling height is 9’– 0”.



32

Base Case #1.4 20’x 22.5’ Core Open Office Performance Factors

Description All Orientations

CFMpeak

325

CFM/Sq. Ft.

0.722

AC Tons

1.020

Sq. Ft./Ton

441

Tons/Sq. Ft.

.0027

kWpeak

1

2.30

kWpeak/Sq. Ft.

.0051

$/Office - Yr3

331.20

$/Sq. Ft.-Yr2

.736

1 Room peak may not be same as building peak. 2 Based on $0.025/kWh, and $9.50/kW, autosized equipment with average loads

33

Prototype #1.4 20’x 22.5’ Core Open Office

Description: Ceiling height is raised to 16’-6” to add a row of clerestory windows. Approximate minimum cost is $250/Lin. Ft., or $5625. At this price, structure is exposed and painted (not shown), as is the acoustical deck. Using a picture mold, with wall reflectance above this line being 0.80 to match the ceiling, increases wall reflectance. Full matte white/white walls preferred to lower contrast in this very tall space. Electric lighting is 20’ long 2-lamp direct/indirect (mounted 10’-6” above finished floor) and (6) 16W task lights (Nighttime: 0.86 W/sf; 30.8 fc). Automatic photosensor controls override half the ambient lighting when not needed in the daytime ($100 adder). Clerestory glass is 2.8’ high, 50.4 sf (S.C. = 0.38), and overhang cut-off angle is 30o. There are no window treatments. This Prototype is not recommended without an overhang for all orientations except North. While East and West orientations are included in the performance data, normal orientation should be North and South. Two of these core open offices are normally placed side-by-side, one with South-facing glass, the other with North-facing glass, with no center partition to create a 40’ wide open office area. Interior glazing, providing horizontal views outward, is highly recommended (adder over drywall partitioning is $12 to $20/ Sq. Ft.). No additional variants are considered.


34

Prototype #1.4 20’x 22.5’ Core Open Office Performance Factors





CFMpeak

298

301

318

334

CFM/Sq. Ft.

.66

.67

.71

.74

AC Tons

.958

.967

1.000

.967

Sq. Ft./Ton

469

465

450

465

Tons/Sq. Ft.

.0021

.0021

.0022

.0021

kWpeak2

1.95

1.96

1.98

1.97

kWpeak/Sq.Ft.

.0043

.0044

.0044

.0044

$/Office - Yr3

273.15

272.70

278.55

275.40

$/Sq. Ft.-Yr3

.607

.606

.619

.612


Documents

The Cool Daylighting Design Approach Workbook Volume 1 ...€¦ · Simple math is used to compare the net differences in first cost ... Cool Daylighting Design Approach Worksheet