AlllOH IMOObfi NBS

PUBLICATIONS

NAT'L INST. OF STAND & TECHI R.I-C

A 11 10 5 aaTQTl

NBSIR 81-2317

Energy Conservation By Multiple

Glazing on Heavy Masonry

Buildings

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Building Technology

Washington, DC 20234

June 1 981

Prepared for: Office of the Architect of the Capitol

DC 20515

100

. U56

81-2317

1981

c.2

NATIONAL BlIRKAU

Or STANDARDS

LIBHAST

SEP i 6 1981

NBSIR 81-2317 n

ENERGY CONSERVATION BY MULTIPLE

GLAZING ON HEAVY MASONRY

BUILDINGS

E. Thomas Pierce

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Building Technology

Washington, DC 20234

June 1981

Prepared for: Office of the Architect of the Capitol

Washington, DC 20515

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS. Ernest Ambler, Director

2>

C

cs O*
k;x. */'. . * YE -

' ' '

• ... . . • U

: O

; ' -

,

- - < •' •

'
ABSTRACT

The BLAST-2 computer program is used to investigate multiple glazing as a means to reduce the energy consumption of two buildings of the Library of

Congress in Washington, D.C. The Thomas Jefferson Building is of very heavy

masonry construction, and the John Adams Building is of heavy masonry. The

techniques of modeling the building load and air system performance are explained. The results are presented and discussed. Typical perimeter modules of various floors simulated with single, double, and triple glazing are

faced in four compass directions. Similar results are obtained over a range

of models. Application of double glazing will save up to ten percent of heating energy, but not much cooling energy, while maintaining present operating

requirements

Keywords: BLAST (computer program); building energy analysis; energy

conservation for non-residential buildings; historic preservation

and energy conservation; load calculation; masonry thermal mass;

multiple glazing; system simulation.

iii
PREFACE

This report was prepared at the request of the Architect of the Capitol to

the Building Thermal Performance Division, Center for Building Technology,

NBS. Support of the study was a cooperative effort by NBS and the Architect

of the Capitol. The patience and encouragement of Mr. J. Raymond Carroll,

P.E., Director of Engineering for the Architect, are much appreciated. The

staff of the Architect assisted in determining the significant architectural

and HVAC parameters of the buildings studied. Particularly helpful were

Scott Birkhead, Douglas Knowles, Gary Lukas, and Philip Riley.

iv
TABLE OF CONTENTS

Page

ABSTRACT iii

PREFACE iv

LIST OF TABLES vi

LIST OF FIGURES vi

CONVERSION FACTORS TO METRIC (SI) UNITS vii

1. INTRODUCTION 1 2. THE BLAST-2 IMPLEMENTATION 2

2.1 BLAST-2 Model Development 2

2.2 Detailed Descriptions of the Models 2

3. SPECIAL CONSIDERATIONS 4

3.1 Masonry Walls and Thermal Mass 12

3.2 Air Handling Units 12

3.3 Solar Energy through Windows 12

3.4 Radiation Exchange Within Spaces 14

4. RESULTS AND CONCLUSIONS 16

5. REFERENCES 20

v
LIST OF TABLES

Page

Table 1. Windows - Layer and Materials 4

Table 2. Constructions/Applications 7

Table 3. Constructions/Areas 8

Table 4. Constructions/Details 11

Table 3A. Cooling Data (Btu x 10^/yr) 17

Table 5B. Heating Data (Btu x lO^/yr) 18

Table 6. Savings of Heating Energy 19

LIST OF FIGURES

Figure 1 . Typical Space 3

Figure 2. Construction of Attic 5

Figure 3. BLAST-2 Control Strategy 13

vi
CONVERSION FACTORS TO METRIC (SI) UNITS

Physical

Quantity Symbol

To Convert

From To Multiply By

Length { ft m 3.05 x 10-i

Area A ft* m2 9.29 x 10

2 Volume V ft 3 m3 2.83 x 10

2

Temperature T Fahrenheit Celsius t c = (tf-32)/1.8

Temp. Diff. AT Fahrenheit Kelvin K = ( AT p)/1.8

Mass lb kg 4.54 x 10-i

Density P lb/ft 3 kg/m3 1.602 x 10i

Thermal

Conductivity k Btu*in/h’ft 2 '°F W/m-K

%

1.442 x 10-i

Thermal

Transmittance

(or Conductance) U Btu/h • ft 2 * °F W/m2 * K 5.68

Thermal Resistance R h • ft 2 • °F/Btu m2 *K/W 0.176

Heat Flux Rate q/A Btu/h • ft 2 W/m? 3.15

Heat Flow <? Btu/h W 2.93 x 10-i

Volumetric Flow

Rate V ft 3 /min m3 /s 4.72 x 10

4

Velocity V ft/min m/s 5.08 x 10

3

Specific Heat C P Btu/lb * °F J/kg'K 4.19 x 10 3

Permeance perm kg/Pa ’s *m2 5.72 x 10-n

vii

1 . INTRODUCTION

The Architect of the Capitol has requested an evaluation of the effects on energy of the installation of multiple glazing for two buildings of the

Library of Congress. This report is the result.

The Thomas Jefferson Building is the large ornate structure directly east

from the U.S. Capitol. Formerly known as the Main Library of Congress Building, it was completed about 1897. Construction is of heavy brick with stone

facing on the exterior. The lower floors are supported by barrel-arched

brick, while the second floor (the lightest floor herfe considered in this

building) is supported by terra cotta arches supported on iron joist beams.

The dead weight of the floors is estimated to range from 780 kg/m^ (160

lbm/ft^) for the second floor to 2300 kg/m^ (480 lbm/ft^) for the basement.

The masonry walls range up to over 1 .6 m (over 5 ft) in thickness.

The John Adams Building has also been known as the Annex (and was also formerly

called the Thomas Jefferson Building). It was completed in the 1930’s, and

is of rather heavy masonry also, though not nearly as heavy as the Thomas

Jefferson Building. The lower floors are of 8-inch concrete, and the masonry

walls range down to about 0.3 m (about 1 ft) in thickness.

1

fwssw

mtssaB m!*-

Library

of

Congress

—

John

Adams

Building
2 . THE BLAST-2 IMPLEMENTATION

2.1 BLAST-2 MODEL DEVELOPMENT

The effectiveness of storm windows for energy conservation would depend on orientation, space geometry, thermal mass, and Heating, Ventilating, Air Conditioning (HVAC) design. For the present work it was necessary to abstract

from the rather complex real buildings in order to develop a set of simplified models which would adequately cover the range of applicable parameters.

The models developed employ typical perimeter spaces, as shown in figure 1.

The spaces or modules are the depth of the perimeter areas, usually from the

exterior wall to the stack wall; the height is the f loor-to-f loor height, and

the width is that of the typical bay or module for the building considered.

Internal furnishings and live load are simulated as partitions at the sides

of the module, adjusted so as have correct radiation exchange with the exterior wall. As in the real buildings, from two to four of these modules are stacked one above the other. Ten such stacks of modules are served by a model of the appropriate HVAC system. The modules are based on the dimensions and heat flow of the real building, and are intended to cover a range

from the moderately heavy construction of the John Adams fifth floor study

rooms to the very heavy construction of the Thomas Jefferson. Each of four

models is studied with rotation to face in each of four compass directions.

Triple as well as double glazing is compared with the present single glazing,

so as to obtain a greater range of energy effectiveness values.

The four series of computer runs were as follows:

1) Series 300, the two floors of the John Adams Building fifth-floor

study rooms.

2) Series 200, the ground through third floors of the John Adams Buiding.

(There are no windows on the fourth floor.)

3) Series 500, the basement through second floors of the Thomas Jefferson

Building, testing treatment of the courtyard windows.

4) Series 400, the same floors of the Thomas Jefferson Building, backed

up against the book stacks, testing treatment of the exterior windows.

2.2 DETAILED DESCRIPTIONS OF THE MODELS

As mentioned above, single, double, and triple glazings were compared,

and Venetian blinds were used on the John Adams Building. The BLAST-2

implementation of these window treatments is as shown in table 1.

An attic was used above series 300, 400, and 500, as shown in figure 2.

Since the purpose of the attic is only to achieve a file of floor surface

temperatures for use in the zone below, an exact model is not required. The

attic constructions were based on those of the John Adams Building, with 0.5

air changes per hour to simulate infiltration. Note that the room below an

2
PARTITION OR INTERNAL

FURNISHINGS (HEIGHT

INCREASED ABOUT 20 PERCENT)

WINDOW

EXTERIOR WALL

Figure 1. Typical space

3
Table 1 . Windows - Layers and Materials

Window - 1 Windows - 11

Glass Glass

V-Blind

Window - 2 Window - 12

Glass Glass

Air Air

Glass Glass

V-Blind

Window - 3 Window - 13

Glass Glass

Air Air

Glass Glass

Air Air

Glass Glass

V-Blind

BLAST-2 Input Text

UNITS (IN = ENGLISH, OUT = ENGLISH),

GLASS = (GLASS, VERY SMOOTH, R = 0.0236, TRANS = 0.870),

AIR = (AIR, R = 0.91),

V -BLIND = (SHADE, REF = 0.250, TRANS = 0.650).

4
Figure 2. Construction of attic. A.n attic is used to achieve a file

of floor surface temperatures for use in the zone below.

5
attic need not have the same construction for its ceiling as that used for

the attic floor.

Table 2 shows the application of the various weight constructions to the

different series of computer runs, where "weight" means the mass per square

foot of the wall or floor area of the construction except in the case of the

last two entries. For MIDBRICK and MAXBRICK, "weight” is the effective or equivalent thermal storage of the construction for use as an interior surface.

Symbol "E" indicates the construction used in the models of the exterior

walls.

A range of weights is represented, with series 300 having the lightest

constructions. The brick is used as a convenient unit for much of the

masonry. Thus, BRICK-3 represents 12 inches of masonry with a density of

120 lbm/ft^. Concrete-4 and -8, however, indicate thickness in inches.

Table 3 shows these applications of the constructions in greater detail, and

table 4 provides appropriate descriptive parameters as input to BLAST-2.

Detailed understanding of other features of the BLAST-2 models may be best

gained from the text of the BLAST-2 input codes, which are available to those

interested

6
Table 2. Constructions/Applications

Item Weight

(lbm/ft2

) Applications

300 200

(Series)

500 400

Attic — X X X

Venetian Blinds — X X

Gallery Ceiling 0 X X

Annex Study Wall 10 X

Brick-1 Furnishings 40 X X X

Concrete-4 45 X

Annex Stack Wall 65 X

Concrete-8 95 X X X X

Brick-3 120 E

Brick-4 160 E X X

Brick-7 280 E E

Midbrick 320 X X

Maxbrick 480 X X

Symbol E indicates the construction used in the models of the exterior walls

7
Table 3. Constructions/Areas

Constructions, Series 300, John Adams Building

Area

(ft2

) Lower Fifth Floor

51.4

16.6

256 .6

88.8

88.8

Upper Fifth Floor

46.4 Brick-3 Exterior Wall

16.6 Test Window

251.6 Annex Study Walls

88.8 Concrete-4 Floor

88.8 Concrete-4 Ceiling to Attic

Constructions, Series 200, John Adams Building

Area

(ft2

> Construction

Ground Floor

174.1 Brick-4 Exterior Wall

35 .9 Test Window

210.0 Annex Stack Wall

469.0 Concrete-8 Floor

469.0 Concrete-8 Ceiling

1206.0 Brick-1 Furnishings

First Floor

170.1 Brick-4 Exterior Wall

39.9 Test Window

210.0 Annex Stack Wall

469.0 Concrete-8 Floor

469.0 Concrete-8 Ceiling

1206.0 Brick- Furnishings

Second Floor

172.0 Brick-4 Exterior Wall

38.0 Test Window

210.0 Annex Stack Wall

469.0 Concrete-8 Floor

469.0 Concrete-8 Ceiling

1206.0 Brick- 1 Furnishings

Construction

Brick-3 Exterior Wall

Test Window

Annex Study Walls

Concrete-8 Floor

Concrete-4 Ceiling
Table 3. Constructions/Areas (Continued)

Constructions, Series 200 (Continued)

Third Floor

Area

(ft2

) Construction

200.0 Brick-4 Exterior Wall

38.0 Test Window

238.0 Annex Stack Wall

469.0 Concrete-8 Floor

469.0 Concrete-8 Ceiling

1206.0 Brick-1 Furnishings

Constructions, Series 500, Thomas Jefferson Building

Area

(ft2

) Construction

Basement

176.7

23.4

176.7

23.4

507.5

507.5

1162.0

First Floor

254.5

50.0

25 4.5

50.0

507.5

507.5

1764.0

Second Floor

387.0

48.0

387.0

48.0

507.5

507.5

25 20.0

Brick-7 Courtyard Wall

Test Window

Brick-7 Exterior Wall

Double-Glazed Window

Maxbrick Floor

Midbrick Ceiling

Brick-1 Furnishings

Brick-7 Courtyard Wall

Test Window

Brick-7 Exterior Wall

Double-Glazed Window

Midbrick Floor

Brick-7 Ceiling

Brick-1 Furnishings

Brick-7 Courtyard Wall

Test Window

Brick-7 Exterior Wall

Double-Glazed Window

Brick-7 Floor

Gallery Ceiling to Attic

Brick-1 Furnishings

9
Table 3. Constructions/Areas (Continued)

Constructions, Series 400, Thomas Jefferson Building

Basement

First Floor

Second Floor

Area

(ft2

) Construction

176.7 Brick-7 Exterior Wall

23.4 Test Window

200.1 Brick-7 Stack Wall

507.5 Maxbrick Floor

507.5 Midbrick Ceiling

1162.0 Brick-1 Furnishings

254.5 Brick-7 Exterior Wall

50.0 Test Window

304.5 Brick-7 Stack Wall

507.5 Midbrick Floor

507.5 Brick-4 Ceiling

1764.0 Brick-1 Furnishings

387.0 Brick-7 Exterior Wall

48.0 Test Window

435.0 Brick-7 Stack Wall

507.5 Brick-4 Floor

507.5 Gallery Ceiling to Attic

2520.0 Brick-1 Furnishings

Constructions, Attic

Area

(% re floor) Construction

Attic for Series 400, 500

109.0

11.5

100.0

Attic for Series 300

109.0

11.5

100.0

Roof

Brick-1 Gables

Concrete-8 Floor

Roof

Brick-1 Gables

Concrete-4 Floor

10
Table 4. Constructions/Details

BLAST--2 Symbols L K CP D

Btu Btu lbm

Units (ft) ( h*ft*°F ) ^lbm»°F^

( ft3

Annex Study Wall, Series 300

Cork .0417 .024 .38 22

Sheet Metal .0052 26.200 .12 489

Cork .1458 .024 .38 22

Sheet Metal .0052 26.200 .12 489

Cork .0417 .024 .38 22

Annex Stack Wall, Series 300

Plaster .0833 .417 .20 116

Clay Tile .3333 .330 .20 70

Airspace (R = 0.91) — — — —

Clay Tile .3333 .330 .20 70

Plaster .0833 .417 .20 116

Roof, Attic

Sheet Copper .0052 227.000 .09 556

Nailing Concrete .2083 .096 .20 40

Concrete .2500 1.000 .20 140

Cork .1458 .024 .38 22

Single-Layer Constructions

Gallery Ceiling (R = 0.07) — — — —

Brick-1 .3330 .420 .20 120

Concrete-4 .3330 1.000 .20 140

Concrete-8 .6667 1.000 .20 140

Brick-3 1.0000 .420 .20 120

Brick-4 1.3330 .420 .20 120

Brick-7 2.3330 .420 .20 120

Midbrick 1.3330 .420 .40 120

Maxbrick 1.3330 .420 .60 120

11
3. SPECIAL CONSIDERATIONS

3.1 MASONRY WALLS AND THERMAL MASS

The modeling of masonry walls requires thickness for both thermal resistivity

and thermal storage. The algorithms within BLAST-2 are able to calculate the

performance of only about two feet of masonry, but the thermal storage may be

augmented by increasing either the density or specific heat of the simulated

masonry used in the model. Selecting masonry for the model is further complicated by voids and sources of heat gain or loss within the wall, and by the

curved paths for heat flow around windows.

BLAST-2 employs a one dimensional model for exterior envelope components such

as walls and windows. This parallel heat-flow model does not provide for the

curving paths of heat flow through the masonry around the windows. The path

length or effective thickness is different from the real wall thickness.

Voids or chases within the wall carry supply air, as well as steam, hot water,

and chilled water for supply to induction unit booster or reheat coils. These

voids thus represent further deviations from a parallel heatflow model, as well as sources of heat gain or loss within the masonry.

Each of these considerations was a factor in developing the detailed

constructions for the models, as described below.

3 .2 AIR HANDLING UNITS

The simulted HVAC system for each of the four modeling series was based on

the BLAST-2 implementation of the systems in the real building. Thus real

primary air quantities and temperatures were simulated, with appropriate

modifications for BLAST-2 limitations such as lack of booster cooling coils,

so as to achieve the proper energy results. Figure 3 shows the BLAST-2 control strategy used. The cold deck temperature is manually reset so as to

maintain a space temperature between 70 and 72°F, as required by the books,

and large heating and cooling capacities assure that the space temperature

is held in that range.

The proper outside air quantity is established by the BLAST-2 exhaust air

volume; supply fan pressure is reduced and cold deck temperature is raised

where supply air volumes must be increased over those of the real systems.

3.3 SOLAR ENERGY THROUGH WINDOWS

Since the subject of this study is energy and storm windows, we also asked

if the reduction of solar energy associated with Venetian blinds might be a problem. Annual runs were performed for a south-facing window with single,

double, and triple glazing, using the Typical Meteorological Year (TMY)

weather file. Two cases were compared: 1) no blinds, and 2) closed

light-weight Venetian blinds (light-colored).

12
Figure 3. BLAST-2 control strategy

Cold deck is manually reset to maintain space temperature. The control

strategy establishes the control profile for the loads calculation. Between

the control temperatures, the capacity is 1.08 (AT) CFM, (UNITS = ENGLISH).

13
The conclusion was that the percentage savings of energy by storm windows are not significantly affected by the presence or absence of the blinds, as long

as there is uniformity among the runs compared. There is, of course, more heating and less cooling energy needed when the blinds are closed.

We chose to have Venetian blinds on the John Adams Building and not on the

Thomas Jefferson Building, as consistent with their projected future occupancies. The Thomas Jefferson Building is in the process of restoration for use,

in part, as a museum.

3.4 RADIATION EXCHANGE WITHIN SPACES

BLAST-2 calculates an energy balance for each hour, which includes the

radiation exchange among the various boundary surfaces of an analysis zone. Owing to the massive constructions of the library buildings, as well as to

the substantial thermal mass of interior furnishings and books, it was desired that most of the exchanged radiation be kept within the space and

away from building exterior surfaces.

The simplified view factor for radiation from surface 1 to surface 2 is

defined in BLAST-2 as

F

12

(area of surface 2)

(total area of surfaces seen by surface 1)

For a cube, this equation is exact, with a view factor F = 0.2 for the

radiation between any two surfaces of the cube, and it is less exact for

other geometries. To assure that no more than 20 percent of interior radiation is calculated to fall on an exterior surface, the total area of interior

surfaces must be five times that of the exterior surface area.

The solar radiation that is received through windows in some energy analysis

programs is distributed uniformly over the surfaces of an analysis zone. This creates a problem when lightly insulated buildings are modeled as a single space. In such a case, where most of the surfaces are exterior, a substantial portion of the solar radiation is placed on the inside of the

exterior surfaces, and then leaves the space during the current hour, without

having the proper effect on the calculated heating or cooling load. The "fix"

adopted in BLAST-2 is to throw 80 percent of the solar radiation onto the

floor surface, and to spread the other 20 percent on the other surfaces.

A third element of the radiation exchange in BLAST-2 is found in what happens

when energy falls on an interior surface. As with an exterior surface, the

surface flux and heat transfer are determined by the conduction transfer functions (CTF) and by the other-side surface temperature. This other-side temperature is the current-hour inner-side surface temperature. Thus, when

80 percent of the solar radiation falls on the floor, the floor may have an excessively raised temperature, but incorrect heat transfer through the floor

should not be a difficulty. The thing to watch out for is excessive radiation

exchange with the exterior envelope of the building, as affected by the view

factors

14
The above aspects of the energy balance and radiation exchange were considered important in developing the BLAST-2 models, and were implemented

in our analysis as follows: 1) the BLAST-2 source code was modified and

recompiled to reduce the floor-surface fraction of solar radiation from 80

percent to 50 percent; 2) interior furnishings were modeled as extra interior

surfaces, to provide additional thermal mass for heat storage, and to assure

that the radiation to exterior surfaces was not excessive; and 3) programcalculated view factors were compared with what they should have been, again

to assure reasonable quantities of radiation exchange. In terms of the model

shown above in figure 1, this means that the side partitions of the module

are made about 20 percent greater in height than the real f loor-to-floor

height.

15
4. RESULTS AND CONCLUSIONS

Table 5 shows the heating and cooling results. Although there is some variation, the results are relatively uniform over the four compass directions. The effects on cooling energy of the storm windows are small, as is

to be expected. Table 6 summarizes the heating data for single and double

glazing and gives two measures of the effectiveness of double glazing: the

percent of heating energy saved, and the savings per square foot of window.

The purchase of storm windows probably cannot be justified solely on the

basis of the cost of the energy alone. For example, if we use simple payback

analysis of the heating energy savings for the 200 series, with distillate

fuel at $7.05 per 10^ Btu [1], and with storm windows at $5.93 per square

foot [2], the payback period is thirteen years. However, with 40 percent

indoor relative humidity, storm windows would greatly reduce the condensation

of water during cold periods.

16
3MS3CO

SZWS:

Table 5A Cooling Data (Btu x 10^/yr)

S

Single Double Triple Double Triple

Glazed Glazed Glazed Saves Saves

Series 300

234.8 233.7 233.0 1.1 1.8

235.4 234.3 233.6 1.1 1.8

237.0 236.0 235.2 1.0 1.8

232.6 231.6 231.1 1.0 1.5

Series 200

725.9 717.3 711.0 8.6 14.9

742.5 733.2 725.4 9.3 17.1

760.1 749.6 740.3 10.5 19.8

691.1 685.7 681.4 5.4 9.7

Series 500

853.3

942.1

939.3

873 .3

856.0 851.7 -2.7 1.5

945.0 939.2 -2.9 2.9

940.7 933.9 -1.4 5.4

878.6 875.5 -5.3 -2.2

Series 400

S 819.0 824.3 820.0 -5.3 -1.0

W 824.7 827.1 821.5 -2.4 3.2

E 843.4 844.9 838.0 -1.5 5.4

N 770.2 776.2 774.1 -6.0 -3.9

17
tZjMSSW

2!M

5

Cfl

25M

£]

</>

25M

Table 5B Heating Data (Btu x 10^/yr)

Single Double

Glazed Glazed

Series 300

S 512.5 495.8

524.6 507.3

521.5 504.2

537.9 520.4

Series 200

917.9 823.4

991.3 890.6

983.4 883.1

1033.4 930.7

Series 500

874.0 817.7

903.5 845.8

903.2 845.1

867.6 810.5

Series 400

699.7 650.9

735.2 679.5

734.8 679.4

743.9 687.1

Triple Double Triple

Glazed Saves Saves

491.3 16.7 21.2

502.4 17.3 22.2

499.4 17.3 22.1

515.0 17.5 22.9

796.1 94.5 121.8

858.9 100.7 132.4

851.3 100.3 132.1

898.0 102.7 135.4

799.9 56.3 74.1

825.8 57.7 77.7

825.0 58.1 78.2

791.2 57.1 76.4

636.6 48.8 63.1

661.8 55.7 73.4

661.4 55.4 73.4

669.0 56.8 74.9

18
Table 6 Savings of Heating Energy

Series

300

Single Glazed,

Btu x 1()6

2096.5

Double Glazed,

Btu x 1()6

2027.7

Savings,

Btu x 1()6

68.8

Savings,

Btu x 10^/ft^

of Windows

.0519

Savings,

Percent

3.28

Series

200

Series

500

Series

400

3926.0 3548.3 2913.6

3527.8 3319.1 2696.9

398.2 229.2 216.7

.0656 .0472 .0446

10.14 6.46 7.44

19
5 REFERENCES

1. Federal Register , Federal Energy Management and Planning Programs;

Methodology and Procedures for Life Cycle Cost Analysis (Average Fuel

Costs), Vol. 45, No. 209, October 27, 1980.

2. Knowles, Douglas, Personal communication of quotation he had received

for acrylic inside storm window panels. Date of quotation was April 29,

1980.

20
NBS-114A (REV. 2-80

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 81-2317

2. Performing Organ. Report No 3. Publication Date

August 1981

4.

TITLE AND SUBTITLE

5. ENERGY CONSERVATION BY MULTIPLE GLAZING ON HEAVY MASONRY BUILDINGS

AUTHOR(S)

E. Thomas Pierce

6.

PERFORMING ORGANIZATION (If joint or other than NBS, see instructions)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

S. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP

Office of the Architect of the Capitol

Washington, DC 20515

10. SUPPLEMENTARY NOTES

[22] Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bi bl iography or literature survey, mention it here)

The BLAST-2 computer program is used to investigate multiple glazing as a means to

reduce the energy consumption of two buildings of the Library of Congress in Washington, D.C. The Thomas Jefferson building is of very heavy masonry construction,

and the John Adams building is of heavy masonry. The techniques of modeling the

building load and air system performance are explained. The results are presented

and discussed. Typical perimeter modules of various floors simulated with single,

double, and triple glazing are faced in four compass directions. Similar results

are obtained over a range of models. Application of double glazing will save up

to ten percent of heating energy but not much cooling energy while maintaining

present operating requirements.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

building energy analysis; energy conservation for non-res idential buildings; historic

preservation and energy conservation; load calculation; masonry thermal mass; system ——

imu. 13. AVAIL

Unl imited

[_ J For Official Distribution. Do Not Release to NTIS

[” j Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

jX^Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

15. Price

$6.50

U SCOMM-DC 6043-P 80
;