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NATIONAL BUREAU OF STANDARDS REPORT

CAPACITY TESTS OF FIVE REMOTE AIR-COOLED

REFRIGERANT CONDENSERS

Manufactured by

Dunham-Bush, Inc.

West Hartford, Connecticut

Mechanical Engineering Division

Quartermaster Research and Engineering Command

Natick, Massachusetts

V

7760

R. J. Dockery and C. W. Phillips

to

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
THE NATIONAL BUREAU OF STANDARDS

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NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

1003-20-10435 November 30, 1962 7760

CAPACITY TESTS OF FIVE REMOTE AIR-COOLED

REFRIGERANT CONDENSERS

Manufactured by

Dunham-Bush* Inc.

West Hartford* Connecticut

by

R. J. Dockery and C. W. Phillips

Mechanical Systems Section

Building Research Division

to

Mechanical Engineering Division

Quartermaster Research and Engineering Command

Natick* Massachusetts

NATIONAL BUREAU OF STANf

Intended for use within the Gov

to additional evaluation and revlt listing of this Report, either in w

the Office of the Director, Natlor however, by the Government age

to reproduce additional copies fi

IMPORTANT NOTICE

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST)

on October 9, 2015.

ress accounting documents

!y published it is subjected

eduction, or open-literature

is obtained in writing from

h permission is not needed,

jared if that agency wishes

<NBS>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
.

.
CAPACITY TESTS OF FIVE REMOTE AIR-COOLED

REFRIGERANT CONDENSERS

Manufactured by

Dunham-Bush, Inc.

West Hartford, Connecticut

by

R. J. Dockery and C. W. Phillips

1.0 INTRODUCTION

This report presents results of tests of five remote

air-cooled refrigerant condensers, of three sizes and four

classes listed in, ’’Purchase Description, Condensers,

Air-Cooled, for use with Dichlorodifluoromethane (F-12),"

dated March 22, 1957- AH five were manufactured by

Dunham-Bush, Inc., West Hartford, Connecticut. All were

constructed with tubes containing the Company’s patented

”Inner-Fin.

The five condensers were:

Specimen No. 1.

Specimen No. 2.

Specimen No. 3.

Specimen No. 4.

Specimen No. 3.

Size B Class 4 Steel Tubes, Steel Fins

NBS Test No. 170-58

Size B Class 3 Aluminum Tubes, Aluminum

Fins NBS Test No. 166-58

Size B Class 2 Copper Tubes, Copper Fins

NBS Test No. 159-58

Size C Class 1 Copper Tubes, Aluminum Fins

NBS Test No. 140-57

Size A Class 1 Copper Tubes, Aluminum Fins

NBS Test No. 138-57

- 2 -

1 . 1 BACKGROUND

The performance evaluations of condensers discussed in

this report represent a resumption in July 1961 of a study

started in 1957 and interrupted for fiscal reasons in 1959.

Apparatus designed and constructed specifically for this

work was originally patterned after a proposed ASRE Standard PS

2.4. During the time the project was. inactive* the proposed

ASRE Standard PS-2.4 was modified and adopted as ASHRAE

Standard 20-60* ’’Methods of Testing for Rating Remote

Mechanical-Draft Air-Cooled and Evaporative Condensers.”

It should be noted that ASRE (American Society of Refrigerating Engineers) and ASHAE (American Society of Heating

and Air Conditioning Engineers) merged in 1959 to form

ASHRAE (American Society of Heating* Refrigerating and

Air Conditioning Engineers). The primary change between

ASRE PS-2.4 and ASHRAE Standard 20-60 affecting this test

series was the substitution of a low side refrigerant

calorimeter for the air-side psychrometric measurement of

heat rejection. In reactivating the project* the airside psychrometric measurement was retained* and the

original test system evaporator was modified- to function

as a low-side refrigerant calorimeter. For some tests

a separate low-side refrigerant calorimeter was used. The

use of a turbine-type electric flowmeter for determination

of the electronic rate of liquid refrigerant flow was

retained.

Neither ASRE PS-2.4 or ASHRAE Standard 20-60 established

requirements for minimum or maximum subcooling of the liquid

refrigerant leaving the condenser. Failure to control the

degree of subcooling to as low a positive value as possible*

and certainly failure to condense completely will result In

unsuitable comparisons of different test condensers. All

tests in both the prior and present series were made with

condensation of all of the refrigerant (indicated by a

sight glass at the condenser outlet) and with subcooling

less than five degrees F in most cases and less than

10.5°F in all cases.

ASRE PS-2.4 included Standard Rating Conditions* ASHRAE

Standard 20-60 does not. QMR&E Purchase Description dated

22 March 1957 entitled ’’Condensers* Air-Cooled for Use with

Dichlorodifluoromethane (F-12)” set forth the following

capacity requirements* at an entering refrigerant

saturation temperature of 135 °P and 25 °E temperature

-3-

difference between the entering air (110°F) and entering

saturation refrigerant temperature (135°F) for the four

series of condensers?

Size A 22,300 Btu/hr (Min.

Size B 35,600 « Btu/hr (Min.

Size C 46,000 Btu/hr (Min.

Size D 57,000 Btu/hr (Min.

Capacities have also been determined at the following

conditions as suggested in ASRE PS-2.4.

High Rate Low Rate

Dry bulb temperature of air

entering unit

Wet bulb temperature of air

entering unit

Dry bulb temperature of ambient

air

Saturation temperature of dry

vapor entering condenser

Actual temperature of dry

refrigerant vapor entering

condenser

95°F

75°F ±5°F

95 °F

130°F

95 °F

75 °F ±5°F

95 °F

105 °F

195 °F ±10°F 170°F ±10°F

Other relevant document changes occurring since the

original implementation of these tests include Military

Specification MIL-C-23122, ’’Military Specifications for

Condensers, Air Cooled, Refrigerant-12” adopted December

27, 1961, and proposed Military Standard ’’Condensers, Air

Cooled, Refrigerant.” (FSC 4130)

2.0 TEST APPARATUS AND PROCEDURES

The test apparatus and procedures used were similar

to those used for tests previously reported in NBS Reports

6378> 6401, 6420, and 6670, except as modified to conform

generally to ASHRAE Standard 20-60, ’’Standard Methods of

Testing for Rating Remote Mechanical-Draft Air-Cooled or

Evaporative Condensers.”
!
Tests were run in general conformance with requirements

of ASHRAE Standard 20-60. A few points of non-conformance

are discussed.

1. The requirement in Section 4-2 of ±0.1 °F accuracy of

of absolute temperature measurements is unrealistic for

normal laboratory-quality measuring systems. ±0.2°F

is more realistic and test results reported were based

on measurements approaching this degree of accuracy.

2. ASHHAE Standard 20-60 requires two simultaneous

measurements of refrigerant flow rate as the means for

determining performance. Tests reported here compare

a psychrometric "air-side" measurement with a simultaneous

refrigerant flow measurement. On each run at least these

two independent determinations of capacity were made.

On some of the runs, the evaporator in the test circuit

was adapted and instrumented to serve as a low-side

refrigerant calorimeter to provide a third measurement,

and a direct comparison with the turbine-type liquid

refrigerant flowmeter determination was made in all runs.

3. ASHHAE Standard 20-60 does not establish requirements

for maximum or minimum subcooling of the liquid

refrigerant leaving the test condenser. In fact only

by inference does it require that all refrigerant

vapor entering the condenser must be condensed. Tests

reported were all run with minimum positive subcooling.

The desired subcooling was controlled by means of ah

adjustable flow valve at the receiver inlet.

The three independent measuring systems can be described

briefly.

1. Air-side or Psychrometric. The test condenser was

mounted in one end of an insulated air duct apparatus

installed in a test room with ambient temperature and

humidity controlled at the specified condenser

entering air conditions. The air was drawn through

the condenser by a selected fan discharging at

atmospheric pressure in a chamber large enough to

simulate free discharge. The air was drawn out of

this chamber through a long radius nozzle by means of

an auxiliary blower which discharged into the surrounding

room temperature and humidity controlling apparatus.

Condenser heat rejection capacity was determined by

measuring air quantity and enthalpy change and correcting

for fan motor energy input.

- 5

-

2. Liquid Refrigerant Flowmeter. The subcooled condensed

liquid refrigerant was metered by means of a totalizing

(integrating; turbine-type flowmeter and heat rejection

capacities were determined from refrigerant mass flow

and enthalpy change.

3. Low-side calorimeter. Liquid refrigerant flow was

determined by means of measurement of the enthalpy

change in the refrigerant and the energy (heat)

required to evaporate the refrigerant in an Insulated,

metered, electrically heated evaporator using one or

the other of two low-side calorimeters. The first was

the original tube-type evaporator equipped with immersion

electric heaters, modified to operate as a dry system

iprimary calorimeter by installing electric energy

meters, thermocouples, and better insulation. Although

this calorimeter was generally satisfactory for the

larger size condensers producing liquid refrigerant

flow rates greater than about 8.0 lbs/min. its overall accuracy was not considered suitable for useful

comparison. For smaller flow rates a secondary

refirgerant calorimeter constructed for a previous

study was used, and results are given for the one

Size A condenser included in this report.

Figures 1 through 8 show certain features of the

test apparatus and instrumentation.

Figure 1. Schematic drawing of complete measuring

apparatus

.

Figure 2. Inclined gauges and manometers for air

pressure measurements, totalizing counter

for refrigerant liquid flowmeter, barometer,

hot and cold temperature reference baths.

Switch box (lower left) controlled

position of auxiliary blower inlet damper.

Figure 3, Wet and dry-bulb thermocouple grid at

test condenser air inlet.

Figure 4. Auxiliary blower (left) and inlet damper

control motor. Blower is at exit end of

air duct apparatus.

- 6

-

Figure 5.

Figure 6.

Figure 7.

Figure 8.

Condensed refrigerant liquid line

leaving test condenser (right). Pressure

tap (right), sight glass (center) and

thermocouple well (left) and part of

measuring system for determining temperature

and degree of subcooling of leaving refrigerant liquid.

Test system refrigerant pressure gauges

and precision galvanometer type potentiometer.

Instruments for measurement of electric

energy, current and voltage, and relative

humidity.

.

Components of condenser test circuit including

compressor, vertical liquid receiver, primary

dry system calorimeter evaporator (in plywood enclosure, top), and various

accessories for controlling and measuring

refrigerant temperatures, . pressures and flow.

•Two pressure gauges (center) indicate

pressure drop across liquid line flowmeter (s)

directly above gauges.

Figure 9* Secondary refrigerant calorimeter.

The vertical liquid receiver shown in Figure 8 was

located near an outside door and during cold weather was

influenced by frequent and excessive changes in ambient

temperatures not experienced during .earlier tests. These

temperature changes interfered with control of subcooling

A water coil was formed around the receiver, with water

flow controlled by receiver refrigerant pressure and the

entire assembly insulated as shown in Figure 8, eliminating

the effect of ambient temperature changes. Water-cooling

the receiver also facilitated pump down of the refrigerant

when changing test condensers.

Additional details concerning apparatus will be found

under "Data and Results."

-7-

3.0 DATA AND RESULTS

Each condenser coil was studied at three different

sets of standard conditions as previously described. Each

test required control of refrigerant inlet temperature and

pressure,, air inlet temperature and pressure, air outlet

pressure and refrigerant subcooling. Although each condenser was supplied with its own fan, and fan motor, tests

were made using a selected military standard fan, and fan

motor conforming to the fan air delivery vs. static

pressure requirements of the purchase description. Figure

10 shows the three fan types and two motors used for the

series.

Figure 11 shows the typical construction of the tube,

"Inner-Fin, " and fin assembly used in all of the condensers

covered by this report. Refrigerant passage is through

the spirally-wound accordian-pleated "Inner-Fin." The

center tube is closed to refrigerant flow. Materials

and dimensions vary as reported. Note the cut raised

sections in the external fins.

Figure 12 is a pressure-enthalpy diag'ram for dichlorodifluoromethane on which the three sets of rating conditions

are shown. Symbols used in the tables of test results are

identified on this diagram.

Photographs and drawings of the five specimen condensers are shown in Figures 13 to 24. Dimensional and

material data and test results are summarized in Tables 1

to 10.

In each table of test results. Items 1 . through 6

are specified test conditions and the corresponding

observed conditions. Items 7 and 8 are performance

observations based on air-side measurements. Items 13

through 23 are ratings derived from both sets of

measurements. Two additional ratings. Items 24 and 25

are given separately for further comparison. They ares

Item 24 Btu per (sq.ft.) (°F) (Hour)

Item 25 Btu per (sq.ft.) (°F) (CFM) (Hour

- 8 -

wheres

sq.ft. = total surface area of the condenser

°F ss log mean temperature difference, refrigerant

to air

CFM = air flow rate

Items 1 through 12, 17, and 18 are observed test

results, corrected for gauge calibration, etc. Items 13

through 16 and 19 through 25 are values which have been

converted from observed test conditions to standard

conditions. Item 14 "Condensing Heat Rejection" includes

desuperheating of the inlet refrigerant. Where a zero

appears in Item 15, the adjusted average value for total

capacity was the same or slightly smaller than condensing

heat rejection as determined from refrigerant flow rate.

Specimen #1, a Size B Class 4 condenser, NBS No. 170-58

was the first unit tested following reactivation of the

test apparatus. Figure 13 is a view of thisv condenser which

had steel tubes and fins, and the tubes contained the

patented "Inner-Fin" made of aluminum. Figure 14 and Table

1 give the dimensional data, and Table 2 gives the test

results for this condenser. In Figure 14, the black tube

connections on the right side view designated tubes which

connect into headers, the clear tube connections are return

bends and do not connect to the headers.

During the collection of these data, a difference in the

degree of liquid refrigerant subcooling between the outlet conditions as observed at the sight glass and as shown

by the pressure temperature relationship was noted. Bubles

appeared in the sight glass where the instruments indicated

a degree or' two of subcooling. The instruments were

checked and the temperature measuring station was relocated

with relation to the sight glass as it was thought that this

might be causing some disturbance. The difference persisted

but because it was slight, nothing more was done at this

time. Later in this test series, the discrepancy was found

to be caused by lack of adequate mixing of the vapor and

liquid leaving the different parallel circuits.

-9-

Specimen #2, was a Size E Class 3 all-aluminum condenser.

It was equipped with an aluminum patented "Inner-Fin .

Figure 15 is a view of this specimen, NBS No. 166-58, with

shroud removed. Coil has been cut at lower left for tube

and fin examination.

The fin bond on this coil seemed to be poor compared

with others in the series.

Figure 16 and Table 3 give dimensional data for

Specimen #2, and Table 4 presents the test results.

Specimen #3 was a Size B Class 2 condenser with copper

fins and copper tubes. It is equipped with a copper

"Inner-Fin." Figure 17 is a view of this condenser, NBS

No . 159-58

.

Figure 18 and Table 5 present dimensional characteristics, and Table 6 gives the test results for Specimen #3 . Specimen #4 was a Size C Class 1 condenser, NBS No.

l40-57j with aluminum fins and copper tubes with aluminum

"Inner-Fin" construction. Figure 19 is a view of this

condenser. Figure’ 20 shows the condenser in place in the

rack designed to position it in the test apparatus, and

Figure 21 shows the entering air face of the coil.

Figure 22 and Table 7 shows the dimensions and Table 8

gives test results of Specimen #4. It will be noted in the

table that two separate tests, on different dates, were

made at the ASRE High Saturation Temperature, both with free

air discharge. Ability of the test apparatus to repeat is

shown by the 2.9 percent agreement for the two air side

determinations, 1.6 percent for the refrigerant side

determination, and 0.14 percent agreement between the two

total heat • re jection ratings. Other similarities can be

seen in Table 8.

Specimen #5 was a Size A Class 1 condenser, NBS No,

138-57 with copper tubes, aluminum fins, and an aluminum

"Inner-Fin" in the tubes. Figure 23 shows this specimen.

Figure 24 and Table 9 give dimensional data and Table 10

presents the test results for Specimen #5 . These test

results were affected by partial restriction at the condenser

inlet. See later discussion.

- 10-

In Table 10 two values are shown for Items 9 and 12 for

each of the three tests reported. The numbers to the left of

each main column represent the refrigerant flow rate and

total heat rejection capacity for Items 9 and 12 respectively*

as determined by the low side secondary refrigerant calorimeter

shown in Figure 9 . Items 9 and 12 in the main column for

each test were derived from the refrigerant liquid turbinetype flowmeter. The agreements obtained between flow rates

determined by the two methods were 2.0* 2.0* and 0.5 par

cent for the three tests. Specimen #5 was the only condenser

of the five in this report for which the secondary refrigerant

calorimeter values were obtained. The liquid refrigerant

flowmeter was used for all tests here reported.

Examination of the condenser following the completion of

the test series showed that the two inlet tubes were partially

restricted by foreign material at the inlet face of the inner

fin. Consequently* these test results should not be considered

representative of those for a similar condenser with no such

restriction.

The foreign material was probably introduced into this

condenser when it was being used at the outset of the test

series to check the performance of the test system. Burnout

of an electric- immersion heater in the system evaporatorcontaminated the system. The condenser was removed and the

system cleaned at that time and the condenser was not tested

until the second part of the test series. The restriction

at the inlet tube was not discovered until the test apparatus

was being dismantled* which prevented running comparative

tests of another specimen of the same type and size.

The effect of the restriction on the capacity is not

known. A previous experience in this test series involving

two Size B condensers also manufactured by Dunham-Bush* Inc.*

one partially restricted* the other clean* was reported

earlier in NBS Report 6378. The difference in capacity at

the QMR&E High Ambient Temperature Conditions for those two

condensers was about 7 per cent.
I
- 11 -

For the Size A condenser in the current test series, the

condenser coil internal pressure drop. Item 10, for the

QMR&E High Ambient Temperature Test was 7.7 psi as shown in

Table 10. There is, of course, some pressure drop for any

condenser, but if it is assumed ideally that all or most

of this observed pressure drop occurred at the inlet

restriction, the refrigerant saturation temperature in the

coil would have been 132°F instead of the 135 °E design

test conditions. With air entering the condenser at 110°F

assuming that neither tube was completely blocked, the

probable capacity reductions can be approximated by the

relationship

:

1 - A32 - 110)- 0.13 or 13#

V135 - 110/

If one of the two tubes was completely blocked, the capacity

reduction was probably more than this amount and less than

50 per cent. It did not appear that either tube was

completely blocked but the first row (in direction of air

flow) contained more foreign material than the second. In

considering these assumptions it must be remembered that

the subcooling of the refrigerant liquid leaving the condenser was controlled at a minimum value as a part of the

test conditions.

COMPARISON OF SEVEN DUNHAM BUSH- CONDENSERS

Table 11 shows the total heat rejection capacity for

seven Dunham-Bush condensers (including two Size B condensers

previously reported in NBS Report 6378. Also shown is the

percent of QMR&E requirement (22,300, 35*600, and 46,000

BTUH for Sizes A, B, and C respectively) for the QMR&E

High Ambient Temperature Test.

“ 12-

TABLE 11

TOTAL HEAT REJECTION OF SEVEN DUNHAM-BUSH CONDENSERS

Condenser Class Size TOTAL HEAT REJECTION, BTUH

NBS No,

ASRE High

Satfn Temp.

ASRE Low

Sat*n Temp.

QMR&E

High Amb.

3* QiMR&E

Req ? mnt

138-57a 1 A 21480 6190 16120

f 72

l39-57a * b 1 B 39400 10600 30100 85

155-58b 1 B 45000 — 32100 90

159-58 2 B 41010 8430 29890 84

166-58 3 B 47940 7170 32810 92

170-58 4 B 38990 8730 ' 27830 78

140-57 1 C 55490 9665 37950 83

a. Foreign material in condenser inlet during tests

b. Previously reported in NBS Report 6378.

-13-

Table 12 lists the Heat Transmission Coefficient, BTUH per

Ft 2

( °F log mean temperature difference), (item 24 in Tables of

Test Results), for the seven Dunham-Bush condensers.

TABLE 12

HEAT TRANSMISSION COEFFICIENT OF SEVEN DUNHAM-BUSH CONDENSERS

Condenser ASRE High ASRE Low QMR&E

NBS No. .Class Size: Sat'n Temp. Sat ' n Temp. High Ambient

Trans. Air Trans. Air Trans. Air

Coeff

.

Face Coeff. Face Coeff. Face

BTUH/ Vel

.

BTUH/ Vel BTUH/ Vel.

ft 2 (°F) FPMC ft 2 fP) -FPMC ft 2 (°F) FPM°

138-57a 1 A 5.03 540 5-32 555 5.30 585

139-57ajb

1 B 5.01 660 4.67 ' 655 5.42 655

155-58® 1 B 5.84 660 -- — 6.00 655

159-58 2 B 5.54 720 4.67 710 5.84 720

166-58 3 B 6.87 675 3-22 685 6.54 690

170-58 4 B 5.18 695 4.15 690 5.46 665

140-57 1 C 4.62 545 3.05 545 4.35 535

a. Foreign material in condenser Inlet during tests.

b. Previously reported In NBS Report 6378

c. Based on CFM at Test Conditions (item J, Tables of Test Results)

-14

Table 13 gives the Heat Transmission Coefficient* BTUH per

Ft* ( °F log mean temperature difference) (CFM)* (item 25 in

Tables of Test Results) for the seven Dunham-Bush condensers

TABLE 13

HEAT TRANSMISSION COEFFICIENT OF SEVEN DUNHAM-BUSH CONDENSERS

Condenser

NBS No. Class. Size Coefficient* BTUH Per Ft 2

( °F log Mtd) ( CFMc

) ASRE High ASRE Low QMR&E

Sat^n Temp. Sat'n Temp. High Amb.

138-57a

1 A 0.00302 Q. 00312 0.00313

139-57a ' b

1 B .00146 .00135 .00162

155-58b

1 B . 00170 N. . 00183

159-58 2 B .00149 . 00125 .00163

166-58 3 B .00192 . 00088 .00187

170-58 4 B .00145 .00114 .00162

140-57 1 C .00127 . 00083 .00122

a. Foreign material in c ondenser inlet during tests.

b. Previously reported in NBS Report 6378

c. Based on standard air* (item 16 in Tables of Test Results)
I
-15-

Table l4 presents the Heat Transmission Coefficient, BTUH

per Ft^ ( °F log mean temperature difference) (FPM entering air

face velocity)

.

TABLE 14

HEAT TRANSMISSION COEFFICIENT OF SEVEN DUNHAM ^BUSH CONDENSERS

Condenser

NBS No. Class Size Coefficient, BTUH Per Ft 2 ( °F log Mtd) (FPM C

) ASRE High ASRE Low QMR&E

Sat ’ n Temp. Sat ’ n Temp. High Amb

.

138-57a 1 A 0.00932 0.00959 0.00906

139-57* ,b1 B .00759 .00713 . 00828

155-58b

1 B .00885 -- .00916

159-58 2 B .00770 . 00658 .00811

166-58 3 B .0102 . 00470 . 00948

170-58 4 B .00746 .00602 .00821

140-57 1 C .00848 .00560 .00813

a. Foreign material in condenser inlet during tests

b. Previously reported In NBS Report 6378

c. Based on FPM entering air face velocity at test conditions
!

.

$
TEST

CHAMBER

,

,

INSULATION

I-<o

APPARATUS

FOR

TESTHG

AIR-COOLED

REFRIGERATION

CONDENSERS

Figure

Figure

Figure

Figure

Pi

CM]

TP

Figure

Figure 9

Figure

10

o

h~

o

UJ

cn

o

UJ

co =

Figure 11

TYPICAL

TUBE

AND

FIN

ASSEMBLY

PRESSURE

(PS

/A )

PRESSURE - ENTHALPY

DIAGRAM

NO SCALE

LAD EL ED IN ACCORDANCE

WITH AS & E PS 2.4

CONDENSER SPECIMEN

DIAGRAM

Figure 12
. 1iIIII
Figure 13



CONDENSER SPECIMEN #1

mfr. Dunham -Bush size B • » A/as NO, 170-58 CLAOO - 4

ITEM PROPERTY REMARKS

COIL TUBE CHARACTERISTICS

1 MATERIAL Steel

Z NUMBER OF ROWS DEEP 2

3 NUMBER OF TUBES HIGH 16 : 4 NUMBER OF CIRCUITS IN PARALLEL 4

5 NUMBER OF TUBES PER CIRCUIT 8

• 6 TUBE DIAMETER , 0. D. , IN. 5/8 With aluminum "Inner Fin"

7 TUBE WALL THICKNESS , IN. . & TUBE RETURN BEND DIAMETER , 0. D. , IN

.

1/2

9 INLET CONNECTION DIAM . ,O.D. t IN. 3 A r 10 LIQUID OUTLET CONN . DIAMETER, O.D, IN. 5/8 i II VERTICAL TUBE SPACING, IN. S 2

12 PRIMARY SURFACE AREA , SQ.FT. 10.75

COIL FIN CHARACTERISTICS

1 MATERIAL Steel

2 TYPE OF FIN Plate Flat with cut raised section

3 FIN SPACING , PER INCH • 8

[ 4 FIN THICKNESS , IN. 0.02

3 SECONDARY SURFACE AREA , SQ.FT. 240.6

1

•

i COIL DIMENSIONS

\ 1 FINNED HEIGHT , IN . K 32

\ 2 FINNED WIDTH , IN. F 25 1/2 • » 3 FINNED DEPTH, IN. V 3

j 4 COIL HEIGHT , IN. H 31

S COIL WIDTH , IN. W 29 — — — ‘—

(

G COIL DEPTH, IN. D 1 1/2 i r 7 COIL DEPTH , OVERALL , IN. N _ _ «= 6 FACE AREA , 3Q. FT.

r— - 5.67 j 9 TOTAL SURFACE AREA, SQ.FT. 260.4 i

'

! OVERALL CONDENSER DIMENSIONS

1 WIDTH , OVERALL , IN. A 32 3/3

2 WIDTH , SHROUD , IN

.

fl 25 3/4

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4 DEPTH , IN. £ 11

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6 BELLMOUTH RADIUS , IN. R 0.406 Annrox. ^

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U5C0MI&“«BS-0C

CONDENSER SPECIMEN #2

MFR .

' Dunham -Bush J/zr - b

ms no. 166-58 - 3

ITEM PROPERTY REMARKS

COIL TUBE CHARACTERISTICS

1 MATERIAL Aluminum

2 NUMBER OF ROWS DEEP 2

3 NUMBER OF TUBES HIGH 16., . 4 NUMBER OF CIRCUITS IN PARALLEL 4

5 NUMBER OF TUBES PER CIRCUIT 8

€ TUBE DIAMETER , 0 . D. , IN. 5/8 With aluminum "Inner Fin"

7 TUBE WALL THICKNESS , IN.

5 TUBE RETURN BEND DIAMETER , 0. 0 . , IN . 1/2 I 9 INLET CONNECTION DIAM . , 0. 0. , IN. 7/8 r 10 LIQUID OUTLET CONN , DIAMETER , 0,0, IN. S/8 i II VERTICAL TUBE SPACING, IN. $ 2

1 2 PRIMARY SURFACE AREA , SQ.FT. 10.50

COIL FIN CHARACTERISTICS

1 MATERIAL Aluminum

2 TYPE OF FIN Plate

1 Flat with cut raised section

3 FIN SPACING , PER INCH 8

4 FIN THICKNESS , IN. 0.011

3 SECONDARY SURFACE AREA , SQ.FT. 244.3

•

. i COIL DIMENSIONS

I FINNED HEIGHT , IN . K 82 1/4 ;

\ 2 FINNED WIDTH , IN. F 25 1/2 %

1 3 FINNED DEPTH, IN. V 3 j

. . . . ......j

! 4 COIL HEIGHT , IN. H 51 . •

J S COIL WIDTH , IN. W 28 3/4 — -

i ___ i

\ € COIL DEPTH, IN. D 1 1/2 j

[ 7 COIL DEPTH , OVERALL , IN. N — a FACE AREA , 3Q. FT. 5-74 ] 9 TOTAL SURFACE AREA , SQ.FT. 254.8 i

i

• j OVERALL CONDENSER. DIMENSIONS

1 WIDTH , OVERALL t IN. A 32 1/2

2 WIDTH , SHROUD , IN. B„ 25 3/4

0 HEIGHT , IN. C _ 34 1/8

4 DEPTH , IN. E 11

i

1 S BELLMOUTH ORIFICE DIAMETER , IN. X 24 1/2

6 BELLMOUTH RADIUS , IN. R o7406

4

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USCOMttrMftSHDC

CONDENSE® SPECIMEN #3

MFR. Dunham -Bush SIZE - B

NBS NO. 159-58 CLASS - 2

ITEM PROPERTY REMARKS

COIL TUBE CHARACTERISTICS

/ material . Copper

2 NUMBER OF ROWS DEEP ‘ 2 . ; 3 NUMBER OF TUBES HIGH 16 . A NUMBER OF CIRCUITS IN PARALLEL 4

5 NUMBER OF TUBES PER CIRCUIT 8

• € TUBE DIAMETER , 0. D. , IN. 5/8

' With copper "Inner Fin"

7 TUBE WALL THICKNESS , IN. —

6 TUBE RETURN BEND DIAMETER t O.D. t IN

.

1/2 ; 9 GAS INLET CONNECTION DIAM. , O.D. , IN. 7/8 i IQ LIQUID OUTLET CONN . DIAMETER t Q.Dt IN. 5/8

II VERTICAL TUBE SPACING , IN. 3 2

(2 PRIMARY SURFACE AREA , SQ.FT. 10.75

COIL FIN CHAKACTEISiaTIca

/ MATERIAL Copper

2 TYPE OF FIN Plate Flat with cut raised sections

S FIN SPACING , PER INCH • 8

4 F/A/ THICKNESS , /A/. 0.006 •

>5 SECONDARY SURFACE AREA , SQ.FT. 240.0 i

i COIL DIMENSIONS

1 FINNED HEIGHT, IN. K 32 i 2 FINNED WIDTH , IN. F 25 3/8 • l. S FINNED DEPTH, IN. V 3

i ... j A COIL HEIGHT, IN, H 31 1 S COIL WIDTH , IN. W 28 7/8

" •"— : "<

i

l 6 C OIL DEPTH , IN. D 1 l/p r r 7 COIL DEPTH , OVERALL t IN. N

6 FACE AREA , SQ. FT. 5.64 i 9 TOTAL SURFACE AREA t SQ.FT. 250.8

OVERALL CONDENSER. DIMENSIONS

1 WIDTH , OVERALL , IN. A 3 ? 1/9

2 WIDTH , SHROUD 9 IN. B 25 3/4

S HEIGHT , IN. C 34 1/8

4 DEPTH , IN. E 11 1 S BELLMOUTH ORIFICE DIAMETER # IN. X 24 1/2 • 6 BELLMQUTH RADIUS , IN. R 0 . 406 Approx. _

‘

i

.

;

Table 5

COu

kia

to

QJ

k,1 <0

klQ£Oo

Table 6
.

'
Figure

19



Figure 21

CONDENSER

SPECIMEN

#4

MFRl

Punham-Bush

Inc.

~NBS

NO.

140-57

SIZE

C

CLASS

TOP

VIEW

Q

Ud

Figure 22

CONDENSER SPECIMEN #4

mfr . Dunham -Bush size ~ c

^ N3S NO. 140-57 Ct/133 « 1

ITEM PROPERTY REMARKS

COIL TUBE CHARACTERISTICS i

/ MATERIAL Copper

2 NUMBER OF ROWS DEEP 2

3 NUMBER OF TUBES HIGH .15 . 4 NUMBER OF CIRCUITS IN PARALLEL 5

5 NUMBER OF TUBES PER CIRCUIT 6

• 6 TUBE DIAMETER ,0.0. , /A/. 5/8 With aluminum "Inner-Fin*1 7 rc/a£ WALL THICKNESS , /A/.

6 TU5£ RETURN BEND DIAMETER t 0. D. , IN

.

1/2

9 G/13 INLET CONNECTION DIAM . ,O.D. t IN. 7/8 r SO LIQUID OUTLET CONN . DIAMETERt 0.0, IN. 7/8 j'

II VERTICAL TUBE SPACING, IN. S 2

12 PRIMARY SURFACE AREA , SQ.FT. 13.57

COIL FIN CHARACTERISTICS

! MATERIAL Aluminum

2 TYPE OF FIN Plate Flat with cut raised section

S FIN SPACING , PER INCH • 8

4 F/W THICKNESS , IN. 0.010

S SECONDARY SURFACE AREA , 3Q. fT. 422.4

COIL DIMENSION'S

1 FINNED HEIGHT, IN. K *

o

j 2 FINNED WIDTH , IN. F 35 1/8 * 1

! 3 FINNED DEPTH , IN. V 4

i

. _J A COIL HEIGHT , IN. H 29 3/8 . _ ’

l

1 r >5 COIL WIDTH , IN. W 38 1/2

!

!

\ G COIL DEPTH , /A/. D 1 1/2 f r7 CO/L DEPTH , OVERALL , IN. N

\ a F/4ce , ao. rr. 7-?2 ! P 9 TOTAL SURFACE AREA, SQ. FT. 436.0 .

i

j

’

•

. ; *

. -r~. - i

' • OVERALL CONDENSER DIMENSIONS • * -J

! / W/DTH , OVERALL , IN. A in i /o

2 WIDTH , SHROUD , IN. B 35 1/8

i S HEIGHT , IN. C 32 1/8

| 4 DEPTH , IN. E 11

.

• ’

. I

| S BELLMOUTH ORIFICE DIAMETER , IN. X 24 1/2 • .. i G BELLMOUTH RADIUS , IN. R 0.406 ADDrox. -

Table 7

CONDENSED

SPECIMEN

#4

mfr

.

Dunham

-Bush

nbs

no.

140-57

size

- C

C£.^5*s

Table 8
'
Figure

23

CONDENSER

SPECIMEN

5

MFR.

DUNHAM

-BUSH

NBS

NO.

138-57

SIZ

E

A

CLASS

LUQ

<0 ^

u. >

LU

.J

Figure 24

CONDENSER SPECIMEN #5

MFR. DUNHAM -BUSH - A

N3S NO. 138-57 CLASS - 1

ITEM PROPERTY REMARKS

COIL TUBE CHARACTERISTICS

1 MATERIAL Copper

2 NUMBER OF ROWS DEEP 2

3 NUMBER OF TUBES HIGH 10 : 4 NUMBER OF CIRCUITS IN PARALLEL 2

$ NUMBER OF TUBES PER CIRCUIT 10

G TUBE DIAMETER , 0. D. , IN. 5/8 With aluminum "Inner Fin"

7 TUBE WALL THICKNESS , IN.

6 TUBE RETURN BEND DIAMETER ,0.D . , IN

.

1/2

9 GAS INLET CONNECTION DIAM . ,O.D. , IN, 5/8 ..

r 10 LIQUID OUTLET CONN. DIAMETER ,0.0, IN. 5/8

II VERTICAL TUBE SPACING , IN. S 2

12 PRIMARY SURFACE AREA , SQ.FT. 6.494

COIL FIN CHARACTERISTICS

1 MATERIAL Aluminum

2 TYPE OF FIN Plate Flat with cut raised sections

S FIN SPACING , PER INCH 8 ; 4 FIN THICKNESS , IN. .010

S SECONDARY SURFACE AREA , SQ.FT. 142.6

•

, COIL DIMENSION'S

i ' FINNED HEIGHT , IN

.

K 20

1 2 FINNED WIDTH , IN. F 24

! 3 FINNED DEPTH, IN. V 3

1 4 COIL HEIGHT , IN. H 19 _ _ _

1 3 COIL WIDTH , IN. W CVJ 11— b- OJ

-|

1 6 COIL DEPTH , IN. D 1 1/2 .

! 7 COIL DEPTH , OVERALL , IN. N

i a FACE AREA , SQ. FT. 3.33 j 9 TOTAL SURFACE AREA, SQ.FT. 149.1

I OVERALL CONDENSER DIMENSIONS

/ WIDTH , OVERALL , IN. A 30

2 WIDTH , SHROUD , IN. B 24 1/8

S HEIGHT , IN. C 22-

4 DEPTH , IN. E 10 7/8 '

; 3 BELLMOUTH ORIFICE DIAMETER , IN. A 18 5/8 j 6 BELLMOUTH RADIUS , IN. R — Conical section

Table 9
-

-


U. S. DEPARTMENT OF COMMERCE

Luther H. Hodges, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director THE NATIONAL BUREAU OF STANDARDS

The scope of activities of the National Bureau of Standards at its major laboratories in Washington, D.C., and

Boulder, Colorado, is suggested in the following listing of the divisions and sections engaged in technical work.

In general, each section carries out specialized research, development, and engineering! in the field indicated by

its title. A brief description of the activities, and of the resultant publications, appears on the inside of the

front cover. WASHINGTON, I). C.

Electricity, Resistance and Reactance. Electrochemistry. Electrical Instruments. Magnetic Measurements

Dielectrics. High Voltage.

Metrology. Photometry and Colorimetry. Refrectometry. Photographic Research. Length. Engineering Metrology.

Mass and Scale. Volumetry and Densimetry.

Heat. Temperature Physics. Heat Measurements. Cryogenic Physics. Equation of State. Statistical Physics.

Radiation Physics. X-ray. Radioactivity. Radiation Theory. High Energy Radiation. Radiological Equipment.

Nucleonic Instrumentation. Neutron Physics.

Anal ytical and Inorganic Chemistry. Pure Substances. Spectrochemistry, Solution Chemistry. Standard Refer- ence Materials. Applied Analytical Research. Crystal Chemistry.

Mechanics. Sound. Pressure and Vacuum. Fluid Mechanics. Engineering Mechanics. Rheology. Combustion

Controls.

Polymers. Macromolecules: Synthesis and Structure. Polymer Chemistry. Polymer Physics. Polymer Characterisation. Polymer Evaluation and Testing. Applied Polymer Standards and Research. Dental Research.

Metallurgy. Engineering Metallurgy. Microscopy and Diffraction. Metal Reactions. Metal Physics. Electrolysis

and Metal Deposition.

Inorganic Solids. Engineering Ceramics. Class. Solid State Chemistry. Crystal Growth. Physical Properties.

Crystallography.

Hnilding Research. Structural Engineering. Fire Research. Mechanical Systems. Organic Building Materials.

Codes and Safety Standards. Heat Transfer. Inorganic Building Materials. Metallic Building Materials.

Applied Mathematics. Numerical Analysis. Computation. Statistical Engineering. Mathematical Physics. Operations Research.

Data frocessing Systems. Components and Techniques. Computer Technology. Measurements Automation.

Engineering Applications. Systems Analysis.

Atomic Physics. Spectroscopy. Infrared Spectroscopy. Far Ultraviolet Physics. Solid State Physics. Electron

Physics. Atomic Physics. Plasma Spectroscopy.

Instrumentation. Engineering Electronics, Electron Devices. Electronic Instrumentation. Mechanical Instru- ments. Basic Instrumentation.

Physical Chemistry. Thermochemistry. Surface Chemistry. iVgnnic Chemistry. Molecular Spectroscopy. Elementary Processes. Mass Spectrometry. Photochemistry and Rf i at ion Chemistry.

Office of Weights and Measures. BOULDER, COLO.

Cryogenic Engineering Laboratory. Cryogenic Equipment. Cryogenic Processes. Properties of Materials. Cryogenic Technical Services.

CENTRAL RADIO PROPAGATION LABORATORY

Ionosphere Research and Propagation. Low Frequency end Very Low Frequency Research. Ionosphere Research. Prediction Services. Sun-Earth Relationships. Field Engineering. Radio Warning Services. Vertical

Soundings Research.

Radio Propagation Engineering. Data Reduction Instrumentation. Radio Noise. Tropospheric Measurements.

Tropospheric Analysis. Propagation-Terrain Effects. Radio-Meteorology. Lower Atmosphere Physics.

Radio Systems. Applied Electromagnetic Theory. High Frequency and Very High Frequency Research. Fre- quency Utilization. Modulation Research. Antenna Research. Radiodetermination.

Upper Atmosphere and Space Physics. Upper Atmosphere and Plasma Physics. High Latitude Ionosphere

Physics. Ionosphere and Exosphere Scatter. Airglow and Aurora. Ionospheric Radio Astronomy.

RADIO STANDARDS LABORATORY

Radio Physics. Radio Broadcast Service. Radio and Microwave Materials. Atomic Frequency and Time-Interval

Standards. Radio Plasma. Millimeter-Wave Research.

Circuit Standards. High Frequency Electrical Standards. High Frequency Calibration Services. High Frequency

Impedance Standards. Microwave Calibration Services. Microwave circuit Standards. Low Frequency Calibration

Services.