/& • o o

NATIONAL BUREAU OF STANDARDS REPORT

CAPACITY TESTS OF FOUR REMOTE AIR-COOLED

REFRIGERANT CONDENSERS

Manufactured by

Kramer Trenton Company

Trenton 5, N.J.

by

C. W. Phillips

to

Mechanical Engineering Division

Quartermaster Research and Engineering Command

Natick Laboratories, U. S. Army

Natick, Mass.

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

8138
U. S. DEPARTMENT OF COMMERCE

Luther H. Hodges, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director

THE NATIONAL BUREAU OF STANDARDS

Functions and Activities

The functions of the National Bureau of Standards include the development and maintenance of the national standards of measurement and the provision of means and methods for making measure - ments consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to government agencies on scientific and technical problems; invention

and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications, including assistance to industry, business and con- sumers in the development and acceptance of commercial standards and simplified trade practice

recommendations. The work includes basic and applied research, development, engineering, instru- mentation, testing, evaluation, calibration services, and various consultation and information services. Research projects are also performed for other government agencies when the work relates

to and supplements the basic program of the Bureau or when the Bureau’s unique competence is required. The scope of activities is suggested by the listingof divisionsand sections on the inside

of the back cover.

Publications

The results of the Bureau’s research are published either in the Bureau’s own series of publications or in the journals of professional and scientific societies. The Bureau itself publishes

three periodicals available from the Government Printing Office: The Journal of Research, published in four separate sections, presents complete scientific and technical papers; theTechnical

News Bulletin presents summary and preliminary reports on work in progress; and Central Radio

Propagation Laboratory Ionospheric Predictions provides data for determining the best frequencies

to use for radio communications throughout the world. There are also seven series of nonperiodical publications: Monographs, Applied Mathematics Series, Handbooks, Miscellaneous Publications, Technical Notes, Commercial Standards, and Simplified Practice Recommendations.

A complete listing of the Bureau’s publications can be found in National Bureau of Standards

Circular 460, Publications of the National Bureau of Standards, 1901 to June 1947 ($1.25), and the Supplement to National Bureau of Standards Circular 460, July 1947 to June 1957 ($1.50), and Miscellaneous Publication 240, July 1957 to June 1960 (includes Titles of Papers Published in Outside Journals 1950 to 1959) ($2.25); available from the Superintendent of Documents, Government

Printing Office, Washington, D.C., 20402.
fslATIONIAL BUREAU OF STANDARDS REPORT

NBS PROJECT

1003-20-10435 December 5, 1963

NBS REPORT

8138

CAPACITY TESTS OF FOUR REMOTE AIR-COOLED

REFRIGERANT CONDENSERS

Manufactured by

Kramer Trenton Company

Trenton 5, N.J.

by

C. W. Phillips

Mechanical Systems Section

Building Research Division

to

Mechanical Engineering Division

Quartermaster Research and Engineering Command

Natick Laboratories, U. S . Army

Natick, Mass.

IMPORTANT NOTICE NATIONAL BUREAU OF ST

for use within the Government, and review. For this reason, thi whole or in part, is not author Bureau of Standards, Washingti

the Report has been specifically'

ss accounting documents intended Approved for public release by the subjected to additional evaluation Director of the Nattonal Institute of

, “£ e^'J,

Standards and Technology (NIST) the Government agency for which on October 9, 20 1 5. °P' es for its own use -

I. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

CAPACITY TESTS OF FOUR REMOTE AIR-COOLED

REFRIGERANT CONDENSERS

MANUFACTURED BY

KRAMER TRENTON COMPANY

TRENTON, NEW JERSEY

by

C. W. Phillips

1 . 0 Introduction

This report presents results of capacity tests of four remote aircooled refrigerant condensers, of three sizes and three classes listed

in "Purchase Description, Condensers, Air-Cooled, for Use with Dichlorodif luoromethane (F-12)", dated March 22, 1957 All four were manu- factured by Kramer Trenton Company, Trenton, New Jersey.

The four condensers were:

Specimen No. 1 Size A Class 1 Copper Tubes, Aluminum Fins

NBS Test No. 134-57

Specimen No. 2 Size B Class 3 Aluminum Tubes , Aluminum Fins

NBS Test No. 145-58

Specimen No. 3 Size B Class 2 Copper Tubes , Copper Fins

NBS Test No. 146-58

Specimen No. 4 Size C Class 1 Copper Tubes, Aluminum Fins

NBS Test No. 150-58

Specimen No. 1 was procured under contract No. DA 19- 129-QM-827

,

and the other three were procured under contract No. DA 19-129-QM-1013

.

1 . 1 Background

This report is the final report of several presenting test data on the performance of a number of air-cooled refrigerant condensers The

study was resumed in July 1959 following a period of inactivity for

fiscal reasons. Results of previous tests in the series have been presented in NBS Reports 6378, 6401, 6420, 6670, and 7760. Apparatus

- 1-

designed and constructed specifically for this work was originally

patterned after a then proposed ASRE Standard, PS-2.4. During the

time the test project was inactive, the proposed ASRE Standard PS-2.4

was modified and adopted as ASHRAE Standard 20-60, 'Tlethods 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 airside psychrometr ic measurement of heat rejection. In reactivating the

project, the air-side 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 electronic flowmeter

for determination of liquid refrigerant flow rate was retained as the

primary flow rate method.

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 con- densers. QMR&E Purchase Description, "Condensers, Air-Cooled for Use

with Dichlorodif luoromethane (F-12), dated March 22, 1957 does not

specify either minimum or maximum degree of subcooling. Military Specification MIL-C-23122, "Condensers, Air-Cooled, Ref rigerant- 12" , dated

December 27, 1961 specifies a minimum subcooling of three degrees F,

and no maximum. All tests described in this and previous reports in

this study were made with condensation of all of the refrigerant (indicated by a clear sight glass at the condenser outlet) and with subcooling less than five degrees F in most cases and less than 10.5

degrees F in all cases.

ASRE PS- 2. 4 included Standard Rating Conditions; ASHRAE Standard

20-60 does not. QMR&E Purchase Description, "Condensers, Air-Cooled

for Use with Dichlorodif luoromethane (F-12)" dated March 22, 1957, set

forth the following capacity requirements, at an entering saturation

refrigerant temperature of 135°F and 25°F temperature difference between the entering air (110°F) and entering saturation refrigerant

temperature (135°F) for the four sizes of condensers:

Size A 22,300

Size B 35,600

Size C 46,000

Size D 57,000

Btu/hr (Min.)

Btu/hr (Min.)

Btu/hr (Min.)

Btu/hr (Min.)

- 2-

Capacities have been determined at these conditions and also at the

following conditions as suggested in ASRE PS-2.4:

Dry bulb temperature of air entering

unit

Wet bulb temperature of air entering

unit

Dry bulb temperature of ambient

air

Saturation temperature of dry re- frigerant vapor entering condenser

Actual temperature of dry refrigerant

vapor entering condenser

High Rate

95° F

75°F ± 5°F

95°F

130°F

195° F ± 10°F

Low Rate

95°F

75°F ± 5°F

95 °F

105°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, 6670,

and 7760, 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 absolute temperature measurements is unrealistic for normal laboratory-quality

measuring systems. ±0.2°F is more realistic, and test results re- ported were based on measurements approaching this degree of

accuracy

.

2. ASHRAE Standard 20-60 requires two simultaneous determinations of

refrigerant flow rate as the means for determining performance.

Tests reported here compare a psychrometric "air-side" measurement

with a simultaneous refrigerant flow rate measurement by an electronic turbine-type flowmeter. 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

- 3

-

a third measurement, in direct comparison with the turbine-type

liquid refrigerant flowmeter determination made in all runs. On

some runs a separate secondary refrigerant calorimeter was used

to provide the comparison with the flowmeter.

3. ASHRAE 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 subcooling. The desired subcooling was controlled by means of an adjustable flow valve at

the receiver inlet.

4. A printing error in ASHRAE Standard 20-60 in the formula for determination of q c , condensing heat rejection, resulted in a lack

of guidance for this somewhat arbitrary calculation. Based on ASRE PS-2.4, it was assumed that q c should be based on the en- thalpy difference between the entering refrigerant vapor (at

]?2c t 2 c ) and refrigerant liquid at saturation temperature cor- responding to the inlet pressure (P 2 C

). Note further discussion

under "Data and Results".

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.

2. Liquid Refrigerant Flowmeter. The subcooled condensed liquid re- frigerant was metered by means of a totalizing (integrating)

electronic 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. One was the original

- 4

-

tube-type evaporator equipped with immersion electric heaters,

modified to operate as a dry system primary calorimeter by installing electric energy meters, thermocouples, and better insulation. Although this calorimeter was satisfactory for the

larger size condensers producing liquid refrigerant flow rates

greater than about eight pounds per minute, its over-all accu- racy was not considered suitable for useful comparison at lower

flow rates, particularly below four pounds per minute. The

probable reason for this was failure to accurately determine

calorimeter heat leakage at the lower evaporator temperatures

occurring at the lower flow rates. A secondary refrigerant calorimeter constructed for a previous study was used for the one Size A condenser (Specimen No. 1) 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 con- denser air inlet.

Figure 4. Auxiliary blower (left) and inlet damper control

motor. Blower is at exit end of air duct apparatus

Figure 5. Condensed refrigerant liquid line leaving test con- denser (right). Pressure tap (right), sight glass

(center), and thermocouple well (left) are part of

measuring system for determining temperature and

degree of subcooling of leaving refrigerant liquid.

A mixer (Fig. 12) was installed between the con- denser and sight glass for most runs.

Figure 6. Test system refrigerant pressure gauges and precision galvanometer type potentiometer.

Figure 7. Instruments for measurement of electric energy,

current and voltage, and relative humidity.

- 5-

00

*T

Fig.

Fig.

Fig . 4



Fig.

i\

Fig.

Figure 8. Components of condenser test circuit including com- pressor, 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. The

vertical liquid receiver 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,

eliminating the effect of ambient temperature changes.

Water-cooling the receiver also facilitated pump down

of the refrigerant when changing test condensers.

Figure 9. Secondary refrigerant calorimeter.

Additional details concerning apparatus will be found under "Data

and Results".

3 . 0 Data and Results

Each condenser was studied at three different sets of standard con- ditions 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 and embossed

plate fin assembly used in all of the condensers covered in this report.

Note the 5/32-in. open slots between alternate pairs of tube openings.

In manufacture, the end of certain of the return bends of the nominal

3/8-in. o.d. serpentine tube coils used for all condensers covered by

this report were flattened, the coils then inserted in the fin assembly

and then expanded hydraulically. This operation reopened the flattened

return bends and also expanded the tubes into the fin collars extruded

from the fins. Final expanded diameter of the tubes was somewhat larger

than 3/8 in., approximately 0.39 in. The determinations of primary,

secondary and total surface areas were based on the following conditions :

- 6

-

I

Fig.

]

Fig . 9
'
Fig.

10

TYPICAL FIN AND TUBE ASSEMBLY

Fig. 11

1. Primary area = Number of tubes x length x tt x diameter minus

area covered by fins based on fin thickness. Fin collars were ignored. Tube outside diameter was taken arbitrarily

as 0.375 in.

2. Area of open slots and tube openings was deducted from total

fin area.

3. End sheets and tube area through and beyond end sheets and

exposed fin edges were not included.

In an earlier report (NBS 6670) of tests of two condensers also manufactured by Kramer Trenton Company area was determined on slightly different

basis in that (1) primary area = total tube area in the finned width,

and (2) secondary area was not corrected for insertion slot area.

Figure 12 shows a mixing device which was used in the condenser

outlet line for all tests except two covered in this report. One of

these two tests was included for comparison; the other was conducted

prior to construction of the mixing device.

Figure 13 shows, schematically, the features of the mixer, which

consisted of an insulated cylinder of 5-in. diameter, about 6 in. high,

with the inlet about 1 1/2 in. from the top and the outlet at the bottom.

During initial tests of one of the condensers in this report, a clear

sight glass in the refrigerant liquid line leaving the condenser was

not obtained with pressure- temperature relationships observed at the

sight glass of less than 4.0 degrees of indicated subcooling. Temperature measurements of the last return bend in each row indicated

the possibility that one or more rows were passing some uncondensed

vapor while the other rows were passing subcooled liquid. After the

mixer was added, satisfactory agreement of subcooling was obtained

between the sight glass and the pressure- temperature relationship of

the refrigerant at the sight glass. Because the mixer was well insulated, it functioned adiabatically and did not increase the total heat

exchange of the condenser. A comparison test with and without the

mixer in the circuit indicated agreement within 0.9 percent, a difference smaller than the ability of the apparatus to provide a precise

comparison. These comparative observations are included in the discussion of test results obtained with Specimen No. 2.

Figure 14 is a pressure-enthalpy diagram for dichlorodif luoromethane (Refrigerant 12) on which the three sets of rating conditions

used for the tests in this report are shown. Symbols used in the Tables

of Test Results are identified on this diagram.

- 7-



CONDENSER OUTLET MIXER ASSEMBLY

PRESS

URE (

PS! A

)

PRESSURE - ENTHALPY

DIAGRAM

NO SCALE

ENTHALPY (BTU/lb)

NOTE > LABELED IN ACCORDANCE

WITH AS R E PS Z.4

CONDENSER SPECIMEN

DIAGRAM

Fig. 14

Photographs and schematic drawings of the four condensers tested

are presented in Figures 15 to 23. Dimensional and material data and

test results are summarized in Tables 1 to 8.

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

9 through 12 are performance observations based on refrigerant- side

measurements; and Items 13 through 23 are ratings derived from both

sets of measurements. Two additional ratings, Items 24 and 25, have

been added for further comparison. They are:

Item 24. Btu per (f t^) (°F) (hour

)

Item 25. Btu per (f t^) (°F) (CFM) (hour

)

where

O Ft^ = total surface area of the condenser in square feet

°F = log mean temperature difference, refrigerant to air

CFM = air flow rate, std.

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 13 is the converted average of Items 8 and 12.

Item 14, "Condensing Heat Rejection", includes desuperheating of the

entering refrigerant vapor. Item 14 was determined using the following

equation:

where q cR

F

h

2c

h '4c

q tR

q tr

q cR

* F(h

2c

' h '4c>

condensing heat rejection, Btu per hour

factor

, (M)

enthalpy at ?2c t 2c Btu P er P ounc* enthalpy of saturation at P2c , Btu P er P ound

total heat rejection, Item 13, Btu per hour

total heat rejection, Item 12, Btu per hour

It will be noted that this method arbitrarily assumes that all condensing

occurs at the inlet pressure.

- 8-

For all tests reported, the agreement between capacities determined

by the air-side or psycbrometric method and the flowmeter method was

closer than 7 percent, and for all tests except two, the agreement was

closer than 4 percent. Agreement for all QMR&E High Ambient Temperature

tests was 3.5 percent or less.

Specimen No. 1 was a Size A, Class 1 Condenser, NBS No. 134-57.

Figure 15 is a view of this condenser which had copper tubes and aluminum fins. Note the straight line vertical parallel tube rows typical

of all condensers in this report as further indicated in Figure 11.

Each plate-type fin in this condenser was the full height of the con- denser. Figure 16 and Table 1 give dimensional data, and Table 2 presents test data for Specimen No. 1. For this specimen, confirming

refrigerant flow rate determinations were made using the secondary

refrigerant calorimeter shown in Figure 9. These measurements are given in Item 9 in Table 2, to the left of each of the flowmeter mea- surements listed in the three main columns of data. Specimen No. 1 was the only condenser in this report tested with the secondary re- frigerant calorimeter. Difference between the two flow rate measure- ments was 3.7, 5.8, and 3.6 percent for the three tests in Table 2. At the QMR&E High Ambient Temperature test, the capacity was 21440

Btu per hour, 96.2% of the requirement of 22300 Btu per hour.

Specimen No. 2 was a Size B, Class 3 Condenser, NBS No. 145-58,

with aluminum tubes and fins. The finned portion was formed in two

sections, the top section 22 in. high, the bottom section 11 7/8 in.

high. There were 215 fins in the top section, 219 in the bottom.

Figure 17 is a view of Specimen No. 2. Figure 18 and Table 3 give

dimensional data and Tables 4 and 4a present test data for this con- denser. Refrigerant test connections to the aluminum manifolds were made using a commercial epoxy resin after difficulty was experienced

in attempts to use aluminum solder. Comparative tests were made at

the QMR&E High Ambient Temperature condition with and without the

mixer (Figures 12 and 13) in the condenser outlet line. Table 4 lists

the performance with the mixer and Table 4a gives the test results

without the mixer. The total heat rejection, respectively, for the

two QMR&E High Ambient Temperature conditions was 34340 and 34640

Btu per hour, an agreement within 0.9%. Confirming refrigerant flow

rate determinations were made using the modified dry system primary

calorimeter. The agreement between the two flow rates was 0.6, 16.7,

0.1, and 0.6 percent for the four tests in Tables 4 and 4a. The

calorimeter flow rates are shown in Item 9 to the left of each main

column of test data. As discussed under "Apparatus and Tests",

the agreement was satisfactory for all tests except the ASRE

Low Saturation Temperature Test, in which the flowmeter indicated

- 9

-

Krame

Fig.

15

- at

co

CO

<

_]

o

o2

<

LaJ yjN

CO

O

UJ

a,

co

an

UJ

CO

co

flD

£

m

>

CL

o

O

Li

0-0 DO OO OO 0-0 OO 0-0 OO OO 0-0 0-0

o o-o OO 0-0 OO OO OO 0-0 OO o-o 0-0 0-0

yOOO-OOO 0-0 0-0 OO 0-0 OO 0-0 OO 0-0

T

Fig.

16

CONDENSER SPECIMEN No. l MFR . KRAMER TRENTON SIZE - A- J NBS NO. 134-57 CLASS - 1 ITEM PROPERTY REMARKS

COIL TUBE CHARACTERISTICS

1 MATERIAL Copper

2 NUMBER OF ROWS DEEP 3

3 NUMBER OF TUBES HIGH 22

A NUMBER OF CIRCUITS IN PARALLEL 3

5 NUMBER OF TUBES PER CIRCUIT 22

6 TUBE DIAMETER , 0. D. , IN. 3/8 nominal,, see text

7 TUBE WALL THICKNESS , IN. 0.025 approx.

& TUBE RETURN BEND DIAMETER t O.D. , IN , 3/8 nominal, see text

9 GAS INLET CONNECTION DIAM . ,O.D. , IN. 5/8 Increased to 7/8"

10 LIQUID OUTLET CONN . DIAMETER , O.D , IN. 5/8

II VERTICAL TUBE SPACING , IN. £ 1

12 PRIMARY SURFACE AREA , SQ.FT. 12.4

COIL FIN CHARACTERISTICS

1 MATERIAL Aluminum

2 TYPE OF FIN Plate Embossed, slotted

3 FIN SPACING , PER INCH 8

A FIN THICKNESS , IN. .011

£ SECONDARY SURFACE AREA , SQ. FT. _145.4

COIL DIMENSIONS

j 1 FINNED HEIGHT, IN. K 21 7/8

2 FINNED WIDTH , IN. F 24 3/4 190 Fins

j 3 FINNED DEPTH , IN. V 3

A COIL HEIGHT , IN. H 21

S COIL WIDTH , IN. W 27 1/4

1

£ COIL DEPTH , IN. D 2

7 COIL DEPTH , OVERALL, IN. N 10 5/8

6 FACE AREA , 3Q. FT. 3.8 1 9 TOTAL SURFACE AREA, SQ.FT. 157.8 1

OVERALL CONDENSER DIMENSIONS

1 WIDTH , OVERALL , IN. A 30 1/8

2 WIDTH , SHROUD , IN . B 24 7/8

3 HEIGHT , IN. C 22 1/8

4 DEPTH , IN. E 11

S BELLMOUTH ORIFICE DIAMETER , IN. X 18 3/8

6 BELLMOUTH RADIUS , IN. R ' m

Table 1
.
CONDENSED

SPECIMEN

No t «o

«04u

U»

«VI •0

t^» ini cno2

<o

OQ2

E5OH

533

O'

u.5 k 'Ul .Uj sfk *9^

or 2Q>

sgtk

OBSERVED

CONDITION Q.UiV &

S3

£0§

LAA-AOJ

aa01—1

VDO

a>

CO

COO1—1

COm1—1LA

LAOx1 1

AIR

FLOW

METHOD

O

-=t O

OJ

O

OaO1—1

OJ

QO

i:k$0

-jkk

Uj0g

01

00

ID

A-A '

ct*

OJ

VO• O

CO

A-1—1

OJ

«9

V3

2:ka> O

-^r 1—1 0 O

avA0

OJ

OAxt

O

COA-1—1

LA1—1• 0

xj- A-r—f 11l AOJArH

A« ArH

AAA1 1

rHA

OJA

A -A

O

O AO

OJ loo 1—1 %0

k-°

J »

CMm0

cm 0 0 Vsn

on

VOav• A

A- 2

5^

kO^

U!<cp

2^5

^<CUj <0 CL

s, 5

*Ui Ok

-4

Q2

U|O

it

6Q

O o u

O t*1»

lyy,

kj <v UjT

Qi 2

k.O9Q

O

COaOJ 0

LAA

-^r 00

A- 0

LAOA

OJLA01 1OO

00

VO1—1 01—1 0

OJ/ 0

onon

Aon0

CO• rH

X)• 0 0• -=t 01—1

00A- 0

co1—1

A- 0

VO0

tk

O

OJ1—1 O

xt

001—1 A1 1 • O

O

cn1—1 ll1 a

00A

Lf

A- 1 AA•-^r \ A-Kt* Axt

CO

A -^OJ AO

co ojo A LAO

oXp

Ak;<>

°-x-%0

•V°

J

CM«

d»

IM •0

os

bu5

Vi0

Vs0“V 0n?

A-O

CT\« rH

XX5•

guj

lO

Cf

k

a^O!

to

k Uj 2c$: ^‘9$ o Ki

p2

-V ." <y k

Uj

Q

£oOu

Ujk0> Ik40k

QO*k

Uj$£0k

01

QO£

510

U^k

Uj

<JkU

Ui

QJ

«o05k

Q/

A-O

A^J"

U] i ko

Qi*0

‘‘•Q 1 1 00CA

OJ

OJLAA

LA

0^

AOJ

LAcr

ACO

aj1—1

OJ

CA1—1 0

VO0

OJ

O

OJLACA

OJ

'd• A- 0• A-A

O

orVQO

or

O

on

-=J* 1—1

on 0AO

on

OA

CO 0

OJ 001—1 ArHO O

vo

A-I 1 ll1 A

orA

OJ

OJ• VO1—1

OJ

OJcA2

A-i

—1 O

OJ-=f 0 • 9 • A-b-O 1 1 O

cn1—19 co o£o,

^£>0 w

os

0)CM

Vs0

vs *nk

Vj0 0n 0

<s<00|

><k50 J

£§3

4k^

02 ^

UUi

^5«y

3<k

*«& cou cn

oO i £ uD 5

Ujk

S' * k0 U. •

Vl • k« ke skO §k

<0 |

ijk

kc s

93 1CO 1k

<0

k

«Q sk0 O£ Ei CQ

k>3k

9J 3k

cs 3k

US ^ S ^ O k

CQ

•§ k

CB W

it

-k»

U

w

w

<o

O

-k»WO

V<1 °§m« k

k*

%ZOi! lq Ul L«5 <H Si

k^

<c«

LJ5:

-C

3<:

<0 vs

SO ?a

X0- L OL

C

LV

Ch

csku

ig3k

uik5 v tk

k«t 0 k k u

«u

hi

**J tk4

hiU

O'

k

in LH

k

O’

V) a i

a.

k

*.-( IN

ki 00 k 

O 1 H Wd24k

SS5 «o 5 2 S x U U 0

•vfOO i—I *-'*. CN

r-l r-N t—1 02

<*

k

0! ? Qd'C U I k U U| k iy i» *’?$ k 2 *M k § 0*

Ulk3

•0“sIgkau

a*k

Uj§0k

•cO

it0

Uj

!!

O

5o

e< *J >u 1m

cs ^W

L.Q

kj§k

1°

l-S

3f

k^

tu <V

*>

kk1

-<

!S!«>

•Qk

QHd

ej

3k

ss

ig 5V

5«T •» %»>b k .<

•7 ig

vi

QJOk§

tubikJU 5 V-

!*k 0

ku!

^u.

Uj (V r1 3 m k N \

§? 5

CSku$

igVk

2v

ik

gi

>t h: k k p x k 0

«s

kkkk0

u!k55

ig13?k

«V

01 4kskg4k

2u? 3

U) 10 Q?? V 0 V 0 k6 0$ Q

k^

Ok? * 38

§?0 k Q k 3 k

*} IV 20k0

Vj3

igkkk

UJX4f0k9 X0ku

igkk10XX

igQXOO

>* 20ku

Uikk%

(324000

cs3

<0

Uikk£0kkk

vj

Uiu25 4 Vj 0 ^

«J UjIV k ^

ig 4 PUJ u Q 5 2 k 0 V 0 UI k. ***» 0kk0k052£d

kOk

Ui

vsk

<3Xukk

cs2

0)

ki 5 k k

Ui 'X %2 v 5 f k (J^

Uj 0

JVk k L 5

Uik XkO

bX 2 k 3 <V k,

uj

U

<V^ 2UK 0

0.

Uj

V 9 k

Ui s: k Q

-I

Ui ^ X <0 N

k1? 5' S 0 P

Ul in k 4 ^ k

Ul 0 Xk

CMCM 0 0 l |jg Cu ^ to to 4 5C Ld 53 53 k A H

Uj PQ PP k2 " " Ok

VJUj = = 3

Ujkk

n: - r

UiX

ns <t in N M M I Table 2

m

—

— l - C 3 S H l

Fig. 17

CONDENSER

SPECIMEN

No

. 2

MFR.

KRAMER

TRENTON

NB3

NO.

145-58

SIZE-B

CLASS

i

co

I Ui

r>

oi

0-0 o-o o-o o-o o-o o-o o-o o-o OO 0-0 0-0 0-0 0-0 0-0 0-0 o-o

0-0 o-o o-o o-o o-o o-o OO o-o OO OO OO OO OO OO OO OO

OO OO OO OO OO OO OO OO OO OO OO OO OO OO OO OO

t I

UIo

<o £

UI

u. ^

UI

-J

V) — A

o

O-C

cm;

> 0-0 OO OO OO OO OO OO OO OO OO OO OO OO OO OO OO

) OO OO OO OO OO OO OO OO OO OO OO OO OO OO OO OO

OO OO OO OO OO OO OO OO OO OO OO OO OO OO OO 0-0 >

S'r - X- — H

Fig. 18

TJSCOMM-NBS-DC

CONDENSER SPEC/MEN No. 2 MFR . KRAMER TRENTON SIZE - B

NBS NO. 145-58 CLASS - 3

ITEM PROPERTY REMARKS

COIL TUBE CHARACTERISTICS

1 MATERIAL Aluminum

2 NUMBER OF ROWS DEEP 3 . 3 NUMBER OF TUBES HIGH 34

4 NUMBER OF CIRCUITS IN PARALLEL 3

5 NUMBER OF TUBES PER CIRCUIT ~W

6 TUBE DIAMETER , 0. D. , IN. 3/8 nominal, see text

7 TUBE WALL THICKNESS , IN. 0.025 approx.

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

.

3/8 nominal, see text

© G43 INLET CONNECTION DIAM . ,O.D. , IN. 7/8

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

“

II VERTICAL TUBE SPACING , IN. £ 1

12 PRIMARY SURFACE AREA , SQ.FT. 20.8

COIL FIN CHARACTERISTICS

1 MATERIAL Aluminum

2 TYPE OF FIN Plate Embossed, slotted

| 3 FIN SPACING , PER INCH 8

4 FIN THICKNESS , IN. 0.011

5 SECONDARY SURFACE AREA , SQ.FT. 254.9

- COIL DIMENSIONS

| 1 FINNED HEIGHT, IN. K 33 7/8

\ 2 FINNED WIDTH , IN. F 27 215 Fins(top section)

| 3 FINNED DEPTH , IN. V 3 219 Pins (bottom sectior}

' A COIL HEIGHT , IN. H 32 3/4

5 COIL WIDTH , IN. W 29 3/8

6 COIL DEPTH , IN. D 2

' 7 COIL DEPTH , OVERALL , IN. N 10 5/8

j 6 FACE AREA , SQ. FT. 6.4 1

: 9 TOTAL SURFACE AREA, SQ.FT. 275.7 i

i OVERALL CONDENSER DIMENSIONS

1 WIDTH , OVERALL , IN. A 32 3/8

2 WIDTH , SHROUD , IN. & 27 1/2

S HEIGHT . IN. C 34 . • 4 DEPTH , IN. E 11

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

€ BELLMOUTH RADIUS , IN. R 5/8 Approx. 1 :

Table 3

CM

] o

LO

25

tk2

Ouj

kfl; UlO

2^

•oQ. S Uj Ok

-J

Ski

Ofj^

JO

X k

<0 0! to k Ui ^«o5 o K

Q

°n Uj S < Z) M.

X k Mk^

h; UUj 0;

O' $ «U

Ul ^o<

QJ v

to <

tQQ

ou

a;b0*0

uio

UJ Hi Uj5

up

A. CpO

“^Zfe.

<X* Q 2

ty O

it

SI

«3 O

O U

O Uj

U. ^4.

Q» {^ k»

Uj

Uj<¥

S?

Q

s£

^uv>.

<*&b.

N

Q; k

Uj q

<oz SoOu

Uik

OfO?

-JO

k

3!

lot

UjO

Qjto

kQ

c

oU Mt

60 I co •H CM MMfO

ki cMMtm

O I i—I *CM H WHOH

<r Q

- Ui <k Uj Ui U.

<0 *» * 5

.

'K. U

U. U_ U

oN

OJ

-=j- co

oo

O'o

p

OJ

CO

is cr 00

CO

kO

IS

kQ

coN

uo

Uls

kJ<u «j !5*o U (J

U

O

Ui

«vk

^ -J

slpS

,?!»»

«§;”5

iS*ui<v Q <* 5 <t

coo

Ok

=t

Ok

cvj =3-

u

o

U|?

41

UiIs

J ^ 3?

Q Uj V *> isQH

00 kO

P

00

1

1

Ok OJ

a* U.O 04

in 5

#(Ok

k 5 $5

u**l SS

Ui<u kU

^Ui * <V 5 « v«

5J« ^ ,< •>U|

IS

O'

IS

I—

I

Ok

<Vo U4

°5

SI

tv k

2*

4«

s*

Slfc k*

51-C q*

(* J*

Ul W

a.!: ojs

<o Ui

O

LT rH

O

kO

00

cr

O

UP oo

cr

tvQ

a.5

tvUlk Ul 5k

o

^u!

^u,

Ul Q|

~J 3 N k N\

§5

O

O

o

-=J* H

osku

Ui

tvk

2 k

Ik

MO

^ J k u

p

* ko

oo

OJOk

IPcr

0JOcs

O'

0Jcr 0O

CO

•=t H

OJ

cr] <r

CVJ o

a

oo

-=t

OJ

oo

•J

't

£

$

J4

5 S o <vQ

SSu.

V) V

uj <o Q»J «

Ul oV

tj a

O'

OJ

kO

-=t

o

£

$ Q

U

J Ok

82

O tv C u

3 'U

<0 t«

O-3-

-=! P

cr

Zo

k

VJ

Ui

“>Ul

tvk

2 v tk

22

o % k «J

O

cr,

cr,

O

OJcr

cr

cr

OlO

oo! OO

OJ Ok

POl 0J

i—1 1

1—

I

o

D

>0

oM

P

IS

o

kO

s

p

-=f

o

vOp

oo

o

kO

OO

oo

o

=t

oo

oo

00

OJ

Uji

l d •» o ij U Ul

IV

<v

Uj m pUl u Q 5

OU

U U|

SM^J00H-cjp

kO

s

OO OJ

OO

OJ o

CO o

1—

1

CO

p

oo

OJi—

I

sooo

OJjOO

OkOO

OJ = soooipj OJOO

ISrHO

oao°

i OJ oo OO rH mis o

isko! p ojo o

CO • • • • • OJ kO OJ Sj-kO o

OJ CO! IS H

I—I I—

I

1

0. U

«j

3: ^In.

k

«Q

U | U. Pk | k

IQ i CO to

j

I U L '

^5P<Vi§

Ui! ^

J

ojuj iv. i(v5

Uj K uj ^ It. Ui * Ul 22

k 4/ o 0

Ul S> Uk

<V tv k^

U 5

unv tu

oSoS

k S) <J.

Uj k

cxv

Uj <?; <V 0 $8

U 2

l O

Uj m

(V M

U X

t k

Uj o tk

U'—

,Cu fk o o

v_x w

tL| Ii| W CO eePQ CQ

„ <T tn 3 CM CM

I! Table 4

CONDENSED

SPECIMEN

No.

LA

00

CO

1 «0«o

**4 u

pa

i •aN

*0

00m

t m

<*

rHd

<0

OQ

2!

ESO

Eh

Ql

u.5

ftig

25

it-

;i£l; ^ y 9

40 <

9QO ou

ty fli u

fti 13 W| *x ftis ?5

§

A-m

03

at

O

o1

1

=t

tk ao

O

o

rHrH

OJ

e LAcn

rH

o

o>

O'

1—

1

y4/i8

FLOW/

METHOD

o

1A 00

cr

oA

CVJ =t

cr Q

0

£

1

o

«Jk

k

s

k

v3

k

0!

LP

rH

cu

« O'

VO

« o

O• -=^ O

CT) LA

LAon

<0

(3k

5Q>

O

sf

VO

sfon

O

t"~ LAon

on

O

A-O

H

o

VO

onon

OJOJ

» o

AA-

-=t

i

i

t A

Ivo Ivo

1—

1

cr

ircr

rr

VO

• xr\ OJ

i—

i

OH

OJOO

onoo

dvdd

rH

4,

y^°

«

0}

0>N

o O Vt

li)

tV£) OJd

2

9^ktw

UjKp

•?k5

<oO.

*ftj O (s, -J

iy O

Sfc

8S

«Q Q O U

Sfcs

4. « 4.

Q; O

->* %

fti

ty 5 «s*;t k<J

S3Q --- rp ^o0

<n°

W

»

(DN

*>m

-,« s w* o\

o

"V.

K

%

%

•

to#

§iy

to

^-k

^cU

v) k *y «5|

5''

t

p*

> .— (u k

Kl Q

<0 ^ SoOu

Ujk

y

(U*$

5!°

3<

Q

Q

£

s

k

o

k

Qi

QO

E

s

k

O

U*k>

«vk

o

?

Ui

£V

<0

13k

(V

ftt! ftjO

QJ*?

*

*v£>.

<r.°

ri

t»» W

(it

01 kn

n dl o

nH.

o»«- M

It) m

I

*o

o S

^§3

UUi Qi

kj ua9

3 ^

ty£k - vs Lj

cso

kJ St- 60 1 CJ O

$

kj

<•

a k<9

i*, *

U.

• k

« k

e s

uu

%

k

«i i

***3 •9

ft.

ft. 1<0 Tk

>S\ 1

63 S

u.u

o

E

i

1

iQ

ft. •0 >

3

k

<ft

ft. 1k

<0

ft.

3k

ftt

j /^N

kK °V^ i ^ <-N FN

4>

<ts -U -tj U

'Jj

U

*4 -w IS

-8 o» <3 k

n

vt

kp

fts

ky

Ul3

fti k

5kIk

y 0

25

o s k y

CM

<*i u

\J*

til vt tH «

(S

*»

CL I

a. ft. •H ni u <r k <N O t H W

o

:?y

ft p

Z *

S 5

ft. *io

st' in rH *cs rH OH

15*

k

ft k

ft: 5

ftl ftj ^ <v « n p$

* £

ft- ft S fti

ft. 5 tu

Vi

01

<0

fti <Xau**%

ft: k

5

o

Of

"1vs

fto

kik

ft y P

So

iS** ty

Q-"

u.o

Uls

k

!(1°

8s5

3f

4

u.

«3

0|!

a:

Vil«

•ft k

v *> O H

ilt

S*

3kLj

«t «5 ass S9

SfC

^ftl So

>-? 5£

*7Uj

«0

a*o

kft. °§

01

ft! k

S in

Si

k*

5?

?V » •it1 a. k

•0 ill

01o

4.5

6!>4kill Sk

^ 'I -OS Ik

% o

«c;

^Ul

<« a: y 3 N k N\

?5

k

oku

Vi

ft! k

Mk

tk

yG

«j

w

k

h;

01*o

fi! k

*

iu

138

•y

a.

0)

45

?«

|

4ft. o ^

2 ft. «o«s ^ 3

Cj «9 s?

2

ft* o ao

0

S Q

5 ra k J Ok

5 y Q

Vi u ft: «l u. 3 'u

ij ft.

2:0*«. ko

ftl 3

Ul

ft! k

X

ftt

4

2o

k

5

0

ku*

U|

ft! k

1

w

UiQ

*o

u

V•s.

2

Q

k

O

$

HI0!k

5

£

13****. y

o

ou

«

3

O

oV.

fti k

ft!

o

il!

ft! «%

vi

2

J

l7 S2

ft! V

uj y pk| u Q 5 ?k

av

U Ul k

§

<v0

k

0

5

5

O

ft!

o

ft.

fti <0

ft! <3t

fti V:

<v•3*5

0)

k

fttftS

fti K %

25

k y

0 3

ftj *9 3

ftik

ft! ft! k

5

ft! ft! tft. d

CM

t ft; 2 ftJ 3ft! ftd

S 3 K *9 o.

v» 3 ft!

fti 1

ft! <3 *§

^Jftl t <6

CM

k

1P

a*

Ik. S o

Oft. ftjy

ft! y

k ^

ft k

o o tk

CM

CSJ

flH P 0 s^sr

^ « «

2

" * o

k

0 - Z

ftj 3

ft!

ft! k

ft _ - 1

"

Table 4a

a flow rate of less than 4 pounds per minute. At the QMR&E High Ambient

Temperature Test with the mixer, the capacity was 34340 Btu per hour,

96.4% of the requirement of 35600 Btu per hour.

Specimen No. 3 was a size B, Class 2 Condenser, NBS No. 146-58,

with copper tubes and copper fins. The fin and tube assembly was as shown in Figure 11, and Figure 19 is a view of this specimen. The

finned portion of the condenser was formed in two sections. The top

section was 22 in. high, with 211 fins, and the bottom section was 12

in. high, with 212 fins. Figure 20 and Table 5 contain dimensional

data, and Table 6 contains test data for Specimen No. 3. Refrigerant

flow rate determination, in addition to the flowmeter measurement, was made using the dry system primary calorimeter for the first two tests

shown in Table 6. The calorimeter flow rates are listed in Item 9 to

the left of each of the first two main columns of test data. Agreement

between the two measurements was 1.1 and 13.4 percent, with the poor

agreement occuring at a flow rate of less than four pounds per minute.

The third test reported in Table 6 was made prior to modification of

the system evaporator to serve as a calorimeter. The capacity at the

QMR&E High Ambient Temperature Test was 33210 Btu per hour, 93.3 percent of the requirement of 35600 Btu per hour.

Specimen No. 4 was a Size C, Class 1 Condenser, NES No. 150-58,

with copper tubes and aluminum fins. The finned portion was divided

into two sections. The top section was 22 in. high, with 301 fins,

and the bottom section was 9 7/8 in. high, with 308 fins. Figure 11

shows the typical tube and fin arrangement. Figure 21 is a view of

Specimen No. 4 showing the fan orifice and manifold end of the con- denser. Figure 22 shows the air inlet face of this condenser in an inverted position. Figure 23 and Table 7 present dimensional data,

and Table 8 contains test data for Specimen No. 4. Refrigerant flow

rate determinations were made using the dry system primary calorimeter

in addition to the flowmeter measurements. The calorimeter rates are listed in Item 9 of Table 8 to the left of the flowmeter rates in each

main column of test data. Agreement between the two measurements of

refrigerant flow rate was 0, 8.1, and 2.1 percent for the three tests.

At the QMR&E High Ambient Temperature Test, the capacity was 47,980 81-u/h*-; 104.3 percent of the requirement.

- 10 -

Fig. 19

CON

DENSE

R

SP

ECIMEN

no.

3

MFR.

KRAMER

TREWTON

MBS

NO.

146-58

SIZE

B

CLASS

TOP

VIEW

CN

Ui

8*” >

u.UJ

jit

T'p

00 0-000 OO 0-0 00 0-0 0-0 0-0 00

0-0 00 0000 0-0 00 00 0-0 00 0-0

OO OO OQ oo 0-0 oo oo oo oo oo

0-0 0-0 0-0 0-0 OO 0-0 0-0

0-0 00 O© OO 00 0-0 00

OO 00 00 0-0 00

J

?T

7

•

Fig.

20

CONDENSEIQ SPECIMEN No. 3

MFR. KRAMER TRENTON SIZE - B

. J N6S NO. 146-58 - 2 ITEM . PROPERTY REMARKS

COIL TUBE CHARACTERISTICS

1 MATERIAL Copper

2 NUMBER OF ROWS DEEP 3

3 NUMBER OF TUBES HIGH 34

4 NUMBER OF CIRCUITS IN PARALLEL 3

5 NUMBER OF TUBES PER CIRCUIT 34

6 TUBE DIAMETER , 0. D. , IN. 3/8 nominal, see text

7 TUBE WALL THICKNESS , IN. 0.025 approx.

& TUBE RETURN BEND DIAMETER , 0. D IN

3/8 nominal j see text

9 GAS INLET CONNECTION DIAM . ,O.D. , IN. 7/8

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

II VERTICAL TUBE SPACING , IN. S 1

12 PRIMARY SURFACE AREA , SQ.FT. 21.1

COIL FIN CHARACTERISTICS

1 MATERIAL Copper

2 TYPE OF FIN Plate Embossed, slotted

S FIN SPACING , PER INCH 8

A FIN THICKNESS , IN. . 009 - 011

S SECONDARY SURFACE AREA , 3Q. FT. 251.3

COIL DIMENSIONS

1 FINNED HEIGHT, IN. K 34

2 FINNED WIDTH , IN. F 27 1/8 211 Pinsftop section)

3 FINNED DEP TH , IN. V 3 212 Pins (bottom section

4 COIL HEIGHT , IN. H 33

S COIL WIDTH , IN. W 29 1/2

£ COIL DEPTH , IN. D 2

7 COIL DEPTH , OVERALL , IN. N 10 5/8

6 FACE AREA , SQ. FT FA j 9 TOTAL SURFACE AREA, SQ.FT. '2.7 2 .

OVERALL CONDENSER DIMENSIONS

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

2 WIDTH , SHROUD , IN. a 27.4

3 HEIGH T , IN. c 34.1. . A DEPTH , IN. E 11

S BELL. MOUTH ORIFICE DIAMETER , IN. X 24 5/8

6 BELLMOUTH RADIUS , IN. R 5/8 i—

Table 5

CONDENSED

SPECIMEN

No.

3

MFR.

.

KRAMER

TRENTON

NBS

NO.

146-58

SIZEB

CLASS

- 2 *5^

tv5o,»

§^Uj

**§

25

t k5§<o <

«QO OU

I^QjU fe

*

a

ss

S5

§

w-=3

- ACM

o

o1—

1

rH

o

LA

tcO

o

1—

1

1—

rMA

OO

i—

1

^t

IC- ON

1

1

I

AI&

FLOW

METHOD

1

o

coA

f*~

O-=}- CMA

OO

Q

o

£

S

£

o

-Jk

k

5

kiO

g

Qi

<y~ <M MO00

A

CM

• oo A

1C- O

MOA

OO

OO

<0

CD*£

o

i—

i

CM

<

r

<r

o

-=t

to- rnA

o

IC1—

(

0A

1

1 on

MO

1

1• o

AOA

1

1

1 A

t-A

i—

1

CM

© CMArH

o

© CM

CM

i—

1

A

OrH

i—1

1—IO orP.

ocoo

rH

cAp,

*% w

<n®

CM Q•**

*»» o

«=»

<02

oA

Ai—

1

o1—

1

2o Uj ktv

kl O

•oQ. Ok-4

Q2

y o ^k<V - kjQ

<oZ

IQO OU

tv °

***» *

kiO

kj <y 85

k

3

. 0

rH COaCM

CMLAA

A

mOACMLACA

CMAO

i—

1

co

i—

I

0-

1

1

o

CM 00cn

0

1

1 (A

-=f

i—

1

A

CMOC cr o

CM A• CM c

1—

i

a

MC

, rH

o

MO

CMA

i—

I

o

o

CM o

1—

1

A

CM

CM

« o

IC- A-3"

1

1

1

MO

CMA

tc1

1 LT

i—

1

MO

^J- tc- MOA

AGO CM O AO =t AO

txlo

olo

°-fr0^°°

«

oiN

ki®

<0«s

«0

01

«oo

Q•*«. IC- ON

OO

0 OO

»?5

k»

gy

2gg ^ k kj^

0Op<

to k kj ^0; ^<0$ o K

i

k»0

qi k

kj q

Soo u

y

k

*

•Vlj

vlO

k

9$

*o

u QO

S

o

k

ty

Q0

£

0

ikk

94

ki

13S

y

01

<0o

5

C

MOOr\| ys:

klk)

Q£<3

k Q

OA

A

CM

1—

1

in

a

rH

1

(A

6-

1—

1

• mCT\

CM

0 o

CO

rH

rHMOO

i—

1

o

MO

00

OO

O

o

00

CMA

ts

r—

l

• or

i—

1

CA

• ^|-

1

1

CM

6 0

1

1

oAi—

i

A

O

-=t ACMA

o

CM

lc- A

O

CM

CMA

OA

A

1—

1

CVJ

• O

-=t MO

-=t

1

1

1 A

OA

CM

0-

• o

1—

1

OJ

A• -=! S'

=* AO f^o O • . . A^_°

1 1

£

o

t

i—

1

on

© on

i—

i

0^0/ ^-<0

^>o<0°

N

ffi

ffl CM

v>®

kj

10

f» <0©

O

2

QXfe M

so®

»<

"i?

•oXs.

O k

^kj

Ulg <V *$kl

oaU

0/^k

*88

c

o

bO 1 CO •HCN

5

kj

k

« ke

U. o

k.

9 k.

0 k© 5

ku

§

k

as

£1

0

k

k

© 1

SO 1

D Q <a 5

k.u

o£

H

1 1

k.

<0

1

k.

| ty

k ] k

© IQ

rs O O

k w

© s r-v fe fa

§

0. ®

fQ

If **

o

*«J5

i3 y

fS 4J 0

4f o- ^5 k*

^3

1V 'H Q#U

cvw

ft! 0

V) c?

e

H. a. H

H4T

klCN O 1 H W

I

* ^ ss5 «o 2 5 5 5

k. u.

<t m

i—i »CS rH O i

0

5^ k

* 2

kl t V

kl ly k « 0

**?$

2 O k

2 k|

k. 5 0!

kj

<v

")

<0

<V0.u's. IVk

kl5

o

IV

«Q

ko

kjs

S 4

8

s©

kj^

<w 3K

Q <t

ei

k!§

k

5 -4 |u

??

j|:*

kjM

k

o

kjs

"t £

|w

>^5*

•a k

v. «> Q't

•i

6f

^5

3 k

k 5

js5 ^kj

fc?

Ui 5«

>-5

c;5

5 kj

«0

V

o kk

°§

kj

IV k

k*S’t 5.*

lu kj « «

5 jv Sfe O

kj N

a. t

<0 kj

V8

0!0

a.1

s

k»u

<V ii

* o

?ik

'ki

kj IV

•4 D

•M k N\

§5

oku

kj

IVk

2k

t k

kO

u

ko

kjk

CV

o

klk

5

2

kio>*

8fkj

tv

0)

M

1

kik

5

JO. O O

2kj

Uj"J Q ^

^kj o k

6

<S*

$ Q

55

°k

2 ^ 82

O iv C k

D 'U

*} Oj

2

0k

VJki

kj«k

5vtk

55

o m; k 0

W

2

0

k

.

kj

kj

IV.

kl2

4

2

ok

3

2

o

k

u

*i

kiklk

?

w

2

2

kjQ

2

oo

v

2o

ku

kjIVk

3

«

24

O

o

t

J

q

3

•0O

kjk

kj

o

k!W

t

V*

X^

ki2

5 d *» o 4

U l«V

V

kl 4

*>2 2

k) u Q2“J Ok

U kj k

a

0.

(V0

ko

5

2

5

©x^

k»

o

u.kj©

ivo

2

kjk

Oj©

2

<f)

tv y

kj^ %

25

k (y Ml 5

kl )

iy M

<v <v

<M 5

kj <V 2<M6

M

2 kl 3<V

'C V.

Ujkj

5 ^

K n

o.

CUV

kj <* iv ts ^8

y ul 2 *o

N

k

i

£k!

S <J l

{

ki in

IV 4

^ k

kj Q tk

N

CM

o O ^ w

w

h » «

IV H S

kj pq cQ

tl2

" * o

kor:

ki

kj

<Vk

'V - s

kjt

cn <J- in

ei C\l CM

Table 6

Fig.

21

Fig. 22

CONDENSER

SPECIMEN

no.

a

MFR.

KfMggffl

1

*

TfWftHf

UBS

NO.

iso-58

SIZE

C

~

CLASS

TOP

VIEW

yjQ

0-00-0 00 0-0 0000 00 00 000J0

0000 00 00 00O0 00 0=0 00 O0

0000 00 00 0-0 0-0 00 0© 00O o 00 00 00 00 00 00 00 0© 000 o

00 00 00 00 O0

00 00 00 00 0Q ©0 00 00 00 00 i 00 00 00 00 ©0§

H

%

Fig.

23

CONDENSER. SPECIMEN No, 4

MFR. KRAMER TRENTON SIZE - C

NBS NO. 150-58 - 1 ITEM PROPERTY REMARKS

COIL TUBE CHARACTERISTICS

1 MATERIAL Copper

2 NUMBER OF ROWS DEEP 4

3 NUMBER OF TUBES HIGH 32

4 NUMBER OF CIRCUITS IN PARALLEL ~T~

S NUMBER OF TUBES PER CIRCUIT 32

6 TUBE DIAMETER , 0. D. ,IN. 3/8 nominal, see text

7 TUBE WALL THICKNESS , IN. 0.025 approx.

& TUBE RETURN BEND DIAMETER t O.D. , IN

3/8 nominal,, see text

9 GAS INLET CONNECTION DIAM . , O.D. , IN. 7/8

10 LIQUID OUTLET CONN. DIAMETER, O.D, IN. 7/8

II VERTICAL TUBE SPACING , IN. S 1

12 PRIMARY SURFACE AREA , SQ.FT. 36.9

COIL FIN CHARACTERISTICS

1 MATERIAL Aluminum

2 TYPE OF FIN Plate Embossed, slotted

S FIN SPACING , PER INCH 8

4 FIN THICKNESS , IN. 0.011

S SECONDARY SURFACE AREA , SQ.FT. 447.8 '

COIL DIMENSIONS

j 1 FINNED HEIGHT, IN. K 31 7/8

j 2 FINNED WIDTH , IN. F 38 1/8 301 Pins (top section.)

\ 3 FINNED DEPTH, IN. V 4 808 Fins (bottom section

A COIL HEIGHT , IN. H 31

S COIL WIDTH , IN. W 39 7/8

:

! 6 COIL DEPTH , IN. D 3 i 7 COIL DEPTH , OVERALL , IN. N 10 5/8

6 FACE AREA , <SQ. FT. . 8,4

i

j © TOTAL SURFACE AREA, SQ.FT. 484.7 j

OVERALL CONDENSER. DIMENSIONS

1 WIDTH , OVERALL , IN. A 43 1/2

2 WIDTH , SHROUD , IN. B 38 1/4

S HEIGHT , IN. C 31 7/8

A DEPTH , IN. E rrr78

S BELLMOUTH ORIFICE DIAMETER , IN. X 24 5/8

6 BELLMOUTH RADIUS , IN. R 3/4 i

Table 7

CONDENSED

SPECIMEN oz

LA VO•

C\J

cr

CVJ I—

VO

ov

VO

b-I—

on

-3"

tO

LA|e VO

co

in

VO

-=t ov

LA

OV

b-i—

4*

a<Uik

ju. o O

Og

SJu.

<0

V

uj Of O'? o*

<J o.

-=t on

OJon o

CVJ bLA VO

w** Q

<4 5

k'1 Ok2 *

4!“ §2u <u «J s 3 'U

*9 <V

O

VO

CO

b-

-=r o

onov *oku

Ul3

•«k5 v tk

40o % k u

Cb LA b-VO

=t -4" o o

b- Ov

Cb

co o

oO CVJ O cr VO <0 VO VO oI—

bCVJ o

VO

-=} on oo

•=r on o

-©ko*5 4 <0 O 5 U tyV V

Uj 4 pUJ u Q 5

SIC ov

(J Uj

ON I VO Ion i b- i •^3“ I O

CVJ

O

tbf Cb

co CA

CVJ ov

-3- on -3- co

r—

rH t>LAO

LAO

O

d"VOO

LA.lAO 0

OV

b-1 1 I I VO O i—

ontOO

rnj cvjUt^d-o

•> •! • • • b-| voiomao

=d" oHiH 1k [ U. U. i { , < t 3 3 3 | k | k 1 k j Q. OQ j «Q CQ

in

CM CM

Table 8

4 . 0 Comparison of Five Kramer Trenton Condensers

Table 9 shows the total heat rejection capacity for five Kramer

Trenton condensers (including two Size B condensers previously reported

in NBS Report No. 6670). 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.

Table 9

TOTAL HEAT REJECTION OF FIVE KRAMER TRENTON CONDENSERS

Total Heat Rejection, BTUH

Condenser

NBS No. Class Size

ASRE High

Sat 'n Temp

.

ASRE Low

Sat'n Temp.

QMR&E

High Amb

.

QMR&E

Requirement

134-57 1 A 31430 7180 21440

%

96.2

147-58 1 B

- - 32750a,b 92.0

146-58 2 B 52940 15460 33210a ’ b 93.3

145-58 3 B 47570 13230 34340 96.4

34640b 97.4

150-58 1 C 66030 18970 47980 104.3

Previously reported in NBS Report No. 6670

^Without mixer

Table 10 lists the Heat Transmission Coefficient, BTUH per Ft 2 (°F log mean temperature difference), (Item 24 in Tables of Test Results), and the air entering face velocity based on CFM at test con- ditions (Item 7, Tables of Test Results), for the five Kramer Trenton

condensers

.

Table 10

HEAT TRANSMISSION COEFFICIENT OF FIVE KRAMER TRENTON CONDENSERS

Condenser

NBS No. Class Size

ASRE High

Saturation Temp.

ASRE Low

Saturation Temp.

QMR&E

High Ambient

Trans

.

Air Trans

.

Air Trans

.

Air

Coef f

.

Face Coef f

.

Face Coef f

.

Face

BTUH/ft 2 (°F) Vel

.

BTUH/ft 2

( °F) Vel. BTUH/ft 2 (°F) Vel.

FPMa FPMa FFMa

134-57 1 A 7.41 540 5.29 530 6.94 535

147-58 1 B

- - - - 5 .84b,c 560

146-58 2 B 7.09 605 7.36 595 6.11b ’ c 560

145-58 3 B 6.07 600 6.10 600 6.08 600

6 . 20 c 600

150-58 1 C 5.48 450 5.44 450 6.05 450

a Based on CFM at test conditions (Item 7, Tables of Test Results)

^Ad justed from value reported earlier in NBS Report No. 6670

cWithout mixer

- 12 -

Table 11 gives the Heat Transmission Coefficient, BTUH per Ft 2 (°F log mean temperature dif f erence) (CFM) , (Item 25 in Tables of Test

Results) for the five Kramer Trenton condensers.

Table 11

HEAT TRANSMISSION COEFFICIENT OF FIVE KRAMER TRENTON CONDENSERS

Coefficient, BTUH Per Ft

2 (°F log Mtd) (CFM'

Condenser

NBS No. Class Size

ASRE High

Sat 'n Temp

.

ASRE Low

Sat'n Temp.

QMR&E

High Amb

.

134-57 1 A 0.00407 0.00287 0.00391

147-58 1 B

- - 0 . 00182b ,c

146-58 2 B 0.00206 0.00210 0 . 0019

b ’ c

145-58 3 B 0.00182 0.00172 0.00181

0 . 00185 c

150-58 1 C 0.00161 0.00158 0.00184

a Based on standard air (Item 16 in Tables of Test Results)

^Adjusted from value reported earlier in NBS Report No. 6670

cWithout mixer

- 13 -

Table 12 gives the Heat Transmission Coefficient, BTUH per Ft^

(°F log mean temperature dif f erence) (FPM entering air velocity).

Table 12

HEAT TRANSMISSION COEFFICIENT OF FIVE KRAMER TRENTON CONDENSERS

Coefficient, BTUH Per Ft 2 (°F log Mtd)(FPMa

) Condenser

NBS No. Class Size

ASRE High

Sat'n Temp.

ASRE Low

Sat ’n Temp

.

QMR&E

High Amb

.

134-57 1 A 0.0137 0.00998 0.0130

147-58 1 B - - 0 . 0104b

146-58 2 B 0.0117 0.0124 0 . 0109 b

145-58 3 B 0.0101 0.0102 0.0101

0 . 0103b

150-58 1 C 0.0122 0.0121 0.0134

a Based on entering air velocity at test conditions

^Without mixer

- 14-

5.0 Discussion and Recommendations

Review of the test results in this report and others which have

preceded it in this series indicates need for specification of maximum

refrigerant pressure drop to be maintained during rating tests for

selection of equivalent-duty condensers. Complete condensing and minimum subcooling consistent with this pressure drop should also be re- quired. These requirements should be added to the other obvious items

such as physical size, weight, materials, capacity at specified conditions, etc.

The present practice, as suggested in ASHRAE 20-60, of listing

the air moving capacity of the fan in a given condenser in units of

standard CFM may be misleading in that the volume of air handled by

a given fan in a fixed system is essentially constant for a range of

temperatures. If a fan in a given condenser under test at 110°F en- tering air temperature and 50 percent relative humidity is found to

move, say, 4000 CFM, that same fan and condenser operating at standard

conditions would still move nearly 4000 CFM but at higher density and

horsepower. Listing the performance of the fan in standard CFM for

the actual flow measured at the test conditions would show approximately

4000 x - 3560 CFM Std.

15.00

assuming standard barometric pressure, whereas the fan volume actually

would not drop to this level even if it were operated at standard con- ditions. It would appear preferable to list the actual CFM at the

test conditions in both ratings and requirements.

The critical effect of placing the fan in the condenser shroud

orifice can be observed by comparing the measured air flow for the

three tests in Table 4, 3850, 3860, and 3850 CFM and in Table 8,

3780, 3760, and 3770 CFM with the measured flow rates in the three

tests in Table 6, 3860, 3820, and 3580. In Tables 4 and 8, the three

tests were made without changing the relative position of the fan and

shroud orifice. In Table 6, the first two tests were made at one time,

and the third test at another time, with removal and reinstallation of

the test condenser occuring between the two times. Even though con- siderable care was given to mounting the same fan in each instance in

similar position, the difference of 260 CFM was probably caused by

dissimilar mounting.

Par. 6.3.4 of ASHRAE 20-60 should be corrected to read, "Condensing heat rejection effect: q c - Wrp

(hr ^~ hf^), Btuh" . Note discussion in "Data and Results" of procedure used to calculate the condensing

heat rejection.

\

- 15 -

The total heat rejection (Item 13 of the Tables of Test Results)

shown for all of the condensers tested in this series was determined

by averaging the heat rejection determined by both the air-side, and

refrigerant flowmeter measurements, and correcting for deviation from

specified test conditions. This method of computation was recommended

in ASRE PS-2.4, and for sake of continuity was continued for all tests

in the series, even though ASHRAE 20-60 recommended a different computation method. ASHRAE 20-60 differs in that the heat rejection calculated from the flow rate measured by the (primary) refrigerant calorimeter is taken as the total heat rejection without correction for

deviation from specified test conditions, provided the confirming flow

rate determined by the (secondary) flowmeter is within ± 5 percent of

the flow rate determined by the calorimeter.

- 16 -

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 engi neer i ng i n 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, D. C.

Electricity. R esistance and Reactance. Electrochemistry. Electrical Instruments. Magnetic Measurements.

Dielectrics. High Voltage. Absolute Electrical Measurements.

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

Mass and Volume.

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.

Analytical and Inorganic Chemistry. Pure Substances. Spectrochemistry. Solution Chemistry. Standard Refer- ence Material s. 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 Characterization. Polymer Evaluation and Testing. Applied Polymer Standards and Research. Dental Research.

Metallurgy. Engineering Metallurgy. Metal Reactions. Metal Physics. Electrolysis and Metal Deposition.

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

Crystallography.

Building 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 Processing 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. Organic Chemistry. Molecular Spectroscopy. Ele- mentary Processes. Mass Spectrometry. Photochemistry and Radiation Chemistry.

Office of Weights and Measures. HOIJLDEH, COLO.

CRYOGENIC ENGINEERING LABORATORY

Cryogenic Processes. Cryogenic Properties of Solids. Cryogenic Technical Services. Properties of Cryogenic

Fluids. CENTRAL RADIO PROPAGATION LABORATORY

Ionosphere Research and Propagation. Low Frequency and Very Low Frequency Research. Ionosphere Research. Prediction Services. Sun-Earth Relationships. Field Engineering. Radio Warning Services. Vertical Soundings Research. Troposphere and Space Telecommunications. Data Reduction Instrumentation. Radio Noise. Tropospheric Measurements. Tropospheric Analysis. Spectrum Utilization Research. 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 Standards Physics. Frequency and Time Disseminations. Radio and Microwave Materials. Atomic Fre- quency and Time-Interval Standards. Radio Plasma. Microwave Physics.

Radio Standards Engineering. High Frequency Electrical Standards. High Frequency Cal ibration Services. High

Frequency Impedance Standards. Microwave Calibration Services. Microwave Circuit Standards. Low' frequency

Calibration Services.

Joint Institute for Laboratory Astrophysics- NBS Group (Univ. of Colo.). USCOMM-NBS-DC