TONS OF REFRIGERATION

(GPM X DELTA WATER TEMP) / 24

AIR-SENSIBLE HEAT (BTUH)

CFM X 1.085 X (DRY BULB 1 - DRY BULB 2)

AIR-LATENT HEAT (BTUH)

CFM X 0.68 X (GRAINS 1 - GRAINS 2)

AIR-TOTAL HEAT (BTUH)

CFM X 4.5 X (ENTHALPY 1 - ENTHALPY 2)

HP - PUMP MOTORS

(US GPM X FT HD) / 
(3960 X PUMP EFFICIENCY)

HP - FAN MOTOR

(CFM X INCHES S.P.) / 
(6356 X STATIC EFFICIENCY)

TCU'S

LOAD + ( 0.5 TONS PER 3/4 HP ZONE)

RECTIFIERS

AMPS X VOLTS X 3.414 = BTUH

1 TON REFRIGERATION

12,000 BTUH

1 TON COOLING TOWER

15,000 BTUH

0.293 WATTS

1 BTU

252 CALORIES

0.252 KG-CAL

-40 F

- 40 C

-30 F

-34.4 C

-20 F

-28.9 C

-10 F

-23.3 C

0 F

-17.8 C

10 F

-12.2 C

20 F

-6.7 C

30 F

-1.1 C

40 F

4.4 C

50 F

10 C

60 F

15.6 C

70 F

21.1 C

80 F

26.7 C

90 F

32.2 C

100 F

37.8 C

1 CU FT

7.481 US GALLONS
0.0283 CU METRES

1 CU METRE

35.31 CU FT
264.2 US GALLONS

1 US GALLON

3.785 LITRES
0.833 IMPERIAL GALLONS

2" DIA. PIPE

0.163 US GALLONS PER FT

2 1/2" DIA. PIPE

0.255 US GALLONS PER FT

3" DIA. PIPE

0.367 US GALLONS PER FT

4" DIA. PIPE

0.653 US GALLONS PER FT

6" DIA. PIPE

1.47 US GALLONS PER FT

8" DIA. PIPE

2.61 US GALLONS PER FT

10" DIA. PIPE

4.1 US GALLONS PER FT

12" DIA. PIPE

5.9 US GALLONS PER FT

1 SQ FT

0.0929 SQ METRES

AREA OF A CIRCLE

(DIA X DIA) X 0.7854

CIRCUM OF A CYLINDER

DIAMETER X 3.1415

VOLUME OF A CYLINDER

(DIA X DIA) X
0.7854 X LENGTH

1 INCH

2.54 CM

1 FOOT

30.48 CM

1 YARD

0.9144 METRES

1 MILE

1.609 KILOMETRES

2,000 FT

0.96

4,000 FT

0.91

6,000 FT

0.87

8,000 FT

0.83

PIPE
SIZE

FLOW
GPM

LOSSES
FT. PER
100 FT.

WATER
VELOCITY
FT./SEC.

FLOW
GPM

WATER
VELOCITY
FT./SEC.

1/2"

4

17

4.2

3/4"

9

19

5.4

1"

16

16.5

5.9

1 1/4"

26

10.3

5.6

1 1/2"

40

10.7

6.3

2"

75

10

7.2

2 1/2"

120

10

8

3"

210

9.7

9.1

90

3.9

4"

400

8.5

10.1

180

4.5

6"

960

5.7

10.7

510

5.7

8"

1800

4.8

11.6

900

5.8

10"

2700

3.3

11

1600

6.1

12"

3600

2.4

10.4

2400

6.9

14"

4500

2.3

10.7

3000

7.1

16"

5600

1.8

10.2

4000

7.3

PIPE
SIZE

STD.
ELBOW

TEE
STRAIGHT
THRU

CHECK VALVE
PORT

BALL VALVE
(OPEN)

GATE VALVE
(OPEN)

1/2"

1.5

3

3.5

0.6

0.3

3/4"

2

4

5

0.8

0.5

1"

2.5

5.5

6

1

0.6

1 1/4"

3.5

7.5

9

1.2

0.8

1 1/2"

4.5

9

10

1.3

0.9

2"

5.5

12

13

1.5

1.1

2 1/2"

6.2

14

16

1.5

1.3

3"

8

16

20

2

1.6

4"

11

22

25

2.3

6"

16

32

40

3.5

8"

21

44

50

4.5

10"

26

55

65

6

12"

30

65

75

7

14"

35

80

90

8

16"

40

90

100

9

PERCENT
VOLUME

FREEZE
POINT

SPECIFIC
HEAT

PERCENT
VOLUME

FREEZE
POINT

SPECIFIC
HEAT

10%

23F

0.957

10%

26F

0.98

20%

14F

0.924

20%

18F

0.96

30%

2F

0.897

30%

7F

0.935

40%

-13F

0.849

40%

-8F

0.895

50%

-36F

0.809

50%

-29F

0.85

COOLING TOWER

= 4 GPM PER TON

CHILLING

= 2.7 GPM PER TON

( GPM X ∆ T  ) / 24 = CHILLER TON

( GPM X ∆ T  ) / 30 = TOWER TON

½ =  2 GPM

2½ = 90 GPM

¾ =  5 GPM

3" = 160 GPM

1" = 10 GPM

4" = 320 GPM

1¼ = 20 GPM

5" = 600 GPM

1½ = 30 GPM

6" = 900 GPM

2" = 50 GPM

8" = 2000 GPM

TONS =

( GPM X ∆ T  ) / 24

Nominal Tons

Pipe

CHW

Size

or

(Inches)

CTW

GPM

  GPM

= GALLONS PER MINUTE

1

3

10

  1 GAL

= 8.3#

1 ½

10

30

1 CU FT

= 7.5 GALLONS

2

17

50

  1 TON

= 12000 BTU/HR

2 ½

30

90

EWT °F

= ENTERING WATER TEMP °F

3

53

160

LWT °F

= LEAVING WATER TEMP °F

4

107

320

°F

°C

°F

°C

°F

°C

0

―17.8

7

―13.9

30

―1.1

1

―17.2

8

―13.3

35

1.7

2

―16.7

9

―12.8

40

4.4

3

―16.1

10

―12.2

45

7.2

4

―15.6

15

― 9.4

50

10.0

5

 ―15

20

― 6.7

55

12.8

6

―14.4

25

― 3.9

60

15.6

To Convert

Multiply

To Convert

Multiply

from

To

by

from

To

by

To Convert

Power

US gpm

liters/min

3.785

ft-lb/sec

watts

1.356

US gpm

liters/hr

227.1

hp

watts

745.7

US gpm

cu m/hr

0.2271

hp

kw

0.7457

cfm

liters/min

28.317

hp

cheval-vap

1.0139

cfm

cu m/min

0.02832

cfm

cu m/hr

1.6992

Unit Weight

Heat

lb/ft

kg/m

1.4881

Btu

gr-cal

252

lb/sq in

gr/sq cm

70.31

Btu

kg-cal

0.252

lb/sq in

kg/sq cm

0.07031

Btu/lb

kg-cal/kg

0.5556

lb/cu in

gr/cu cum

27.68

Btu/sq ft

gr-cal/sq cm

0.2713

lb/cu ft

kg/cu m

16.018

Btu/cu ft

kg-cal/cu m

8.899

Length

Weight

inches

mm

25.40

grains

grams

0.0648

inches

cm

2.540

ounces

grams

28.350

inches

meters

0.0254

ounces

kg

0.02835

feet

meters

0.3048

pounds

kg

0.4536

feet

km

0.0003048

pounds

tonnes

0.000454

yards

meters

0.9144

US tons

kg

907.2

yards

km

0.0009144

US tons

tonnes

0.9072

miles

km

1.609

long tons

kg

1016

long tons

tonnes

1.0160

Volume

Area

cu inches

cu cm

16.387

sq inches

sq mm

645.2

cu inches

 liters

0.01639

sq inches

sq cm

6.452

cu feet

cu meters

0.02832

sq feet

sq meters

0.09290

cu feet

liters

28.317

sq yards

sq meters

0.8361

cu yards

cu meters

0.7646

sq miles

sq km

2.590

fl ounces

cu cum

29.57

acres

hectare

0.4047

US gal

cu meters

0.003785

US gal

liters

3.785

60 HERTZ

50 HERTZ OPERATION

GPM

X 0.833 (17%)

HEAD

X 0.694(31%)

B.H.P.

X 0.58 (43%)

3500 RPM

2900 RPM

1750 RPM

1450 RPM