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Whether its Air

Conditioning or

Refrigeration

May 2006

RefrigerationCalculations

by: Garth Denison

Senior Application Engineer

The Sporlan Division of Parker Hannifin assumes no obligation or liability for any advice furnished or for anyresults obtained with respect to this information. All such advice is given and accepted at users risk. This dis-closure of information herein is not a license to operate under, or a recommendation to infringe any patent ofSporlan Division of Parker Hannifin or others.

Registered trademark of Sporlan Division of Parker Hannifin, Washington, MO 63090 USA

Copyright 2003 by Sporlan Division of Parker Hannifin, Washington, MO 63090 USA

This document may be copied and distributed for educational purposes only.

Cold W.A.R. Issue 027

A collection of short

pointed topical papers.

27

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Page 2 - Cold W.A.R. Issue 27

1. Net Refrigeration

Effect, Btu/lb

2. Net Refrigerating

Effect, Btu/lb

3. Net refrigerating

Effect, Btu/lb

4. Refrigerant Circulated,

lb/min

5. Compressor

Displacement, cu ft/min

6. Compressor

Displacement, cu ft/min

7. Heat of Compression,

Btu/lb

8. Heat of Compression

Btu/lb

9. Compression Work,

Btu/min

10. Compression

Horsepower

Heat content of

Vapor leaving

Compressor, Btu/lb

Heat content of

Vapor entering

Compressor, Btu/lb

Refrigerant circulated, lb/min

Compression work, Btu/min

Conversion factor, 42.41 Btu/min - hpor

Btu/hr

2546 Btu/hr - hp

Capacity, Btu/min

Refrigerant circulated, lb/min

Load or capacity, Btu/min

Net refrigeration effect, Btu/lb

Latent heat of

vaporization,

Btu/lb

Change in heat content

of liquid from condensing

to evaporator temperature, Btu/lb

Heat content of

vapor leaving

evaporator, Btu/lb

Heat content of

liquid entering

evaporator, Btu/lb

Refrigerant

circulated, lb/min

Volume of gas

entering compressor, cu ft/lbX

Capacity

Btu/min

Volume of gas

entering compressor, cu ft/lb

Net refrigerating effect, Btu/lb

X

Heat of compression,

Btu/lbRefrigerant circulated,

lb/minX

(42.41 Btu/min - hp) (compression horsepower)

Refrigeration Calculations

Pressure-enthalpy charts are toolsto use in better understanding refrigeration cycles, for judging

whether the operation is normal, and for estimating the effect of change in operation. Learning

how to read the charts and to do the calculations involved will pay rich dividendsin all phases of

refrigeration work.

Examples of various refrigeration calculations are shown below.

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Cold W.A.R. Issue 27 - Page 3

11. Compression

Horsepower

12. Compression

Horsepower

13. Compression

Horsepower per Ton

14. Power, watts

15. Coefficient of

Performance

16. Capacity,

Btu/min

17. Capacity,

Btu/min

18. Capacity,

Btu/min

Heat of compression,Btu/lb Capacity, Btu/min

(42.41 Btu/min - hp) Net refrigeration effect, Btu/lb

Capacity, Btu/min

(42.41 Btu/min - hp) Coefficient of performance

4.716

Coefficient of performance

Compression horsepower per Ton 745.7 w - ton/hp

Net refrigeration effect, Btu/lb

Heat of compression, Btu/lb

Refrigerant circulated, lb/min Net refrigerating effect, Btu/lb

Compressor displacement, cu ft/min

Volume of gas entering compressor, cu ft/lb

Net refrigerating effect, Btu/lb

Compression

horsepower

42.41

Btu/min - hpNet refrigerating

Effect, Btu/lb

Heat of compression, Btu/lb

200

42.41= 4.716

X

X

X

X

X

X

XX

Reference: Fluorocarbon Refrigerants Handbook

Enthalpy

(Btu/lb)

R-134a

erus

se

rP

(

ai

sp

)

45.

1

108.

8

118.

9

40 F

100 F139.0

49.8SST

SCT

Example of # 15

COP =Net refrigeration effect

Heat of compression=

63.7

10.1= 6.61

NRE is108.8

- 45.1

63.7

H of C is118.9

-108.8

10.1

SCT is Saturated Condensing Temperature

SST is Saturated Suction Temperature

Refrigeration Calculations