The Refrigeration Load - HVAC and Refrigeration Information Links
The Refrigeration Load - HVAC and Refrigeration Information Links The Refrigeration Load - HVAC and Refrigeration Information Links
ALLOWANCE FOR RADIATION FROM THE SUNThe primary radiation factor involved in the refrigerationload is heat gain from the sun’s rays. If the walls of therefrigerated space are exposed to the sun, additionalheat will be added to the heat load. For ease in calculation,an allowance can be made for the sun load inrefrigeration calculations by increasing the temperaturedifferential by the factors listed in Table 6.This table is usable for refrigeration loads only, and isnot accurate for air conditioning estimates.RECOMMENDED INSULATION THICKNESSAs the desired storage temperature decreases, therefrigeration load increases, and as the evaporatingtemperature decreases, the compressor efficiencydecreases. Therefore, from a practical and economicstandpoint, the insulation thickness must be increasedas the storage temperature decreases.Table 7 lists recommended insulation thickness from the1981 ASHRAE Handbook of Fundamentals. The recommendationsare based on expanded polyurethane whichhas a conductivity factor of .16. If other insulations areused, the recommended thickness should be adjustedbase on relative k factors.© 1968 Emerson Climate Technologies, Inc.All rights reserved.12-8
QUICK CALCULATION TABLE FORWALK-IN COOLERSAs an aid in the quick calculation of heat transmissionthrough insulated walls, Table 7A lists the approximateheat gain in BTU per 1°F. temperature difference persquare foot of surface per 24 hours for various thicknessesof commonly used insulations. The thickness ofinsulation referred to is the actual thickness of insulation,and not the overall wall thickness.For example, to find the heat transfer for 24 hoursthrough a 6’ x 8’ wall insulated with 4 inches of glassfiber when the outside is exposed to 95°F ambienttemperature, and the box temperature is 0°F., calculateas follows:1.9 factor x 48 sq. ft. x 95°TD = 8664 BTU12-9© 1968 Emerson Climate Technologies, Inc.All rights reserved.
- Page 2 and 3: FOREWORDThe practice of refrigerati
- Page 4 and 5: INDEX OF TABLESTable 4 Typical Heat
- Page 7 and 8: VALUES OF THERMAL CONDUCTIVITY FORB
- Page 9 and 10: 12-5© 1968 Emerson Climate Technol
- Page 11: 12-7© 1968 Emerson Climate Technol
- Page 16 and 17: © 1968 Emerson Climate Technologie
- Page 18 and 19: © 1968 Emerson Climate Technologie
- Page 20 and 21: © 1968 Emerson Climate Technologie
- Page 22 and 23: © 1968 Emerson Climate Technologie
- Page 24 and 25: LATENT HEAT OF FREEZINGThe latent h
- Page 26 and 27: © 1968 Emerson Climate Technologie
- Page 28 and 29: © 1968 Emerson Climate Technologie
- Page 30 and 31: Section 15SUPPLEMENTARY LOADIn addi
- Page 32 and 33: (A)HEAT TRANSMISSION LOAD(E) REQUIR
- Page 34 and 35: © 1968 Emerson Climate Technologie
- Page 36 and 37: © 1968 Emerson Climate Technologie
- Page 38 and 39: © 1968 Emerson Climate Technologie
- Page 40 and 41: © 1968 Emerson Climate Technologie
- Page 42 and 43: Table 18Table 19© 1968 Emerson Cli
- Page 44: Form No. AE 103 R3 (10/06)Emerson®
QUICK CALCULATION TABLE FORWALK-IN COOLERSAs an aid in the quick calculation of heat transmissionthrough insulated walls, Table 7A lists the approximateheat gain in BTU per 1°F. temperature difference persquare foot of surface per 24 hours for various thicknessesof commonly used insulations. <strong>The</strong> thickness ofinsulation referred to is the actual thickness of insulation,<strong>and</strong> not the overall wall thickness.For example, to find the heat transfer for 24 hoursthrough a 6’ x 8’ wall insulated with 4 inches of glassfiber when the outside is exposed to 95°F ambienttemperature, <strong>and</strong> the box temperature is 0°F., calculateas follows:1.9 factor x 48 sq. ft. x 95°TD = 8664 BTU12-9© 1968 Emerson Climate Technologies, Inc.All rights reserved.
Change language