Diseño+de+una+caja+de+refrigeración+por+termocélulas

REFRIGERATION SELECTION GUIDE
For Condensing Units & Unit Coolers

Today’s Solution To Your Total Range Of Refrigeration Needs.

© Carrier Corporation 10/91, Rev A 06/03

www.totaline.com

Literature Number: 570-545

REFRIGERATION SELECTION GUIDE
Table of Contents
Introduction: Using The Totaline® Refrigeration Condensing Unit Selection Guide.............................................................. 3 Section One: Performing A Job Survey and Determining Refrigeration Load Job Survey ...............................................................................4 Site Conditions .........................................................................4 Refrigeration Load Calculations ............................................... 4 Refrigeration Load Segments...................................................4 Transmission (Wall Load) .........................................................4 Air Change or Ventilation Load ................................................ 4 The Product Load .................................................................... 5 Other Considerations Specific Heat Latent Heat Heat of Respiration Product Load Formulae MiscellaneousLoads ............................................................... 5 Safety Factor and Other Considerations .................................. 6 Total Load ................................................................................ 6 Load Calculation Forms 8 For rooms below 32°F (sample) ....................................... 8 For rooms below 32°F (blank).......................................... 9 For rooms above 32°F (blank) ........................................ 10 For rooms above 32°F (sample) ......................................11 Section Two: Equipment Selection Considerations Evaporator Coil Selection - System Temperature Difference and Relative Humidity ........................................... 12 Run Time and Defrost Operations..........................................12 Electric Defrost Hot Gas Defrost Water Defrost General Defrost Considerations Compressor / Condensing Unit Selection .............................. 13 Evaporator Selection ...................................................... 13 - 15 Gravity Fin Coils Gravity Booster Unit Coolers (low air units) Space Coolers Unit Coolers Product Coolers Evaporator Layout................................................................. 15 Selecting Thermal Expansion Valves ..................................... 15 Selecting A Heat Exchanger ................................................... 15 Section Three: Tables Table 1 - “U” Values of Various Insulations .......................... 16 Table 2 - Transmission Heat Gain Factors ............................. 16 Table 3 - Average Air Changes Per24 Hours For Storage Rooms ................................................ 17 Table 4 - Heat Removed In Cooling Air To Storage Room Conditions ...................................... 18 Table 5 - Storage Requirements and Properties of Perishable Products ................................... 19 - 23 Table 6 - Approximate Heat of Respiration Rates at Temperature Indicated........................................... 24 Table 7 - Heat Equivalent of Electric Motors ......................... 25 Table 8 - Heat Equivalent of Occupancy ............................... 25 Table 9 - Summer Outdoor Design Data ........................25 - 26 Table 10 - Operating Conditions for Fur Storage .....................27 Table 11 - Insulation Requirements for Storage Rooms ......... 27 Table 12 - SuggestedFreezer Temperatures °F ........................27

2

REFRIGERATION SELECTION GUIDE

Introduction: Using The Totaline® Refrigeration Selection Guide
The Totaline® Refrigeration Selection Guide presents data and examples to assist the installing contractor or engineer when preparing actual refrigeration load estimates and selecting refrigeration equipment. Section One of this publication...