TECHNICAL RESOURCES

J8 Q U E S T I O N S ? C A L L 4 1 0 . 7 9 9 . 6 2 0 0 O R V I S I T W W W . B A L T I M O R E A I R C O I L . C O M

TECHNICAL RESOURCES

This section contains tables that are commonly used for the design and sizing of evaporative cooling equipment, reproduced from Chapter 14 of the 2013 ASHRAE Handbook-Fundamentals.

› OverviewThe data presented in the tables represents different climatic conditions throughout North America. Dry-bulb temperature data represents the sensible component of outdoor air, whereas wet-bulb temperature data represents the amount of moisture that the air can evaporate. Evaporative cooling equipment selection is based on wet-bulb temperature, as units rely on the process of evaporation to reject heat.

Columns in the table are organized to present dry-bulb and wet-bulb temperatures corresponding to 0.4%, 1% and 2% annual cumulative frequency of occurrence. Each temperature in a column represents the value that is exceeded by the indicated percentage of hours in a year (8,760). For instance, according to Appendix: Design Conditions for Selected Locations from the 2013 ASHRAE Handbook-Fundamentals, the wet-bulb temperature in Huntsville, Alabama will exceed 78.4ºF as shown in Evaporation WB/MCDB column on average 35 hours (0.4%) in any given year. As cooling systems must be designed to meet the peak cooling load, most comfort cooling and light industrial application designs are based on 0.4% annual cumulative frequency of occurrence.

Pages J9 to J21 are Copyright 2013, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org).

Reprinted by permission from 2013 ASHRAE Handbook-Fundamentals. This text may not be copied nor distributed in either paper or

digital form without ASHRAE’s permission.

Wet-Bulb Temperature Selection

P R O D U C T & A P P L I C A T I O N H A N D B O O K V O L U M E V J9

J10 Q U E S T I O N S ? C A L L 4 1 0 . 7 9 9 . 6 2 0 0 O R V I S I T W W W . B A L T I M O R E A I R C O I L . C O M

Reprinted with permission from the 2013 ASHRAE Handbook-Fundamentals. Copyright 2013.

P R O D U C T & A P P L I C A T I O N H A N D B O O K V O L U M E V J11

J12 Q U E S T I O N S ? C A L L 4 1 0 . 7 9 9 . 6 2 0 0 O R V I S I T W W W . B A L T I M O R E A I R C O I L . C O M

Reprinted with permission from the 2013 ASHRAE Handbook-Fundamentals. Copyright 2013.

P R O D U C T & A P P L I C A T I O N H A N D B O O K V O L U M E V J13

J14 Q U E S T I O N S ? C A L L 4 1 0 . 7 9 9 . 6 2 0 0 O R V I S I T W W W . B A L T I M O R E A I R C O I L . C O M

Reprinted with permission from the 2013 ASHRAE Handbook-Fundamentals. Copyright 2013.

P R O D U C T & A P P L I C A T I O N H A N D B O O K V O L U M E V J15

J16 Q U E S T I O N S ? C A L L 4 1 0 . 7 9 9 . 6 2 0 0 O R V I S I T W W W . B A L T I M O R E A I R C O I L . C O M

Reprinted with permission from the 2013 ASHRAE Handbook-Fundamentals. Copyright 2013.

P R O D U C T & A P P L I C A T I O N H A N D B O O K V O L U M E V J17

J18 Q U E S T I O N S ? C A L L 4 1 0 . 7 9 9 . 6 2 0 0 O R V I S I T W W W . B A L T I M O R E A I R C O I L . C O M

Reprinted with permission from the 2013 ASHRAE Handbook-Fundamentals. Copyright 2013.

P R O D U C T & A P P L I C A T I O N H A N D B O O K V O L U M E V J19

J20 Q U E S T I O N S ? C A L L 4 1 0 . 7 9 9 . 6 2 0 0 O R V I S I T W W W . B A L T I M O R E A I R C O I L . C O M

Reprinted with permission from the 2013 ASHRAE Handbook-Fundamentals. Copyright 2013.

P R O D U C T & A P P L I C A T I O N H A N D B O O K V O L U M E V J21