// CODE SNIPPET
E 503.5.6.4 Supply Air Temperature Reset Controls
JUMP TO FULL CODE CHAPTER
Multiple zone HVAC systems shall include controls that automatically reset the supply air temperature in response to representative building loads, or to outdoor air temperature. The controls shall reset the supply air temperature to not less than 25 percent of the difference between the design supply air temperature and the design room air temperature. Controls that adjust the reset based on zone humidity shall be permitted. Zones that are expected to experience relatively constant loads, such as electronic equipment rooms, shall be designed for the fully reset supply temperature.
- Climate zones 0A, 1A, 2A, and 3A.
- Systems that prevent reheating, recooling, or mixing of heated and cooled supply air.
- Systems where not less than 75 percent of the energy for reheating, on an annual basis, is from site recovered or site solar energy sources. [ASHRAE 90.1:18.104.22.168]