Where used to control
both heating and cooling, zone thermostatic controls
shall be capable of and configured to provide a temperature range or dead band of not less than 5°F
(3°C) within which the supply of heating and cooling
energy to the zone is shut off or reduced to a
minimum.
Exceptions:
- Thermostats that require manual changeover between heating and cooling modes.
- Special occupancy or special applications where wide temperature ranges are not acceptable (such as retirement homes, process applications, museums, some areas of hospitals) and are approved by the Authority Having Jurisdiction. [ASHRAE 90.1:6.4.3.1.2]