14
*Only the high limit control devices listed are allowed to be used and at
the setpoints listed. Others such as Dew Point, Fixed Enthalpy,
Electronic Enthalpy, and Differential Enthalpy Controls, may not be
used in any climate zone for compliance with Section 140.4(e)1 unless
approval for use is provided by the Energy Commission Executive
Director.
†At altitudes substantially different than sea level, the Fixed Enthalpy
limit value shall be set to the enthalpy value at 75°F and 50% relative
humidity. As an example, at approximately 6,000 foot elevation, the
fixed enthalpy limit is approximately 30.7 Btu/lb.
NOTE: Table 2 is based on 140.4-b Air Economizer High Limit Shut Off
Control Requirements.
Table 2 — California Title 24 Regional High Limit Dry Bulb Temperature Settings
DEVICE TYPE
CLIMATE ZONES
REQUIRED HIGH LIMIT (ECONOMIZER OFF WHEN:)
DESCRIPTION
FIXED DRY BULB
1,3,5,11-16
Outdoor Air Temperature Exceeds 75°F
2,4,10
Outdoor Air Temperature Exceeds 73°F
6,8,9
Outdoor Air Temperature Exceeds 71°F
7
Outdoor Air Temperature Exceeds 69°F
DIFFERNTIAL DRY BULB
1,3,5,11-16
Outdoor Air Temperature Exceeds Return Air Temperature
2,4,10
Outdoor Air Temperature Exceeds Return Air Temperature Minus 2°F
6,8,9
Outdoor Air Temperature Exceeds Return Air Temperature 4°F
7
Outdoor Air Temperature Exceeds Return Air Temperature 6°F
FIXED ENTHALPY* + FIXED DRY BULB
All
Outdoor Air Enthalpy Exceeds 28 Btu/lb Of Dry Air† Or Outdoor Air Temperature
Exceeds 75°F
