Commissioning Instructions

California Title 24 zone level requirements
A6V12035398
Unrestricted
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California Title 24 zone level requirements
2019 CA Title 24 has four zone level requirements that are met by a DXR with proper
configuration connected to Insight 3.14/3.15 or Desigo CC. These requirements
include:
• Dual Maximum Heating (PRESCRIPTIVE)
o §140.4(d)
• Automatic Demand Shed Control (MANDATORY)
o §110.12(b)
o §120.2(h)
o §120.5(a)10
• Demand Control Ventilation (MANDATORY)
o §120.1(c)3
o §120.1(c)4
o §120.1(d)
o §120.1(f)
o §120.5(a)5
• Fault Detection and Diagnostics (MANDATORY)
o §120.5(a)12
Title 24 requires that zones served by VAV systems that are designed to reduce, to a
minimum, the volume of reheated, recooled or mixed air are allowed only if the DDC
controls meet the following requirements:
The volume of primary air that is reheated, recooled or mixed air supply shall not exceed the
larger of:
a) 50 percent of the peak primary airflow; or
b) The design zone outdoor airflow rate as specified by Section 120.1.
ii. The volume of primary air in the deadband shall not exceed the larger of:
-20 percent of the peak primary airflow; or
-The design zone outdoor airflow rate as specified by Section 120.1.
iii. The first stage of heating consists of modulating the zone supply air temperature setpoint up
to a maximum setpoint no higher than 95ºF, while the airflow is maintained at the deadband flow
rate.
iv. The second stage of heating consists of modulating the airflow rate from the deadband flow
rate up to the heating maximum flow rate.
This zone terminal box control sequence is called Dual Maximum VAV Control.
Verification of Dual Maximum VAV control sequence is typically done by the project
CxA. Title 24 requires that acceptance form NRCA-MCH-13A AUTOMATIC FAULT
DETECTION AND DIAGNOSTICS FOR AIR HANDLING UNITS AND ZONE
TERMINAL ACCEPTANCE, SECTION B3 must be completed for zone terminal units
with reheat coils (modulating hot water or electric)