Washington Administrative Code › Title 51 - Enterprise Services, Department of (Building Code Council) › Chapter 51-11C - State Building Code adoption and amendment of the 2021 edition of the International Energy Conservation Code, Commercial › Section 51-11C-40342 - Section C403.4.2-Off-hour controls

Current through Register Vol. 24-14, July 15, 2024
C403.4.2
Off-hour
			 controls.
For all occupancies other than Group R, each
zone
shall be provided with thermostatic setback controls that
			 are controlled by either an automatic time clock or programmable control
			 system.
EXCEPTIONS:
1.
Zones
that will be operated
						  continuously.
2.
Zones
with a full HVAC load demand
						  not exceeding 6,800 Btu/h (2 kW) and having a manual shutoff switch located
						  with
ready access
.
C403.4.2.1
Thermostatic setback.
Thermostatic setback controls shall be
			 configured to set back or temporarily operate the system to maintain
zone
temperatures down to 55°F (13°C) or up to
			 85°F (29°C).
C403.4.2.2
Automatic setback and shutdown.
Automatic time clock or
			 programmable controls shall be capable of starting and stopping the system for
			 seven different daily schedules per week and retaining their programming and
			 time setting during a loss of power for at least 10 hours. Additionally, the
			 controls shall have a manual override that allows temporary operation of the
			 system for up to 2 hours; a manually operated timer configured to operate the
			 system for up to 2 hours; or an occupancy sensor.
C403.4.2.3
Automatic start and
			 stop.
Automatic start and stop controls shall be provided for each HVAC
			 system. The automatic start controls shall be configured to automatically
			 adjust the daily start time of the HVAC system in order to bring each space to
			 the desired occupied temperature immediately prior to scheduled occupancy.
			 Automatic stop controls shall be provided for each HVAC system with direct
			 digital control of individual zones. The automatic stop controls shall be
			 configured to reduce the HVAC system's heating temperature setpoint and
			 increase the cooling temperature setpoint by at least 2°F (1.1°C)
			 before scheduled unoccupied periods based upon the thermal lag and acceptable
			 drift in space temperature that is within comfort limits.
C403.4.2.4
Exhaust system off-hour
			 controls.
For all occupancies other than Group R, exhaust systems
			 serving spaces within the conditioned envelope shall be controlled by either an
			 automatic time clock, ther-mostatic controls or programmable control system to
			 operate on the same schedule as the HVAC systems providing their make-up air.
EXCEPTIONS:
1. Exhaust systems requiring continuous
						  operation.
2. Exhaust systems that are controlled by occupancy
						  sensor control configured with automatic on and automatic shutoff within 15
						  minutes after occupants have left the space.
C403.4.2.5
Transfer and
			 destratification fan system off-hour controls.
For all occupancies other than Group R, transfer fan or mixing
				fan systems serving spaces within the conditioned envelope shall be controlled
				by either an automatic time clock, thermostatic controls or programmable
				control system to operate on the same schedule as the associated HVAC
				systems.
EXCEPTION:
Transfer fan and destratification fan systems that are
						  controlled by occupancy sensor control configured with manual on and automatic
						  shutoff within 15 minutes after occupants have left the space.