Commissioning Instructions

App Configuration
Supply Chain Air 11
25
Siemens Industry, Inc.
A6V11668992
Building Technologies
Restricted
2019-03-12
Appendix
Duct Static Pressure Reset – Standards and Guidelines
ASHRAE
90.1-2018
6.5.3.2.3
VAV Setpoint Reset
“For multiple-zone VAV systems having a total fan system motor nameplate horsepower
exceeding 5 hp with DDC of individual zones reporting to the central control panel, static
pressure set point shall be reset based on the zone requiring the most pressure; i.e., the
set point is reset lower until one damper is nearly wide open. Controls shall provide
the following:
a. Monitor zone damper positions or other indicator of need for static pressure.
b. Automatically detect those zones that may be excessively driving the reset logic and gen-
erate an alarm to the system operator.
c. Readily allow operator removal of zones from the reset algorithm.”
IECC -
2017
C403.6.8
Setpoints for direct
digital control
“For systems with direct digital control of individual zones reporting to the central control
panel, the static pressure setpoint shall be reset based on the zone requiring the most
pressure. In such case, the setpoint is reset lower until one zone damper is nearly
wide open. The direct digital controls shall be capable of monitoring zone damper posi-
tions or shall have an alternative method of indicating the need for static pressure that is
configured to provide all of the following:
1. Automatic detection of any zone that excessively drives the reset logic.
2. Generation of an alarm to the system operational location.
3. Allowance for an operator to readily remove one or more zones from the reset algorithm.”
California
Title24 -
2019
Energy Standard:
140.4(c)2B
“For systems with direct digital control of individual zone boxes reporting to the central
control panel, static pressure setpoints shall be reset based on the zone requiring the
most pressure; i.e., the set point is reset lower until one zone damper is nearly wide
open.”
Compliance Manual:
4.5.2.3 VAV Supply
Fan Controls
“For systems with DDC to the zone level the sensor(s) may be anywhere in the distribu-
tion system and the duct static pressure set point must be reset by the zone demand.
Typically, this is done by one of the following methods:
1. Controlling so that the most open VAV box dampers are 95 percent open.
2. A trim and respond algorithm to continually reduce the pressure until one or more zones
indicate that they are unable to maintain airflow rate set points.
3. Other methods that dynamically reduce duct static pressure setpoint as low as possible
while maintaining adequate pressure at the VAV box zone(s) of greatest demand.”
Compliance Docu-
ments: 2019 NRCA-
MCH-07-A Supply
Fan Variable Flow
Controls (A.2.d.i.)
“IF the system includes a direct digital control of individual zone boxes reporting to the
central control panel, THEN static pressure setpoints will be reset based on the zone
requiring the most pressure (i.e., the set point is reset lower until one zone damper is
nearly wide open)”