UpCodes logo
Jump To Full Code Chapter
The purpose of this test is to ensure that both the chilled water and hot water supply temperatures are automatically reset based on either building loads or outdoor air temperature, as indicated in the control sequences. Many HVAC systems are served by central chilled and heating hot water plants. The supply water operating temperatures shall meet peak loads where the system is operating at design conditions. As the loads vary, the supply water temperatures shall be permitted to be adjusted to satisfy the new operating conditions. The chilled water supply temperature shall be permitted to be raised as the cooling load decreases, and heating hot water supply temperature shall be permitted to be lowered as the heating load decreases.
This requirement applies to chilled and hot water systems that are not designed for variable flow, and that have a design capacity greater than or equal to 500 000 Btu/h (147 kW).
E 805.9.1 Test Procedure
The procedure for performing a functional test for supply water temperature reset controls shall be in accordance with Section E 805.9.1.1 and Section E 805.9.1.2.
E 805.9.1.1 Construction Inspection
Prior to functional testing, verify and document the supply water temperature sensors shall be either factory or field calibrated.
E 805.9.1.2 Functional Testing
The functional testing shall be in accordance with the following steps:
Step 1: Change reset control variable to its maximum value. Verify and document the following:
  1. Chilled or hot water temperature setpoint is reset to appropriate value.
  2. Actual supply temperature changes to meet setpoint.
  3. Verify that supply temperature is within 2 percent of the control setpoint.
Step 2: Change reset control variable to its minimum value. Verify and document the following:
  1. Chilled or hot water temperature setpoint is reset to appropriate value.
  2. Actual supply temperature changes to meet setpoint.
  3. Verify that supply temperature is within 2 percent of the control setpoint.
Step 3: Restore reset control variable to automatic control. Verify and document the following:
  1. Chilled or hot water temperature setpoint is reset to appropriate value.
  2. Actual supply temperature changes to meet setpoint.
  3. Verify that supply temperature is within 2 percent of the control setpoint.
E 805.9.2 Acceptance Criteria
The supply water temperature sensors are either factory calibrated (with calibration certificates) or field-calibrated. Sensor performance shall comply with the specifications. The supply water reset is operational.

Related Code Sections

E 805.9 Sustainable Practices, Supply Water Temperature Reset Controls (Form MECH-9A)
for performing a functional test for supply water temperature reset controls shall be in accordance with Section E 805.9.1.1 and Section E 805.9.1.2 ...
E 804.2 Sustainable Practices, Tests
served by the same primary pumps through a common header (Form MECH-8A). Supply water temperature reset control strategies programmed into the building ...
E 805.15 Sustainable Practices, Thermal Energy Storage (TES) System (Form MECH-15A)
resetting the coolant temperature that indicates a full charge to a higher temperature than the current tank leaving temperature. Verify that the tank ...
E 805.15.1 Sustainable Practices, Test Procedure
The functional testing shall be in accordance with the following steps: Step 1: Verify that the TES system and the chilled water plant is controlled ...