Commissioning Instructions

Step 7 – Default values

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A6V12035398

Step 7 – Default values

To configure a DXR to meet Title 24 requirements, the following features must be

configured as necessary:

• Heating coil

• Ventilation control

• Supply air VAV

• Extract air VAV

Heating coil

To support dual maximum VAV control (“Dual Max”), the following changes must be

made to the heating coil default values.

1) Set the Max.supply air temp.setpoint for heating to be 95°F or lower.

2) Ensure that the Min.supply air temp.setpoint for heating will be lower than the

supply air temperature from the air handler. (eg 50°F).

3) Check the box for Gain to be “Avail. on AS”. The Gain will need to be tuned for

each heating coil as the default value may cause instability of the valve position.

Use this formula as a good starting point for the Gain value:

Gain = 0.8 * ( deadband CFM / max heating CFM ) * default gain

Ventilation control

If the area being served by the DXR is required to provide Demand Control Ventilation

(DCV), then the following ventilation control default values MUST be modified.

Step 1: In the DXR, each room operating mode has its own Minimum room air volume

flow setting. (Check “Avail. on AS” as needed.) For DCV, the min air volume flows for

Comfort and Pre-Comfort may typically be the same value. Minimum room air volume

flow should be determined using a minimum ventilation airflow rate of 0.15 CFM/sq ft.

for the area of the room being served by the VAV terminal box. (e.g., 0.15 CFM/sq ft. x

1,000 sq ft = 150 CFM)

Step 2: Set the ventilation control parameters for Comfort and Pre-Comfort

configurations to MinVntDCV - Minimum ventilation and DCV. (a minimum ventilation is

required due to off gassing of VOCs)

Economy and Protection can be set to Off.

Step 3: Set configuration of DCV to use proportional control only. Turn off the integral

control by setting the parameter Integral action time Tn to zero (0).