Accessing the Damper Characterization Table

Manually Entering Damper Characterization Data

While not ideal, the damper characterization data can be calculated and entered manually in the AFMS Table. This should only be done if — in the allotted time for Setting Up an AFMS — the ΔT is unlikely to be greater than the Min Delta Temp for the duration of Learning Mode. In that case, for reliability, running Learning Mode at a later available time is still recommended.

Accessing the AFMS Table

  1. Go to AFMS , then select the Device Name of the AFMS controller.

  2. Select theTune tab.

Select the Tune tab.

Interpreting the AFMS Table

Label Description

OA Fraction

Flow

Percentage (expressed as a decimal) of the supply airflow that is outside airflow at the given outside air damper position

Diff Pressure

(pressure assist application only)

The pressure differential (in inches of water column) at the given outside air damper position

See the AFMS documentation for pressure assist information.

Outside Air Closed

Outside air damper at closed position

Outside Air 5

Outside air damper at 0–5% open

Outside Air 10

Outside air damper at 5–10% open

Outside Air 15

Outside air damper at 10–15% open

Outside Air 20

Outside air damper at 10–20% open

Outside Air 30

Outside air damper at 20–30% open

Outside Air 40

Outside air damper at 30–40% open

Outside Air 50

Outside air damper at 40–50% open

Outside Air 60

Outside air damper at 50–60% open

Outside Air 70

Outside air damper at 60–70% open

Outside Air 80

Outside air damper at 70–80% open

Outside Air 90

Outside air damper at 80–90% open

Outside Air 100

Outside air damper at 90–100% open

Calculating the damper characterization data

Use the %OA equation found in ASHRAE Standard 111, section 7.6.3.3: "Flow Rate Approximation by Temperature Ratio".

Note: Find ASHRAE Standard 111 on this page of read-only versions of ASHRAE standards.

Note: See Controlling Airflow with an AFMS for how to set the outside air damper to the required positions for the measurements.

Note: See Monitoring with an AFMS for where to find the sensor readings.

Continue to Operating an AFMS.

Verifying the Damper Characterization Data

Should the damper characterization data require verification, measurements should only be made using NIST-traceable instruments and the method described in ASHRAE Standard 111. (See the details in Manually Entering Damper Characterization Data.)