Testing Procedures

Required Instruments

A fully equipped NCI residential system performance specialist carries the following instruments:

Digital manometer (dual-port): The primary instrument for static pressure measurement. Must be capable of reading 0.001 to 10.000 inches w.c. with +/- 1% accuracy. The dual-port capability allows simultaneous supply and return measurement for direct TESP reading. Recommended models: The Energy Conservatory DG-700 or DG-8, Fieldpiece SDMN6, or equivalent.

TrueFlow air handler flow grid: A calibrated flow measurement plate that replaces the filter for total airflow measurement. Must match the filter size of the system being tested. Carry multiple sizes (16x20, 16x25, 20x20, 20x25) or an adjustable model.

Digital thermometer (dual-channel): For simultaneous supply and return air temperature measurement. Type K thermocouple probes with at least 6-inch length. Resolution of 0.1 degree F. Recommended: dual-input digital thermometer with thermocouple probes.

Powered flow hood: For measuring airflow at individual supply and return registers. The hood must be large enough to capture the entire register. Carry adapters or reducers for different register sizes. Accuracy of +/- 3% when properly sized.

Supporting tools:

• Drill with 3/8-inch bit (for test holes)
• Static pressure tips and tubing
• Test hole plugs
• Screwdriver set
• Mirror and flashlight (for visual inspection)
• Digital camera or phone camera (for documenting conditions)
• Combustible gas detector (for safety check)
• CO detector (personal monitor)

Instrument Calibration

Before every testing session, verify instrument accuracy:

Manometer zero: With both ports open to the same air (no tubing connected), the reading should be 0.000 inches w.c. If it is not, use the zero function to reset. If the manometer cannot zero, it needs service.

Thermocouple verification: Place both thermocouple probes in the same location (in a cup of water works well) and verify they read the same temperature within 1 degree F. If they disagree by more than 1 degree, note the offset and apply it to your readings, or replace the probe.

Flow hood verification: Flow hoods should be factory-calibrated annually. Between calibrations, a spot-check against a known airflow (measured by pitot traverse or the temperature rise method) verifies continued accuracy.

Pre-Test Customer Interaction

Before touching any equipment, spend 5-10 minutes with the homeowner:

1. Explain what you will do: "I am going to run a series of tests on your heating and cooling system to measure how well it is performing. I will test the air pressure in the ducts, the airflow at each register, and the temperatures throughout the system."
2. Ask about their experience: "Are there any rooms that are consistently too hot or too cold? Have you noticed any changes in comfort or energy bills recently? Does the system make any unusual noises?"
3. Set expectations for time: "The full testing process takes approximately 60-90 minutes. I will need the system running for most of that time."
4. Ask about the thermostat: "I may need to adjust the thermostat during testing to put the system in different operating modes. I will return it to your preferred setting when I am done."

Carry a digital manometer, TrueFlow grid, dual-channel thermometer, and powered flow hood as your core instrument set. Verify calibration before every testing session - zero the manometer, cross-check thermocouples, and confirm flow hood accuracy annually. Begin every visit with a brief customer interaction to understand their concerns and set expectations for the testing process.