## 13.35. NA7.10.1 Electric Resistance Underfloor Heating Systems

At-A-Glance

NA7.10.1 Electric Resistance Underfloor Heating Systems
Use Document NRCA-PRC-08-A
Purpose of the Test
This test ensures that the electric resistance underfloor heating system is thermostatically controlled and disabled during the summer on-peak period defined by the electric utility provider. The test verifies that the electric resistance heater is controlled according to the underfloor temperature, and is forced off during the summer on-peak period, as required per §120.6(a)2.
Instrumentation
Performance of this test will require measuring the amperage of the electrical circuit(s) powering the underfloor heating system. The instrumentation needed to perform the task may include, but is not limited to:
A clamp on amp meter
Test Conditions
The test will be performed by varying the control parameters used by the underfloor heater control system. Therefore, the underfloor heater control system must be installed and operating, including completion of all start-up procedures per manufacturer’s or designer’s recommendations, to perform the test.
Document the value of the initial control parameters before starting the test.
Estimated Time to Complete
Construction inspection: 2 hours (for one system)
Functional testing: 4 hours (for one system)
Acceptance Criteria
The underfloor electric resistance heater must do the following: Turn off when the temperature setpoint is lower than the underfloor temperature (including any dead band or offset).
Turn on when the temperature setpoint is higher than the underfloor temperature (including any dead band or offset). Automatically turn off (and remain off) if the date and time of the control system falls within the summer on-peak period of the electric utility provider, regardless of the underfloor temperature.
Potential Issues and Cautions
Coordinate test procedures with the refrigeration or controls contractor or the facility supervisor since they may be needed to assist with manipulation of the control system.

A. Test Application

Newly Constructed Buildings with Electric Underfloor Heating Systems: Applies to functional testing and verification of the electric resistance underfloor heating system controls.

B. Construction Inspection

The Field Technician should review that the summer on-peak period is programmed into the electric resistance underfloor heating systems.

C. Functional Testing

Step 1: Using the control system, lower the underfloor temperature setpoint to cycle off the electric resistance heater.

Verify and Document:

• Measure the current of the electric heater circuits(s) to confirm the electric resistance heater circuit is off.

Step 2: Using the control system, raise the underfloor temperature setpoint to cycle on the electric resistance heater.

Verify and Document:

• Measure the current of the electric heater circuits(s) to confirm the electric resistance heater circuit is on.

Step 3: Using the control system, change the control system’s date and time to correspond to the local utility company summer on-peak period.

Verify and Document:

• Measure the current of the electric heater circuits(s) to confirm the electric resistance heater circuit is off.

Step 4: Restore the control system to correct date and time, and underfloor temperature control setpoints.

Confirm that the control system is restored back to correct date and time, and that the control system is restored to the initial conditions for the underfloor temperature setpoint and schedules.