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.