Advanced Rooftop Controls Subcommittee Meeting: October 5, 2017

This online discussion is a follow-up from the October 5, 2017 subcommittee meeting.  Please provide your feedback by Wednesday, October 12, 2017.

Question:

Should the ARC UES measure assume some percentage of RTU’s go from ventilation-only mode “off” (baseline) to ventilation-only mode “on” (efficient-case)? Please explain your reasoning.

Assumptions:

  • Outdoor Air CFM (when fan running at 100% with the baseline damper setting) = Outdoor Air CFM (when fan running at 40% with efficient-case damper setting, and for full-ARC, where DCV is calling for design outdoor airflow)
    • This will be studied in the research strategy
  • CAT recommends adding the following specification to the measure: “The building’s decision-maker shall understand the measure installation will cause a significant increase in energy consumption if they did not otherwise intend to ventilate the building using the RTU.”

Options:

  1. No, where the RTU is set to operate with the ventilation-only mode “on” in the efficient-case, we should assume 0% of the RTU’s would have operated with the ventilation-only mode “off” in the baseline.
    1. Pick one (or more):
      1. The building’s decision-maker is rational so the counterfactual really is a ventilated building
      2. I don’t care about the counterfactual because ventilation was needed anyway
      3. Other: _______
  2. Yes, where the RTU is set to operate with the ventilation-only mode “on” in the efficient-case, we should assume __% of the RTU’s would have operated with the ventilation-only mode “off” in the baseline.
    1. Pick one:
      1. Reasoning: Even with the “building’s decision-maker understanding” measure specification above, the counterfactual will include some unventilated cases, and we shouldn’t dictate our opinion on ventilation needs of the building
      2. Reasoning: Pre-conditions UES measures should use the observed energy consumption prior to measure installation
      3. Reasoning: _____