RTF Quarterly Newsletter: Quarter No. 48 April-June 2022

With another quarter in the books, the newest class of RTF members is hitting their stride and keeping the RTF running seamlessly. This quarter members were able to update some long standing measures, approve some new ones, and even tackled updating some underlying supporting materials that RTF measures are built on. With the year halfway done we’re enjoying the fresh eyes and perspectives this new group is bringing to the RTF and we’re excited to continue our work together. You can stay up to date on all RTF decision and news as it happens through the RTF website which is updated throughout the quarter.

Residential HPWH: Update on Exhausted Unit Savings

In April the RTF approved minor updates to the Residential HPWH UES. These updates came out of a study on exhaust-ducted HWPH modeling and energy savings. The previous RTF energy savings estimates looked very different from other published estimates (ACEEE Paper from Larson and Widder). This difference was raised by a stakeholder so contract analyst took another look. They found that exhaust-ducted savings are highly variable and sensitive to, how often HPWH compressor is running, how much outdoor air the compressor is bringing in, and the temperature of that outdoor air. The resulting updates did not result in a significant change in savings or cost-effectiveness

Compressed Air Standard Protocol

In May the RTF approved updates to the Compressed Air Standard Protocol. This protocol establishes methods for estimating the energy savings due to compressed air system retrofit and upgrade projects. Estimation methods in the Protocol are based on an engineering model of energy consumption using parameter inputs informed by the compressed air challenge program documentation and regional expertise. For this update contract analysts worked closely with the compressed air subcommittee to incorporate new measure applications that were proposed since the measure was last updated. These new applications included efficient single speed compressors, demand reduction including switching to an alternate power source, pressure reduction, and desiccant dryers.

Single Family Duct Sealing

After updating MH duct sealing last quarter, the RTF tackled the Single Family Duct Sealing UES and approved updates to the measure at their June meeting. This measure seals the ductwork for central electric or gas HVAC systems where the duct work meets the pre-conditions outlined in the specification. The primary focus of this update was to improve the specification to better align savings to the specification and hopefully support more robust savings into the future. This measure continues to be considered “Planning”, and requires research to ensure savings are reliable. This measure has been planning for many years and if there isn’t demonstrated interest in trying to prove this out, the CAT is likely to recommend deactivation at the next update.

New Measure: Irrigation Pressure Reduction Standard Protocol 

At the last update of the irrigation hardware UES in March 2022, the RTF opted to break out pressure reduction from the measure. This quarter the RTF adopted a new standard protocol for irrigation pressure reduction that reduces pump size or speed to efficiently meet pressure requirement when existing pump is oversized for the irrigation system. Inefficient alternatives use mechanical controls like throttle valves or return loops to add artificial heads or flow to the pump, pressure reduction saves energy by reducing the hydraulic work. The intent of this protocol is that the savings it calculates may be added to the savings from existing irrigation maintenance and upgrades UES’.


Upcoming at the RTF


  • Fridge/Freezer Decommissioning
  • Residential Lighting UES
  • New Measures:
    • Floating Pressure Controls MultiPlex
    • Gas Fireplaces


  • Green Motor Rewind
  • SF & MH Weatherization
  • New Measure: Variable Volume Lab


  • Mid-Stream Lighting UES
  • Potential New Measures:
    • PTHPs for commercial and multifamily
    • Gas packaged rooftop units

Updating Represenatitive Weather Stations for Modeling & Mapping Climate Zones

The RTF approved updates to the calculation methodology and representative cities used in RTF measure analysis. This has been an evolving process, historically, with the RTF always striving to find the most accurate way to represent the region’s climate. The latest evolution was in 2019 when the group updated their methodology for selecting representative weather cities, by characterizing the climate in geographic population clusters using NOAA climate actuals and using those to select the TMY3 station best reflective of the climate within each of the 9 heating zone and cooling zone combinations. At the April 2022 meeting, Justin Sharp and Ben Larson shared with the RTF their analysis of potential new weather data sets that could better model the changing weather in the pacific northwest. They recommended TMYx, which is designed to match TMY3 data format, but has more recent data which will better match today’s weather and climate.

Then, at their June 2022 meeting, the RTF was presented with the results of the data update, from TMY3 to TMYx, and an update to the NOAA climate actuals to a more current data set. Based on these updates, contract analysts recommended new representative cities for the 9 regional heating zone/cooling zone combinations which the RTF approved for use in future measure analysis.


Subcommittee Roundup

  • Agricultural Irrigation Subcommittee: The Irrigation Subcommittee met to review a standard protocol for pressure reduction associated with system upgrades
  • Compressed Air Subcommittee: The Compressed Air Subcommittee met to review the existing standard protocol for Compressed Air systems and the proposed revisions to it.
  • Duct Sealing Subcommittee: The Duct Sealing Subcommittee met to discuss upcoming updates to the RTF’s Single Family Duct Sealing UES
  • Small and Rural Utilities Subcommittee: The Small/Rural Subcommittee meets once a quarter to discuss how to support the specific needs of small and rural utilities. At this quarter’s meeting the group shared their utility’s successes and current efforts that might interest other member and also had a discussion about multi-party initiatives and their applicability to specifically small rural utilities.
  • Operations Subcommittee: The Operations subcommittee meets before each RTF meeting to review and discuss the RTF meeting agendas, decisions, and contracts.

Approved Measure Updates

  • Updated the Residential Line Voltage Thermostats measure as presented. Kept the status Active, the category Planning, updated the specification to include DI versus retail as appropriate, and set the sunset date to April 30, 2025.
  • Adopted updates to the MH Replacement Calculator as proposed and set the review date to May 31, 2027.