RTF Quarterly Newsletter: Quarter No. 40 April-June 2020

This quarter has seen the RTF into uncharted territory, we had our first all remote meeting in March and haven’t met in person since. With four such meetings now under our belt, the RTF is adjusting and adapting, making the most out of every meeting despite the restrictions of our new format. We have found half day meetings to be more accommodating of our members’ work from home schedules though we have added on an extra day to meetings so the RTF doesn’t fall behind on this year’s work plan. We can’t know how the rest of the year is going to go, but in light of this uncertainty, the RTF has shifted all meetings until the end of the year to a webinar format. So far this new arrangement has proven effective and meetings this quarter have been productive and engaging. The RTF is still updating measures, developing new measures, conferring with subcommittees and supporting our members and stakeholders as best we can. 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.

New Measures Developed by the RTF

Consumer Heat Pump Water Heaters in Commercial Applications

The RTF adopted a new Planning UES for Consumer Heat Pump Water Heaters in Commercial Applications. Heat pump water heaters save energy by using ambient heat to raise the temperature of water, rather than relying solely on electric resistance heat such as with a conventional electric storage water heater. This measure applies specifically to consumer heat pump water heaters replacing electric storage water heaters in commercial buildings. To be considered ‘consumer’ a water heater must have a nameplate input less than or equal to 12 kW, use single phase power, have between 20 and 120 gallons of storage, and be designed for less than or equal to 180 F outlet.

This measure adjusts the RTF residential HPWH UES to apply to commercial buildings, and plans to develop UES for other commercial water heaters. Along with this measure the RTF also adopted a research strategy to address uncertainty around water use adjustment. The aim is to better understand the hot water use of consumer electric water heaters in commercial buildings. The strategy directs this be done by auditing and interviewing 300 sites in order to estimate hot water use and submetering hourly hot water draw for 27 tanks to calibrate common assumptions for audits/interviews.

Force Circulation Generator Engine Block Heaters for Nonresidential Standby Generators

The RTF adopted a new Planning UES to apply a Forced Circulation Generator Engine Block Heater to a Standby Generator. Standby generators (gensets) are used to power buildings in the event of an electric grid outage. As they are often needed to turn on within a matter of seconds, gensets utilize heaters to keep their engine blocks warm and at the ready. The conventional style of engine block heaters simply rely on natural convection alone to circulate coolant throughout the engine. A newer type of block heating, called forced circulation, utilizes a pump to circulate coolant, rather than relying on convection alone and do not need to maintain such a large temperature gradient in the coolant loop. This can lead to lower average loop temperatures resulting in potential energy savings and less coolant system wear and tear.

In developing this measure, staff used data from BPA and Avista to look at the relationship between the outdoor air temperature and the kWh use. They then applied that relationship to TMY data to estimate a pre-retrofit energy and applied the average percent savings to that annual energy use to estimate energy savings as a function of generator size, finding that savings go up with generator size and heating zone.

ENERGY STAR Ice Makers

The RTF approved a new Small Saver UES for ENERGY STAR Ice Makers. The previous ice maker UES, approved in 2008, was deactivated in 2013 primarily due to a lack of regional interest. However, in light of a new ENERGY STAR specification that went into effect in January 2018 the RTF allocated resources to developing a new measure at the end of last year. There are two general categories of ice maker, batch and continuous. Batch-type icemakers operate with alternate freezing and harvesting periods and typically produce cube-type ice. Continuous-type ice makers continually freeze and harvest ice at the same time and primarily produce flake or nugget ice. For both types, energy saving opportunities arise from efficiencies in heat exchangers, compressors, fans and motors. An ENERGY STAR batch ice maker is ~10% more efficient than a standard model while an ENERGY STAR continuous ice maker is ~16% more efficient. For this new measure, identifiers are broken out to align with the ENERGY STAR specification. While there is some uncertainty around duty cycle, the RTF opted to assume a 60% duty cycle rather than ENERGY STAR’s 75%, the measure being a small saver means that no additional research is warranted.

Expanding Weatherization Analysis for Gas Heating Homes

Single Family and Manufactured Home Weatherization

The RTF updated the Single Family and Manufactured Homes Weatherization UES’ in November of last year, but revisited the measures this quarter to update them to include gas heated homes The analysis for gas was generally the same as for the electric side, but with some refinements. The RTF added applications for condensing, non-condensing and any gas system types, though it’s important to not that programs need to choose either the ‘any’ or the ‘condensing/non-condensing’ path and cannot mix and match. The modeling approach and assumptions are the same as those used on for electric homes and SEEM outputs were converted from kWh to therms and an average AFUE based on the RBSA was applied. The SEEM gas calibration that the RTF approved in March was applied as well. The measure continues to be planning for all electric applications and windows in gas homes ,as the RTF felt more evaluations were necessary to ensure a good calibration with SEEM results. The measure is Proven for non-windows weatherization measures in gas heated single family homes and Small Saver for gas heated manufactured homes.

Efficient Pump Systems

Subcommittee Roundup

Approved Measure Changes

In addition to the items highlighted above, in the third quarter of 2019 the RTF voted to approve the following changes to UES measures and Standard Protocols:

Approved the Anti-Sweat Heater Controls UES as presented. Changed the category to Small Saver, the status to Active, and the sunset date to June 30, 2025.
Deactivated the Residential and Commercial Showerheads UES measures.
Approved the updates to the Thermostatic Shower Restriction Valve UES measure as proposed. Kept the category at Planning, the Status at active and the sunset date to June 30, 2023.
Deactivated the Multifamily New Construction (ID and MT) UES measure.
Extended the sunset dates for the New Homes Standard Protocol and School Weatherization UES measures to September 2020.
Approved the updates to the New Manufactured Home and HVAC UES measure as proposed. Specifically set the fraction of heat pumps to 40% and zeroed-out the supplemental NEI’s. Kept the category at Planning, the Status to Active and the sunset date to May 2023.
Approved the proposed research strategy for Commercial and Industrial fans and changed the measure status from Under Review to Active.
Extended the sunset date for the New Manufactured Homes and HVAC UES measure to July 2020.
Approved the proposed research strategy for the High Efficiency Residential Central Air Conditioner UES measure as presented and set the measure status to Active.