Research Newsletter Summer 2022

Jul 20, 2022
man repairing AC unit

This post complements our quarterly research newsletter, which features updates on CEE's research projects. Sign up to get this information in your inbox.

ACEEE 2022 Summer Study on Energy Efficiency in Buildings  

CEE staff will present multiple papers at the 2022 Summer Study on Energy Efficiency in Buildings Pacific Grove, CAfrom August 21–26, hosted by the American Council for an Energy-Efficient Economy (ACEEE). This year’s conference is dedicated to “Climate Solutions: Efficiency, Equity, and Decarbonization.” The theme is an urgent one: buildings account for about a third of U.S. greenhouse gas emissions and will play a critical role in decarbonizing the economy and creating a clean energy future. CEE’s presentations will span advances in air source heat pump technology, energy efficiency in affordable rental housing, the new Minnesota Efficiency Technology Accelerator, and more. CEE presenters will include:

  • Ranal Tudawe, Research Analyst, “Electric Utility Rates are Critical to Broad Space Heating Electrification”
  • Ben Schoenbauer, Senior Research Engineer, “Why We Should Never Install Another Air Conditioner!”
  • Josh Quinnell, Senior Research Engineer, "It's All About the Envelope, Silly"
  • Rebecca Olson, Senior Director of Residential and Community Energy, “Energy Efficiency to Preserve Affordable Rental Housing in Minnesota”
  • Sarah Northrup, Workforce Program Manager, “Equity Focused Minnesota Workforce Development Program”
  • Carl Nelson, Senior Director of Program Development, “How the Minnesota Efficiency Technology Accelerator Will Advance Market Transformation”

Learn more about ACEEE's 2022 Summer Study


Heat Pumps for ACs

AC replacement installationBackground: Manufacturers are adapting to challenges in the adoption of air source heat pump (ASHP) systems by developing new equipment to better integrate with existing systems rather than replace them. This study will use characterization and modeling efforts to examine an emerging market product category of interest to manufacturers: ASHPs sold as central air conditioning (CAC) replacements.

Update: This project is reaching its final stages and will be presented in a CARD webinar on August 4. In addition to conversations with installation contractors, equipment distributors, and manufacturers, input from consumers looking to replace their CACs has informed an assessment of the current opportunities and barriers posed. By exploring different ASHP system archetypes (representing lowest to highest efficiency) and homeowner variables such as existing furnace and CACs, weather, and cost of electricity and natural gas, the research team found that there is an effective heat pump system available for almost every scenario. Further, the flexibility of dual fuel applications supports the ability of heat pump systems to meet the user’s objective, including cost, environmental, and comfort sensibilities — all factors that impact consumer decisions when replacing their current CAC system.

Learn more and register for the webinar

Visit the project page

This project is supported by a grant from the Minnesota Department of Commerce, Division of Energy Resources through the Conservation Applied Research and Development (CARD) program, which is funded by Minnesota ratepayers. 

Operation and Control of Power over Ethernet Technologies 

power over ethernetBackground: Power over Ethernet (PoE) devices are now being integrated across more building systems covering lighting, plug loads, and HVAC controls as a tool to improve buildings’ energy efficiency. PoE devices are connected to network switches, which provide an energy management capability where building automation systems are not in place. Through the use of network switches, the project team will examine how PoE can power and control lighting, plug loads, and HVAC for energy saving purposes.

Update: This spring, the project team presented on this topic in a webinar hosted by the Conservation Applied Research and Development (CARD) program. So far, their findings indicate that PoE systems have the potential to be more efficient than AC systems to manage building energy systems. Most end uses in offices are electronic devices that are natively low-voltage DC, such as LED lamps and DC power supplies, which makes PoE an optimal management system as there is less need to convert between AC and DC. Though AC-powered network systems also have standby modes, the nature of PoE systems allow users to monitor energy loads in a way that can’t be accomplished by an AC system.

Learn more and watch the recorded webinar

Visit the project page

This project is supported by a grant from the Minnesota Department of Commerce, Division of Energy Resources through the Conservation Applied Research and Development (CARD) program, which is funded by Minnesota ratepayers

Variable Capacity Heat Pump Product Assessment and Analysis

air source heat pumpBackground: Northwest Energy Efficiency Alliance (NEEA) enlisted CEE to conduct research on the centrally ducted variable capacity heat pump (VCHP) market. To evaluate the different VCHP products and their key performance features like coefficient of performance, the project team developed representative archetypes. A robust VCHP modeling tool was then created to compare these archetypes and gain a better understanding of the impact these key performance features have on annual energy usage and peak load.

Update: NEEA published the final report for this project and made it available for download on their website. The report describes the heat pump archetypes and outlines the energy consumption impacts of short cycling, sizing, defrost, and duct sealing. The report also compares the levelized lifecycle cost of heating and cooling across the heat pump archetypes. The modeling tool enables users to compare the different heat pump archetypes and understand what performance metrics, attributes, and equipment features lead to better heat pump performance and the lowest levelized cost of ownership for homeowners.

Learn more in the NEEA report