How Emerson’s compression solutions are advancing cold climate and peak-load heat pump challenges
A global evolution in the technologies that provide comfort space/water heating and power industrial boilers/furnaces is underway. According to the International Energy Association (IEA), heating for homes, commercial buildings, industry, and related applications accounts for half of all global energy consumption. In the quest for eco-friendly alternatives, electric heat pump technologies have been identified as a proven strategy for transitioning from legacy, fossil fuel-intensive heating technologies.
Already widely implemented in various global regions — including increasing levels of adoption in the U.S. — heat pumps have proved effective in helping homeowners to establish an eco-friendly, energy-efficient, all-in-one heating and cooling strategy. For commercial building and industrial business owners, heat pumps offer a viable means for driving corporate sustainability goals and facilitating the march toward achieving Net Zero greenhouse gas (GHG) emissions-reduction targets.
Federal- and state-sponsored legislation is helping to promote heat pump adoption by offering incentive programs to offset investment costs in new and retrofit applications. The Department of Energy (DOE) and the Environmental Protection Agency’s (EPA) ENERGY STAR® program are actively advancing heat pump technologies through research and development (R&D) efforts and the establishment of energy-efficiency standards.
Ongoing collaboration among these agencies, industry organizations, utility providers and private companies is focused on creating heat pump solutions for more rigorous and/or challenging application requirements:
- Developing cold climate heat pumps (CCHPs) for regions with low ambient (outside) temperatures
- Covering wide heating-to-cooling ratios for combined heating/cooling solutions
- Improving energy efficiencies, regardless of application requirements
- Pioneering large-scale commercial and heavy-duty industrial heating applications
Compression technology is the foundation of current and next-generation heat pump technologies, including progressively more sophisticated strategies to support these increased demands. From light residential to heavy-duty industrial sectors, Emerson is supporting the wider adoption of electric heat pumps with compression technologies that address a full spectrum of application requirements.
Heat pump requirements and emerging challenges
Heat pump technologies work on the principle of capturing available heat — from outside air, water or ground sources — and transferring it for use in indoor spaces and/or water heating. This process is reversed for cooling purposes, capturing indoor building and/or process heat and transferring it outside. As residential and commercial heat pumps have evolved, stakeholders have encountered scenarios that presented challenges to heat pump effectiveness:
- Regions with lower annual ambient (outside) temperatures
- Applications with wide heating-to-cooling ratios or those that have higher load requirements
- High demand for domestic hot water heating
Meeting these application challenges requires the use of more advanced heat pump design strategies and compression technologies. Various types and configurations of fixed-speed, two-stage, three-stage and variable-speed compressors — including those with enhanced vapor injection (EVI) capability — are the enabling technologies for overcoming next-generation heat pump challenges.
Industrial-grade heat pump and compression strategies are required not only in traditional industrial applications but also in larger-scale commercial heating and cooling scenarios, including:
- Large facilities, campuses and district heating
- Boiler and furnace replacement
- Industrial process cooling and heating
Industrial heat pump systems offer reliable and eco-friendly alternatives to legacy fossil fuel-powered solutions. Industrial-duty compression technologies must be purpose-built to withstand the rigors of persistent, peak load conditions while keeping sustainability in mind.
With decarbonization targets as the end goal, it’s important to evaluate the energy efficiency and/or other environmental impacts of residential, commercial and industrial heat pump applications. Although heat pumps provide electric alternatives to fossil fuels, maximizing energy efficiency is equally important in reducing energy costs and minimizing the load placed on the electrical grid.
Compression strategies that leverage capacity-modulation technologies are not only capable of meeting peak load heat pump challenges, but they also help to increase energy efficiency by matching the heating and cooling loads required —enabling heat pumps to ramp up to meet the high demand periods and modulate down for lower demand periods.
Depending on the application and/or the capabilities of the local grid, a hybrid (dual-fuel) system that relies on a fossil fuel-burning technology such as natural gas for peak load periods may offer the most sustainable solution for some geographies at this time. Leveraging refrigerants with low global warming potential (GWP) and those that offer safe, high-efficiency performance is also an important consideration in the sustainability equation.
Advanced compression solutions for heat pump applications
For more than a decade, Emerson has collaborated with original equipment manufacturers (OEMs), national research labs, universities, and utility companies to develop current- and next-generation compression solutions for heat pumps. This includes participation in cooperative research and development agreements (CRADAs) that leverage our next-generation compression solutions to advance heat pump technologies in key applications and market segments.
Emerson has made significant R&D investments to create compression technologies that address the full range of heat pump requirements — from temperate weather and low-load requirements to cold climate strategies and the most difficult peak-load conditions. Emerson has launched — and is continuing to develop — a full suite of heat pump compression solutions that address everything from smaller, residential heat pump applications to progressively larger and more robust commercial and industrial requirements.
Our emerging solutions and CRADA engagements build upon the same proven Copeland™ scroll compressor platform that has led the HVACR industry in reliability and efficiency for decades.
Residential compression solutions
Copeland scroll fixed-speed compressors are already used in many warm-climate residential heat pump applications. Tandem configurations (i.e., two compressors) have proven effective for CCHP applications (see tandem case study).
Copeland scroll two-stage compressors enable capacity modulation for low- and peak-load conditions. By enabling two levels of capacity modulation — at 65 and 100 percent capacities — these two-stage options deliver improved energy efficiency compared to fixed-speed models. To expand upon this capacity modulation range, Emerson is currently testing a Copeland scroll with three-stage capabilities (see case study).
Copeland variable-speed compressors enable the benefits of full variable-capacity modulation. New models are being developed to support the development of CCHPs for lower ambient conditions and conditions that have high heating-to-cooling ratios.
As experts in EVI technology, Emerson is seeking to expand its use in our next generation of heat pump compression and controls platforms in North American markets. EVI enables a significant system capacity boost for the most challenging heat pump requirements.
Tandem compressor, CCHP case study
Between 2012 and 2015, Oak Ridge National Laboratory (ORNL) and Emerson engaged in a CRADA to develop a high-efficiency CCHP for the U.S. residential market. After conducting an exhaustive technological survey to evaluate energy-efficient and cost-effective components, the solution was comprised of tandem (parallel) fixed-speed compressors — one compressor rated for the building’s design cooling load, and the option to run both compressors to meet the 75 percent capacity goal of -13 °F (-25 °C).
The tandem solution delivered significant coefficient of performance (COP) at various load conditions:
- 2 COP at 47 °F (8.3 °C)
- 9 COP at -13 °F (-25 °C, at 76 percent heating capacity)
- 9 COP at 17 °F (-8.3°C)
Three-stage compressor, CCHP case study
In another collaboration with ORNL, Emerson developed and tested a three-stage Copeland scroll compressor in a CCHP scenario. This prototype was designed to replace previous tandem compressor configurations to economize the investment and compressor footprint while delivering improved performance, efficiency and capacity.
The three-stage compressor solution delivered 50, 67 and 100 percent capacity modulation, using the middle stage to provide the rated heat pump capacity of the heat pump (HP). Compared to a tandem configuration, the innovative solution delivered 17 percent nominal capacity gains and a roughly 30 percent cost reduction. While still in the prototype phase, the three-stage compressor reflects Emerson’s commitment to solving challenging CCHP requirements.
Commercial compression solutions
Emerson’s compression solutions for commercial heat pumps offer expanded capacities and scalable solutions for a wide range of application requirements. Multiple Copeland scroll compressors are often used in parallel, including tandem (pair) and trio (three) compressor configurations. Copeland scroll two-stage and variable-speed compressors offer a single-compressor alternative to multiples in certain scenarios.
Globally, the commercial sector is driven by the push toward Net Zero GHG emissions and a mandate to meet increasingly aggressive sustainability targets. Heat pump technologies have already been successfully deployed throughout Europe and other global regions where environmental policies are accelerating the electrification of commercial heating systems.
Already available in global commercial heat pump markets, the application of more advanced Copeland compression technologies is currently being explored in the U.S. and North America. For example, Copeland variable-speed compressors can be leveraged to address challenging CCHPs and high peak-load scenarios, while the integration of EVI technologies across the Copeland compression and controls portfolio has proved effective in Eurasian markets.
U.S. HVAC industry stakeholders have recognized the potential to leverage these advanced Copeland compression technologies for use in the commercial heat pump sector. Emerson is currently pursuing national lab and OEM collaboration opportunities to accelerate research, development and testing of these technologies. Our efforts are focused on expanding commercial heat pump adoption and addressing known challenges in space/water heating and light industrial process heating applications:
- Evaluating CCHP technologies
- Supporting high-temperature heating load requirements
- Developing lower-GWP refrigerant architectures
- Exploring solutions for new building construction and retrofits
Industrial compression solutions
The Vilter™ single-screw industrial compressor is ideal for large commercial and heavy industrial heat pump applications. This proven compressor platform is well-suited for delivering large capacities and maximum reliability in industrial heat pump applications.
Vilter’s latest single-screw offering leverages the A1-rated CO2 refrigerant (R-744) for low-GWP sustainability and application safety, removing the toxicity and flammability concerns of using ammonia (R-717) in highly populated areas, such as large commercial facilities and/or district heating solutions.
For stakeholders who are familiar and comfortable with using ammonia, the Vilter single-screw compressor is already rated and proven as the industry standard. Both CO2 and ammonia options deliver high performance while contributing to overall decarbonization and ultra-low GWP refrigerant goals.
Large commercial heat pump proof-of-concept
In a collaboration with Canadian utility Hydro Quebec, Emerson recently completed 10,000 hours of testing on a large-scale heat pump system using a Vilter CO2 single-screw compressor. Launched in 2020 at the Hydro Quebec Energy Technologies Laboratory (ETL) in Shawinigan, Quebec, Canada, the system was designed to optimize heat pump performance and control in a simulated environment with real-world building load conditions.
The innovative heat pump proof-of-concept demonstrates how the solution can be used to deliver simultaneous, high-efficiency heating and cooling for large buildings such as schools, hospitals, office complexes and industrial facilities. To date, the 1.3 MW system has produced 99.6 percent fewer GHG emissions than comparable boiler/chiller technologies.
Conclusion: Pioneering the next generation of heat pump technologies
Through significant R&D investments in compression technologies, collaborations with national labs, universities, industry organizations and partnerships with leading OEMs, Emerson is helping to advance the heat pump technologies in residential, commercial and industrial sectors. On the path toward wider heat pump adoption in North America, Emerson is already providing the compression solutions to help electrify comfort heating and cooling in many regions.
Over the next several years, we will continue to add to our heat pump compression portfolio, bringing to market new solutions that will address the most challenging application requirements. As our research efforts continue to produce results, we will work toward making these emerging solutions available to the heat market.