High-efficiency all-electric HVAC systems continue to be a priority for CalNEXT. This includes maturing products such as high-efficiency air-to-air packaged heat pumps as well as less mature product markets, like air-to-water heat pumps intended for gas boiler replacements. CalNEXT is also focused on deploying scalable HVAC solutions and advancing decarbonization design strategies that target the commercial and large multi-family sectors.
The Research Initiatives tables below describe the most important topic areas these technology research areas should be focused on, and the simplified icons indicate where the topic areas stand along the path of progression to technology transfer. The tables are meant to encourage research projects to fill the current gaps and advance the topic areas on the technology transfer path of progression.
High Understanding |
Research in Progress |
Immediate Needs |
Future Research Needed |
CalNEXT expects to take on most or all of the work and cost burden.
CalNEXT has highlighted this technology family as having high impacts within the Technology Category.
Efficient, rapidly deployable HPs that require minimal professional installation and are suitable for compact spaces where HPs can replace electric space heaters or where traditional split-systems are too costly or onerous to deploy. They should connect with standard 110V/120V NEMA 5-15 outlets, without any field-installed refrigerant lines. They can appear in the market in several form factors such as saddle, portable, and through-the-wall. The saddle units are generally do-it-yourself (DIY), while others may require infrastructure costs. Typical uses include single-family, ADUs, multifamily, mobile homes, hospitality, assisted living facilities, and schools. The condensate in these units is managed via either drip-free melt water atomization and/or water dispersion into the internal air or outside air.
| Research Initiatives | Performance Validation | Market Analysis | Measure Development | Program Development |
|---|---|---|---|---|
| Window HPs (Room Heat Pumps) |  |  |  |  |
| Portable HPs | | | | |
| Through-the-wall HPs (PTHPs/SPVHP) | | | | |
Mass deployment of Micro HPs has the potential to rapidly electrify space heating and simultaneously replace existing portable space heaters and older, less efficient room air conditioners with more efficient HPs. Advancements in this technology family may be especially important for DAC and HTR customers since they are a majority renter group with limited options to improve their HVAC infrastructure. These products have the potential to provide a low up-front cost alternative, compared with traditional central heat pump systems, that are significantly more efficient than current systems (portable electric resistance heaters and gas-fired heaters). The adoption of new MHPs will bring in tangible real-world benefits, when compared with single-speed products. Prospective ET studies should investigate deployment costs of 110V/120V HPs when compared with more traditional HVAC solutions and investigate in-field heating performance of these products, to ensure they can fully displace existing electric resistance heaters, since these products have historically been optimized for their cooling performance, rather than their heating performance. Studies investigating customer usage patterns may also help inform the real-world efficiency and electrification potential of these products. Other considerations may include in-field performance of the units to validate any noise, defrost and/or dehumidification, ventilation and/or air-filtration issues, and consumer research detailing the usage patterns, ease of self-installation and customer satisfaction, as these products start to become more widely available. The research opportunities may be “inclusive” of any variant or form factors of these units.
Most MHP products are adaptations of familiar products, such as room air conditioners or portable air conditioners. CalNEXT has made initial investments in this technology family to better understand product costs, product availability, and validate performance. Additional research can inform product usage patterns, customer sentiment, and understand overall market awareness, as these are all anticipated to be early implementation barriers. Installation practices are likely to vary on this product, but much of the appeal is that installation could be performed by end-users. Identifying common installation challenges, in turn, for different product types is needed. For example, these challenges might include the setting of the outdoor air damper position, sealing around the unit, practices related to decommissioning existing equipment, or thermostat control setting.
One major challenge has been the lack of heating performance testing and metrics. It is, however, an area that is quickly evolving as ENERGY STAR® is continuing to develop a test procedure for window heat pumps that is expected to be released in 2024. The new standard(s) will attempt to capture the benefits of variable speed equipment and other advanced features that are not appropriately captured under current metrics. This new standard may be a template for test procedures of other equipment types. This may be particularly important for the predominately mild heating needs of California and common oversizing practices.
CalNEXT expects to take on most or all of the work and cost burden.
CalNEXT has highlighted this technology family as having high impacts within the Technology Category.
Commercial air-to-air heat pump equipment with over 65,000 btu/h cooling capacity (5.4 tons) or smaller capacity roof top units (RTUs), serving commercial space, capable of providing both space cooling and heating. Commercial air-to-air heat pump equipment includes unitary split and packaged units. Common examples include variable refrigerant flow (VRF) and heat pump RTUs. Other technologies that are considered part of this technology family includes those that complement heat pump systems, such as heat recovery; innovative market interventions that lead to increased heat pump adoption; and strategies to reduce the need for additional electrical service.
| Research Initiatives | Performance Validation | Market Analysis | Measure Development | Program Development |
|---|---|---|---|---|
| Heat Pump RTUs | | | | |
| Efficient Ventilation (DOAS/HRV/ERV) | | | | |
| VRF: transitioning to low-leak and sub-750 GWP refrigerants | | | | |
Note: The VRF refrigerant topic may end up being relocated into the “Installation, Operations, and Maintenance” Technology Family pending feedback.
The increased adoption of commercial air-to-air heat pumps systems represent a significant opportunity for energy efficiency and decarbonization of the HVAC energy end use in commercial buildings. While technically mature, the commercial market for high efficiency packaged equipment is still relatively new. Rooftop units represent the most common commercial HVAC equipment in California, yet the large replacement market has been largely driven by minimum-efficiency products with like-for-like replacements, continuing the use of AC-units with gas-fired furnaces, despite higher efficiency alternatives. While California ET programs have historically supported high-efficiency decoupled designs such as VRF, persistent challenges of refrigerant leakage continue and VRF systems will need to both reduce leaks and transition to refrigerants below 750 GWP to remain viable under CARB’s new regulations. Finally, efficient ventilation and, specifically, the use of heat recovery remains an underutilized opportunity in California, particularly for the growing population centers in the more extreme Central Valley. This is even more obvious when considering the different value of energy under the TSB metric, which assigns greater value to energy savings associated with winter and summer peak conditions.
While the commercial HVAC market is very mature, there has been a limited uptake of commercial heat pumps, even with the general growth of heat pumps from other HVAC markets. One of the key barriers is supply chain product availability. While many high-efficiency heat pumps have been developed in multiple HVAC product lines, they commonly need to be custom ordered, a significant challenge in terms of bringing a level playing field for heat pumps to compete with air conditioners. There also needs to be a better understanding of the installation process around the need for electrical upgrades and whether the weight of heat pump equipment would trigger a structural review. In addition, several of the “high efficiency” features are either not well-defined or not mature within the incentive ecosystem, which currently only has an IEER-rating based calculations and is unable to properly account for the performance benefits of variable-speed equipment and does not have a simple way to incentivize heat recovery. CalNEXT should continue its focus on these market barriers and look to coordinate with efforts such as CalMTA’s Efficient RTU (ERTU) market transformation initiative.
CalNEXT expects to take on most or all of the work and cost burden.
CalNEXT has highlighted this technology family as having high impacts within the Technology Category.
A holistic design that is aimed at achieving a high-efficiency, low-emissions HVAC system in both new and existing buildings.
| Research Initiatives | Performance Validation | Market Analysis | Measure Development | Program Development |
|---|---|---|---|---|
| Large building all-electric design (new construction) | | | | |
| Large building all-electric design (existing buildings) | | | | |
| Standardization and interoperability of component systems (e.g. heat recovery chillers, thermal storage, and air-to-water heat pumps) | | | | |
| Standardized and scalable control for all-electric and hybrid central plant operation | | | | |
Emerging technology (ET) research in this technology family will yield strong energy efficiency (EE) savings potential and decarbonization by electrifying space heating, enabling energy recovery, or removing design barriers to future decarbonization in large commercial buildings. Prospective research should focus on:
HVAC designs have been evolving to meet the needs of a decarbonized building future. While technical understanding is growing, particularly in the new construction market, the existing building sector needs research to overcome considerable technical and market barriers in transitioning these complex systems. Research is needed on cost-effectively retrofitting and electrifying HVAC systems in the existing building market, as well as understanding the appropriate program designs and deployment mechanisms to address these technical and market barriers.
CalNEXT expects to take on most or all of the work and cost burden.
CalNEXT has highlighted this technology family as having high impacts within the Technology Category.
This technology family is focused on advancements in commissioning tools, techniques, and practices that improve the installation, operations, and maintenance of HVAC equipment. The goal is to optimize the performance and efficiency of HVAC equipment at the time of installation through quality installation practices, commissioning, and sustaining the optimal performance through continuous commissioning and maintenance.
| Research Initiatives | Performance Validation | Market Analysis | Measure Development | Program Development |
|---|---|---|---|---|
| Scalable technologies and approaches for quality installation and continuous commissioning | | | | |
| Tools for continuous commissioning in small to medium buildings | | | | |
| Refrigerant leak mitigation | | | | |
| Guideline 36 Advancement | | | | |
Improvements in installation, operations, and maintenance have a moderate potential for energy savings, demand flexibility, and reduction in refrigerant-related emissions. Under a 2020 Lawerence Berkely National Lab (LBNL) study, research found median simple payback time for existing building commissioning (EBCx) to be less than two years. The continued advancements within the Normalized Metered Energy Consumption (NMEC) programs means there is the potential for program delivery improvements within this technology family.
Prospective research should focus on: (1) the demonstration of low-cost approaches to existing building commissioning, continuous commissioning, and quality installation programs; (2) the demonstration of tools to help operators incorporate sophisticated asset monitoring; and (3) improvements to existing program models to improve the quality of installations, maintenance practices, and ultimately the persistence of energy efficiency measures.
Technical understanding of installation, operations, and maintenance is mature. To date, adoption of commissioning has been mostly driven by mandatory building code requirements or voluntary code requirements such as California Green Building Standards (Title 24, Part 11) (CALGreen) or Leadership in Energy and Environmental Design (LEED) ratings. While research indicates that existing buildings still have significant cost-effective energy savings opportunities through proper installation, operations, and maintenance, deployment across building types needs to be tailored to the unique needs of each market. Initial cost also remains a significant barrier, especially for small to medium buildings. Utility incentive-based approaches may continue to be important to develop the market capabilities, while California’s policy makers further assess systematic existing building policy approaches, such as the development of building performance standards.
CalNEXT expects to take on most or all of the work and cost burden.
CalNEXT has highlighted this technology family as having high impacts within the Technology Category.
Commercial hydronic heat pumps serve space conditioning and service water needs for multifamily or non-residential buildings with large heating needs, such as a commercial kitchen or a large office building. These may be air-to-water heat pumps (AWHP) designed as boiler replacements or water-to-water heat pumps, such as heat recovery chillers, which can provide partial heating and cooling for facilities with simultaneous loads. This technology family is focused on advancements of the product itself.
Note: This technology family will not focus on the holistic system design or interoperability with other large components, which are spread across several technology families.
| Research Initiatives | Performance Validation | Market Analysis | Measure Development | Program Development |
|---|---|---|---|---|
| Heat Recovery Chiller | | | | |
| Air-to-Water Heat Pumps | | | | |
| Software tool development to support product specification | | | | |
| Test Method Development & Validation | | | | |
Hydronic heat pumps can provide multiple hydronic services to a building to address efficiency and decarbonization market needs across the California multifamily and non-residential sectors. Opportunities for emerging technology research include:
There are a number of barriers to hydronic heat pumps that could be addressed through emerging technology efforts:
CalNEXT expects to take on most or all of the work and cost burden.
CalNEXT has highlighted this technology family as having moderate overall impacts within the Technology Category.
Residential multifunction heat pumps (MFHPs) use an efficient compressor system to serve both space conditioning and water heating requirements of a household, typically configured as a primarily hydronic system. MFHPs can come in multiple formats. Two-function (or combination) heat pump systems serve space heating and water heating demands. Three-function MFHPs provide space cooling in addition.
| Research Initiatives | Performance Validation | Market Analysis | Measure Development | Program Development |
|---|---|---|---|---|
| 2-function: Water Heating & Space Heating | | | | |
| 3-function: Hot Water, Space Heating & Space Cooling | | | | |
| Selection Guidelines | | | | |
Residential MFHPs offer a novel pathway to decarbonization, providing an efficient alternative to existing gas-fired equipment or the current approach of multiple heat pumps (HPWH and a packaged central heat pump). MFHPs can potentially replace space heating, space cooling, and water heating with a single system, depending on the configuration and design. MFHPs have the potential to provide much higher total system benefits by extending the benefits of thermal storage to space heating (and potentially space cooling). In addition, the single heat pump may free up a home’s electrical panel capacity for other electrification uses and could be deployed with lower overall refrigerants than current heat pump practices.
MFHPs are relatively new to the US market, and, as a result, there are many opportunities to improve the understanding of their performance and impact on the residential sector. Opportunities for research include:
As an emerging technology in the US market, there are many barriers to MFHP adoption that could be addressed. Understanding the performance of MFHPs in the context of US homes, the development of testing and installation standards, and the development of equipment selection guidelines are all necessary for understanding the efficacy of MFHPs in meeting California’s decarbonization goals and encouraging MFHP use in California. Specific barriers include:
CalNEXT is interested in collaborating and co-funding projects.
CalNEXT has highlighted this technology family as having moderate overall impacts within the Technology Category.
Advancement of high efficiency air-to-air HP units for use in the residential market, including ducted unitary HPs and ducted or ductless split systems. This technology family includes strategies to ensure adequate part-load performance (proper system sizing or use of variable-speed equipment), commissioning techniques and connected features that improve the installation, operation, and maintenance of residential systems, and deployment of smart thermostats to ensure proper control of variable speed systems and the ability to participate in demand response programs.
| Research Initiatives | Performance Validation | Market Analysis | Measure Development | Program Development |
|---|---|---|---|---|
| Connected Controls/Commissioning | | | | |
| Smart Thermostats | | | | |
| Systems and Services for Coil Cleaning | | | | |
California’s residential HP market has seen significant activity as the market continues to take shape through large market transformation efforts such as TECH Clean California. However, in order to maximize their overall impact, continued efforts are needed to ensure that they are energy efficient and deployed with demand flexible capabilities. The Inflation Reduction Act’s (IRA) 25C tax credit provides market support to encourage higher-efficiency products. Aside from the equipment, additional CalNEXT research should focus on ways to improve high-performing systems from itself, by validating new digital tools in support of quality installations, and by supporting deployment of quality controls to ensure systems have demand flexible capabilities and are properly compatible with the higher-efficiency variable-speed systems.
New thermostats optimized for variable capacity HVAC systems remain an untapped opportunity. To date, there has been limited performance data illustrating the performance differences, despite requests from EPA as part of the ENERGY STAR® Specification v2.0 update. New research should seek to validate the performance of variable-capacity smart thermostats to inform future product standards.
In addition, manufacturers are beginning to release tools that allow for easier commissioning, control, and troubleshooting of residential HVAC systems, often allowing a user or contractor to communicate directly with the HVAC system, even when not physically present. The use of such systems can allow for more seamless commissioning at time of installation and troubleshooting of future problems.
Air-to-Air HPs constitute a well-researched field with mature ratings systems and testing methods. While new ratings and metrics took effect last year for a transition to EER2/SEER2/HSPF2, 2024 will continue to see additional changes, as equipment in the residential market begins to comply with CARB regulations and transition to refrigerants below 750 GWP, such as R-32 and R-454B. These new standards may continue to under-represent the benefits of variable speed equipment and other advanced features that are poorly captured under current metrics. This may be particularly important for the California market, given its predominately mild climate and low heating needs and the common oversizing practices. This can lead to uncertainty as to the real-world benefits of these products, when compared with single-speed products. Continued research will be helpful to ensure the right-sizing of products and may help programs fully account for the known benefits of high-efficiency, variable-speed products.
First cost continues to be a key driver in the residential market. Impactful new product features, such as smart thermostats and connected controls, continue to be seen as premium features. CalNEXT research validating the performance benefits may be important to support faster transfer to programs such as TECH Clean California, as well as statewide IOU programs such as Comfortably California or the Statewide Quality Residential HVAC Services program.
CalNEXT is interested in collaborating and co-funding projects.
CalNEXT has highlighted this technology family as having moderate overall impacts within the Technology Category.
Heat energy-based systems in commercial buildings capable of decoupling the coincident time of HVAC loads and HVAC energy input. Commercial, scalable thermal storage systems can reduce peak demand and shift energy inputs to a time period when electric grid power is lower cost and less GHG-intensive, with either greater or lesser energy efficiency. Scalable systems have been implemented in commercial or residential building applications, could be implemented in larger sizes and higher percentages of building projects, and have the potential for innovative improvements in terms of load shift, efficiency, and cost-effectiveness.
| Research Initiatives | Performance Validation | Market Analysis | Measure Development | Program Development |
|---|---|---|---|---|
| Hot Water hydronic thermal storage | | | | |
| Cold water/ ice hydronic thermal storage | | | | |
| Building mass thermal storage | | | | |
Incorporating thermal storage into HVAC systems has the potential for significant demand flexibility and can reduce the energy consumption, by shifting the HVAC cooling and heating loads to periods with a lower energy cost and less GHG-intensive energy supply. Thermal storage can reduce peak demand by spreading heating and cooling loads over longer periods of time and by shifting to non-peak hours. Commercial thermal energy storage can also support decarbonization by allowing electric heat extraction and heat rejection systems (e.g., air-to-water HPs, heat recovery chillers, etc.) to serve the non-simultaneous heating and cooling loads commonly found in larger HVAC systems. Prospective emerging technology studies should build upon the ongoing research of the CA IOU CASE Team on this topic , as well as pursue lab and field demonstrations with a viable path to scalability. As this is an emerging technological space, there is a need for new market studies to characterize different emerging product types and their uses for commercial building types and HVAC system typologies.
Significant technical and market barriers exist, including a higher capital cost, an added complexity of design and controls, additional space requirements for equipment, added risk of equipment failure, and the need for additional cross-trade coordination. Technical and market barriers can be addressed with packaged product solutions and application guidance for designs, installers, and operators. Thermal storage ideas and projects should identify barriers and provide strategies for mitigating or removing such barriers.
Please refer to the Emerging Technologies Coordinating Council for a complete list of active and completed projects to ensure your project is not duplicative.