HVAC

Definition

Micro heat pumps are 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 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. Saddle units are generally do-it-yourself (DIY), while others may require infrastructure costs. Typical uses include single-family, accessory dwelling units (ADUs), multifamily situations, mobile homes, hospitality spaces, assisted living facilities, and schools. Unit condensate is managed through drip-free meltwater atomization or water dispersion into air, inside or outside.

Research Initiatives

Research Initiatives	Performance Validation Needs	Market Analysis Needs	Measure Development Needs	Program Development Needs
Window HPs (Room Heat Pumps)
Portable HPs
Through-the-wall HPs (PTHPs/SPVHP)

Opportunities

Micro HPs have the potential to rapidly electrify space heating, replacing existing portable space heaters and older, less efficient room air conditioners with more efficient HPs. As these products become more widely available, some opportunities are emerging. For example:

• This technology family may be especially important for disadvantaged communities and hard-to-reach customers where the majority of households are renters with limited options to improve their electrical or HVAC infrastructure by way of 120V plug-in options.
• Customer usage patterns can help inform the real-world efficiency and electrification potential of these products, for example:
  • Ease of self-installation and customer satisfaction.
  • Cost and performance compared to central heat pumps.
• Value-add to residential space when changing tenants and portability if moving is required.
• In-field performance testing of the units may be of particular interest, as these products become more widely available, to validate issues such as noise, defrost and dehumidification, and ventilation and air-filtration.
  • Cost and performance compared to central heat pumps.
  • Verify value to consumer in sell ownership and portability when moving.
  • Usage patterns that can quantify real-world efficiency and electrification potential.
  • Ease of self-installation and customer satisfaction.
    
    

Barriers

Barriers may include the following:

• Implementation barriers, including product usage patterns, customer sentiment, and understanding overall market awareness.
• Installation practices, including identifying common installation challenges. For example, the setting of the outdoor air damper position, sealing around the unit, decommissioning existing equipment, and thermostat control setting (especially to avoid conflict with controls of central systems) may be challenging.
• Lack of heating performance testing and metrics. This is 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 2025.
• Evaluate the extent to which micro-HPs overcome the split-incentive issue in rental properties by allowing the technology to be owned by the tenant rather than the building owner; this would be a measure barrier as there is an immediate need to account for equipment moving out of the IOU territories.
• A general lack of awareness, including uncertainty around reliability, performance, and long-term savings. A related lack of strong local or community support and education.
• Micro heat pumps are not currently included as standard measures in mainstream low-income programs such as PG&E, SCE, and SDG&E’s Energy Savings Assistance programs or Low-Income Weatherization Program.

Definition

This category includes commercial air-to-air heat pump equipment with over 65,000 btu/h cooling capacity (5.4 tons) or smaller-capacity rooftop units (RTUs), serving commercial spaces and capable of providing both space cooling and heating. Commercial air-to-air heat pump equipment includes split and packaged units. Common examples of air-to-air heat pumps include variable refrigerant flow (VRF) and heat pump RTUs. Other technologies that are considered part of this technology family include those that complement heat pump systems such as improved control systems.

Research Initiatives

Research Initiatives	Performance Validation Needs	Market Analysis Needs	Measure Development Needs	Program Development Needs
Heat Pump RTUs Controls and Infrastructure
Efficient Mechanical Ventilation Strategies
VRF System Optimization for Efficiency

Note: The heat pump refrigerant maintenance topic is noted in the “Commercial HVAC Equipment Installation, Operation, and Maintenance” technology family.

Opportunities

The increased adoption of commercial air-to-air heat pump equipment represents a significant opportunity for energy efficiency and decarbonization of the HVAC energy end use in commercial buildings. Opportunities for increased system efficiency and decarbonization include:

• Optimizing operation and control strategies of packaged equipment.
• Reducing reliance on supplemental heating systems.
• Understanding air-source heat pump equipment retrofit feasibility by region, building type, and baseline system.
• Modeling and infield evaluation of HVAC system efficiency and performance, including system equipment and components that are readily available.
  
  

Barriers

Addressing barriers to heat pump adoption will increase uptake of heat pumps in the commercial HVAC market. Example barriers to increased adoption include:

• An equipment replacement market historically driven by the selection of minimally compliant, standard efficiency equipment and like-for-like replacement.
• Refrigerant leakage, charge management, and a transition to low GWP options.
• A retrofit focus on equipment efficiency ratings over system optimization for efficiency.
• Existing infrastructure limits.
• Limited understanding of the scope of options and costs associated with electrical infrastructure upgrades.

Definition

These are complex HVAC systems with holistic design aimed at achieving high efficiency and low emissions in both new and existing buildings.

Research Initiatives

Research Initiatives	Performance Validation Needs	Market Analysis Needs	Measure Development Needs	Program Development Needs
All-electric Design for New Construction
All-electric Design for Existing Buildings
Standardization for Interoperability of Component Systems
Standardized and Scalable Control Systems

Opportunities

Emerging technology research in this technology family will yield strong energy efficiency savings potential and decarbonization by electrifying space heating, enabling energy recovery, or removing design barriers to decarbonization in large commercial buildings. Example opportunities include:

• Field validation of the performance and cost-effectiveness of electrifying “difficult” existing building HVAC systems, such as those using large boilers for hydronic space heating.
• Assessment of electrical infrastructure impacts, especially in retrofit applications.
• Technoeconomic assessment of benefits — such as floor area, operating cost, total cost of ownership, and TSB — relative to decarbonization solutions.
• Development of design guides and design tools to support market actors to electrify new and existing buildings most cost effectively.
• Development of program strategies for overcoming technical and market barriers.
  
  

Barriers

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 to overcome considerable technical and market barriers in transitioning these complex systems, such as:

• The difficulty of cost-effectively retrofitting and electrifying HVAC systems in the existing building market.
• Lack of understanding the appropriate program designs and deployment mechanisms to address technical and market barriers.

Definition

This technology family is focused on advancing commissioning tools, techniques, and practices that improve the installation, operations, and maintenance of HVAC systems. The goals are to optimize the performance and efficiency of HVAC equipment at the time of installation through quality installation practices and commissioning, and to sustain optimal performance through continuous commissioning and maintenance.

Research Initiatives

Research Initiatives	Performance Validation Needs	Market Analysis Needs	Measure Development Needs	Program Development Needs
Scalable technologies and approaches for quality installation and continuous commissioning
Tools for continuous commissioning in small to medium buildings

Opportunities

Improvements in installation practices, operations, and maintenance will result in energy savings, demand flexibility, and a reduction in refrigerant release emissions. A 2020 Lawerence Berkeley National Lab study found the median simple payback for existing building commissioning is less than two years. The continued advancements within the various normalized metered energy consumption (NMEC) programs mean there is the potential for program delivery improvements within this technology family.

Example opportunities for improving installation, operations, and maintenance of HVAC equipment include:

• Low-cost approaches to existing building commissioning, continuous commissioning, and quality installation.
• Tools to help facility managers and operators incorporate into practice quality installation, operation, and maintenance of HVAC equipment.
• Tools and methods for mitigating refrigerant leaks.
• Program design that helps improve the quality of installations, maintenance practices, and the persistence of energy efficiency measures.
  
  

Barriers

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 and maintenance, some barriers have been identified that could hinder the adoption of the most efficient options, such as:

• Complexity, with operations and maintenance practices needing to be tailored to the unique needs of each building.
• High initial cost for small to medium buildings.
• Lack of dedicated building staff to manage and maintain the HVAC systems and energy.

Definition

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

Research Initiatives	Performance Validation Needs	Market Analysis Needs	Measure Development Needs	Program Development Needs
Heat Recovery Chiller
Air-to-Water Heat Pumps
Software tool development to support product specification
Test Method Development & Validation

Opportunities

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:

• Laboratory applications testing and field demonstration of various multifunction AWHP systems in new construction and existing buildings.
• Data collection to support development of AWHP performance maps and possibly future programs and building codes infrastructure.
• Measure development for heat recovery chillers and AWHPs to support partial or complete fuel substitution in large buildings.
• Conducting cost benefit analysis of retrofitting existing buildings with VRF with hydronic systems.
• Develop multiple standardized system designs for optimal performance in selected applications.
  
  

Barriers

There are several barriers to hydronic heat pumps that could be addressed through emerging technology efforts:

• While manufacturers have developed test procedures under AHRI 550/590, this test procedure has not been adopted by mandatory standards or voluntary standards, which limits the broad reach needed for this market adoption.
• Load flexibility of multifunction AWHPs has not been explored. Controls that incorporate function switching, thermal energy storage (dedicated or DHW volume), and load up/shed all require data, modeling, development, and testing.
• Early adopter approaches are often custom-engineered, site-built systems. Packaged designs are needed for design, equipment, installation, and commissioning cost compression.

Definition

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.

Note: This technology family is cross-listed with the Water Heating TPM.

Research Initiatives

Research Initiatives	Performance Validation Needs	Market Analysis Needs	Measure Development Needs	Program Development Needs
Two-function: Water Heating & Space Heating
Three-function: Hot Water, Space Heating & Space Cooling
Selection Guidelines

Opportunities

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 less overall refrigerant charge 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:

• Laboratory testing of MFHPs to evaluate system performance in various applications.
• Field demonstration or performance validation of MFHP in new construction and existing building applications.
• Market assessment of MFHP for California homes, including cost and requirements associated with MFHP installation in new construction and existing buildings.
• Assessment of the potential TSB value of MFHPs (energy performance, demand flexibility, fuel substitution, and refrigerant emissions) compared with the efficiency of single-function separate heat pump, HVAC, and water heating equipment.
• Assessment of the bill impacts and customer economics of MFHPs (total costs of operation, operating costs under current rate structures, increased value of load shed, etc.) compared with the efficiency of single-function separate heat pump, HVAC, and water heating equipment.
• Development of modeling tools to compare various MFHP types and guide program development and/or support early adopting market actors.
• Understanding workforce needs related to upselling practices to customers, comfort level of installation, and maintenance needs.
• Validation of customer amenity and confirmation that proper hot water temperature and space temperatures can be met.
• Field demonstration and cost-saving or bill performance validation for disadvantaged communities and hard-to-reach residences in a fuel-switch scenario where electrical panel capacity is commonly limited.
  
  

Barriers

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:

• Absence of standardized testing procedures for MFHP evaluation include heat recovery and simultaneous modes of operation.
• Lack of MFHP product offerings compared to international markets, particularly those where hydronic heating is common.
• Limited understanding of how well MFHP systems managing occupant thermal comfort.
• Absence of a standardized installation procedure and contractor or installer knowledge.
• Absence of understanding of the efficiency and decarbonization opportunities of MFHPs compared to independent systems.
• Need for market assessment of MFHP for California homes, including cost and requirements associated with new construction and retrofits.
• Absence of MFHP modeling and design tools.
• Lack of performance standards.
• Lack of awareness, knowledge of benefits, and understanding of sentiment within disadvantaged and hard-to-reach communities for this technology group.

Definition

These are advanced, high efficiency air-to-air heat pump (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; 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

Research Initiatives	Performance Validation Needs	Market Analysis Needs	Measure Development Needs	Program Development Needs
Integrated or Connected Controls
Optimized Design and Quality Installation
Commissioning and Continuous Maintenance

Opportunities

California’s residential heat pump market has seen significant activity as the market continues to take shape through large market transformation efforts such as TECH Clean California. However, to maximize the overall impact of heat pumps, we need continued efforts to ensure that they operate efficiently while satisfying heating and cooling needs, and that they are capable of providing grid services through flexing electric demand.

Example opportunities for increased efficiency and performance in the residential air-to-air heat pump market include:

• Validating new digital commissioning tools in support of quality installations.
• Supporting development of integrated, connected controls to optimize system efficiency as well as energy cost and greenhouse gas savings.
• Development of standards for assessment and design of ductwork for centrally ducted heat pumps (retrofit and new applications).
• Development of smart thermostat technology that controls heat pump and auxiliary heating to optimize energy costs.
• Market-assessment and field performance of “all-in-one” heat pumps and energy recovery ventilator products.
  
  

Barriers

Example barriers to increased adoption of residential air-to-air heat pumps include:

• Compatibility concerns and high costs to purchase and install integrated controls for ductless mini splits, and unknown return on investment.
• Poor existing duct work not well suited for ducted heat pump retrofit applications
• Lack of appropriate controls for variable-speed equipment

Definition

Commercial scalable thermal storage systems encompass 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 greenhouse-gas-intensive, with either greater or less 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

Research Initiatives	Performance Validation Needs	Market Analysis Needs	Measure Development Needs	Program Development Needs
Hot Water Hydronic Thermal Storage
Cold water or Ice Hydronic Thermal Storage
Phase Change Material Thermal Storage
Building Mass Thermal Storage

Opportunities

Thermal storage systems have been in commercial use for decades and present an opportunity for an increased scale of application for decarbonization and higher efficiency. Example opportunities include:

• Storage to serve the non-simultaneous heating and cooling loads commonly found in larger HVAC systems with vapor compression heating and cooling equipment, e.g., air-to-water HPs, heat recovery chillers, etc., and eliminate fossil fuel heating.
• Integration of heating and cooling loops with high mass building structure to reduce equipment cost and control complexity.
• Packaged product solutions and application guidance for designs, installers, and operators.
  
  

Prospective emerging technology studies should build upon the ongoing research of the California IOU CASE Team on this topic, as well as pursue lab and field demonstrations with a viable path to scalability.

Barriers

Technical and market barriers exist for various thermal storage technologies and system types. Example barriers to address include:

• Additional capital cost of thermal storage.
• Additional complexity of design and controls, and need for cross-trade coordination.
• Additional space requirements for equipment.
• Additional risk of equipment failure.
  
  

Thermal storage ideas and projects should identify barriers and provide strategies for mitigating or removing such barriers.