Library

Guide describing how to choose energy-efficient water heaters, including heat pump models, with tips on installation, rebates, and incentives for maximizing energy savings.

ENERGY STAR webpage describing how a heat pump water heater works.

Article describing how to use radiator inlet orifices optimize two-pipe steam heating systems.

Factsheet describing how to partially install a heat pump in a manufactured home in the manufactured home factory.

Report describing the identification of barriers and proposed practical solutions for the design, installation, and market adoption of heat pump water heaters in new low-rise multifamily housing, focusing on studio and one-bedroom units.

Factsheet outlining the advantages of using heat pumps, which are an efficient way to heat and cool a home.

Webpage providing curriculum with links to presentations and problem sets for teaching an understanding of sizing cold climate heat pumps.

Report providing information about energy-efficient heating, ventilation, and cooling (HVAC) equipment options to help homeowners cut their energy use, reduce their carbon footprint, and increase their homes comfort, health, and safety.

Report evaluating the relative effectiveness of various control and distribution strategies to improve hydronic space heating performance in existing low-rise multifamily buildings

Journal article detailing laboratory and simulation studies quantifying the impact that heat pump and air conditioner installation faults have on system capacity and efficiency.

Report presenting improved air conditioner (AC) and heat pump (HP) modeling methods in the context of whole-building simulation tools.

Presentation on Improving Air-Conditioner and Heat Pump Modeling.

Report describing the performance, economics, space heating impacts, and user satisfaction of heat pump water heaters (HPWHs) in the upper Midwest, based on a field study and survey of participants in the MECA HPWH incentive program.

Factsheet describing techniques for installing ductless heat pumps in cold climate locations.

Report describing the objective evaluation of space conditioning interactions between heat pump water heaters and home heating systems during winter 2016-2017, revealing a smaller than anticipated impact on space conditioning loads.

Report on performance of current diagnostics as well as a draft test method for use in future air flow evaluations.

Guidance on performance of current diagnostics as well as a draft test method for use in future air flow evaluations.

Report presenting lab evaluation of five heat pump water heaters available in the US market today.

Report proposing mini-split heat pumps as a new retrofit option to replace resistance heating in the Pacific Northwest.

Report describing research conducted to support California’s Title 24, Part 6 Building Energy Efficiency Standards by analyzing the impact of installation location and ventilation on heat pump water heater (HPWH) performance, emphasizing the need for proper installation to maximize efficiency...

Web article describing two options for sizing ductless minisplit heat pumps, including a free HVAC sizing tool.

Report on the long-term performance of mini-split heat pumps.

Report identifying the target market for solar water heaters and potential pathways and cost/performance targets that must be met for these systems to realize large energy savings.

Document providing information on the impact of various defects and the potential energy savings that can result from proper maintenance, and describing a two-step process for diagnosing and correcting faults. This document is targeted towards home performance contractors who are relatively...

Report providing step-by-step instructions for heating contractors and hydronic designers for selecting the proper control settings to maximize system performance and improve response time when using a thermostat setback.

Document with evaluation of 14 heat pump water heaters (including three recently released HPWH products) installed in existing homes in the northeast region of the United States.

Research study outlining results of monitoring a low temperature heat pump.

Report describing a lighting and smart power strip retrofit evaluation that was conducted on 56 all-electric, existing Florida homes to see how lighting and miscellaneous electric loads might be reduced.

This report investigates whether mini-split heat pumps can live up to their potential for one market segment: multifamily retrofits.

Study in which a central heat pump water heater system was monitored in detail and used to create a model for assessing similar systems in various climates.

Database compiling extended capacity data for numerous cold climate heat pump manufacturers and models.

Document on the development of two simple in-home efficiency test methods that can be used by technicians, researchers, or interested homeowners to verify the correct operation and energy efficiency of a homes air conditioning and heating equipment.

Research study using modeling to determine optimal combination(s) of components/pumps, high efficiency heat sources, plumbing configurations and controls that result in the highest overall efficiency for a hydronic system.

Report describing the key findings from the first third-party field validation of 120-volt heat pump water heater (HPWH) technology, addressing the significant barriers to their adoption and emphasizing their potential role in reducing carbon emissions from residential water heating.

Report describing a laboratory assessment on the performance of Rheem 120-volt heat pump water heaters (HPWH), aimed at identifying optimal installation locations for these new "plug-in" models based on comprehensive testing under various conditions.

Fact sheet describing best practices in installing leak-free refrigerant systems, including specifics on creating flare joints and brazed joints, pressure testing, vacuum testing, and charging the system with refrigerant.

Report describing information from DOE about rules and standards for residential air conditioners and heat pumps.

Webpage describing a DOE Cold Climate Heat Pump Challenge. The challenge engages industry partners and focuses around the Cold Climate Heat Pumps, a more environmental and efficient heating alternative to traditional heating.

Research study identifying the best performing, most energy-efficient and cost- effective techniques to provide controlled mechanical ventilation and humidity control in hot- humid climates with thermally efficient building envelopes.

Paper covering a parametric study of foundation heat exchanger-based ground source heat pump systems for several house configurations in a range of European locations, with an emphasis on determining feasible combinations.

Report discussing instrumentation methods and field operation characteristics of two GSHPs in test houses, including a comparison between the manufacturers listed COP values and the COPs calculated from field data.

Report summarizing the results of laboratory testing of 20 advanced power strip products.

This project analyzed combined condensing water heaters or boilers and hydronic air coils to provide high efficiency domestic hot water (DHW) and forced air space heating. Called "combi" systems, they provided similar space and water heating performance less expensively than installing two...

This research paper outlines residential HVAC advanced controls and sensors. It includes a technology review, applications, maintenance and commissioning, occupant behavior and a summary of the state-of-the-art technologies for advanced controls for residential HVAC.

Document reviewing current and potential ventilation technologies for residential buildings with particular emphasis on North American climates and construction.

Article explaining the energy cost reduction and other benefits associated with installing a heat pump clothes dryer

Infographic providing details on choosing the right advanced power strip based on your habits to reduce the electricity wasted when your electronic devices are idle.

Technical study exploring the impact of different installation faults on heat pump performance in a single-family house.

Information sheet describing how to select a properly sized water heater based on household usage patterns, peak demand, and heater type—whether tankless, solar, or storage-based—to ensure efficiency and adequate hot water supply.

Fact sheet describing field validations of a smart ventilation system to assess its effectiveness in assisting low-load homes in humid environments by maintaining acceptable indoor humidity conditions while ensuring adequate ventilation and indoor air quality.