Library

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.

News article describing the state of the residential battery storage market.

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.

Study investigating measured cooling energy savings in homes across the U.S. from the installation of roofing with higher solar reflectance.

Study investigating measured cooling energy savings from the installation of wall finishes with higher solar reflectance.

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

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.

DOE Energy Saver webpage providing a brief summary of natural ventilation for houses.

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

Report discussing the benefits of modern evaporative cooling systems for use in hot dry climate zones.

Document describing recommended modeling rules, potential compliance credits, and eligibility criteria for residential night ventilation cooling systems for California’s Title 24 energy efficiency standards.

Report describing the experimentally evaluated potential of a novel residential night cooling concept.

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.

Book describing passive cooling techniques from a technical and academic perspective.

This study evaluated 11 measures for passive cooling using four heat resilience metrics with and without grid power in Fresno CA and found the two most effective measures were installing solar-control window films and adding roof insulation; natural ventilation also helped reduce overheating in...

Website providing guidance on passive heating, cooling, and lighting methods.

Paper summarizing passive and low-energy cooling systems for buildings.

Blog article describing considerations for how to use trees for shading to reduce cooling energy demand.

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.

Large scale simulation study investigating the effects of cool roofs and walls on buildings of various vintages across the U.S., with special attention given to California.

Searchable database of over 3,000 roofing products that have undergone solar reflectance and thermal emittance testing.

Searchable database of wall cladding and coating products that have undergone solar reflectance and thermal emittance testing.

This study used an advanced airflow, energy and humidity modeling tool to evaluate the potential for residential mechanical pre-scooling strategies to reduce peak electriciy demand.

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.

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 evaluating mechanical AC precooling strategies in homes as a method for improving the load factor by shifting cooling operation from on-peak to off-peak hours.

DOE report characterizing the installed base of windows and window coverings, and how users operate window coverings in order to enable precise quantification of energy savings.

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...

Web page providing an overview of room-level air conditioning systems such as window units and mini-splits.

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

Webpage discussing the characteristics of sunlight and how cool roofs work to reduce solar heat gain.

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

Study conducted to help determine cost-effective solutions for heating and cooling houses that are designed to be energy efficient.

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.

Webpage describing the STEP campaign encouraging the use of smart diagnostic tools to reduce installation faults.

Website providing consumers with resources to find, select and install heat pump water heaters.