Library

Article investigating how a linear input/output relationship can be used as a simple model of the performance of a combination hydronic heating system over heating only, DHW only, and combined loads.

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.

Research project aimed to verify whether homes in the New Jersey HPwES program achieved 30% source energy savings, and if so, what measures were implemented to achieve them.

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.

Website with information and research about residential hot water distribution systems.

Brochure with information on residential solar hot water systems.

A retrofit sheet providing information on elevating and securing water heaters to protect against damage during a flood.

Report presenting results of a laboratory experiment studying combi systems as a mode to eliminate safety issues associated with natural draft appliances.

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...

Information sheet describing tankless hot water heating systems in existing homes.

Document discussing changes in testing the annual performance ratings for solar water heaters.

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

A fact sheet providing homeowners with guidance on properly securing water heaters to prevent them from tipping in an earthquake.

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

Report comparing the performance of seven differing types of residential water heating systems in a side-by-side test configuration over a full year period.

Document about testing of seven water heating systems in the Hot Water Systems laboratory in central Florida.

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.

A website providing information on how to properly size a water heater based on tank size, volume, peak hour demand and other factors.

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.

Report providing a synopsis of a project to evaluate the performance of a roof-integrated solar water heating system.

Website describing how solar water heaters -- also called solar domestic hot water systems -- can be a cost-effective way to generate hot water for your home.

Outlines the minimum criteria for a solar water heating system installed by a Solar Water Heating Program trade ally under Energy Trust of Oregon’s Solar Water Heating Program.

Report providing information based on research and case studies, to remodelers and consumers about opportunities to increase home energy performance.

Report describing the equipment selection of a split system air conditioner and furnace for an example house in Chicago, Illinois, as well as a heat pump system for an example house in Orlando, Florida.

Report about proper water heater selection developed to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

A research paper discussing the use of foundation heat exchangers for ground source heat pump systems in European climates.

Question and Answer article in Energy Design Update describing the cost and savings benefits of electronically commutated motors (ECMs) for HVAC equipment.

Report providing performance results of a home's heat pump water heater and whole-house dehumidifier over a six-month period.

Information for properly sizing gas lines for use with tankless water heaters and other gas appliances.

Document about laboratory testing of five integrated heat pump water heaters (HPWH).

Conference paper summarizing the relative performance of currently available Heat Pump Water Heaters (HPWH) models, the energy implications of different installation locations (garage, basement, or conditioned space) and ducting configurations (exhaust ducting, full ducting, or no ducting), as well...

Case study of new home construction in the hot-humid climate.

Case study of new home construction in the hot-dry and mixed-dry climate zones.

Report about partnership to build three communities of net zero houses.

Presentation report detailing Heat Pump Water Heater (HPWH) interaction with space conditioning systems in real-life test scenarios that explains some of the problems arising from these interaction and information that can be used to make the system more efficient.

Users guide to help contractors and homeowners use the Cold Climate Heat Pump Sizing Support Tools developed by NEEP to size and select the best air source heat pumps for their cold climate location.

Report on investigating the effectiveness of using solar thermal water heaters to address heat losses from piping while recirculating water in multifamily buildings.

Research study comparing TRNSYS Type 604 pipe model against laboratory pipe heat loss test data and detailed field monitoring data.

Report about a project with successful integration of numerous energy-conservation and renewable-energy features into a beautiful, comfortable, and very energy-efficient off-grid home.

State building energy code for the State of Washington.

A info sheet providing information on ENERGY STAR certified water heaters and the various criteria water heaters must undergo to become ENERGY STAR certified, including metrics on efficiency and performance.

A preparedness guide guiding homeowners on how to secure an indoor home water heater safely to wall studs.

Website containing useful resources regarding central heat pump water heater systems.

Fact sheet describing four different efficient hot water delivery (HWD) systems, the trunk-and branch, core, whole-house manifold, and recirculation, with emphasis on system schematics, piping materials, and regulations to design and verify the systems.