BASC Search | Building America Solution Center

These plots compare sizing approaches in terms of the approximate annual heating load a heat pump might carry throughout the year for a hypothetical home in Minneapolis, MN.

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Evaluation of the Thermal and Moisture Performance of Insulating Shades

Reference

DOE-sponsored report describing a study investigating condensation buildup on windows when using insulating shades.

This plot shows a heat pump’s minimum and maximum heating capacities overlaid with a home’s heating load line, allowing a designer to assess how well-suited the equipment is for the specific home.

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This plot shows a heat pump’s minimum and maximum heating capacities overlaid with a home’s heating load line, allowing a designer to assess how well-suited the equipment is for the specific home.

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This plot shows a heat pump’s minimum and maximum cooling capacities overlaid with a home’s cooling load line, allowing a designer to assess how well-suited the equipment is for the specific home.

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Wrong: This heat pump is oversized even for Approach 4, and its modulating zone has a small overlap with the home’s heating load line, resulting in a large amount of short-cycling.

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Air Source Heat Pumps Tax Credit

Reference

This is a federal tax credit for complying air source heat pumpe. Units located in the "North" must meet ENERGY STAR's cold climate heat pump criteria.

Energy and IAQ Implications of Residential Ventilation Cooling

Reference

This study evaluates the energy, humidity and indoor air quality implications of residential ventilation cooling in all US IECC climate zones.

Wrong: Sized per Approach 3, there is small overlap between this heat pump’s modulating zone and the home’s heating load line, resulting in excessive short-cycling; it will require backup heat when the temperature is below 5°F

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This plot shows a heat pump’s minimum and maximum heating capacities overlaid with a home’s heating load line as well as the annual heating load hours for the home, allowing a designer to assess how well-suited the equipment is for the specific home.

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Right: Sized per Approach 3, this heat pump’s modulating zone has a large overlap with the home’s heating load line; it will require backup heating but could still contribute significant heating for all hours of the heating season

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Wrong: Sized per Approach 1 or 2, this heat pump’s modulating zone has a small overlap with the home’s heating load line, resulting in a large amount of short-cycling; the unit will require backup heat when the temperature is below 25°F

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Right (decent): For a relatively high-capacity ccASHP sized per Approach 3 or 4 to meet nearly 100% of the heating load, this heat pump’s modulating zone has a decent overlap with the home’s heating load line, reducing short-cycling.

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Wrong: Sized per Approach 3, there is minimal overlap between this heat pump’s modulating zone and the home’s heating load line, causing excessive short-cycling; it will require backup heat and may not contribute significantly at temperatures below 5°F

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2023 ASHRAE Handbook - HVAC Applications

Reference

Guidebook covering basic principles and data used in the HVAC&R industry. This is the 2023 edition of the handbook, which can be purchased physically or digitally at the reference link in versions using either I-P units of measurement or SI units of measurement.

Measure Guideline: Combined Space and Water Heating Installation and Optimization

Reference

Report describing the installation and operation of forced-air heating and domestic hot water combi systems in residential homes.

Calculating Design Heating Loads for Superinsulated Buildings, Ithaca NY

Case Study

Case study describing heating loads for super-insulated buildings.

Encapsulated Ducts

Guide

Guide that illustrates how and when to encapsulate ductwork in unconditioned attics, increasing the R-value of duct insulation, mitigating condensation issues, and reducing air leakage.

Right: Sized per Approach 3 or 4, this heat pump’s modulating zone has a large overlap with the home’s heating load line, resulting in minimal short-cycling; the unit may require a small amount of backup heat during the very coldest hours of winter.

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Right: Sized per Approach 1, this heat pump will have minimal short-cycling; since sized using Approach 1, it will require backup heat when temp is below 30°F but could still contribute significant heating down to heating design temp (-6°F) and lower

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Combined Space and Water Heating: Next Steps to Improved Performance

Reference

Report describing combined space- and water-heating (combi) systems using a high-efficiency direct-vent burner.

Combustion Safety Simplified Test Protocol Field Study

Reference

Report on a simplified test procedure for combustion safety that is easier to implement and should produce fewer false positives than the previous procedure.

Expert Meeting Report: Recommendations for Applying Water Heaters in Combination Space and Domestic Water Heating Systems

Reference

Expert meeting describing meeting details for recommendations for applying water heaters in combination space and domestic water heating systems.

Mini-Split Heat Pumps Multifamily Retrofit Feasibility Study

Reference

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

Geothermal (Ground-Source) Heat Pumps: Market Status, Barriers to Adoption, and Actions to Overcome Barriers

Reference

Report investigating the status of the geothermal heat pump (GHP) industry and technology in the United States, assembling GHP energy savings potential, identifying key barriers to application of GHPs, and identifying actions that could accelerate adoption of GHPs.

Baseboard radiators are one means of distributing hot water heat

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Split-system air source heat pump

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Interaction between Heat Pump Water Heaters or Other Internal Point Source Loads and a Central Heating System

Reference

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.

Direct Vent Equipment

Guide

Guide describing categories of direct-vent combustion space- and water-heating equipment and combustion safety testing.

An Integrated Control Method for Supplemental Minisplit Heat Pumps in Existing Homes

Reference

Technical report describing how the FSEC Energy Research Center explores low-cost space-conditioning upgrades for existing homes by integrating centrally located, high-efficiency ductless mini split heat pumps with older but functional central space conditioning systems, aiming to achieve energy...