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Guides and Case Studies for All Climates

The Map of the United States shows climate zones in different colors. The Marine zone contains the Pacific coast from the CanadiThe U.S. Department of Energy (DOE) Building America program has developed a series of best practices guides and technology-specific case studies that may be applicable to all climate zones.

Technology Solutions for New and Existing Homes

These case studies from Building America research teams and national laboratories describe energy-saving solutions for both new and existing homes, classified into four basic categories:

Building Envelope

Project: Application of Spray Foam Insulation Under Plywood and OSB Roof Sheathing
Technology Focus: Insulation, existing homes with unvented cathedralized roofs
Profile: Building Science Corporation conducted hygrothermal modeling and explorations of 11 in-service roof systems that used spray polyurethane foam to study the performance of this system for air sealing in complex assemblies, particularly roofs.

Project: Capillary Break Beneath a Slab: Polyethylene Sheeting Over Aggregate
Technology Focus: Foundation, water management
Profile: In this project, IBACOS worked with a builder of single- and multifamily homes in southwestern Pennsylvania (climate zone 5) to understand its methods of successfully using polyethylene sheeting over aggregate as a capillary break beneath the slab in new construction.

Project: Cladding Attachment Over Thick Exterior Insulating Sheathing
Technology Focus: Exterior insulation, new and existing homes
Profile: In this project, Building Science Corporation investigated the benefits—and limitations—of adding insulation to the exterior of buildings as an effective means of increasing the thermal resistance of wood-framed walls and mass masonry wall assemblies.

Project: Cold Climate Foundation Wall Hygrothermal Research Facility
Technology Focus: Building envelope and wall systems
Profile: .This case study describes the University of Minnesota’s Cloquet Residential Research Facility in northern Minnesota, which features more than 2,500 ft2  of below-grade space for building systems foundation hygrothermal research.

Project: Complete and Fully Aligned Air Barrier
Technology Focus: Air sealing, insulation
Profile: This research project, conducted by Pacific Northwest National Laboratory, focused on eliminating excessive humidity in the attic of a multi-floor, single-family home that was causing condensation and water damage along the roof and eaves.

Project: Excavationless: Exterior-Side Foundation Insulation for Existing Homes
Technology Focus: Insulation, foundations
Profile: This project describes an innovative, minimally invasive foundation insulation upgrade technique on an existing home that uses hydrovac excavation technology combined with a liquid insulating foam. Cost savings over the traditional excavation process ranged from 23% to 50%.

Project: Insulating Concrete Forms
Technology Focus: Building envelope
Profile: This Pacific Northwest National Laboratory project investigated insulating concrete forms—rigid foam, hollow walls that are filled with concrete for highly insulated, hurricane-resistant construction.

Project: Interior Foundation Insulation Upgrade - Madison Residence
Technology Focus: Building envelope
Profile: This basement insulation project included a dimple mat conveying inbound moisture to a draintile, airtight spray polyurethane foam wall and floor insulation, and radiant floor heat installation..

Project: Interior Foundation Insulation Upgrade - Minneapolis Residence
Technology Focus: Building envelope
Profile: This interior foundation project employed several techniques to improve performance and mitigate moisture issues: dimple mat; spray polyurethane foam insulation; moisture and thermal management systems for the floor; and paperless gypsum board and steel framing.

Project: Moisture Durability of Vapor Permeable Insulation Sheathing
Technology Focus: Exterior insulation, existing homes with vapor open wall assemblies
Profile: In this project, the Building Science Corporation team researched some of the ramifications of using exterior, vapor permeable insulation on retrofit walls with vapor permeable cavity insulation.

Project: Moisture Management of High-R Walls
Technology Focus: Exterior insulation, existing homes with vapor open wall assemblies
Profile: This project by the Building Science Corporation team focuses on how eight high-R walls handle the three main sources of moisture—construction moisture, air leakage condensation, and bulk water leaks.

Project: Predicting Envelope Leakage in Attached Dwellings
Technology Focus: Building envelope, multifamily housing
Profile: The Consortium for Advanced Residential Buildings team analyzed blower door test results from 112 attached dwelling units in four apartment complexes, in efforts to create a simplified tool for predicting air leakage to the outside in attached housing.

Project: Preventing Thermal Bypass
Technology Focus: Fully aligned air and thermal barriers
Profile: This project highlights the importance of continuous air barriers in full alignment with insulation to prevent thermal bypasses and achieve high energy performance, and recommends use of ENERGY STAR's Thermal Bypass Inspection Checklist.

Project: Stand-Off Furring in Deep Energy Retrofits
Technology Focus: Exterior wall envelope
Profile: This research project, conducted by IBACOS and GreenHomes America, investigated cost-effective deep energy retrofit solutions for improving the building shell exterior while achieving a cost-reduction goal, including reduced labor costs to reach a 50/50 split between material and labor..

Project: Stud Walls with Continous Exterior Insulation for Factory Built Housing
Technology Focus: Walls for factory built housing
Profile: This profile describes the Advanced Envelope Research project, managed by ARIES Collaborative, which will provide factory homebuilders with high performance, cost-effective alternative envelope designs that will meet stringent energy code requirements..

Low-load Heating, Ventilation, Air Conditioning

Project: Balancing Hydronic Systems in Multifamily Buildings
Technology Focus: Space heating
Profile: In this project, the Partnership for Advanced Residential Retrofit team and Elevate Energy explored cost-effective distribution upgrades and balancing measures in multifamily hydronic systems, providing a resource to contractors, auditors, and building owners on best practices to improve tenant comfort and lower operating costs..

Project: Buried and Encapsulated Ducts
Technology Focus: HVAC systems, duct work and attic insulation
Profile: In a study of three single-story houses in Florida, the Consortium for Advanced Residential Buildings team investigated the strategy of using buried and/or encapsulated ducts to reduce duct thermal losses in existing homes.

Project: Ducts in Conditioned Space in a Dropped Ceiling or Fur-down
Technology Focus: HVAC systems, ducts
Profile: This case study examines an inexpensive, quick and effective method of building a fur-down or dropped ceiling chase, which brings the duct system into the interior of the house to reduce air leakage and improve durability and indoor air qualityhomes.

Project: Ducts Sealing Using Injected Spray Sealant
Technology Focus: HVAC duct sealing
Profile: In this project, the Raleigh Housing Authority worked with the Advanced Residential Integrated Solutions Collaborative to determine the most cost-effective ways to reduce duct leakage in its low-rise housing units.

Project: Homeowner's Guide to Window Air Conditioner Installation for Efficiency and Comfort
Technology Focus: HVAC systems
Profile: This step-by-step guide developed by the National Renewable Energy Laboratory describes proper installation of window air conditioning units, in order to improve energy efficiency, save money, and improve comfort for homeowners.

Project: Hydronic Systems: Designing for Setback Operation
Technology Focus: Space heating, water heating
Profile: This guide, developed by Consortium for Advanced Residential Buildings, provides 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..

Project: Improving Comfort in Hot-Humid Climates with a Whole-House Dehumidifier
Technology Focus: HVAC systems, humidity control
Profile: Researchers from the Consortium of Advanced Residential Buildings team monitored the operation of two AC systems coupled with a whole-house dehumidifier for a 6-month period, to study how comfort can be improved while reducing utility costs.

Project: Improving the Field Performance of Natural Gas Furnaces
Technology Focus: HVAC systems, natural gas furnaces
Profile: In this study, the Partnership for Advanced Residential Retrofit team examined the impact that common installation practices and age-induced equipment degradation may have on the installed performance of natural gas furnaces, as measured by steady-state efficiency and AFUE.

Project: New Insights for Improving the Designs of Flexible Duct Junction Boxes
Technology Focus: HVAC, duct design
Profile: IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance.

Project: Optimizing Hydronic System Performance in Residential Applications
Technology Focus: Space heating, water heating
Profile: In this project, the Consortium for Advanced Residential Buildings team worked with industry partners to develop hydronic system designs that would address performance issues and result in higher overall system efficiencies and improved response times.

Project: Properly Sized and Located Return Air Inlet
Technology Focus: HVAC systems, ducts
Profile: For this project, Pacific Northwest National Laboratory researchers improved the duct systems in an existing home to increase safety, comfort and energy performance of HVAC equipment.

Project: Raised Ceiling Interior Duct System
Technology Focus: HVAC systems, ducts
Profile: This project describes a Habitat for Humanity builder’s efforts to construct a home to new DOE Zero Energy Ready Home standards using a fur-up or raised ceiling chase.

Project: Retrofit Integrated Space and Water Heating - Field Assessment
Technology Focus: HVAC systems, water heating
Profile: In this project, the NorthernSTAR team analyzed combined condensing water heaters or boilers and hydronic air coils to provide high efficiency domestic hot water and forced air space heating.

Project: Sealed Air Return Plenum Retrofit
Technology Focus: HVAC systems
Profile: In this project, Pacific Northwest National Laboratory researchers greatly improved indoor air quality and HVAC performance by replacing an old, leaky air handler with a new air handler with an air-sealed return plenum with filter; they also sealed the ducts, and added a fresh air intake.

Project: Steam System Balancing and Tuning for Multifamily Residential Buildings
Technology Focus: HVAC systems, steam heating distribution system and controls
Profile: The Partnership for Advanced Residential Retrofit team conducted a study to identify best practices, costs, and savings associated with balancing steam distribution systems through increased main line air venting, radiator vent replacement, and boiler control system upgrades.

Energy Efficient Components

Project: Air-to-Water Heat Pumps with Radiant Delivery in Low Load Home
Technology Focus: Water heating
Profile: Researchers from Alliance for Residential Building Initiative worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation.

Project: Heat Pump Water Heater Retrofit
Technology Focus: Water heating
Profile: In this project, Pacific Northwest National Laboratory studied heat pump water heaters, an efficient, cost-effective alternative to traditional electric resistance water heaters that can improve energy efficiency by up to 62%.

Project: Performance of a Heat Pump Water Heater in the Hot-Humid Climate
Technology Focus: Water heating
Profile: For a 6-month period, the Consortium for Advanced Residential Buildings team monitored the performance of a heat pump water heater, discovering that it performed 144% more efficiently than a traditional electric resistance water heater and could save approximately 64% on annual water heating costs.

Project: Replacement of Variable Speed Furnace Motors
Technology Focus: HVAC systems
Profile: In this project, the Consortium for Advanced Residential Buildings team tested the Concept 3 replacement motors for residential furnaces in eight homes in and near Syracuse, New York, to test how these brushless, permanent magnet motors can use much less electricity than their permanent split capacitor predecessors.

Project: Replacing Resistance Heating with Mini-Split Heat Pumps
Technology Focus: HVAC systems
Profile: In this project, the Advanced Residential Integrated Solutions team investigated the suitability of mini-split heat pumps for multifamily retrofits.

Indoor Air Quality: Assured Safety, Health, and Durability

Project: Combustion Safety for Appliances Using Indoor Air
Technology Focus: HVAC systems and appliance safety
Profile: In this case study, the Partnership for Advanced Residential Retrofit team provides guidance on how to assess and carry out the combustion safety procedures for appliances and heating equipment that uses indoor air for combustion in low-rise residential buildings.

Project: Impact of Infiltration and Ventilation on Measured Space Conditioning Energy and Moisture Levels in the Hot-Humid Climate
Technology Focus: HVAC systems ventilation
Profile: This case study describes research by the Building America Partnership for Improved Residential Construction team to assess the moisture and cooling load impacts of airtightness and mechanical ventilation in two identical laboratory homes in the hot-humid climate over the cooling season.

Guides for All Climates

DOE has developed several Best Practices guidebooks that are applicable across all climate regions.

For additional, updated information on hundreds of building science topics that can help you build or retrofit to the most recent high-performance construction criteria, including the latest version of ENERGY STAR and the DOE Challenge Home requirements, see the Building America Solution Center.