BASC Search | Building America Solution Center

Specially designed roof trusses come with a two-foot by two-foot notch cut next to the center post providing space to install an insulated duct chase inside the home’s conditioned space but above the normal ceiling height.

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This Habitat for Humanity builder ordered roof trusses with a 2-foot by 2-foot notch next to the center post then lined the cutout with rigid foam to form an insulated central duct chase to bring the heating and cooling ducts within the conditioned space.

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HVAC ducts, cavities used as ducts, and combustion inlets and outlets may pass perpendicularly through exterior walls but shall not be run within exterior walls unless at least R-6 continuous insulation is provided on exterior side of the cavity

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The fiberglass insulation stuffed into the large hole around this HVAC duct will not prevent air leakage from the unconditioned basement to the conditioned space above; the large gap should be sealed with a rigid air barrier and caulked or spray foamed.

Fiberglass insulation stuffed into the large hole around this HVAC duct won't prevent air leakage from the unconditioned basement to the conditioned space above; the large gap should be sealed with a rigid air barrier and caulked or spray foamed.

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Right - The precast insulated concrete walls of the basement provide a conditioned space for the high-efficiency (18 SEER, 9.5 HSPF) air-source heat pump, with its variable-speed fan, five-stage compressor, and MERV 11 filter.

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Encapsulated Ducts

Video

Video describing air sealing and insulation for encapsulated ducts.

Compact Buried Ducts in a Hot-Humid Climate House

Reference

Report on heating and cooling air-distribution ducts that are insulated, installed close to the ceiling in a vented attic and covered with attic insulation to minimize energy loss.

Ducts in Raised Ceiling Sections

Guide

Guide describing method for designing and installing ducts in a raised ceiling chase.

Building America Top Innovations 2013: Buried and Encapsulated Ducts

Case Study

Case study describing a DOE Building America Top Innovation on HVAC ducts located in vented attics that are encapsulated in foam and buried in attic insulation.

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.

Support at Intervals for Flex Ducts

Guide

Guide describing how to hang HVAC ducts with supporting straps or saddles to adequately support ducts so they do not sag and are not pinched or compressed.

Sufficient Cavity Space for Flex Ducts

Guide

Guide describing how and where to install ducts, to ensure enough cavity space to avoid compression of the flex ducts or duct insulation.

Builders Challenge High Performance Builder Spotlight: David Weekley Homes, Houston, Texas

Case Study

Case study describing new home construction in the hot-humid climate, optimizing thermal enclosure, HVAC, water heating and lighting measures.

Sealed Attics?

Reference

Article describing how insulating and air sealing unfinished attic spaces can lead to reduced energy bills in some homes.

Building Code Training - Residential Thermal Envelope - Air Sealing

Presentation

Presentation describing the Georgia State Minimum Standard Energy Code air barrier requirements, envelope concepts including air flow and thermal properties, and common missed insulation and air-sealing opportunities.

HVAC Ducts Shall Not Be Run within Exterior Walls

Guide

Guide describing the use of building cavities as supply or return ducts.

Coastal Habitats

Case Study

Case study describing a construction project in Hilton Head, SC utilizing a whole-house performance approach.

Diagram of buried ducts

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New Whole-House Solutions Case Study: Schneider Homes, Inc.

Case Study

Case study describing a new construction project in the marine climate zone.

Air Sealing Duct and Flue Shafts

Guide

Guide describing how to air-seal duct and flue shafts.

Burried and encapsulated ducts in a ceiling plane

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Encapsulated ducts are sprayed with ccSPF in an unconditioned attic

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Ceiling gypsum board has been installed

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Baxter Community - High Performance Green Building

Case Study

Case study describing a building project in the mixed-humid climate zone.

Technology Solutions Case Study: Buried and Encapsulated Ducts, Jacksonville, Florida

Case Study

Case study describing how using buried and/or encapsulated ducts can reduce duct thermal losses in existing homes.

GreenCraft Greenspoint House Prototype

Case Study

Case study describing a building project in the mixed-humid climate zone.

New Whole-House Solutions Case Study: ICI Showcase House Prototype

Case Study

Case study describing a building project in the hot-humid climate zone.

Mercedes Homes: Hot, Humid Climate Region 40+% Energy Savings

Case Study

Case study describing a building project in the hot-humid climate zone.

Show Home Targets Energy Efficiency in Hot-Humid Climates

Case Study

Case study describing the New American Home project.

Measure Guideline: Reducing Thermal Losses and Gains With Buried and Encapsulated Ducts in Hot-Humid Climates

Reference

Document covering the technical aspects of buried and insulated ducts (BEDs), as well as the advantages, disadvantages, and risks of BEDs compared to alternative strategies.