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Title: Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance (Rutkowski, H. Manual D -- Residential Duct Systems, 3rd edition, Version 1.00. Arlington, VA: Air Conditioning Contractors of America, 2009.). IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations (Beach, R., Prahl, D., and Lange, R. CFD Analysis of Flexible Duct Junction Box Design. Golden, CO: National Renewable Energy Laboratory, submitted for publication 2013). These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressuremore » losses when using junction boxes with flexible ducts.« less
Authors:
;
Publication Date:
OSTI Identifier:
1127284
Report Number(s):
DOE/GO-102014-4396
KNDJ-0-40341-03
DOE Contract Number:
AC36-08GO28308
Resource Type:
Technical Report
Resource Relation:
Related Information: Work performed by IBACOS, Inc., Pittsburgh, Pennsylvania
Research Org:
National Renewable Energy Laboratory (NREL), Golden, CO.
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy Building Technologies Office
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 42 ENGINEERING RESIDENTIAL; RESIDENTIAL BUILDINGS; IBACOS; BUILDING AMERICA; FLEXIBLE DUCTS; JUNCTION BOXES; DUCT SIZING; PRESSURE LOSSES IN HVAC SYSTEMS; BALANCING DAMPERS IN HVAC SYSTEMS; RESIDENTIAL HVAC SYSTEMS; FRICTION RATE; EQUIVALENT LENGTH (DUCTS); STATIC PRESSURE; AVAILABLE PRESSURE; Buildings