An Engineers Newsletter Preview: Selecting DX Coils for Both Cooling and Heating

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About the author

Dustin Meredith, Lead Systems Development Engineer

Dustin began his career more than 20 years ago supporting airside products for Trane. Since joining the systems and applications engineering team in 2005, his role has been to develop integrated customer solutions for HVAC products & systems providing a link between the sales, design, and manufacturing organizations. He has specific expertise in fans, acoustics, air system design and overall system optimization including unitary and variable refrigerant flow systems. Dustin holds multiple patents and has been instrumental in advancing cutting-edge fan and motor applications to industry. He has authored a wide variety of technical bulletins, white papers, articles and Trane Engineers Newsletter LIVE programs that have been widely published.

Dustin is a licensed professional engineer and earned his mechanical engineering and computer science degrees from the University of Kentucky. He continued his education by receiving an MBA from the Gatton College of Business and Economics. Dustin is an active member of ASHRAE® having received awards at the local, regional, and society level including the society’s Distinguished Service Award. Dustin has been an ASHRAE® Section Head and past Chair of the committee that oversees all ASHRAE® technical committee activities. He also serves on the “Fans” and “Sound and Vibration” technical committees, including as past Chair of the latter. He is Trane’s voting member for Air Movement and Control Association International, Inc. (AMCA) and serves on a number of AMCA committees including instrumental, first edition standards on the Fan Efficiency Grade (FEG) and Fan Energy Index (FEI) metrics.

Trane Engineers Newsletter: Selecting DX Coils for Both Cooling and Heating
The need to heat without the use of onsite fossil fuels (i.e., electrification of heat) has become an urgent initiative as the built environment focuses on decarbonization. Paramount to these goals is the broader use of heat pumps.

Often, the refrigeration components that make up a heat pump are manufactured and assembled in a factory, and then shipped to the jobsite as a “packaged” piece of equipment. But sometimes the components are shipped separately and then connected with field-installed refrigerant piping at the jobsite. The latter is generally referred to as a “split system.” When an indoor direct-expansion (DX) coil is separate from the outdoor components of a heat pump split system, additional effort is needed to properly match the indoor coil with the other components.

In this Engineers Newsletter (EN), Trane systems development engineer Dustin Meredith introduces an approach for selecting the equipment in a split system that needs to heat, as well as cool, the building. After reviewing some basics of refrigeration and heat pump operation, this EN provides guidelines on how to select an indoor DX coil for a split system heat pump. Most variable refrigerant flow (VRF) systems are capable of both cooling and heating operations, so this EN also addresses the indoor DX coils that might be used as part of a VRF system.

More information on Trane® split system heat pumps can be found on trane.com. Also, information on Trane® VRF systems can be found on trane.com/VRF.

To read this EN:
This new issue of the Trane® Engineers Newsletter is now available to read or download from trane.com/EN.

More about Trane Engineers Newsletters
Engineers Newsletters are topical, informative articles that provide engineering professionals who design HVAC systems with reliable, objective, and technologically current information in a non-commercial format. They've been published by Trane’s Applications Engineering team since 1972 and have long been a trusted technical resource throughout the industry. Subjects range from HVAC system configurations to acoustics to interpretation of ASHRAE standards.

Engineers Newsletters are provided to customers free-of-charge. Current and past issues can be viewed on trane.com/EN, and you can even subscribe to receive e-mail notification when a new issue is published.