Improvement of unitary equipment and heat exchanger testing methods

Md Yearn Hossain, Romit Maulik, Hyunjin Park, Mansoor Ahmed, Christian K. Bach, Omer San

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Current trends in the HVAC industry lead to increased airflowrates to improve air conditioner's efficiency compared to when testing standards were originally developed. However, such increases in air flowrate lead to a reduction in the enthalpy and temperature change across the heat exchanger coil, with a similar effect observed for the built equipment. In parallel, the dimensions of unitary equipment have increased leading to challenges when including current standard's inlet ductwork which recently became mandatory in the US. Based on our experience, different testingfacilities use different designs for inlet ductwork and air sampling to enable installation in legacy testingfacilities. This leads to differences in the measured performance between labs and can lead to "false testing failures" caused by differences in testing method. This paper presents the work that has been done as part of ASHRAE RP 1733 and 1743 to address these challenges on the equipment as well as on the component (heat exchanger) level. In general, achieving repeatable test results and accurate airside measurement requires either a large length for mixing and flow development or a shorter length at the expense of additional airside pressure drop.

Original languageEnglish (US)
Title of host publicationASHRAE Transactions - 2019 ASHRAE Annual Conference
Number of pages8
ISBN (Electronic)9781947192355
StatePublished - 2019
Event2019 ASHRAE Annual Conference - Kansas City, United States
Duration: Jun 22 2019Jun 26 2019

Publication series

NameASHRAE Transactions
ISSN (Print)0001-2505


Conference2019 ASHRAE Annual Conference
Country/TerritoryUnited States
CityKansas City

All Science Journal Classification (ASJC) codes

  • Building and Construction
  • Mechanical Engineering

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