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Description 2024 ASHRAE Handbook—HVAC Systems and Equipment

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Table of Contents, 2024 ASHRAE Handbook—HVAC Systems and Equipment

The 2024 ASHRAE Handbook—HVAC Systems and Equipment delves into various systems and the equipment (components orassemblies) they comprise, and describes features and differences. This information helps guide system designers and operators in selecting and using equipment. ASHRAE Technical Committees in each subject area have reviewed all chapters and revised them as needed for current technology and practice.

Some of the volume’s revisions and additions are as follows:

  • Chapter 11, Steam Systems, now includes a new table of safety factors for steam traps sizing by application.
  • Chapter 12, District Heating and Cooling, has updated cost estimates to reflect recent pricing changes, and an expanded terminology section.
  • Chapter 17, Germicidal Ultraviolet Lamp Systems, has expanded its safety and lamp terminology sections, as well as adding new information on installation and commissioning UV-C lamps.
  • Chapter 18, Variable Refrigerant Flow, contains new guidance on controls.
  • Chapter 19, Duct Construction, has updated its discussion of means and methods of duct construction, and added extra clarification to tables.
  • Chapter 22, Humidifiers, has added discussion of environmental conditions in relation to the COVID-19 pandemic and how humidity affects transmission of infectious aerosols.
  • Chapter 24, Desiccant Dehumidifiers, added a section discussing three-way desiccant heat exchangers.
  • Chapter 32, Boilers, now includes a new section focusing on heat pump boilers.
  • Chapter 38, Compressors, updated descriptions of reciprocating compressors and their components, and includes a discussion of spool compression technology and tri-rotor screws. The latest low-global-warming-potential refrigerants are also now covered.
  • Chapter 43, Liquid-Chilling Systems, has expanded discussion to include scroll-to-reciprocating liquid chillers and chiller heaters for heat pumps. Coverage now also includes new refrigerants.
  • Chapter 46, Valves, has been reorganized for better flow and clarified throughout, and added guidance for six-way control valves.

This volume is published, as a bound print volume and in electronic format as a PDF download and online, in two editions: one using inch-pound (I-P) units of measurement, the other using the International System of Units (SI).

Corrections to the 2021, 2022, and 2023 Handbook volumes can be found on the ASHRAE website at and in the Additions and Corrections section of this volume. Corrections for this volume will be listed in subsequent volumes and on the ASHRAE website. Reader comments are enthusiastically invited. To suggest improvements for a chapter, please write to Handbook Editor, ASHRAE, 180 Technology Parkway NW, Peachtree Corners, Georgia 30092, or email