2020 ASHRAE Handbook – HVAC Systems and Equipment

The newly published 2020 ASHRAE Handbook – HVAC Systems and Equipment includes updated information to help system designers and operators select and use equipment that is the best fit for a particular application or scenario.

The 2020 ASHRAE Handbook – HVAC Systems and Equipment discusses various systems and the equipment (components or assemblies) they comprise, and describes features and differences. Subject matter experts on ASHRAE Technical Committees in each subject area have reviewed all chapters and revised them as needed for current technology and practice.

A new feature of the Handbook is the annotatable PDF download. Users can highlight relevant text and add their own notes and comments.

The volume contains several new updates. Chapter 51,Dedicated Outdoor Air Systems, is entirely new and presents detailed information on DOAS. Chapter 9, Applied Heat Pump and Heat Recovery Systems, has new content on waste heat recovery, district applications, and industrial process heat pumps, while Chapter 24, Desiccant Dehumidification and Pressure‑Drying Equipment, has expanded content on applications, air filters, and liquid strainers, plus recommendations from ASHRAE research project RP-1339 on rating equipment at altitude.

Other updates that likely will impact many users include: Chapter 19, Duct Construction, extensive revisions on system leakage and air dispersion systems; Chapter 25, Mechanical Dehumidifiers and Related Components, new content on psychrometrics, outdoor air, controls, and industrial dehumidifiers; and Chapter 37, Solar Energy Equipment, new data on worldwide solar technology use, plus an expanded section on photovoltaic equipment.

Other revisions and additions include:

• Chapter 18, Variable Refrigerant Flow, has new sections on modeling and system commissioning, and an updated system design example.
• Chapter 20, Room Air Distribution Equipment, has updates for current technology, with new information on specialized components and air curtains.
• Chapter 26, Air-to-Air Energy Recovery Equipment, has new information on heat pipes and desiccant and heat wheel systems.
• Chapter 28, Unit Ventilators, Unit Heaters, and Makeup Air Units, has revisions on standards, controls, and fan selection for makeup air units.
• Chapter 29, Air Cleaners for Particulate Contaminants, has updates on standards and performance testing.
• Chapter 31, Automatic Fuel-Burning Systems, has added content on pneumatically and electronically linked gas/air ratio burner systems.
• Chapter 38, Compressors, has revisions on general theory; screw and scroll compressors; and bearings, including oil-free technologies.
• Chapter 44, Centrifugal Pumps, has new content on vertical, inline, split-coupled pumps; hydronic system pump selection; and differential pressure control.
• Chapter 46, Valves, has new content on control valve sizing; electronic actuators; and ball, butterfly, flow-limiting, and pressure-independent control valves.
• Chapter 49, Room Air Conditioners and Packaged Terminal Air Conditioners, has updates for efficiency standards.

ASHRAE has completed distribution of complimentary copies to members and is now offering this essential resource to the public.

The volume is published as a bound print volume, as a downloadable PDF, and online, and in two editions: one using inch-pound (I-P) units of measurement, the other using the International System of Units (SI). The cost of the print bound volume is $230 in I-P or SI. Individual chapters may also be purchased as digital downloads in PDF format.

To purchase, visit ashrae.org/bookstore