scope:

Preface

ASHRAE strives to maintain the highest standards for the Handbook. Unfortunately, the 2021 ASHRAE Handbook-Fundamentals, as originally published, omitted some updates that had been intended for publication.

This revised edition presents those chapter updates as originally intended by the cognizant Technical Committees (TCs). We regret the omissions, and are revising procedures to ensure that such an oversight does not occur again.

The affected chapters and selected highlights of the updates include the following:

• Chapter 1, Psychrometrics: updates to properties tables and expanded discussion of transport properties of moist air

• Chapter 2, Thermodynamics: expanded discussions of reverse Brayton and reverse Stirling cycles

• Chapter 5, Two-Phase Flow: corrected I-P value for liquid-phase mass transfer coefficient

• Chapter 6, Mass Transfer: corrected equations for Sherwood number for laminar and turbulent flow

• Chapter 13, Indoor Environmental Modeling: updates to text throughout

• Chapter 14, Climatic Design Information: example city calculations updated throughout the chapter

• Chapter 16, Ventilation and Infiltration: expanded discussion of residential ventilation and infiltration

• Chapter 17, Residential Cooling and Heating Load Calculations: editorial tweaks to text for clarity

• Chapter 18, Nonresidential Cooling and Heating Load Calculations: updates to heat and moisture emittance rates for humans, lighting densities, efficiencies for motors, and cooking appliances

• Chapter 19, Energy Estimating and Modeling: new discussions on occupant modeling and passive heating and cooling.

• Chapter 20, Space Air Diffusion: terminology updates

• Chapter 23, Insulation for Mechanical Systems: new discussion of insulation system moisture resistance

• Chapter 24, Airflow Around Buildings: new equation for wind-induced pressure difference between indoor and outdoor environments

• Chapter 31, Physical Properties of Secondary Coolants (Brines): expanded discussion on service considerations

• Chapter 34, Energy Resources: updated figures and discussion of energy resources to reflect recent consumption figures

• Chapter 35, Sustainability: new discussion of commissioning

• Chapter 38, Measurement and Instruments: new coverage of resistance sensors and vortex shedding in airflow measurement

Future corrections for this volume will be listed in subsequent volumes and on the ASHRAE website. Any extensive out-of-sequence updates in future will be posted to ASHRAE Handbook Online as a supplemental feature.

Reader comments are welcomed. To suggest improvements for a chapter, please comment using the form on the ASHRAE website or write to Handbook Editor, ASHRAE, 180 Technology Parkway, Peachtree Corners, GA 30092, fax 678-539-2168, or e-mail hkennedy@ashrae.org.