2021 ASHRAE Handbook: Fundamentals SI Edition

The 2021 ASHRAE Handbook—Fundamentals covers basic principles and data used in the HVAC&R industry. The ASHRAE Technical Committees that prepare these chapters provide new information, clarify existing content, delete obsolete materials, and reorganize chapters to make the Handbook more understandable and easier to use.

This edition includes a new chapter on global climate change. Individual Handbook chapters have long addressed sustainability, global warming potential, greenhouse gases, recycling, and reclamation as they apply to those chapters’ specific topics, but ASHRAE is pleased to present an entirely new chapter dedicated entirely to designing and operating in a changing world environment.

Other 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