International Mechanical Code 2021

Also known as: IMC 2021

About This Book

The International Mechanical Code (IMC) establishes minimum standards for mechanical systems through both prescriptive and performance-based provisions. Developed around broad fundamental principles, the IMC is designed to accommodate new materials, methods, and design approaches.

Key updates in the 2021 IMC include:

  • Clothes dryer exhaust terminals must now be located at least 3 feet from any building opening.
  • Polyurethane spray-applied foam on the exterior of ducts in attics and crawl spaces must meet specific smoke and flame spread index requirements.
  • Fire and smoke dampers must be equipped with approved access points to facilitate inspection and maintenance.
  • Refrigerant tables have been updated to reflect the addition of new refrigerants.
  • Condensate systems now require termination identification markings and are subject to new discharge restrictions.
  • Factory-built combination intake/exhaust terminations are now permitted, easing the previous separation requirements.
  • Whole-house balanced ventilation systems benefit from a 30% reduction in minimum mechanical ventilation requirements.
  • Manicure and pedicure station exhaust systems are now required to operate continuously.
  • Grease duct horizontal cleanouts must be installed within 3 feet of a horizontal discharge fan.

Practice Tests Using This Book

This book is required or recommended for 4 licensing exams. Our practice tests include questions based on this material.