Donald L. Crawshaw is the Department Chair and Instructor of the HVAC program at Pikes Peak Community College (PPCC), Colorado Springs, Colorado. Mr. Crawshaw earned an Associates of Arts degree in Technical Theatre from Independence Community College (ICC), Independence, Kansas. He served part-time as Stage Manager for the local community auditorium in Independence for about 10 years. While attending ICC, he started working as a helper for a sheet metal installation crew for a local HVAC company. He has remained in the HVACR field ever since, over 30 years, working in Kansas, Utah, and Colorado. Don has worked in the areas of installation, service, and energy management for residential, commercial, and supermarket systems. He had been involved with in-house training in just about every company he worked for previously. Mr. Crawshaw started his professional teaching career with Intellitec College in Colorado Springs and later accepted his current position at PPCC. The 30 plus years of experience in many different areas and responsibilities in the HVACR field has allowed him to be able to teach many different topics and subjects. Along with his teaching and department chair duties, he also serves as the State Discipline Chairman for the Colorado Community College System HVAC discipline and is the Career and Technical Studies representative from the college to the State Faculty Curriculum Council. In 2011, Don was invited to sit on a panel for the National Assessment of Educational Progress (NAEP) to help conduct an NAEP HVAC Judgmental Standard-Setting Study, looking into how math relates to entering into HVAC training. In 2012, Don earned the title of Certified Master HVACR Educator (CMHE) from HVAC Excellence. He was also voted Best Instructor Runner-up by The NEWS and Air-Conditioning, Heating, and Refrigeration Institute (AHRI) that same year. Jerry Killinger and LaDonna Killinger established this text with excellent content and organization. Mr. Killinger had extensive experience installing and servicing air conditioning, refrigeration, and heating systems. He worked with industrial, commercial, and residential systems ranging from heat pumps to boilers to cooling towers to refrigerated food cases to solid-state environmental control equipment. Jerry spent over 20 years teaching traditional vocational classes as well as various semi- nars and workshops on refrigeration, air conditioning, and electricity for industrial maintenance personnel at facilities of major manufacturers across the United States. About the Author Heating and Cooling Essentials aligns with curriculum standards for HVAC Excellence and PAHRA accreditation. iv Copyright Goodheart-Willcox Co., Inc.