New and updated features of this title Enhanced series NEW: An HVAC Excellence partnership and endorsement was awarded to NCCER's 4-part HVACR program, since the last edition. This means the series meets HVAC Excellence accreditation standards and prepares trainees to sit for HVAC Excellence certification tests. NEW: On-the-job case studies throughout the curriculum demonstrate skill performance in the HVACR field. UPDATED: Enhanced electrical safety content ensures trainees can safely interact with electrical systems, across HVACR functions. Level 4 curriculum updates UPDATED: Training-wide curriculum updates further engage students while providing the best training possible. UPDATED: The content has been updated to include the most recent information regarding hydronics, psychrometrics, HVACR support systems and installation planning. UPDATED: Modernized art and updated tables were incorporated into all modules.