PE Mechanical HVAC
PE Mechanical: HVAC and Refrigeration
CodesEnglish
Exam overviewPractice session
ASHRAE Standard 15 classifies refrigerants by toxicity (A or B) and flammability (1, 2L, 2, 3). What is the safety classification of R-32 and R-454B that drives charge-limit and ventilation requirements in 2026 installations?
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