Type III — Low-PressureCâu 189 / 240
Which refrigerant is a CFC once widely used in low-pressure chillers and now available only as reclaimed stock?
a.CFC-11
b.HFC-134a
c.HCFC-22
d.HFC-410A
Giải thích
CFC-11 (R-11) was the classic low-pressure chiller refrigerant, but U.S. CFC production ended January 1, 1996, so it is now available only from recovered and reclaimed stock. R-134a, R-410A, and R-22 are not low-pressure CFC chiller refrigerants. This scarcity makes careful recovery of R-11 especially important.
Luyện miễn phí toàn bộ 240 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A recovery cylinder used for a large low-pressure chiller should be:
- During leak testing, some technicians raise the pressure in a low-pressure chiller just above atmospheric so that:
- Low-loss fittings on recovery hoses are important on low-pressure work because they:
- A machine room housing a low-pressure chiller should have a refrigerant monitor and ventilation mainly to protect against:
- The main reason a torch must never be used to warm a low-pressure chiller during recovery is that:
- In a low-pressure chiller, the evaporator normally operates:
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