What are differences between Hydrocarbons (HCs) and Hydrochlorofluorocarbons (HC

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试卷: LEED GA模拟题E[查看]
What are differences between Hydrocarbons (HCs) and Hydrochlorofluorocarbons (HCFCs)?(choose 2)
A: HCs can be used as refrigerants in new buildings while LEED requires zero use of HCFC-based refrigerants in new base building
B: HCs have a lower global warming potential (GWP) than HCFCs
C: HCs are an ideal replacement for CFCs while HCFCs are not
D: HCs are environmentally benign to the atmosphere while HCFCs are not

参考答案: BD

本题解释:
Notes:

Reference: The Treatment by LEED of the Environmental Impact of HVAC Refrigerants

A:LEED requires zero use of CFC-based (not HCFC-based) refrigerants in new base building elements for Fundamental Refrigerant Management, with the intent of reducing stratospheric ozone depletion.
B: HCs are benign to the atmosphere and thus have a low direct global warming potential (GWP). Because HCs are less efficient they require more energy to achieve the same level of refrigeration and the increased use of fossil fuels indirectly increases global warming.
C:HCs are not an ideal replacement for CFCs because they require a greater amount of energy to achieve the same level of cooling as HFCs and HCFCs.
D: HCs, or hydrocarbons, are natural refrigerants that include propane, butane, ethane, isobutene, and isopentane. Natural refrigerants are benign but they require a greater amount of energy to achieve the same level of cooling as refrigerants such as HFCs and HCFCs.