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BU (2018-현재) · TDI 2.0

2026. 8. 15. 작업

난이도 & 준비물

증상

My understanding is that a heat pump (as a heat source) is essentially an "air conditioner running backwards" -- given that, and since air conditioning is an (almost) universal feature in modern cars, I'm wondering why some EVs (for example Chevy Bolts and VW ID.4 in the US) don't have heat pumps? What has to be added to or modified in an air conditioning system so that it can also be used for heating? What are the trade-offs that lead to cars like the Bolt with resistance heating and air conditioning?

처리 내용

In theory, a heating-capable heatpump differs from a cooling only one only by the presence of a 4-way valve that switches the refrigerant direction. Thus, almost for free, you get 3x more efficient heating. Then again, some caveats apply: The comfort. A heatpump is slower to start heating, compared to a resistive heater. The defrost cycle. Are you ok with your heating system stopping once in a while in order to remove the ice buildup on the external radiator? Well, one can always add a resistive heater to switch to. Both the efficiency and the max heating power go down when it gets colder, in contrast with the heat loss. In effect you need to carry more powerful heatpump all the time only for the worst case (it both costs more and is heavier).