Heat pumps provide heat by reversing the cooling cycle.

• A. By reversing the cooling cycle
• B. By consuming more energy with no effect
• C. By increasing ambient temperature only
• D. By converting mechanical energy to heat without vapors

Answer: (A)

Heat pumps heat by reversing the refrigeration cycle. They use the same components that cool a space, but switch the direction so heat is moved into the indoor space rather than out of it. In heating mode, a reversing valve flips the flow so the outside air becomes the heat source and the indoor coil acts as the condenser, releasing heat into the room. The refrigerant absorbs heat when it evaporates in the source coil and releases it when it condenses in the indoor coil, so the system transfers heat rather than creating it with fuel or electricity alone. This explains why heat pumps can provide warmth efficiently compared to electric resistance heating.

The other statements don’t fit because a heat pump does not simply consume more energy with no effect, nor does it increase ambient temperature only in a blanket sense; it moves heat. It also relies on the refrigerant phase-change cycle, not a process that converts mechanical energy to heat without vapor.