Ducted air source heat pumps work by moving heat, rather than generating it, to either warm or cool your home using a network of ducts. Think of it like a refrigerant-based air conditioner, but with the ability to run in reverse.
Here's a breakdown of the process:
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Heat Extraction/Rejection: The heat pump has an outdoor unit containing a coil that absorbs heat from the outside air (even in cold temperatures) during the heating season. In the cooling season, this process is reversed, and heat from inside the home is rejected to the outside air. A refrigerant cycles through this coil.
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Refrigerant Cycle: The refrigerant, a fluid that easily changes between liquid and gas states, plays a crucial role.
- Heating: The outdoor coil absorbs heat and boils the refrigerant into a low-pressure gas. This gas is compressed by a compressor (also located in the outdoor unit), which raises its temperature further.
- Cooling: The indoor coil absorbs heat from inside the house and boils the refrigerant into a low-pressure gas. The gas travels to the outdoor unit to reject the heat outside.
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Heat Transfer to Air: The heated (or cooled) refrigerant then flows to an indoor coil.
- Heating: Air is blown across the hot coil, warming it. This warmed air is then circulated through the ductwork.
- Cooling: Air is blown across the cold coil, cooling it. This cooled air is then circulated through the ductwork.
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Ductwork Distribution: The warm or cool air is then distributed throughout the home via a network of ducts typically located in the ceiling, attic, or crawlspace. Registers or vents in each room allow the conditioned air to enter the living space.
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Refrigerant Cycle Completion: After releasing (or absorbing) heat, the refrigerant changes state (back to a liquid in heating, and back to a liquid after releasing its heat outdoors in cooling) and returns to the outdoor unit to repeat the cycle.
In essence, ducted air source heat pumps don't "create" heat; they transfer it from one place to another, offering an energy-efficient way to heat and cool your home. Because they move heat rather than generate it directly, they can be more efficient than traditional furnaces or electric resistance heating, especially in moderate climates.
