How Hybrid (heat-Pump) Water Heaters Work

 

Heat pump water heaters (HPWHs) use electricity to move heat from the surrounding air into water to heat it, rather than generating heat directly like traditional electric water heaters.

 

Here’s a simple breakdown of how they work:

1. Heat Absorption: The HPWH pulls in warm air from its surroundings (like a room or basement) using a fan.

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  2. Heat Transfer: The warm air passes over an evaporator coil containing a refrigerant.

      The refrigerant absorbs heat from the air, causing it to evaporate into a gas.

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  3. Compression: The gaseous refrigerant is compressed, which increases its temperature significantly.

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  4. Heat Exchange: The hot refrigerant gas transfers its heat to the water in the storage tank through a heat exchanger. As the heat is transferred, the refrigerant cools and returns to a liquid state.

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  5. Cycle Repeats: The process repeats, continuously drawing heat from the air to warm the water. The cooled air is then released back into the environment.

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  6. Backup Heating: If the air is too cold or hot water demand is high, a backup electric resistance element may kick in to ensure a consistent supply.

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Key Features:

• Efficiency: HPWHs are 2–3 times more energy-efficient than traditional electric water heaters, as they move heat rather than create it.

• Environment: They work best in spaces with ambient temperatures between 40°F and 90°F and require adequate airflow.

• Cooling Bonus: They slightly cool and dehumidify the surrounding space, which can be a perk in warm climates.

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Considerations:

• They need space for air circulation and may produce some noise (similar to an air conditioner).

• Installation costs are higher than traditional water heaters, but energy savings can offset this over time.

• Ideal for homes in moderate climates, though advanced models can work in colder conditions.​