Can a heat pump replace your air conditioner?

Is a heat pump the same as an air conditioner?

They share the same parts: a compressor, two coils, a fan and refrigerant. A conventional air conditioner moves heat in one direction only, from inside to outside. A heat pump adds a reversing valve that can flip the flow. In cooling mode the indoor coil is cold and extracts heat from the house air, and the outdoor coil releases that heat outside. In heating mode the roles swap, as shown in our heat pump explainer.

A heat pump therefore does the air conditioner’s job with no extra equipment. Ductless, ducted and multi-zone types can all cool, as outlined in air-to-air heat pumps.

How does a heat pump cool and dry the air?

Warm indoor air passes over the cold indoor coil. The coil takes away heat, and moisture in the air condenses on it and drains away through a condensate line. That is why a cooling system also lowers humidity, and why the drain should be checked each spring. Many units also offer a dry mode that runs more slowly to remove moisture without much temperature change.

Cooling efficiency is rated separately from heating, usually with a seasonal energy efficiency ratio. A higher number means less electricity for the same cooling, and the exact scale on the data sheet tells you how to compare models.

Which summer settings help most?

• Cool or auto mode. Auto changes between heating and cooling on its own, but it can swap too often in shoulder seasons, so many owners set the mode by hand.
• Moderate set point. Energy use climbs with each degree of extra air conditioning, so a modest setting saves money.
• Fan speed. Low speeds remove more moisture, high speeds cool faster.
• Clean filters and coils. Dirty parts cut airflow and efficiency. The maintenance checklist lists what to check.

Is one size right for both heating and cooling?

In much of Canada the winter heat loss is larger than the summer cooling load, so the unit is usually sized for heating and has more cooling capacity than the house needs. Oversizing can cause short cycles that remove less moisture, which is why variable-speed models and proper load calculations matter. The reasoning in heat pump load calculations and sizing for cold climate homes applies to cooling as well. Houses with large south-facing windows or little shade can have a bigger cooling load than expected.

When does replacing an air conditioner with a heat pump make sense?

The best moment is when the air conditioner, the furnace or both are near the end of their life. Instead of buying one cooling-only machine, a heat pump can provide heating and air conditioning with one system, using less gas or other fuel depending on local energy prices. The heat pump versus furnace comparison and the guide on high-efficiency furnace versus heat pump cover the choice. A heat pump usually costs more than an air conditioner alone, and the heat pump cost guide explains the drivers.

Rebates may apply to heat pumps and not to cooling-only equipment, and terms change, so check federal, provincial and utility pages before buying.

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