Heat Pump vs Air Conditioner — What are the Key Differences?

As you consider HVAC systems for your home or commercial building you may be debating the use of a heat pump.  Heat pump vs air conditioner — what are the key differences?  That is our focus in this article.  We will highlight the differences and then offer suggestions for when to consider a heat pump system and when to consider an air conditioner system.  First we provide a brief description of each system.

Air conditioner: An air conditioner system uses the condensing unit for air conditioning only.  Heat is typically supplied by a gas or propane furnace, though electric furnaces or alternate heat sources are also a possibility.

Heat pump: A heat pump system uses the condensing unit for both air conditioning and heating.  The condensing unit of a heat pump is modified to contain a reversing valve that changes the direction in which the refrigerant works.   In air conditioning mode, the refrigerant absorbs heat when it enters the indoor coil, removing it from the home and shedding it in the outside coil where it radiates out and is dispersed by the condensing unit fan.  In heating mode, the refrigerant collects heat as it passes through the outdoor coil and sheds it in the indoor coil where it radiates out and is distributed into the home by the blower.  In simple heat pump split systems, an air handler replaces a gas furnace.  It contains a coil and a blower.  Heat pump split systems are also available that use dual heat.  They are matched with a gas furnace so that a choice of electric heat pump heat or gas heat is offered at any given time.

It’s important to understand these systems in order to evaluate which one is best for your situation.

Heat Pump vs Air Conditioner — What are the Key Differences?

Heat pump systems and air conditoner systems each have their place.  The differences go beyond the fact that a heat pump does double duty as the source of air conditioning and heating while an air conditioner only cools air.  Here are key differences between heat pumps and air conditioner/gas furnace systems to consider.  As you see, since they both provide air conditioning, the primary differences between air conditioners and heat pumps involve the heating side of the equation.

1. Heat pumps provide gentler, more balanced heating preferred by most homeowners.  Heat pumps don’t produce air as hot as gas furnaces do.  Therefore, the heating of the home is more gradual.  A benefit of this is more balanced heating throughout the home.  With a gas furnace, the temperature rise within the home is faster. The air around the thermostat may reach the programmed temperature, shutting off the furnace, before air in some parts of the home is sufficiently warmed, causing cold spots or zones.  This is far less likely to happen when the heat is supplied by a heat pump.

2. Heat pump systems provide better humidification than a furnace when a humidifier is incorporated into each system.  Because heat pumps heat more slowly than gas furnaces, they run more consistently.  And since the humidifier only functions when the system is running, a heat pump system will deliver more moisture into the home/building than a gas furnace system.

3. Heat pumps may be more expensive to operate than gas furnaces but it depends on the efficiency of the two units.  A 7.7 HSPF heat pump will be more costly to run than a 95% AFUE furnace, but a 10.0 HSPF heat pump will cost less to run than an 80% furnace.  To know exactly which one is more cost effective requires complex math, but suffice to say, the “average” heat pump will be slightly more expensive to run than the “average” gas furnace in most areas.

4. Heat pumps offer more versatility when they are part of a dual fuel system.  Duel fuel is also known as hybrid heat. You have the option of heating with the heat pump or a gas furnace which makes them more versatile than air conditioners.  Many homeowners use the heat pump until temperatures sink into the 30’s and then switch to heating with the gas furnace.  Most heat pump systems can be set to switch from heat pump to gas heat at a selected outdoor temperature.

Conclusion

Knowing these heat pump vs air conditioner facts will help you determine which one is right for your situation.  Most homeowners like the gentler, consistent heat provided by heat pumps.  Keep in mind that heat pumps are effective for heating in warm to moderate climates but become inefficient in very cold weather.  That’s where a heat pump hybrid system is an outstanding solution.

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