The Difference Between a Heat Pump and AC
When it’s time to install or replace a new HVAC system in your home or business, you often face the difficult decision of choosing between a heat pump or conventional air conditioning system. While these systems generally work the same when cooling your home, there are some major differences on the heating side. This post will cover the basic differences between a new heat pump system and central air conditioning unit installation, how they work, and the factors you should consider before purchasing a new system, including price, energy efficiency, and climate.
AC vs. Heat Pump
Both a central AC unit and heat pump systems are considered a type of central air HVAC system as they transfer (or pump) heat from inside the structure to the outside to cool inside temperatures. The major difference between an AC unit and a heat pump is that heat pumps can reverse their air flow direction and transfer heat from the outside to raise indoor temperatures by utilizing a reversing valve built into the compressor. A conventional air conditioning system on the other hand must rely on electric resistant heat strips within the air handler or utilize a gas furnace unit to produce/distribute warm air.
Heat Pump vs. AC Costs
While most heat pump systems cost only about 5% higher than the base cost of central air conditioners, you can expect to pay slightly more for heat pump installation. Since heat pumps handle both cooling and heating, they run year round—which shortens their lifespan significantly when compared to a conventional air conditioner which could also lead to higher prices for service contracts through your HVAC contractor and affect the overall warranty due to the wear and tear on the system.
It’s best to get an estimate for the cost of a new heat pump or conventional air conditioning system, but it must be noted that parameters specific to your property/jobsite and climate can affect the final cost. Check out our HVAC cost calculator to get an idea of what the project will cost and then follow-up by contacting your HVAC contractor for the most accurate estimate for HVAC installation. To get exact pricing, talk to local heat pump installers today about your project specifics.
How a Heat Pump vs. AC Works
While heat pumps and conventional air conditioners differ, they rely on the same principals to condition inside air temperatures. Both systems utilize a compressor to compress refrigerant contained within the system. Inside the compressor, gas is compressed, causing its temperature to rise significantly. The gas then flows through the condensing coil where it cools to ambient temperature. As the gas enters the evaporator coil—located inside the house—it expands, causing its temperature to rapidly drop and cool the evaporator coil.
A fan or blower assembly within the air handler draws air through the cooled evaporator coil to provide conditioned air to the home’s interior. The main difference between the two systems is that a heat pump can reverse the process by switching the function of the evaporator and condenser coils to raise inside temperatures.
Choosing the Best Option
Choosing between a conventional central air installation and a heat pump depends on several factors with the most notable being your climate. Most of the top central AC unit brands offer heat pump installation options as well. Areas of the country subjected to temperatures 40-degrees and lower for extended periods are not ideal for a heat pump installation. The reason being is as the temperature drops, heat pumps work harder to maintain desired comfort levels. This results in more energy use, driving up your utility bill.
In addition, once the temperature drops below 40-degrees, most heat pump systems lose their heating efficiency and must switch to emergency heat mode, which utilizes electric resistant heat strips that use more electricity.
In extremely cold regions of the country or those where electricity prices are high, you would probably be better served with a conventional HVAC system with supplemental heat such as a furnace or boiler.
Energy Efficiency of Heat Pumps
Since heat pump HVAC systems are more energy-efficient than central air conditioners, purchasing one of these systems may qualify you for a tax incentive or rebate from the federal government, state, or local utility company, which will reduce the overall cost of the system.
To search for rebate and incentive programs in your area, visit the Database of State Incentives for Renewables & Efficiency. DSIRE is the most comprehensive source of information on rebates and incentives that support energy efficiency and renewables in the country.
Since the cooling capacities of both a heat pump and conventional air conditioner are about the same, the heating capacity should carry the most weight when choosing one system over the other. Conventional air conditioners are less expensive to purchase, maintain and operate, while heat pumps provide conditioned air more efficiently which reduces monthly energy costs. The coldest regions of the country—those with extended periods below 40-degrees—are better suited with conventional air conditioning supplemented with an alternative heating source. Regions of the country with milder winters are ideal locations for heat pump installation.