Heat Pumps Vs. Air Conditioners: What's The Difference?

Heat Pumps Vs. Air Conditioners: What's The Difference?

Heat Pumps and Air Conditioners: Similar Technology, But Heat Pumps Offer Cost-Effective Solution

There’s a good chance that you’re reading this article in a building with at least one air conditioning unit.

According to the Energy Information Administration’s 2009 Residential Energy Consumption Survey, 87% of residential households have AC—and about 91% of those homes also have central space heating equipment. Those systems work together to keep buildings comfortable, using ductwork to transfer warm air in the winter and cool air in the summer. 

Unfortunately, these traditional HVAC systems aren’t always efficient (or healthy), particularly when they rely on combustion of fossil fuels during the heating season. While central air conditioners are fairly effective at moving cold air from place to place, older heating systems can waste 30-44% of the energy they generate. Heat pumps offer an alternative: By drawing heat energy from air, air source heat pumps can provide both heating and cooling.

If your home or building relies on window air conditioning units, heat pumps represent a big upgrade. Aside from being noisy eyesores, window ACs use up to 3X as much energy as a heat pump to keep you comfortable in summer heat. 

So, what’s the difference between a heat pump and an AC unit—and if you need to replace your AC, should you consider an upgrade? 

At BlocPower, we specialize in designing eco-friendly air-source heat pump systems, employing technology that offers extensive benefits over standard HVAC systems. 

BlocPower users save an average of 20-40% on their annual utility bills compared to inefficient HVAC systems. 

Find out how a heat pump can help you cut your energy bills. Get started by answering a few questions about your building.

Heat Pumps Vs. Air Conditioners: Understanding The Basics

Air conditioners and heat pumps use the same basic process to keep indoor spaces cool, but heat pumps can also reverse that process to provide heating. You read that right: when you upgrade to a heat pump system, it cools and heats—eliminating your need for a boiler or furnace. 

To understand how this works, here’s an overview of how home cooling works with an AC:

  1. The air conditioner’s indoor unit is the evaporator unit. Ambient air moves across coils with liquid refrigerant, which remove heat and humidity from the air. As the liquid refrigerant heats up, it turns into a gas. 
  2. A large electric pump called a compressor applies pressure to the gas, turning it back into a liquid. 
  3. The outdoor unit contains a condenser coil. A large fan pulls in ambient air from outside and passes it across the condenser coil, releasing the heat energy.

When operating in cooling mode, air source heat pumps and central air conditioners are practically identical. Heat pumps and AC units have a similar appearance, noise level, and energy efficiency rating. Again, this is only true for central air conditioning—not noisy and inefficient window units. 

Regardless of AC type, an air source heat pump has a component that sets it apart: a reversing valve. This allows the heat pump to operate the indoor unit as either an evaporator during the cooling season or a condenser during the heating season. When the indoor unit functions as the condenser, the unit brings heat energy into your building. This is how a heat pump keeps you comfortable in any season.

Heat pump systems fall into two installation categories—ducted and ductless (mini or multi-split). Ducted systems are comprised of a central unit, generally installed in the basement that, can be connected to the building existing ductwork to provide both heating and cooling. In this case, the existing furnace and central cooling system are abandoned.

Ductless systems, commonly referred to as mini split or multi split, consist of one or more outdoor units connected via refrigerant lines and electrical wiring to the indoor units. This solution has the advantage of allowing for room-by-room temperature control, as opposed to the ducted solution that only allows zone control. Additionally, ductless air conditioning systems are considerably more efficient than ducted systems, because the cool air is delivered directly to your space. Ducted systems have to work harder to deliver cooling (or heating) to a room, in part because of heat transfer between the ductwork and the air in the ducts.  

For more information about how heat pumps function, read our article: What Is An Air Source Heat Pump (ASHP)? Your Go-To Guide.

Is a heat pump more efficient than an air conditioner?

Modern central air conditioning units work extremely well. Efficiency is measured by Seasonal Energy Efficient Ratio (SEER), which the Department of Energy defines as the ratio of total heat removed during the cooling season divided by the unit’s total electrical energy consumption. High-efficiency air conditioning units have a SEER of 14 or above. Heat pump systems also have SEER ratings, and most heat pumps meet the same threshold. 

In other words: Heat pumps are just as efficient as air conditioning units during the cooling season. The primary advantage of a heat pump is right in the name: Heat pumps can heat your home, and they’re significantly more efficient than a furnace or boiler. Over time, heat pumps provide an excellent return on investment.

One study performed by the Northeast Energy Efficiency Partnerships found that residential homes saved an average of $948 per year by replacing heating oil systems with heat pumps designed for cold climates. When replacing electric resistance heaters, heat pumps saved an average of $459 per year.

Apart from energy savings, heat pumps have a few other advantages over a traditional HVAC system:

Heat pumps are eligible for more energy incentives.

Many high-efficiency air conditioners and heat pumps are eligible for rebates under the Department of Energy’s ENERGY STAR program. However, other programs are specifically designed to reduce the cost of heat pump installation.

For example, in previous BlocPower projects, our team utilized the New York State’s Clean Heat Statewide Heat Pump Program to cut the overall cost of some systems by tens of thousands of dollars. BlocPower’s team will help you take advantage of applicable energy incentives when designing your system.

Heat pumps can improve air quality.

Like air conditioners, heat pumps are equipped with air filters to capture larger particles like dust or hair. Many heat pump systems can also be outfitted with more robust filtration systems such as antimicrobial filters, and can even use UV lights to kill bacterials and viruses. Because heat pumps don’t combust fuel when operating in heating mode, they can drastically improve air quality for indoor spaces. Fossil fuel burning boilers and furnaces reject combustion fumes directly to the outside of the building and into the neighborhood. In dense urban areas, building occupants that open their window to bring in “fresh air” may actually be letting in this combustion furnace polluted air.

Additionally, ductless deliver purified air directly through their indoor units, which can reduce the concentration of pollutants that trigger asthma and other health conditions. Read more about how heat pumps purify air.

Heat pumps improve comfort and boost tenant satisfaction.

Because many heat pump systems offer room-by-room temperature control, they’re more precise and responsive to comfort needs when compared to central systems that are complex to manage and commonly produce uneven temperatures across rooms. Residents have complete control over their environment with a heat pump system, reducing complaints and improving tenant retention.

Do air conditioners have any advantages over heat pumps? 

If you’re determining whether to install a heat pump or an air conditioning unit, cost will be an important factor. This is where air conditioners have a potential advantage: an air conditioner is less expensive than a heat pump (though labor and accessories are effectively the same). But when you remember the additional benefits offered by modern heat pump technology, it’s not exactly a fair comparison. 

Energy efficiency rebates and tax incentives can reduce heat pump costs substantially. BlocPower also offers Energy Service Agreements (ESAs) to help building owners realize immediate savings with no money down. 

What about operating lifespan? Generally, air conditioners can run reliably for longer than heat pumps. Heat pumps operate all year round, and on average, their warranties cover an expected operating lifespan of 10–15 years. An AC unit can last longer—but older air conditioners are less efficient than modern units. 

Running an old air conditioner can add to your property’s cost of ownership, and once you’ve owned your AC unit for more than a decade, you’ll need to upgrade. Per, replacing air conditioners after about 10 years of operation can cut cooling bills by 20% or more. 

The Best Time to Upgrade to Heat Pumps Is When You Need a New Air Conditioner

Heat pump and air conditioner technology is virtually identical—but by offering a clean, efficient source of heating, heat pumps offer enormous advantages over traditional HVAC systems. 

Upgrading to a heat pump can make sense in many scenarios, but if your central AC unit is reaching its end of life, there’s no better time to make the switch. Instead of a replacement in kind, invest in the benefits of a heat pump system. 

BlocPower can be your turnkey partner—designing, procuring, installing and maintaining the perfect solution for your building’s heating and cooling. Our experts will make building-specific recommendations while securing available incentives and rebates. It’s a streamlined process that maximizes your savings and reduces your stress.  

Ready to upgrade to a heat pump system? Complete this brief questionnaire to get started.