When you are looking for sweet relief from summer heat it probably doesn’t matter to you whether you have a heat pump or an air conditioner – you just want it to work. But when you are looking to install or replace an HVAC system that efficiently heats and cools your home and keeps your family comfortable it is nice to know your options. It can be confusing when it comes to figuring out the differences between a heat pump and an air conditioner. We are here with a crash course in heat pump and air conditioning knowledge.
The Basics of Air Conditioning and Heat Pumps
When in cooling mode heat pumps and air conditioners do the basic same job – transfer hot air from inside your home to outside. In HVAC terminology, heat pumps and air conditioning systems are specific types of units that keep you cool. But the heat pump has a second job it can do. Let’s look under the hood of both and see how they each work.
What is a Heat Pump?
Heat pumps work on the principle that it is generally easier to move something than make something. On that concept, they have been used for years to cool homes by simply removing heat from the inside of homes to the outside and reversing that process to heat homes.
The Components of a Heat Pump
A typical air source heat pump is made of two parts – also called a split system – that have an indoor air handler and an outdoor unit. The heat pump system includes an array of components:
- Compressor that moves refrigerant through the system
- Coils, both condenser and evaporator coil that heats or cools the air
- Reversing valve that changes the flow of the refrigerant
- Thermostatic expansion valves that regulate the flow of refrigerant
- Accumulator that adjusts as the seasons need
- Refrigerant lines that connect the inside and outside components
- Heat strips used for additional heat on cold days
- Air ducts that allow the hot or cold air to flow throughout the home
Refrigerant is a compound that goes from a liquid to gas easily and absorbs heat from the environment and transfers it elsewhere — a process known as heat exchange.
How does a Heat Pump Heat?
When cooler temperatures come along in the fall and winter, a heat pump has a magical reversing valve that switches the system from cooling to heating, pulling heat from the outside air into the home. A heat pump normally can pull enough heat from the outside air to heat a home at 70 degrees as long as the outside air temperature is above 30.
But when the temperature dips below 30 degrees the heat pump kicks in the auxiliary or supplemental heat mode because there isn’t enough heat in the outside air to pull in. When the thermostat calls for a significant increase in temperature the system will switch to its supplemental heat source to heat the home faster and save energy/money.
Pros & Cons of Heat Pumps
Now that we have overviewed how a heat pump works let’s review the pros and cons of having one.
Pros of a Heat Pump
One of the advantages of a heat pump is that they use electricity, reducing the need to have access to natural gas or keeping a propane tank. Because heat pumps use a whole home duct system the warmth produced is evenly distributed throughout the house, reducing the number of cold spots and keeping everyone comfortable.
Efficiency is also a great advantage to a heat pump, particularly geothermal heat pumps. Generally, heat pumps put out more cool and warm air by volume than the amount of energy it takes to run them. Heat pumps are also more advantageous to maintain because, during the twice-a-year maintenance, the technician will look at both parts of the system to keep everything running smoothly.
Cons of Heat Pump
For people living in moderate climates, heat pumps are an excellent option. But If your area dips below freezing often in the winter a heat pump will not be an efficient or comfortable choice. And the advantage of being powered by electricity also becomes a disadvantage if the power goes out and you are left without AC or heat. This is also a problem if the unit breaks – you lose both heat and cooling.
Heat pumps also cost more than furnaces to purchase and install. Longevity is another disadvantage to a heat pump. There are a lot of variables that influence an HVAC system’s life expectancy, with the biggest one being how often it is used. Because heat pumps are used year-round vs seasonally, they tend to wear out more quickly, usually lasting about 15 years.
What Size of a Heat Pump do You Need?
Choosing the right size heat pump for your home is critical to a well-functioning and efficient heating and cooling system. If your heat pump is too small then it will struggle to keep your home cool and warm. On the other hand, if it is too big it will waste energy by producing too much hot or cool air, cycling on and off constantly, and stressing out the motor. There are a number of factors that go into sizing your unit properly.
- Local climate
- Home square footage
- Window and doors
- Insulation in the home
- How many people are in the home
- Temperature preferences of home residents
- Other appliances that can generate heat
Having an expert evaluate your home and needs is the best way to find out if a heat pump is a good option for you.
What is Central Air Conditioning?
An air conditioner works like a heat pump, extracting heat from inside and moving it outdoors. The main difference is that a central air conditioning unit does one thing really well – it cools your home. Central air conditioning is different from other types of AC – like ductless air conditioning units – using invisible ductwork throughout the home to distribute cool air to rooms.
How does an Air Conditioner Cool
We have created an in-depth guide on air conditioning that walks through the deeper details of how an AC system works but here are the basics. Like a heat pump, a central air conditioner is a split unit containing:
- A compressor and condenser unit on the outside of the house
- An evaporator coils on the inside of the home
- A series of refrigeration lines connect the inside and outside units
- Refrigerant that circulates through the indoor and outdoor units
- Air intake and fan that distributes air through ducts to rooms of the home
- A thermostat that controls your home’s temperature
Also, like the heat pump, AC units rely on refrigerants to do the heavy lifting of pulling in heat from your home and releasing it outside. Technically, air conditioners do exactly what their name suggests – condition or dehumidify the air. Humidity — or water vapor – in the air makes it hard for our bodies to regulate temperature, making us feel overheated when the mercury rises. Air conditioning pulls humidity from the air and makes our skin feel cooler.
Pros & Cons of Central Air Conditioning
Central air conditioning is good for large homes or homes that already have existing ductwork. As its name implies – central AC centralizes everything – fans and cooling systems cycle the air through your home by way of ducts that keep the rooms in your home cool and comfortable.
Pros of Air Conditioning
The benefit of central air conditioning is its specialization. Air conditioners are the best way to keep your home consistently cool. They produce a lot of cool air that is distributed to rooms through the ductwork. For those with larger homes, air conditioning is a quiet and efficient way to cool your whole home. Central air conditioning systems also filter air improving indoor air quality and reducing allergens.
Cons of Air Conditioning
The biggest disadvantage to air conditioners is that they cannot create heat. For those whose area dips below 60 degrees in the winter, heat is non-negotiable. Air conditioners must be paired with a furnace for a full heating and cooling system. Because you need both a furnace and an air conditioning unit you are going to need space for both pieces of equipment. It also means an air conditioning system can be expensive.
Related: Ductless Mini Split vs Central Air: A Quick Comparison
Deciding Between the Two
There are a lot of similarities between heat pumps and air conditioning systems. Both heat pumps and central air conditioning use existing ducts within the home and both use electricity. When in cooling mode, both heat pumps and air conditioners cool by moving heat and humidity from inside the home and depositing it outside. So how can you decide which is right for you?
Everyone’s situation is going to be different but the main factor for many people is the cost to purchase and install the system. The cost of installing an AC or heat pump system is based on a number of factors that vary regionally. Air conditioning systems can range from $5,000 to $10,000 in the Northwest and a heat pump can be $7,000 to $13,000.
If you have an existing ductwork system then the cost of a thorough inspection might be all you need. If your ductwork is damaged then the extra cost of repair could run between $1,500 and $5,000.
Related: How Much Does It Cost to Install AC in My Home?
Energy Efficiency and Cost to Operate
Air source heat pumps and air conditioning systems’ energy efficiency are rated by their Seasonal Energy Efficiency Ratio (SEER) or Heating Seasonal Performance Factor (HSPF). SEER measures the cooling output of a system over a typical summer, whereas HSPF measures the efficiency of a heat pump’s heating mode. Think about it like the miles per gallon (MPG) rating for your car. You can potentially get high MPG but if you are going to drive like you are in the Indy 500 that MPG is going to be drastically lower.
SEER ratings are the maximum cooling efficiency rating for your system and if you are constantly changing temperatures or your home is a southern exposure on a tropical island the efficiency of any system will go down. In summer, a heat pump and air conditioner might cost about the same to operate but in mild winters the heat pump’s cost to heat can be lower than heating with a furnace. But those energy savings will decrease if the outdoor temperatures drop since a heat pump’s supplemental heating system will require more energy to keep your home warm.
Related: HVAC Efficiency Ratings Explained
As mentioned, heat pumps work year-round, potentially reducing their life expectancy. An air conditioning system only works seasonally and gets a break in the winter when a furnace or other heating system kicks in, extending the AC’s longevity. However, a heat pump’s shorter life span might be offset by lower cost-to-operate heating during mild winters.
Because heat in the air is free, heat pumps work really well at above freezing temperatures only needing enough energy to maintain comfortable warm temperatures in the home. Both will have their longevity greatly extended by regular annual tune-ups that keep your system running at maximum efficiency.
How Jacobs Can Help
Finding the right HVAC system for your home is crucial to your comfort — and for your wallet. Jacobs Heating & Air Conditioning experts are ready to make sure that you have the best system for your home and lifestyle. We will guide you through the decision so you can avoid extra costs, fewer repairs and enjoy a long-lasting system. No matter what you need we’re always just a phone call away. You are welcome to review our statement on COVID-19 and how we’re taking precautions to protect you, our team, and our communities.
This post and infographic were last updated on July 13th, 2022 to reflect 2022 prices.