Whether looking to heat or cool your home, what type of system you have in the present or purchase in the future can add up to huge installation and energy costs if chosen incorrectly. This is why it is important to know the difference between some of the most standard cooling and heating systems in the country: the heat pump and the air/conditioning heat system.
This system is often shaped like a box and smaller than an air conditioner. Like an air conditioner, it uses coil technology and refrigerants to heat and cool air and can often have separate components located on the interior and exterior.
The process a heat pump uses to make hot air begins with drawing air in through the outdoor coil, sometimes called the evaporator. This air is then pressurized in a
compressor and refrigerants are added to remove heat and turn the air into vapor. The vapor is then sent to the indoor coils for another round of heating, this time with radiators, and then is blown into the home with the aid of an exhaust fan.
However, heat pumps don’t just heat air, they can also cool it since it employs similar technology as an air conditioner. To make cool air, the heat pump again draws in air through the outdoor coil. This time the refrigerants are again used to remove heat from the air and send in cool air to the indoor coil. This coil also works to cool the air before blowing it into the home. The process has an added layer of efficiency because refrigerants are recycled back into the system.
Pro’s and Con’s of Heat Pump
Traditional heat pumps work best in moderate climates where it doesn’t get too hot or too cold for extended periods of time, as in Tennessee or the middle South. Another advantage of the heat pump is that it works year round and does not sit idle like the cooling and heating components of an air conditioning and heat system. Heat pumps are also less of a hassle in installing and maintaining with only one system to tend to.
Drawbacks to heat pumps include their inability to consistently provide heat at temperatures lower than 40 degrees Fahrenheit, or 4 degrees Celsius. They can also be less energy efficient when cooling homes for long periods of time.
Air Conditioning and Heat System
Also called all-in-one systems, the air conditioning and heat system has separate cooling and heating components, unlike a heat pump. They can be powered by electricity, gas, or both.
The air conditioner works to cool air in a similar manner to the heat pump. It has four major components. The compressor takes in refrigerant and compresses it to give it both a high temperature and high level of pressure. The condenser takes in this refrigerant and sends it throughout its coil system, which cools the refrigerant while releasing excess heat outdoors. The metering device then helps regulate the low and high pressure sides of the air conditioner, and the evaporator absorbs even more heat from the refrigerant before it gets blown into the home.
On the heating side, the heating system available with an air conditioner is commonly a furnace type system, which is simpler than the cooling process. The major component used in this type of system is a heat exchanger. Often made of metal tubes, they retain heat by utilizing resistance electricity to heat the air. The process is similar to how a hair dryer heats air. The hot air is then blown into the home.
Pro’s and Con’s of Air Conditioning and Heating System
These types of systems work best in climates where the AC is used more than the heater, since air conditioning is the best way to cool a home in the long term. These hotter climates include states such as California, Florida, and Texas.
The downside to an all-in-one system is that one component sits idle for extended periods of time, whether it’s the cooling or heating system. But these all-in-one systems can also be installed and maintained simultaneously.
Other Types of Heat Pumps
Gas Heat Pumps
With the emergence of more homes and businesses using natural gas for heating purposes, heat pumps also come with the option to be powered by gas. Advantages of this system are that gas is normally a cheaper and more efficient means of powering the system than traditional electricity. It can also produce fewer emissions than an electric heat pump. However, as with any system powered by gas, the unit can leak toxic carbon monoxide into the home when malfunctioning. When factoring the cost of a unit and installation, it is advisable to consider a gas heat pump in homes or buildings of more than 4,000 square feet, or 372 square meters.
Sometimes called absorption heat pumps, gas heat pumps use the gas or propane to heat the refrigerant solution, raise its pressure, and extract the heat. It is then sent to the evaporator where more heat is extracted. The refrigerant is then combined with leftover water from the original flame-heating chamber in a low-pressure heat exchanger or absorber. Their combined heat creates hot air that is then sent throughout the home with the remaining liquid sent back to repeat the process.
Hybrid Heat Pumps
Also called hybrid heat and/or split systems, these pumps work with both gas and electricity to heat and cool the home. These systems are designed to use each when most advantageous and can have high Energy Star ratings. In fact, they are programmed to automatically switch power sources when the conditions call for it. Another advantage to these systems is the option to exclusively power it by one source. For example, if the price of coal skyrockets, the system can be programmed to specifically run on gas, or vice versa.
However, they can come with added costs for both the unit and installation, which should be considered before purchasing one.
Heat Pumps and Standard AC and Heat Systems Efficiency
When looking for the most efficient models, there are three items to know: AFUE, SEER, and Energy Star.
Annual Fuel Utilization Efficiency (AFUE)
AFUE is used to measure the efficiency of a furnace and its heating capacity. It is expressed as a percentage of heat created per energy use. For example, if a furnace has an AFUE of 80%, it means that the furnace has used 80% of the energy it takes in to create heat. The Department of Energy requires all furnaces sold in the U.S. have a minimum AFUE of 78%, with mobile home furnaces required to have a minimum AFUE of 75%. In 2015, the minimum AFUE rises to 80% for non-weatherized gas furnaces, 83% for weatherized gas furnaces, and 80% for mobile homes. The AFUE only applies to gas furnaces, since electric ones have an AFUE of 100%.
Seasonal Energy Efficiency Ratio (SEER)
This rating is calculated by total cooling output in BTU’s from the unit divided by its total energy input during normal annual usage. The higher the SEER rating, the better its efficiency. As of 2006, all residential air conditioners were required to have minimum SEER of 13. Window units are exempt from these standards. Beginning in 2015, residential air conditioners installed in Alabama, Arkansas, Delaware, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and Virginia must have a minimum SEER of 14.
This program is part of the EPA and used to determine the efficiency of a number of products, appliances, and even homes. Heat pumps and all-in-one systems acquire the Energy Star label when they meet a certain standard of efficiency and greenhouse gas reduction. It is not required that your cooling or heating system be Energy Star certified, but the reduction in energy bills can well be worth the label.