Almost everyone knows what an air conditioner is. After all, most of us have central air conditioning in our homes. However, many people think that air conditioners cool a home by producing cold air. They actually cool your home by removing the heat.
Standard air conditioners use a refrigerant to absorb the unwanted heat inside your home and transfer it to the outside. This happens by changing the pressure of the refrigerant fluid. At low pressures, the refrigerant will absorb heat available in the air and evaporate from a liquid to a gas. At high pressures, the gas refrigerant is higher energy than the outside air, so it passes heat to the surrounding air and the refrigerant condenses back to a liquid when it cools. By controlling the pressure of the refrigerant, an air conditioner can extract heat from your home, even on very hot days.
Heat pumps are not quite as well known. A heat pump can remove heat from your home just like an air conditioner. However, it can also reverse the direction the refrigerant flows, pushing warm air into your home to heat it up. There are several different types of heat pumps. Most of the discussion about heat pumps today is about air-source, split-system, ducted heat pumps. Ductless heat pump systems are available as well. They are also referred to as mini-split or multi-split systems. They can consist of one or more outdoor units connected via refrigerant lines and electrical wiring to indoor evaporator units. Ductless systems with multiple indoor evaporators allow you to have zoned temperature control. If you are considering installing a new air conditioner, replacing your current one or replacing your entire HVAC system, it could be a good time to consider a heat pump. If you have existing ductwork, a ducted heat pump can be added to your system much like a central air conditioner. Without existing ductwork, a ductless system might be easier to install.
When operating in cooling mode, air source heat pumps and central air conditioners are practically identical. Air source, ducted heat pump and air conditioning units have a similar appearance, noise level, and energy efficiency. They both run on electricity. The real difference is in the heating. Air conditioners don’t run in reverse so they do not provide a heating option.
When properly installed, an air-source heat pump can deliver 175% to 300% more energy than it consumes. High-efficiency gas furnaces are only about 95% efficient. This is possible because a heat pump transfers heat rather than converting it from a fuel. Depending on the local prices for gas and electricity, a heat pump might cost less to run than a gas furnace. However, this changes as the outside temperatures drop to freezing and below.
Because heat pumps extract heat from the outside air, the lower the temperature drops outside, the less efficient a heat pump becomes. Although heat pumps can pull heat from the air even in incredibly low temperatures, it takes more energy to do so. This can make them less efficient than a standard gas or electric furnace when the weather is really cold. A gas furnace, on the other hand, produces heat with the use of a fuel. When the outside temperature drops, even well below freezing, a gas furnace can continue to produce heat with no problems. Many Colorado homes with heat pump systems have a backup source of heat for cold days or long periods of low temperatures when the heat pump system is inefficient. These backup sources can be natural gas, propane, electric or pellet.
So, heat pump or air conditioner? Following are some things to consider when choosing a system to heat and cool your home.
Cost
Heat pumps utilize more technology, have more components, and can do more when it comes to bringing comfort to your home. So generally, the initial cost of a heat pump is more than an air conditioner when comparing similar sized units.
While heat pumps have a higher initial cost than an air conditioner, they can provide significant savings in your heating costs over the long run depending upon your current HVAC system. For homes using baseboard heating or an electric furnace, you’ll likely see significant savings in your electric bill by using a heat pump for your heating. For those heating with a gas furnace or boiler, you’ll need to examine the cost of natural gas or propane vs electricity. Heat pumps may cost less to operate if you are currently heating with propane due to its high cost. If you are heating with natural gas then the savings are not nearly as significant.
Environmental Impact
For cooling, both air conditioners and heat pumps run on electricity. But for heating, heat pumps are one of the most environmentally friendly options. You only need to use natural gas or propane if that’s your backup heating source when it is very cold out. As the world becomes more environmentally focused, moving away from natural gas is preferred. Using propane is significantly better for the environment than natural gas but it is significantly more expensive.
Energy Efficiency
In cooling mode, both heat pumps and air conditioners come in models with high SEER2 ratings, providing energy efficient cooling during the warm summer months. The higher the SEER2, the more efficient the unit. In heating mode, heat pump efficiency is expressed in HSPF2. The higher the HSPF2, the higher the efficiency. In many ways, the energy efficiency and cost to operate factor comes down to location. In areas with moderate temperatures, a heat pump is a better option for efficient heating than in areas with extremely cold winters.
Longevity
Both heat pumps and air conditioners should last between 10-15 years. There are no hard and fast rules. However, air conditioners generally last longer. They only run when the air needs cooling, while heat pumps are called on to operate year-round. The life span of your heat pump or air conditioner depends upon many factors, including how often you use it and how well you maintain it. The climate you live in can also affect the life expectancy of either system. Both tend to last longer in cooler climates than in warmer ones.
Electrical considerations
Both heat pumps and air conditioners require electricity to run. You may need to upgrade your electrical panel for the installation of a new system. If you have a home equipped with solar panels or a solar photovoltaic system, you may have an advantage in using a heat pump for heating. Your electrical costs may be minimal if solar power is available.
Heat pump heat
In general, the air from a heat pump isn’t as hot as what you get from a gas furnace. It still warms your home, but it “blows cooler.” Some people don’t like that.
Tax incentives
There are tax incentives available at the Federal, State and many local levels for the installation of certain energy efficient air conditioning and heat pump systems. Even some local utilities offer various installation incentives. Of course, the incentives available are dependent upon a number of different factors. These incentives could factor into your final decision.
We hope this information has given you a better understanding when comparing heat pumps and air conditioners. As far as cooling goes, heat pumps and air conditioning units are practically the same. The main differences are when it comes to heating. Here in Colorado, we experience freezing and below freezing temperatures, but they don’t usually last for long periods of time. We install both heat pumps paired with a backup heating source as well as air conditioners with conventional gas furnaces. Either system can work well in our climate. Which is right for you may depend upon your current HVAC system and your personal preferences.
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