What Is a Split System?
The most common type of central air conditioning system used in the U.S. is the “split” type of system. It’s called a “split” system because it’s comprised of two main components, one located inside the home and one located outside the home. The interior component, also known as the air handler, has a blower and evaporator coil to distribute cool air through the ducts of the home, and the outside unit houses a compressor and condensing coil which pumps refrigerant into the system.
A split air condition system uses electricity as it power source and utilizes the ducts in a home to distribute cool air and warm air when needed. Using the same network of ducts for both heating and cooling makes the split system one of the most efficient types of air conditioning systems available.
To learn more about other types of systems, click here.
You can also watch this system explainer video which contains a condensed overview:
How a Split Air Conditioning System Operates
The compressor, which is housed in the outdoor metal cabinet, is a motorized unit that pumps a liquid coolant through pipes (also known as “refrigerant lines”) to the interior unit, where it then removes heat and moisture from the home. It does this through a process called phase conversion, where warm air blows over the evaporator coil causing the liquid refrigerant to change from a liquid state to a gaseous state (vapor). When a substance changes from a liquid to a gas, a unique result is the removal of heat from the air. Within the air handler, the cooler air is then blown through the vents into the home while the vapor is transferred back to the outside air conditioning unit where the condenser coil changes it back to a liquid and the process begins all over again.
Air conditioning has come a long way since a young engineer named Willis Carrier invented the first air modern air conditioning unit in 1902. While working for a printing press, Carrier was asked to solve the humidity problem in the plant, which was causing the pages of the magazines wrinkle and curl up at the edges. The system he designed controlled the humidity by sending air over water-cooled coils. Recognizing the usefulness of his invention, he went on to form his own company which focused on developing and improving the air conditioning system.
Today, air conditioning is considered an essential part of modern living allowing us to remain cool in our homes, places of work, restaurants, schools, hospitals, etc. Air conditioning has become an important and integral part of our everyday lives. In fact, Americans consume more energy each year running air conditioners than the rest of the world combined. According to the U.S. Department of Energy, nearly 6% of all the electricity produced in the United States is used by air conditioners, costing homeowners almost $30 billion in annual costs and producing nearly 117 million metric tons of carbon dioxide in the air each year.
This is why energy standards have been adapted for manufacturers to produce more energy-efficient appliances and air conditioning units. The air conditioners manufactured today are 50% more efficient than those produced just ten years ago, saving consumers millions of dollars and reducing the amount of harmful pollutants being released into the environment.
Split air conditioning systems are one of the most energy efficient systems you can find. With SEER (Seasonal Energy Efficiency Ratio) values ranging in the high 20s, split systems are a great choice for the environmentally and budget-conscious consumer.
The Air Conditioning, Heating and Refrigeration Institute also has a number of resources to help homeowners understand their systems here.
Split Air Conditioning Installation
The most important aspect of the split AC system is the installation. If it’s done properly, your system will perform at its optimum level, but if it is not installed properly, then the result could be higher utility bills, frequent maintenance problems, and uneven cooling. Before installing the two parts of a split air conditioning system, first it must be determined where the inside component should be located. Typically, the indoor unit is placed in a closet or cabinet, but if neither of those is available, then another space must be used.
Some interior units of a split system are housed in the attic. There are many contractors, however, who believe installing the air handler in the attic is not the best idea as attics are typically not air conditioned and, therefore, get very hot in the summer. This can affect the efficiency of the indoor unit. Ducts expand and contract with temperature changes and an area with unregulated temperature, such as the attic, could cause leaks and loosening of the duct seals. Additionally, with the indoor unit housed in the attic, one may forget about it and not perform regularly required maintenance, or may not want to if the unit is hard to get to. In older homes where space is limited, there may be no other option than the attic for the location of the indoor unit. In this case, it’s important that the ductwork be properly sealed and insulated and the installation is done by an AC professional.
The garage is a location many people think is ideal for installing the air handler as there is usually plenty of space, it’s not as hot as the attic, and there’s enough room to easily access the unit for repairs. However, there is a case to be made that the garage is probably the worst place for the air handler. Many people use their garages to store items such as pesticides, lawn mowers, paint, and their automobiles that often have the engine running before the garage door opens or closes. This can cause garages to have high levels of carbon monoxide and various other pollutants that contaminate the air, which could be getting sucked into your home through leaks or gaps in the air handler. Poor indoor air quality is a health concern and may result in serious health issues. If the garage is the only place available for your air handler, then it is recommended that it is placed in an insulated and air-sealed closet to reduce contaminants from entering the system. Other actions you should take would be to make sure the duct system is properly sealed and purchase a carbon monoxide monitor for the inside of your home.
Crawl Space Installation
Installing the air handler in a crawl space is a popular option as it keeps the unit “out of the way.” However, many crawl spaces are damp and dark and can get hot and humid during the warmer months. Therefore, it’s important to make sure your crawl space in encapsulated and not vented to the outside as this could cause mold growth and reduce air quality, especially if you live in a more humid climate. Installing a dehumidifier in the crawl space is beneficial as well.
Basements are also a place where air handlers can be installed as it offers an “out of sight” location like attics and crawl spaces, although the basement allows for easier access to the unit.
How Much Does a Split System Cost?
There are several factors which will affect the cost of an AC unit, but the usual range for installing a new split air conditioning system is between $3,700 and $7,200. The size of your home, whether or not ducts need to be installed, repaired, or replaced, and installation rates are the top determining factors affecting the cost of your new AC system. Also, it’s important to make sure you purchase the right-sized air conditioner for your home. This is where a professional AC contractor is key helping you determine the best AC fit for your needs.
First, the contractor will determine how much cooling power your home will need by performing a load calculation. This measurement takes in account a variety of factors affecting the temperature of your home such as square footage, number and types of windows, how much heat loss your home experiences, insulation levels, whether or not your home is located in the shade, etc. This data is then analyzed to determine how much air your air conditioning system is likely to lose and which system is the best one for efficiently cooling your home.
The climate in which you live is also an important factor that will determine the type of AC unit that will be best for your home. If you live in a hot, humid climate, you will want an air conditioning system that effectively cools and dehumidifies your home. You will also likely want a unit with a higher SEER rating for energy savings as an air conditioner in a state like Florida is going to work a lot harder in the summer than one in a state such as Minnesota. If you live in a drier or milder climate, then a lower-rated SEER model should suffice.
It’s important to make sure your HVAC equipment is sized properly for your home as a system that is too small won’t effectively cool the air, and one that is too large won’t properly remove all the humidity in the air, cause uneven cooling, and increased utility bills.
The SEER number you choose for your split system will also affect the price. Higher-rates SEER units will save you more money each month, but the upfront costs are more expensive than lower SEER models. To learn more about SEER, click here. To find out about SEER minimums where you live view this Seer Mimimums Map.
Pros and Cons of Split Air Conditioning Systems
- Split systems are large and bulky with a unit located not only outdoors, but indoors as well. A significant amount of space is needed to house the large, unattractive metal cabinet of the indoor air handling unit and some smaller houses don’t have a lot of space to give up to begin with.
- Ductwork needs to be installed if not already present and this can be costly. Also, if ductwork is present and was installed years ago, it will likely need to be cleaned, repaired, or even replaced if it is not a good fit for the new air conditioner.
- Installation is more complicated and tricky with an indoor component, outdoor component, and lengthy network of ducts. There’s more opportunity for something to go wrong or mistakes to occur.
- The indoor air handling unit may be housed in an area that is difficult to get to and repair.
- Higher repair costs – with more parts, there’s more that can go wrong.
- A consistent temperature is easily maintained and distributed throughout the home with central air conditioning.
- The AC components are hidden away behind walls, in out-of-the-way-places, or outside.
- Split systems have more availability of higher SEER rated options for saving even more money and energy than standard models. The U.S. Department of Energy has mandated that a minimum SEER rating of 15 will go into effect for southern states in 2023 (SEER 14 for northern states), but many manufacturers are already producing split system units with SEER ratings as high as 28.
- Split air conditioning systems are better at removing humidity and cooling larger spaces.
What Is the Difference Between a Split System and a Ductless System?
A ductless air conditioning system is also split into two parts with an indoor and outdoor component, just like the split central air conditioning system, however, a ductless system does not require ducts. Ductless systems are a great option for those homeowners who don’t have a network of ducts already installed in their home, don’t want to tear up their walls installing ducts, or just don’t have the room for them.
Besides no ducts, this type of system differs from split systems in that instead of one air handler in the home, there are multiple “mini” air handlers which are installed in every room, usually high up on the wall. This type of installation allows for the temperature of each room to be individually controlled by the thermostat on the air handler unit. Therefore, if one person prefers a room temperature of 78 while another prefers their room temperature to be 72, then this system offers that type of temperature control variability.
Air Filters & Maintaining Your Split Air Conditioning System
Once you’ve installed your new central AC system, it’s important to perform regular maintenance, service, and repair to extend its life and make sure it operates at maximum efficiency. One of the most important ways to take care of your air conditioner is to replace the filters regularly. The large amount of air traveling through your AC system contains dust, debris, allergens, and pollutants, which is cleaned when pulled through the air filter. If the filter gets dirty and clogged, then the air cannot be cleaned as effectively and air flow is reduced. Clean filters equal clean air, dirty filters… less so. It’s best to check your air filters at least every two weeks and replace them as soon as they look dirty.