Central air conditioning systems require ductwork to transport and circulate cooled air throughout the building. If your home doesn’t have an existing ductwork system, you may be wondering whether it is still possible to install an air conditioning system. The answer is yes, but it depends on what type of AC system you want and how much you’re willing to pay for it. To understand why, let’s look at how air conditioning works in homes without ductwork.
An Introduction to Ductless Mini-Split Air Conditioning
If your home doesn’t already have a ductwork system, retrofitting one into the building is a huge task. In many cases, it simply isn’t possible due to how the building was designed and built. Even if it is feasible, it will require major construction work and will cost at least a few thousand dollars. This means that if your home doesn’t have ductwork, you should probably just forget about the idea of having central AC. However, this doesn’t mean that you have to go without air conditioning altogether.
Ductless mini-split air conditioners are a relatively new type of AC unit that doesn’t require any ductwork. These units are similar to a central AC system in that they use an outdoor condenser unit and an indoor air handler. The difference is that the air handler pumps cool air directly into the space instead of circulating it through a duct system.
Most mini-split systems have a single air handler, which means that they can only provide cooling to one space. As a result, you would need multiple air handlers in different parts of the house to cool the entire building. Luckily, such systems exist. Often referred to as a multi-split system, this type of ductless AC can run multiple air handlers from the same outdoor condenser unit.
How Ductless Air Conditioning Works
Ductless mini-split systems provide cooling using the same heat transfer process as a central air conditioner or any other type of AC. Air conditioning works by using a cold refrigerant to absorb heat from the air inside the building.
The job of the condenser is to supply refrigerant to the evaporator coil inside the air handler. The air handler draws hot air in and forces it over the evaporator coil. When this happens, heat energy is automatically transferred from the hot air to the cold refrigerant. This, in turn, cools the air, and the system then pumps out the cooled air to lower the temperature in the building. At the same time, the heated refrigerant is pumped back out to the condenser, which releases the heat and re-cools the refrigerant.
Ductless air conditioners work similarly to a portable or window AC unit in that they absorb heat from a single space and pump the cooled air back into that space. However, ductless mini splits provide far more effective cooling while also using much less energy.
Similar to a central heat pump, most ductless mini-split systems are also able to provide heating as well as air conditioning. During the winter, the heat transfer process is reversed. When heating, the condenser uses extremely cold refrigerant to absorb heat from the air outside. This raises the temperature of the refrigerant.
The heated refrigerant is then pumped into the air handler. As the cooler indoor air flows over the coil filled with hotter refrigerant, heat automatically flows from the refrigerant into the air. The result is that the air coming out of the air handler is warmer than the rest of the air inside the building, which raises the temperature inside.
Like central heat pumps, ductless mini-split systems are one of the most energy-efficient heating methods available. They function best when the outdoor temperature is above freezing, but they can continue to provide an effective heating option even if the outdoor temperature is below 0 degrees Fahrenheit.
How Is a Ductless Mini-Split System Installed?
One of the biggest benefits of opting for a ductless AC system is that they are fast and relatively simple to install. The first step is to mount the condenser unit on a concrete pad outside the building close to wherever the air handler will be located. Whether you are installing one or multiple air handlers, each one typically needs to be located within 75 feet of the condenser.
The further away from the condenser the air handler is, the harder the condenser motor will have to work to pump the refrigerant through the lines. This is why there is also a limit as to the total length of all refrigerant lines in the entire system. This is usually somewhere between 200 and 300 feet depending on the size of the condenser.
After mounting the condenser, the next step is to cut a small diameter hole in an exterior wall in the room where the air handler will be located. This hole is used to run a conduit that contains the refrigerant lines, condensate drain line and electrical wiring.
In most situations, the air handler is then mounted on the exterior wall directly over the hole that houses the conduit. Wall-mounted systems are the most common as they provide effective cooling while also being the easiest method of installation.
You can also choose to mount the air handler on the floor or the ceiling. Mounting it on the floor generally isn’t recommended as this will cause all of the cold air to settle to the ground and reduce the system’s effectiveness.
If you’re mounting it on the ceiling, you can either have the unit surface mounted or recessed into the ceiling. While recessed is definitely best in terms of aesthetics, it does increase the time and cost of the installation.
The air handler doesn’t necessarily need to be installed on an exterior wall. Nonetheless, if you’re mounting it on an interior wall, then it will be necessary to run the conduit into an exterior wall and then through the wall, floor or ceiling to connect to the air handler. As with recessed ceiling mounts, this increases the cost and difficulty of the installation.
How Efficient Is Ductless Air Conditioning?
Ductless mini-split systems are typically much more energy efficient than any other type of AC system. AC efficiency is measured in SEER or Seasonal Energy Efficiency Ratio. Central ACs are usually between 14 and 20 SEER although some models are as high as 28 SEER. On the other hand, even the most basic ductless mini-split systems are usually at least 20 SEER, and some systems reach well into the thirties.
However, it is important to understand that energy efficiency isn’t the only factor to consider in terms of cooling costs. If you are running multiple air handlers, each one will consume additional power whenever running. As a result, a multi-split system will often end up using the same or more electricity than a central AC despite being more energy efficient.
On the other hand, each air handler has its own separate remote and can be controlled independently. This means that you don’t need to run all of the air handlers at the same time. You can also adjust the temperature for each air handler individually to provide more cooling where it is needed and less in rooms that don’t get much use.
If you have any questions about ductless air conditioning, the team at Fahnestock HVAC is happy to help. We have been providing professional cooling and heating services to customers in the Wichita area since 1946, and our HVAC technicians have years of experience installing, repairing and maintaining heating and cooling systems. To learn more about the benefits of ductless AC or to schedule a consultation, give us a call today. We also offer plumbing, geothermal, and electrical services.