What is a Ductless System
There are a few types of ductless indoor units but the most common type is what many refer to a ‘ductless mini-split'. The reason it's called a split unit, is because there are two separate units. A common misconception is that ductless indoor units don't have an outdoor unit, however, there is an outdoor unit. The ductless condensing unit is similar to a central AC condensing unit. The condenser sits outside, and the air handler is located inside. It is common in Florida to have the condenser installed in the garage, or in an interior closet. Every once in a while you will see a condenser unit that has been installed in an attic.
How Ductless Systems Work
Central ducted AC systems have two units connected with two copper lines. These copper lines carry the refrigerant to and from the outdoor and indoor unit. One is called the suction line, and the other is called the liquid line. These lines carry the refrigerant in its different states between the compressor and the evaporator coil, with a metering device in between.
Mini split's are the same except they are set up a bit differently. The outdoor condenser has two refrigerant line sets that connect to the indoor unit. That indoor unit is where you'll see some variants in the different types of ductless units that are available.
Three Types of Ductless Indoor Units
There are ductless indoor wall mounted units, ceiling recessed units, and floor mounted units. Some manufacturers offer some different style products. Quite often you will see, for example, Mitsubishi offers a ducted option that can be paired with their outdoor condenser. This article is going to focus on the three most common types.
Wall Mounted Ductless Indoor Unit
Wall mounted ductless indoor units are exactly like it sounds, they mount on to the wall. It's a rectangular shape, usually about 11 inches high by about 3 feet wide, and the dimensional and BTU size can vary depending on the manufacturer. For aesthetic reasons, the copper line set and electrical whip that comes into the unit, most often comes directly into the back of the unit.
There is a drain line that is also connected to the indoor air handler unit. The drain line is normally a gravity fed drain, meaning that it doesn't need any sort of pump to pump the water (caused by normal condensation) out of your space to the exterior of the home.
With central AC systems in most cases, about 90% of the time you will not see a condensate pump, which is the type of pump mentioned above in order to pump the water out of the drain line and out of the house.
Common with many ductless installations, a gravity fed drain will be positioned straight down into a platform and into what is referred to as chase pipe. The chase pipe is something that runs basically underneath the house. It is a 6 inch PVC pipe that is laid down before the foundation is poured, so when a ductless unit is being used in a retrofit application, the drain line is always an important consideration.
Mounting the ductless unit air handler on an exterior wall will allow the copper line set, electrical, and the drain line, to be installed directly off the back of the unit. When you're in the interior of the home, all you see is the wall mounted unit suspended which looks like it's just hanging on the wall, similar to what you would see with a wall mounted TV, or a picture. You won't see any of the hanging straps or hardware. Everything is mounted on the back of the unit.
Ceiling Recessed Ductless Indoor Unit
The second type of ductless indoor air handler unit is a ceiling recessed unit. This type of ductless unit, commonly installed in master bedrooms, is becoming more popular in The Villages and in the Clermont Florida area.
This type of ductless indoor unit, instead of hanging on the wall, is suspended inside the attic. About 9 to 10 inches of the unit sits recessed up in the attic, similar to what you would see with can lighting.
The bottom of the unit, which is seen from the living space, has about a 22 inch wide ceiling grill. The grill has a return in it that has a baffle on all four sides that air blows out of. The baffle spreads the cooler or hotter air throughout the room, depending on the heat or cool setting.
With ceiling recessed units, the drain line is attached to a lift assembly, and so once again, no condensation drain pump is required. These units are specifically designed to lift the moisture upwards with a small crank, and that moisture then exits down the drain line. Although these type do not allow for a very long drain line, they still work with a gravity fed drain without requiring a pump.
Ceiling recessed units are gaining more popularity because aesthetically they have less of a footprint in the home. Because they are recessed, a larger portion of the air handler is located in the attic where you can't see it.
Floor Mounted Ductless Indoor Unit
The third type of unit is one that is also going to be gaining more popularity in the future especially in situations where there's not enough headroom to do a wall mounted unit, and where there is not enough room between the joist or the trusses in a home to do a ceiling recessed unit is the floor mounted ductless unit. Floor mounted ductless units are best used where the trusses are 16 inches apart instead of 24, and where the headroom above a window is a lot less, which is common in an older homes, and in wood frame homes.
Floor mounted ductless units also have a drain line and a copper line set that attaches to it. These types of units are mounted very close to the floor and allow for a nice, easy, gravity fed drain since they are so close to the ground.
Usually floor mounted ductless units can have the drain line mounted directly off the back of the unit and have the drain run through the outdoor area where it's inconspicuous. Because the drain line is so close to the ground, it can be hidden behind a bush or a plant which makes it aesthetically pleasing.
Floor mounted ductless units will also appear to just hang, usually right above the baseboard, and will give you the ability to cool or heat a room, just like the other types do. Instead of being able to see them on the wall or in the ceiling, you would see this type down near your feet.
Many people up north replace their boilers with floor mounted ductless units because they have the same sort of look, similar to what you see in hotel room PTAC units, mounted near the floor, but with a lot smaller footprint.
In conclusion, the three main types of ductless indoor units most common in the Central Florida market are wall mounted, ceiling recessed, and floor mounted ductless indoor units. We install all three types of ductless indoor units here at Kalos Services. If you have any questions, call our office at 352-243-7088 or contact us online and we'll be happy to answer them.
