There are several important decisions you'll have to make amidst any construction project. One of them is how to supply heat and air conditioning to a particular room. For this, you generally have two options: connect the room to the central air system, or put in a single-room heating, ventilation, and air conditioning system.
Why Connect to Central
In the United States, it has been common to connect most or all rooms in a home or building to the central air system. If the ductwork has already been completed, or isn't challenging to install, this option might be an ideal way to bring heating and cooling to a room. This is primarily because of the cost. Single-room HVAC, also known as slimline, ductless, or mini-split systems, can run a consumer between $1,500 and $2,000 per ton of cooling capacity - about 30 percent more than connecting to central.
Single-room HVAC systems also don't always have the same aesthetics as a central system. They can look out of place, and most require a way to collect and redirect condensation from the unit. On the other hand, ducts for a central system often look more professional and built for the room.
Why Choose a Mini-split System
While single-room systems might cost a bit more than connecting to a central air conditioning system, if the right size is chosen and installed properly, there's a good chance you can lower your energy costs. Ducts can lose about 30 percent of the air conditioning consumption in a home. But by using single-room systems and strategically choosing which rooms to heat or cool, and when, you can reduce these losses.
They are also often easier to install in existing construction than connecting a room to the central system. Ductless systems only require a small hole in the wall to accommodate the conduit. Plus, they come in a variety of designs that allow you to mount them to the ceiling, or wall, or place them on a floor stand. Many models come with remote controls, making them easy to adjust.
Another reason to opt for a mini-split system is to improve air quality. Air ducts commonly collect dust and other allergens, and require frequent cleanings to maintain high air quality. Ductless systems are usually equipped with a filtration system that will keep pollen, dust, bacteria, and any other particulates at bay.
Why Choose Both
Most people will wind up either choosing to install ducts in the room or going with a mini-split system. However, there are times when both systems can be advantageous. For example, areas of the country that experience colder winters might benefit from having a ductless system hooked up for supplemental heat during the coldest days of the year. Some school districts have benefited from this system because as many as 50 classrooms can be connected to the same system, making heating specific areas of the building much easier. Additionally, when building onto a home that has a central heating system, it might make sense to use the mini-split system in the new room while maintaining the central heating system in the rest of the house.