Air conditioning long ago quit being seen as a luxury. Almost 75% of American homes have air conditioning, and that number is certainly higher in hotter regions of the country, like in the Dallas-Fort Worth area. You may decide that you want to install air conditioning in your home for a number of reasons. Perhaps you have an older home that’s been getting by with window-mounted units. Or, maybe you are planning to add an addition to your home. In these cases and others, you’ll find that the two most popular options are adding central air-conditioning through an HVAC system, or employing ductless mini-split air conditioning units.
In this guide, we’ll explain how each of these systems works, installation considerations, their energy use, maintenance requirements, and summarize the pros and cons of each.
Central air conditioning systems function as a part of a home’s HVAC (Heating Ventilation Air Conditioning) system. The vast majority of new homes are constructed with a central HVAC system, but there are a substantial number of older homes that are not so equipped. Homes that have an existing duct system that’s used for heating are excellent candidates for adding central air conditioning, although it’s certainly possible to add central air to a home that is not so equipped.
There are two types of central air conditioning systems.
Split systems have two primary components, one mounted inside the house and one mounted outside. The outside unit consists of either an air conditioner or heat pump, with the condenser and compressor equipment inside, while the indoor unit contains an electric or gas furnace for heating. You’ll need room in your home for the indoor unit, in a basement, attic, or utility closet.
Packaged systems combine all of the machinery — air conditioner and furnace — into a single outdoor unit. This option provides more flexibility for small homes that don’t have space for the indoor HVAC unit.
Both mini-split systems and packaged HVAC systems require ductwork to circulate air throughout the home and are controlled by centrally located thermostats.
We’ve touched upon some of the basics of a central air conditioning system. Now let’s examine some of the important considerations that may come up when installing a new central air conditioner.
You’ll need ductwork. Since central air conditioners circulate cool air from a central location, ductwork is essential. If your home is already equipped with ducts, these can be employed for the new central air system. It’s a good idea to have the ductwork thoroughly cleaned and inspected prior to the installation of your new air conditioner to ensure peak efficiency.
Don’t have ducts? That doesn’t mean you can’t install a central air conditioner, but the process will take more time and cost more money. Your contractors will need to route the ducts through your walls, attic, or floors, which can cause some serious disruption in the use of your home.
What if I’m adding an addition? If your central air conditioning will be used to cool an addition to your home, installing ductwork will not be as big a problem as it would be in retrofitting a home that doesn’t have existing ducts. However, if you have an existing system you’ll probably need to upgrade your equipment to the proper size to handle the increased square footage.
Cooling your home during hot Texas summers can take a lot of energy. In fact, it’s estimated that air conditioners use about 6% of all the energy produced in the United States. When you’re considering an air-conditioning unit, it only makes sense to factor the ongoing expense of running the unit into your personal finances equation.
If you’re currently getting by with single-room window-mount air conditioners, you’ll achieve much greater energy efficiency by switching to a central air conditioning system. When shopping for a central air conditioning system, look for high EER (Energy Efficiency Ratings) and SEER (Seasonal Energy Efficiency Ratings). The higher the number, the more efficient the system. It’s also important to size your unit properly. Units that are too small will have to work longer and harder to cool your home, while units that are too big may not remove enough humidity, leaving your home’s interior feeling damp and clammy.
All air conditioning systems should have regular maintenance to ensure effective and efficient operation. With central air conditioning systems, one important task is regular cleaning and inspection of your ducts. If leaks develop in the ducts you’ll lose much of the cooling power of the system before it arrives in the rooms it should be cooling. That means your system will have to work harder to accomplish its goal. And cleaning your ducts will help maintain the best possible air quality in your home.
You can stay on top of regular maintenance tasks like changing filters and keeping outside units free of vegetation and debris yourself. But be sure to have qualified technicians check your system out regularly to make sure that is operating properly.
There are advantages and disadvantages to employing a central HVAC system to cool your home. Here are some of the key elements to consider.
Lower upfront costs – The cost of an air conditioning system for your home relies on many variables, so every cooling system is different. As a general rule, installing a central air-conditioning system will usually be less expensive than outfitting the home with mini-split units. That does assume that the home already has ductwork installed.
Invisible equipment – The only evidence of a central air conditioning system in your home is the registers that deliver the cool air. Ductless systems require a wall- or ceiling-mounted unit in each room.
Indoor Air Quality – The ducts that deliver air throughout your home can trap dirt, allergens, and other undesirable substances, causing allergies and other health problems. If you choose a central air conditioning system, be sure to have the ducts cleaned regularly. In addition, you can add air purification units to central air conditioning to ensure that you have clean air in your home.
“One size fits all” temperature control – A central air-conditioning system is centrally controlled. But because of location and environmental factors, different parts of your home may need more or less cooling. That can result in some rooms being too cool or some too warm.
Higher operating costs – Cooled air must travel through the ducts in your home to reach each room. Duct losses can cause significant energy losses, particularly if the ducts are uninsulated.
Central air conditioning can be an excellent option for cooling your house. It’s particularly well-suited when your home already has a central heating system with ductwork installed. In these cases, you can add a split system or replace your existing furnace with an all-in-one package system that provides heating as well as cooling.
While central air conditioning is a proven and popular choice for American homeowners and builders, there’s a newer technology popular in the rest of the world that is growing in popularity in the United States. That’s ductless mini-split systems.
Ductless mini-split air conditioning systems consist of two components: an external compressor, mounted outside your home, that connects to one or more indoor units located in the rooms you need to cool. Each of the indoor units can be controlled separately, so each room’s temperature can be tailored precisely.
Both central and ductless air conditioners operate using the same basic science. Warm air is drawn in and then the heat in the air is released into the outside. Unlike a central cooling system, though, cool air is returned directly to each room in which you’ve installed an indoor unit. That eliminates the energy losses that occur when ducts are used, like in a central air-conditioning system. Here are the specific functions of each part of a ductless system:
The indoor unit consists of a blower and evaporator that pulls in warm air from the room and blows cold air out.
The outdoor unit is a condenser that receives the heat from inside your home and releases it to the outside.
A conduit connects the two units. It carries a power cable, refrigerant line, and a drain. Its job is to provide power to the two units and send the heat that the indoor unit has collected to the outdoor unit.
Ductless systems usually require less time to install than a central air conditioning system. There are only two major components, the indoor air handlers, and the outdoor unit, and these are connected by single slim control and refrigerant line that requires only a small hole in the wall. Here are some things to keep in mind about the installation of a ductless system.
No need for ducts. As the name suggests, ductless air conditioners don’t require a system of ducts and registers to cool your home. If you have an older or historic home that you want to add an air conditioning system to, that eliminates the time-consuming and expensive task of adding ductwork. The other side of the coin is that you’ll need an indoor unit for every room that you want to cool.
Space for the outdoor unit. As we’ve noted, ductless systems have two separate components — the indoor unit that is placed in the room, and the outdoor unit that one or more indoor units are connected to. You’ll need a space to locate this outdoor unit that is within about 50 feet of the indoor units.
Wall Space for Interior Units. Each room that requires cooling will need space for the indoor unit. These are usually mounted on the wall, although there are options with some models for ceiling mounting.
Ductless air conditioners have some advantages over central air conditioning in their energy use. Here are three distinct advantages of ductless systems.
No energy loss in the ductwork. With a central air conditioning system, cool air will gradually warm as it moves through the ducts. A ductless mini split system produces cool air at the location where it is located, so there’s no loss of energy.
Ductless systems can employ zoning. Many ductless systems employ multiple air handlers connected to a single outdoor unit. Each of the indoor units has its own thermostat, allowing you to set temperatures independently. You won’t waste energy cooling unused rooms, and individuals can set the temperature in the room they’re in to the temperature they desire.
Variable speed fans improve efficiency. Search for ductless systems that have variable speed fans. These systems will cool the room to the desired temperature, then operate at lower speeds to keep the temperature consistent.
Regardless of the type of air conditioning system you have, regular maintenance is important. Properly maintained systems will operate more efficiently and effectively and will last longer as well. Because ductless air conditioning systems don’t require a network of ducts to distribute air throughout your home, you’ll avoid one of the main potential maintenance issues of central air conditioning systems, inspecting and cleaning the ductwork.
You will need to perform regular maintenance tasks like changing or cleaning filters, and it is essential that you keep the outside unit of your ductless mini-split system clear of debris and vegetation. And you should have qualified technicians check your mini-split system out according to the maintenance schedule suggested by the manufacturer.
There are advantages and disadvantages to choosing a ductless mini-split system to cool your home. Here are some of the key elements to consider.
Installation flexibility – Since mini-split systems don’t rely on ductwork to distribute cool air, you can install them in a variety of locations. It is necessary to connect each indoor air handler with the outdoor unit, but that only requires routing the relatively small conduit.
Energy efficiency – Ductless mini-split systems are generally more efficient than central air conditioning systems. The ability to operate each indoor unit independently and the use of variable-speed fans also allows for energy savings in operation.
Zoning capabilities – Because you can adjust the temperature settings of the indoor units individually, ductless mini-split systems are an excellent choice if you’re remodeling your home to incorporate an individual apartment, like for elders or young couples.
Home size limitations – Most ductless systems are limited in their cooling capabilities and are not a good choice for larger homes.
Visible indoor units – Unlike the nearly registers used with central air-conditioning, each room cooled with a mini-split system will need to have an indoor unit mounted on the wall or ceiling.
Higher initial investment – The upfront cost of a ductless system is generally about 30% more expensive than a central air conditioning system. You’ll want to balance that against the generally lower cost of operation.
We’ve seen that ductless mini-split systems have both advantages and disadvantages when compared to central air conditioning systems. When you’re considering a ductless system, you’ll need to carefully consider your particular circumstances to see if it's a good way to go.
A ductless system can be an excellent choice for your home if you don’t have existing ductwork. And with a ductless system, you’ll have the option of controlling the temperature in single rooms or zones. For older homes, plus additions and remodeling, a ductless mini-split system can be an excellent option.
We’ve discussed how central air and ductless systems cool your home, but it’s important to consider the other capabilities of these systems.
Central air conditioning systems are almost always part of a comprehensive HVAC system that also includes heating. In the case of a package system, a furnace is built into a single outdoor unit that provides both heat and cooling capabilities, while split systems combine an indoor furnace with an external air conditioning unit. If you’re retrofitting a home with an existing forced-air furnace and ductwork, the air conditioning can be added externally to the existing system, or you can replace the old furnace with either a new split system or a package system. From the standpoint of efficiency, it’s a smart move to replace the existing furnace with a newer, energy-efficient model.
Many ductless mini-split systems have heating capabilities as well as cooling, so they’re certainly suitable for handling both heating and cooling needs for the rooms that they’re installed in.
If you’re building a new home, going with a central HVAC system with air conditioning is usually the best choice. Ductwork is easily installed during construction, and having a single centralized system makes future upgrades easier and less expensive. To achieve optimal energy efficiency when building a new home, choose units with the highest EER (Energy Efficiency Ratings) and SEER (Seasonal Energy Efficiency Ratings). In addition, make sure that ductwork is insulated to prevent heat and cooling loss, particularly if ductwork runs through uninsulated areas of your home, like attics or crawl spaces.
The flexibility of ductless mini split HVAC systems makes them an excellent choice when you’re adding on or remodeling an unfinished space. You won’t need to retrofit your home to add ductwork or worry about whether your existing HVAC system has the capacity to handle the increased square footage in your addition. And if you’re remodeling your home to create an en suite apartment for an elderly relative adding a ductless system will let them set the temperature to a level that’s comfortable without affecting the rest of the home.
Choosing the right HVAC system to cool your home depends on a number of factors that aren’t all related to the individual merits of each type of system. Both central air conditioning and ductless mini-split systems are effective methods for cooling. Making the best choice for your home depends on your home’s existing configuration and size, plus personal considerations like aesthetics and the desire for individualized control.
When you’re making your choice you’ll be well served by consulting with an licensed HVAC installer. You’ll have questions and you’ll need expert advice on how well your ideas will work in your home. That’s where Team Enoch comes in. Our team of experienced HVAC professionals can answer your questions and help you decide on the right way to go. And remember, estimates are free with Team Enoch, so contact us right away. We’ll be happy to help you make a smart decision when it’s time to choose a new air conditioning system for your home.