What’s the Difference Between Ductless HVAC and Central Air Conditioning?

Apr 2, 2024Air Conditioning, Blog

Your heating and cooling system keeps your home cool in summer and warm in winter. HVAC systems also reduce the humidity to make the house seem cooler. There are two main types of heating and cooling systems, central air conditioning and ductless HVAC. Central air conditioning was the first type of AC system developed, and ductless is a more recent type of indoor climate control system. Both have advantages and disadvantages, but let’s establish how each of these systems work.

What is a Ductless HVAC System?

A ductless mini-split system has two components, and outdoor condenser/compressor and a series of indoor air handlers. Ductless mini-split systems are technically a type of heat pump and not an air conditioner. Each air handler is mounted in a different room, or “zone”, allowing temperature control of each individual room. The size of your home and number of air handlers will determine how fast and efficiently your home is cooled or heated. The main difference between ductless and conventional central air conditioning is ductless does not require ductwork to move heated or cooled air. This makes it ideal for certain types of homes, such as mid-century Eichler homes, single second story bedrooms, one to two bedroom homes, or ADUs, where adding ductwork is impractical or undesirable. Heat is moved through refrigerant lines between the air handlers and condenser/compressor to cool or heat the rooms of the home.

What is a Central Air Conditioning System?

A central air conditioning system has an outdoor unit and an indoor unit. The outdoor unit is a condenser/compressor, and the indoor unit includes a blower fan which distributes cooled air through the house. There are three main components in the system: a condenser coil, compressor, and evaporator coil, which work together to remove and absorb heat. Refrigerant which runs through the coils will switch from gas to liquid form and then back to gas. The chemical refrigerant absorbs and redistributes heat to cool the house. A thermostat controls when the AC system goes into a cooling cycle. The cooled or heated air is blown through the house using ductwork, which is usually built into the walls or ceiling. Inside air is pulled through return registers and ducts where heat is absorbed by an evaporator coil. The evaporator is attached inside the air handler or mounted to the furnace. Refrigerant inside the evaporator coil absorbs heat and humidity from inside the home and moves it outside to be dispersed by the condenser-compressor.

Pros of Ductless HVAC

1. Built in Flexible Zoning

Ductless mini-splits give homeowners the ability to have control over the temperature in each room or “zone”. The air handlers mounted in each room each have individual controls, so each zone can be cooled to a precise temperature. This is vastly different than ducted central air conditioning, where the air must be pushed to each room. The room-to-room precision that ductless offers provides potential savings on heating and cooling bills.

2. Energy Efficiency

Ductless HVAC systems are much more energy efficient compared to traditional central AC systems. In central air, the conditioned air moves through ductwork, which can lose energy through gaps or cracks, as well as natural inefficiencies. Ductless HVAC systems control the temperature and humidity in individual rooms using air handlers instead of pushing air through ductwork.

3. Cost Effectiveness & Lower Energy Bills

The initial cost of installing ductless heat pump systems is slightly more than central air conditioning, but the efficiency and zoning capabilities mean your energy bills will be lower month to month. Ductless is less expensive to operate over the long run than central air conditioning.

4. Quicker Easier Installation

Installing a ductless mini-split system is quicker than installing central air conditioning. For homes that do not already have ductwork installed, ductless is a great choice. Installing ductless air conditioning requires no structural disruption to your home. A small hole is drilled through your wall to run the refrigerant line to the outside, where an exterior unit is installed. Each room (zone) has its own air handler which can be mounted on the wall or ceiling.

5. Quiet Operation

Ductless HVAC systems run more quietly than ducted central air systems. The air handlers are smaller and less noisy, and you will never hear ductwork popping, thumping, or cracking as the heating or cooling runs.

6. Saves Space

Ductless systems are often referred to as “mini-splits” because the air handling units are much smaller than the infrastructure required for central air conditioning. These space-saving units are ideal for small homes, ADUs, small apartments, or oddly-shaped rooms.

7. No Need for Existing Ductwork

For older homes or homes without ductwork, a ductless mini-split is the perfect solution. Ductwork is time-consuming and expensive to install, and for some homes that are architecturally designed to exclude ductwork, ductless preserves the intended aesthetic. Mini-splits are also perfect for room additions or ADUs.

Cons of Ductless HVAC

1. Aesthetics May Seem Awkward

Ductless HVAC systems have a refrigerant line that runs between the internal air handlers and external condenser-compressor unit. The line runs down the side of the house, and if it isn’t hidden or blended with the exterior paint, it can look awkward. Also, the internally mounted air handlers should be in an inconspicuous space to preserve the room’s aesthetics.

2. Drainage Should be Planned

Ductless mini-split systems collect humidity from the air by collecting moisture into a condensate line, which in most cases, uses gravity to move condensate moisture to a drain. In some cases, a condensate pump is needed to move the moisture outside. These pumps can increase cost and maintenance.

3. Limited Coverage in Larger Homes

You can use multiple air handlers for each zone, but mini-splits don’t work as well for large homes or larges rooms with lots of square footage space. The air handlers work best in individual rooms or smaller homes. For large homes with large rooms, central air conditioning works best.

4. Maintenance

Any HVAC system needs maintenance to stay functioning at a high level. Without proper maintenance, both ducted and ductless systems can operate less efficiently, increase your energy bills, and even cause AC repair issues. Ductless HVAC systems have filters which need to be cleaned regularly. Some homeowners get busy and may skip cleaning the unit at proper intervals.

5. Choosing the Right Type of System

A few ductless mini-split systems are more inexpensive because they are designed for cooling only, and not heating. Make sure that you choose a system that is designed for both heating and cooling.

6. Higher Upfront Cost

The installation cost on a ductless system is about 30% higher than a central air conditioning system (without ductwork). The upside is that the energy efficiency is higher than central air so the initial cost comes back to you over time.

7. Poor Ventilation vs Ducted AC

Ductless HVAC conditions the air within the home, and no fresh air from outside is moved through the system, Ducted AC systems have air filters that catch some of the dust and pollen, especially if you are using HEPA filters.

Pros of Central Air Conditioning Systems

1. Consistent Temperature

Central air conditioning is designed to cool your entire home to one consistent temperature. The air moves through the ductwork and keeps your home at one stable temperature.

2. Integration with Heating Systems

Central air systems are often integrated with a furnace in more temperate climates. This allows you to control the temperature of your home from one thermostat.

3. Cools Larger Areas and Bigger Homes

Central air is designed to cool large rooms and homes with larger floor plans. Ductless HVAC requires air handlers for each zone, or room, while central air uses ductwork to cool the entire home at once.

4. Smart Home Capabilities

Many newer central air conditioners come with a smartphone app that lets you control when the air runs. You can set the air conditioner on a schedule that ensures your home is cool when you get home from work and runs at specific times to help you save money on your energy bills.

5. Potentially Better for Home Resale Value

Central air systems last for decades and can be good for the resale value of your home if you plan on selling in the near future. Check with your local real estate agent to gauge the local market.

6. Better Aesthetics

Some homeowners prefer the near invisibility of central air. The only components visible inside the home are the vents and registers which distribute and move air. The main unit inside the home containing the evaporator coil and blower fan are usually in a utility closet, the garage, or a basement.

7. Convenient to Maintain

Central air conditioning systems have a singular system to maintain, whereas ductless HVAC has multiple air handlers. It can be easier to change and regulate the temperature of the entire house with central air.

Cons of Central Air Conditioning

1. Higher Installation Cost if Ductwork is Required

Some older homes do not have ductwork installed and this is absolutely necessary for central air conditioning. If your home needs ductwork installed, then the total cost of your central air system will be higher than normal. You might also need to upgrade your electrical wiring to support a central air conditioning system.

2. Regular Maintenance is Required

Central air systems have both an outdoor unit and an indoor unit, in addition to internal ductwork. Scheduling a air conditioning tune up once a year, getting your air ducts cleaned in the spring, Cleaning the outside of your compressor unit, keeping brush and vegetation away from it, and keeping the condenser and evaporator coils clean will help prevent costly repairs. Changing the air filters for the ductwork regularly will also help prevent system failure.

3. Less Energy Efficient than Ductless

One important note about central air is it is less energy efficient than ductless HVAC. Because ducted central air tries to cool the entire home at once, there is some inefficiency compared to ductless. You’re cooling rooms that aren’t being used in order to cool the rooms where you are active. This leads to higher energy bills, especially in summer.

4. Choosing the Right Size Requires Expert Calculation

One thing that is tricky about choosing a central air conditioner is figuring out how big a unit you need. HVAC contractors can do the calculation of how many tons of cooling power you need. In the HVAC industry, a ton is a measurement of a unit’s cooling or heating capacity, and AC systems are measured in tons. If you choose a AC unit that is too small, your home will still be warm in the summer months. Conversely, choosing a central AC system that is too large will result in inefficiencies that cause higher energy bills. Consult with an experienced HVAC contractor like Ventwerx to help you choose the right size air conditioner system for your home.

5. Not Efficient for Multi-Story Homes

When it gets hot in summer, heat rises to upper floors in a multi-story house. The result can be a cool lower level and warmer upper-level rooms. Central air doesn’t have the zoning flexibility that ductless HVAC offers. A central air conditioning system will try to cool all the rooms equally, and cooling a multi-story home will cause your energy bills to run high in the summer.

6. Noisier Operation

Central air systems can make some noise, due to the ductwork expanding and contracting, causing some thumping and popping. The blower fan in central air systems can make some noise too.

Which Air Conditioning System Is Right For You?

Whether you choose central air conditioning, or a ductless heat pump system will depend on your individual needs, the design of your existing home, whether you have ductwork installed or not, and your goals for monthly energy savings. Mediterranean climates like California are ideal for both ductless HVAC and central air conditioning, while climates with more extreme temperatures may be better suited to central air with a furnace. Be sure to consider upfront costs and the energy ratings of each heating and colling system when deciding. Talk to a local HVAC contractor if you have any questions, they can help lead you to make the right selection for your needs.

HVAC Repair and Installation in San Jose and Morgan Hill

If you need professional help making a decision between a ductless HVAC system and a central AC system, the heating and cooling experts at Ventwerx can help you make the best choice for your home. Our professional HVAC technicians can assess your home, recommend the optimal AC system, and install your heating and cooling system. To get a no-obligation heating and cooling estimate for your home in San Jose, in Morgan Hill or Gilroy, call us at (408) 422-2987.