What is a Split HVAC System? Your Guide To Split AC Units
An HVAC split system is a heating and cooling solution that divides components into two separate units: one located inside the home and one outdoors. Connected by refrigerant lines (copper tubing), this design allows for quiet operation and high energy efficiency compared to packaged units.
How does air conditioning work in this setup? In a traditional split system HVAC configuration, the outdoor condenser unit houses the compressor, while the indoor unit contains the evaporator coil or air handler. This separation is what distinguishes it from HVAC packaged units, where all components are contained in a single outdoor cabinet.
Whether you need a split air conditioner for cooling or a heat pump for year-round climate control, Carrier split systems offer innovative solutions tailored to your home’s unique needs.
5 Different Types of Split System Cooling and Heating Systems
Homeowners have several options when choosing a split system air conditioner or heater. Larger homes may even require multiple units to ensure consistent comfort.
1. Split System Heat Pumps + Air Handlers
Heat pumps are versatile split units that run on electricity to transfer heat rather than generate it. In the summer, they act like an AC; in the winter, they draw heat from the outdoor air—even when it's cold—and transfer it inside. The outdoor unit contains the compressor and heat exchanger, while the indoor air handler circulates conditioned air. Learn more about how heat pumps work. Air handlers are indoor units that move air over a coil to heat or cool it, depending on the season. They are often paired with heat pumps to distribute air through ducts.
2. Split System: Air Conditioners + Furnace
Standard split system air conditioners feature an outdoor cabinet with a condenser and compressor, paired with an indoor unit that houses the evaporator and air filters. This setup is dedicated specifically to cooling your home efficiently. Learn more about how central air conditioning works. Furnaces serve as the indoor component to pair with many air conditioners. They burn fuel, such as natural gas or propane, to generate heat, which is then distributed through your home's ductwork. Learn more about how a furnace works.
3. Ductless vs. Ducted Systems
Split system HVAC designs can be adapted to your home's infrastructure:
- Ducted Systems: Use existing air ducts to circulate air from a central furnace, air handler, or heat pump.
- Ductless Systems: Also known as ductless mini split systems, these use individual air handlers mounted in specific rooms. They are ideal for spaces without ductwork or for adding zoning to specific areas. To learn more about how these systems compare, explore our guide on heat pump vs mini split.
What Are the Benefits of a Split HVAC System?
Investing in a split unit HVAC system offers significant advantages over traditional HVAC packaged units, specifically regarding customization and efficiency that pays for itself.
Efficiency
HVAC split systems are often highly energy-efficient, with some high-end models reaching up to 24 SEER2 ratings. Choosing an energy efficient split system can help lower your monthly energy bills compared to base-model units. By upgrading to a high-efficiency HVAC split system, you invest in long-term savings.
Customization
Because the components are separated, split system HVAC setups offer flexible HVAC installation options. You can mix and match furnace and AC combinations or utilize ductless heads to address hot or cold spots in specific rooms.
Out of Pocket Savings
While the initial investment in a high-efficiency split air conditioner may be higher, the reduction in energy consumption helps the system pay for itself over time. Adding zoning capabilities allows you to condition only the rooms you are using, further reducing energy waste.
What Are the Downsides of a Split HVAC System?
Higher Installation Costs
Because a split HVAC system involves installing two separate units and connecting them with refrigerant lines, the installation is more labor-intensive than a packaged unit. AC installation or heat pump installation costs can vary depending on the distance between units and the complexity of the home's layout. Learn more about air conditioner price and heat pump price.
Potential for Outside Noise
The outdoor unit contains the compressor, which generates sound. If AC maintenance or heat pump maintenance is neglected, this can create noise in your yard. However, modern Carrier units are engineered to be quiet.
Outdoor Space Requirements
You need adequate yard space or a suitable mounting location for the outdoor cabinet. In dense urban environments or small yards, finding the right spot for a split unit AC can be challenging.
Contact an HVAC Expert About Carrier Split Systems
Ready to upgrade your home comfort? Your local Carrier dealer can help you select the perfect Carrier split system for your needs and budget. Find a dealer near you to start the process of purchasing your new system or to schedule AC service.
Frequently Asked Questions
A split HVAC system consists of two primary components connected by refrigerant lines: an indoor unit (such as a furnace or fan coil) and an outdoor unit (an air conditioner or heat pump). This separation allows for efficient heat transfer and quiet indoor operation.
An air conditioner split system is a cooling setup where the heat-releasing components (compressor and condenser) are located outside, while the cooling components (evaporator and fan) are located inside. This is the most common type of central air conditioning.
A traditional split system uses ductwork to distribute air throughout the entire house from a central unit. A mini split (or ductless split) uses individual indoor air handlers for specific rooms and does not require ductwork, making it ideal for zoning or older homes.
Yes, a central split system air conditioner is designed to cool an entire home through ductwork. Even ductless multi-split systems can cool a whole house by connecting multiple indoor heads to a single outdoor unit.
The primary disadvantage is the higher upfront cost and more complex installation compared to window units or portable ACs. However, the long-term benefits of energy savings, improved air quality, and superior comfort can outweigh the initial expense.
About The Expert Reviewer: Michelle Notaro is a Product Manager for Residential Air Conditioners at Carrier Corporation, where she helps shape innovative cooling solutions that meet evolving homeowner needs, industry trends, and regulatory requirements.
About The Author: Ryan Mayes is a Senior Digital Brand Marketing Manager at Carrier who focuses on creating clear, helpful resources on HVAC topics. Ryan’s goal is to guide readers toward smart, confident decisions about their indoor comfort.