HVAC System and HVAC Unit
The main types of HVAC systems are split, ductless mini-split, packaged, and geothermal; the main HVAC units are heat pumps, air conditioners, furnaces, fan coils, evaporator coils, and boilers. Carrier offers these HVAC solutions in a range of configurations, capacities, and efficiency levels to meet different HVAC installation needs.
Quick Answer: Types of HVAC Systems and Units
| HVAC system or unit | What it does |
|---|---|
| Split system | Uses separate indoor and outdoor equipment to provide heating and/or cooling through ductwork. |
| Ductless mini-split | Provides heating and cooling to individual rooms or zones without requiring ductwork. |
| Packaged system | Combines major heating and cooling components in one outdoor cabinet connected to the home's ductwork. |
| Geothermal system | Uses underground loops to transfer heat between the home and the earth for heating and cooling. |
| Heat pump | Transfers heat between indoors and outdoors to provide both heating and cooling. |
| Air conditioner | Removes heat and humidity from indoor air and transfers the heat outdoors. |
| Furnace | Generates heat and distributes warm air through the home's ductwork. |
| Fan coil | Moves air across a heating or cooling coil before distributing conditioned air throughout the home. |
| Evaporator coil | Absorbs heat from indoor air as refrigerant evaporates inside the coil. |
| Boiler | Uses hot water or steam to provide radiant heat through radiators, baseboards, or underfloor systems. |
For sizing context, residential air conditioners commonly range from 1.5 to 5 tons, or approximately 18,000 to 60,000 BTUh. Actual equipment sizing should be determined through a professional load calculation rather than square footage alone.
What is an HVAC System?
An HVAC system (Heating, Ventilation, and Air Conditioning) is a comprehensive climate control solution designed to regulate indoor temperature, humidity, and air quality. Unlike a standalone unit, a system consists of interconnected components working in unison to create a healthy, comfortable, and energy-efficient home environment.
The Three Core Functions
To achieve total home comfort, an HVAC system relies on three primary pillars:
- Heating: Keeps your home warm during colder months using furnaces, boilers, or heat pumps.
- Ventilation: Exchanges stale indoor air with fresh outdoor air. It filters out pollutants, allergens, and odors to significantly improve indoor air quality.
- Air Conditioning: Cools and dehumidifies indoor spaces during warm weather, ensuring a consistent and comfortable climate.
Why is an HVAC System Important?
Beyond basic temperature control, a modern home HVAC system provides year-round thermal comfort and can help manage indoor humidity and air quality. The specific capabilities of an HVAC system depend on the equipment, controls, ductwork, ventilation, and indoor air quality products installed.
Types of HVAC Systems
Carrier offers split, ductless, packaged, and geothermal HVAC systems, each designed for different home layouts, climates, and comfort requirements. Efficiency varies by model and system configuration, so the ratings below represent examples of current Carrier equipment rather than universal ranges for every system.
Split Systems
Carrier split HVAC systems use separate indoor and outdoor equipment connected by refrigerant lines, with the indoor equipment typically distributing conditioned air through ductwork. Carrier's current residential air conditioner lineup includes models with up to 21 SEER2 cooling efficiency in the Infinity 21 Air Conditioner (26VNA1), while the Infinity® 23 Heat Pump (27VNA3) features SEER2 cooling efficiency of 23.
- How it works: An outdoor unit (containing the condenser and compressor) pairs with an indoor unit (containing the evaporator coil and air handler). The indoor unit distributes conditioned air through ductwork.
- Best for: Homes with existing ductwork looking for reliable, whole-home comfort.
- Learn more: What is a split system?
Key Components and Benefits
- Outdoor Unit: Houses the compressor and condenser coil, responsible for releasing heat in the summer.
- Indoor Unit: Contains the evaporator coil and a blower motor to circulate air.
- Energy Efficiency: Modern split systems feature high SEER2 (Seasonal Energy Efficiency Ratio), EER2 (Energy Efficiency Ratio), HSPF2 (Heating Seasonal Performance Factor 2,) and AFUE (Annual Fuel Utilization Efficiency) ratings, reducing monthly energy bills.
- Reliability: Proven technology that provides consistent, whole-home comfort even in extreme weather conditions.
What is an HVAC System?
An HVAC system (Heating, Ventilation, and Air Conditioning) is a comprehensive climate control solution designed to regulate indoor temperature, humidity, and air quality. Unlike a standalone unit, a system consists of interconnected components working in unison to create a healthy, comfortable, and energy-efficient home environment.
The Three Core Functions
To achieve total home comfort, an HVAC system relies on three primary pillars:
- Heating: Keeps your home warm during colder months using furnaces, boilers, or heat pumps.
- Ventilation: Exchanges stale indoor air with fresh outdoor air. It filters out pollutants, allergens, and odors to significantly improve indoor air quality.
- Air Conditioning: Cools and dehumidifies indoor spaces during warm weather, ensuring a consistent and comfortable climate.
Why is an HVAC System Important?
Beyond basic temperature control, a modern home HVAC system is essential for well-being. It provides thermal comfort year-round, regulates humidity to prevent mold or dryness, and filters out contaminants to help you breathe easier.
Types of HVAC Systems
HVAC systems come in several configurations, each engineered to solve specific infrastructure and comfort challenges. Here is an overview of the most common types.
Split Systems
A split HVAC system is the most common residential setup. It separates the heating and cooling functions into two main parts connected by copper tubing.
- How it works: An outdoor unit (containing the condenser and compressor) pairs with an indoor unit (containing the evaporator coil and air handler). The indoor unit distributes conditioned air through ductwork.
- Best for: Homes with existing ductwork looking for reliable, whole-home comfort.
- Learn more: What is a split system?
Key Components and Benefits
- Outdoor Unit: Houses the compressor and condenser coil, responsible for releasing heat in the summer.
- Indoor Unit: Contains the evaporator coil and a blower motor to circulate air.
- Energy Efficiency: Modern split systems feature high SEER2 (Seasonal Energy Efficiency Ratio) and AFUE (Annual Fuel Utilization Efficiency) ratings, reducing monthly energy bills.
- Reliability: Proven technology that provides consistent, whole-home comfort even in extreme weather conditions.
Ductless Mini Split Systems
Carrier ductless systems deliver heating and cooling directly to individual rooms or zones without requiring traditional ductwork. Current Carrier ductless models range up to 35.1 SEER2 in the 37MPRA.
- How it works: An outdoor condenser connects to one or more indoor air handlers mounted on walls or ceilings.
- Best for: Retrofitting older homes without ducts, room additions, or homeowners who want precise temperature control in individual rooms.
- Learn more: What is a ductless mini split
Packaged HVAC Systems
Carrier packaged systems combine major heating and cooling components into a single outdoor cabinet that connects directly to the home's ductwork. Current Carrier packaged systems are available in 2- to 5-ton capacities (24,000 to 60,000 BTUh), with examples reaching 15.2+ SEER2.
- How it works: These units connect directly to the home's ductwork through a secure wall or roof opening. They can be electric cooling/gas heating, all-electric, or heat pump configurations.
- Best for: Homes with limited indoor space for a furnace or air handler.
Geothermal HVAC Systems
Carrier geothermal systems use underground loops to transfer heat between the home and the earth, providing heating and cooling from a stable ground-temperature source. Current Carrier geothermal heat pumps offer heating efficiency up to 5.2 COP and cooling efficiency up to 37 EER in certain open-loop configurations.
- How it works: Fluid circulates through pipes buried underground (loops), absorbing heat from the earth in winter and dissipating heat into the ground in summer.
- Best for: Homeowners prioritizing maximum energy efficiency and eco-friendly technology.
- Learn more: What is geothermal heating
Types of HVAC Units
Carrier HVAC systems use several types of heating, cooling, and air-moving equipment. The primary HVAC units include heat pumps, air conditioners, furnaces, fan coils, evaporator coils, and boilers.
Heat Pumps
Carrier heat pumps transfer heat rather than generate it through combustion. In the winter, they extract heat from outside air (or the ground) to warm your home. In the summer, they reverse the process to cool your space. For example, Carrier's Infinity® 23 Heat Pump (27VNA3) offers up to 23 SEER2 and 10.5 HSPF2, with heating operation down to -13°F.
Air Conditioners
Carrier air conditioners use a refrigeration cycle to remove heat and humidity from indoor air and release that heat outdoors. Current Carrier residential air conditioner models like the Infinity 21 Air Conditioner (26VNA1) offer up to 21 SEER2, depending on the model and matched system.
Furnaces
Carrier furnaces generate heat and distribute warm air through ductwork. Gas furnaces in Carrier's current lineup range from 80% AFUE to up to 98.5% AFUE, depending on the model.
- Modulating furnaces: Adjust heat in tiny increments for precise comfort. For example, the Carrier Infinity® 98 Gas Furnace can modulate from 40% to 100% capacity in 1% increments.
- Two-stage furnaces: Offer high and low speeds for better efficiency.
- Single-stage furnaces: Operate at full capacity whenever on.
Air Handlers
An air handler complements your heat pump or AC. It moves air across a coil to heat or cool it before blowing it into your living spaces. It is the "lungs" of many split systems.
Evaporator Coils
A Carrier evaporator coil is the indoor heat-exchange component where refrigerant absorbs heat from the home's air during cooling. Located inside the indoor unit, it allows refrigerant to evaporate and absorb heat from air passing over the coil.
Boilers
A boiler uses hot water or steam to provide radiant heat. Instead of blowing air, it warms radiators, baseboards, or underfloor systems for consistent, dust-free warmth.
Indoor Air Quality Products
Carrier also offers indoor air quality products that can complement an HVAC system, including:
- Air purifiers trap pollen, viruses, and bacteria.
- Humidifiers and dehumidifiers balance moisture levels.
- Ventilators swap stale indoor air for fresh outdoor air.
- UV lamps neutralize mold on cooling coils.
How To Choose the Right HVAC System For Your Home
Choosing the right HVAC system requires evaluating your home's existing infrastructure, your local climate, and your long-term energy goals.
A traditional split system is better suited for large homes with intact ductwork, while a ductless mini split works best for room additions or older homes without ducts.
Clint Newsome, owner of Albany Air Conditioning and Heating Co. in Albany, GA says homeowners should take time to research their options and work with a knowledgeable HVAC dealer when selecting a new heating and cooling system.
“Some dealerships may have a live showroom where you can put your hands on the equipment and see the different types of systems that are offered,” Newsome said. “That’s one way to help homeowners decide what they want to do and to hear how noisy or quiet the units are.”
“Many dealers have links to the product listings on manufacturer websites of products that they sell so homeowners can do some of their own research,” Newsome added.
Size of Your Home
Proper sizing is non-negotiable. An undersized system will struggle to keep up, while an oversized system can cycle on and off more frequently and may not provide optimal humidity control. A professional load calculation should be used to determine the appropriate equipment capacity for your home. Learn more about AC size, furnace size, heat pump size, and mini split size.
Climate
Your geographic location dictates your needs. Extreme winters may require powerful furnaces or cold climate heat pumps, while hot, humid regions benefit from high-efficiency ACs or heat pumps.
Energy Efficiency & Smart Tech
Look for the ENERGY STAR® label to ensure your HVAC unit meets strict efficiency guidelines. High SEER2 (for ACs) and AFUE (for furnaces) ratings mean lower monthly energy bills. Modern systems also integrate with smart thermostats, allowing you to optimize performance and savings from your smartphone.
HVAC System Lifespan
The expected service life of HVAC equipment varies by unit type, installation quality, climate, operating conditions, and maintenance. Carrier's published guidance generally places modern HVAC systems in the 15- to 25-year range, although individual equipment can have shorter or longer service lives.
- Air conditioners: Typically 15–20 years
- Heat pumps: typically 10–15 years, depending on equipment and operating conditions
- Gas furnaces: typically 15–20+ years, depending on equipment and maintenance
- Ductless mini-splits: typically 10–15 years or longer with proper maintenance
- Geothermal heat pump indoor equipment: 20+ years; underground loops can last 25–50 years
Connect With A Carrier Dealer
At Carrier, we combine visionary innovation with proven reliability. Our HVAC systems include split, ductless, packaged, and geothermal solutions designed for different home layouts, climates, and comfort needs. Connect with a local Carrier dealer for a consultation on the best HVAC system for your home and for professional HVAC installation and HVAC service.
Types of HVAC Units
An HVAC unit refers to the specific device component within the larger system. Understanding these units helps you select the right equipment for your climate and efficiency goals.
Heat Pumps
A heat pump is a versatile all-in-one solution that transfers heat rather than generating it. In the winter, it extracts heat from outside air (or the ground) to warm your home. In the summer, it reverses the process to cool your space. They are highly efficient and ideal for moderate climates.
Air Conditioners
An air conditioner is dedicated to cooling. It circulates refrigerant through coils to absorb indoor heat and humidity, releasing it outdoors. This process creates a cool, dehumidified environment essential for summer comfort.
Furnaces
A furnace is a heating powerhouse that distributes warm air via ductwork. They use natural gas, oil, or electricity.
- Modulating furnaces: Adjust heat in tiny increments for precise comfort.
- Two-stage furnaces: Offer high and low speeds for better efficiency.
- Single-stage furnaces: Operate at full capacity whenever on.
Fan Coils
A fan coil complements your heat pump or AC. It moves air across a coil to heat or cool it before blowing it into your living spaces. It is the "lungs" of many split systems.
Evaporator Coils
The evaporator coil is the critical point where cooling happens. Located inside the indoor unit, it allows refrigerant to evaporate and absorb heat from the air passing over it.
Boilers
A boiler uses hot water or steam to provide radiant heat. Instead of blowing air, it warms radiators, baseboards, or underfloor systems for consistent, dust-free warmth.
Indoor Air Quality Products
Enhance your HVAC system with add-ons designed for health:
- Air purifiers trap pollen, viruses, and bacteria.
- Humidifiers and dehumidifiers balance moisture levels.
- Ventilators swap stale indoor air for fresh outdoor air.
- UV lamps neutralize mold on cooling coils.
Connect With A Carrier Dealer
At Carrier, we combine visionary innovation with proven reliability. Our HVAC systems are designed to be quiet, efficient, and seamlessly integrated into your life. Connect with a local Carrier dealer for a consultation on the best HVAC system for your home.
Frequently Asked Questions
An HVAC system is the complete setup (heating, cooling, ventilation, ducts, thermostats) working together. An HVAC unit refers to a specific piece of equipment within that system, such as a furnace, air conditioner, or heat pump.
HVAC systems typically cost between $8,000 and $25,000. The final price depends on the system type (e.g., split vs. geothermal), the size of your home, installation complexity, and energy efficiency ratings.
AC (air conditioning) specifically refers to cooling your home. HVAC (Heating, Ventilation, and Air Conditioning) is the broader term that includes heating, cooling, and air quality management.
The $5,000 rule helps you decide whether to repair or replace an older unit. Multiply the estimated repair cost by the age of the equipment in years. If the total exceeds $5,000, replacement is generally the smarter financial investment.
A well-maintained HVAC system typically lasts 15 to 25 years. Furnaces generally last 15–20 years, while air conditioners and heat pumps often last 12–15 years depending on usage and maintenance
Yes. Investing in a modern, energy-efficient HVAC system increases property value, significantly lowers monthly energy bills, and ensures a healthier, more comfortable living environment for your family.
About The Author: Travis Baugh is a Digital Brand Marketing Manager for Carrier, where he develops informative, straightforward content to help homeowners better understand heating, cooling, and indoor air quality. His writing is focused on empowering homeowners to make confident, well-informed choices about their home comfort systems.
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.