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How does split AC work?

Split AC systems have revolutionized the way we cool our homes and offices, offering a sleek, efficient, and versatile alternative to traditional air conditioning methods.

But what goes on behind the scenes of these modern cooling marvels? This article demystifies split AC systems, from their core components and various types to installation and maintenance essentials.

Whether you’re considering an upgrade or simply curious about how split ACs operate, you’ll find everything you need to know right here.

How does split AC work?

Split AC works by moving heat out of your apartment via a refrigerant pipe. an internal unit or series of internal units absorb heat from your indoor spaces. this heat is then moved via the refrigerant pipe to an outdoor unit where the heat is released into the atmosphere. 

Split AC units are also sometimes referred to as Mini splits. they are called split AC systems because they work with several individual internal units that absorb heat from your home. 

Split AC systems take advantage of a difference in pressure between refrigerant in the external units and refrigerant in the internal units. When refrigerant is pumped to a higher pressure, this increases its temperature and causes the refrigerant to heat up.

More detail than anyone wanted…

This is a bit technical but bear with me. The heat that you feel when you touch something is actually thermal energy. When you squeeze a substance to a higher density, you increase the amount of thermal energy in the same space.

This makes denser refrigerant feel hotter.

A pump in the split AC increases the pressure of refrigerant in the outdoor components. An exhaust valve stops as much refrigerant from re-entering the indoor components and lowers the pressure as a result. 

So the refrigerant in the internal unit is much colder than your indoor air and absorbs heat, cooling your home down. 

This heat is then carried to the outside unit via a pump. Its pressure rises and so does its temperature, causing the excess heat to transfer to the outside air.

Some split AC and mini-split systems are heat pumps. A heat pump can both heat up and cool down your home. 

A split AC heats your home by reversing the pressure difference that it uses for air conditioning. By increasing the refrigerant pressure indoors a split AC can actually warm up your living spaces.

The external unit switches to being low pressure. As a result, the refrigerant becomes colder than the outside air and absorbs heat. 

Switch it up

This process even works when outdoor temperatures are below freezing. The refrigerant can still get colder than outside air and can suck some heat out of even frigid surroundings.

This is part of the reason why mini-splits use refrigerant rather than water or air to conduct heat. Refrigerant is a chemical that can get much colder than water without freezing. It can also reach high temperatures without expanding massively and putting pressure on pipes. 

Split AC parts list

A split AC system consists of various components that work together to cool your space efficiently. Here’s a breakdown of its core parts and their functions:

  • Outdoor Unit Components:
    • Compressor: The heart of the AC system, it compresses the refrigerant from a low-pressure gas to a high-pressure gas, moving it through the system.
    • Condenser Coil: This coil releases the heat from the compressed refrigerant into the outdoor air. It’s usually equipped with a fan to aid in cooling the refrigerant.
    • Fan: Located in the outdoor unit, it helps in dissipating the heat from the condenser coil to the outside air.
    • Expansion Valve: Situated between the indoor and outdoor units, it regulates the flow of refrigerant into the evaporator, lowering its pressure and temperature.
  • Indoor Unit Components:
    • Evaporator Coil: This coil absorbs heat from the indoor air, allowing the refrigerant to evaporate and cool the air.
    • Air Filter: Positioned in the indoor unit, it traps dust, pollen, and other airborne particles, improving the indoor air quality.
    • Blower/Fan: It circulates the indoor air over the evaporator coil to be cooled and then redistributes the cooled air back into the room.
    • Drain Pan and Drain Line: These components collect and channel the condensation away from the indoor unit, preventing water leakage and damage.
  • Refrigerant: The substance that flows within the AC system, absorbing and releasing heat through phase changes from liquid to gas and vice versa.
  • Control Panel and Remote: These allow users to set the desired temperature, control modes, and adjust other settings for customized cooling.
  • Thermostat: This sensor measures the indoor air temperature and communicates with the AC system to maintain the desired temperature settings.

Types of Split AC Systems

Split air conditioning systems offer versatility and efficiency, making them a popular choice for residential and commercial cooling needs. Understanding the different types of split AC systems can help you select the best option for your specific requirements. Here’s an overview of the various types:

1. Mini-Split Systems

  • Description: Mini-split systems are the most common type of split AC, designed for single-room applications. They consist of one outdoor unit connected to one indoor unit, making them ideal for homes without existing ductwork.
  • Best For: Small apartments, individual rooms, or adding air conditioning to spaces where extending ductwork is impractical.

2. Multi-Split Systems

  • Description: Multi-split systems connect multiple indoor units to a single outdoor unit. Each indoor unit can be controlled independently, allowing for different temperature settings in various rooms.
  • Best For: Larger homes or offices where individual room control is desired, without the need for multiple outdoor units.

3. Ductless and Ducted Mini-Splits

  • Ductless Mini-Splits: These are the standard mini-split models that do not require ductwork, with the indoor unit mounted on the wall or ceiling.
  • Ducted Mini-Splits: These systems use a small network of ducts to distribute air from the indoor unit to different parts of the room or adjoining spaces, offering a more integrated look.
  • Best For: Ductless units are suited for retrofitting or adding to spaces without existing ducts, while ducted options are ideal for new construction or areas where a more concealed installation is preferred.

4. Inverter Split Systems

  • Description: Inverter technology allows the compressor to operate at variable speeds, adjusting the cooling output as needed for more efficient energy use and consistent temperature control.
  • Best For: Energy-conscious users seeking higher efficiency and comfort levels, especially in areas with significant temperature fluctuations.

5. Smart Split Systems

  • Description: Equipped with Wi-Fi connectivity and smart home compatibility, these systems offer remote control and monitoring through smartphones or voice-activated devices.
  • Best For: Tech-savvy users who value convenience and are looking to integrate their cooling systems with other smart home devices for enhanced functionality.

Frequently Asked Questions (FAQs)

Q1: Can split AC systems cool multiple rooms?
A1: Yes, multi-split AC systems can cool multiple rooms. They involve one outdoor unit connected to several indoor units, each of which can be controlled independently, allowing for different temperature settings in various rooms.

Q2: Are split AC systems energy-efficient?
A2: Split AC systems are generally more energy-efficient compared to traditional window units, especially models equipped with inverter technology that adjusts cooling output to maintain desired temperature levels, reducing energy consumption.

Q3: How long do split AC systems typically last?
A3: With proper maintenance, split AC systems can last 10 to 15 years or more. Regular servicing, such as cleaning filters and checking refrigerant levels, is crucial to their longevity.

Q4: Do I need to have ductwork installed for a split AC system?
A4: No, one of the main advantages of split AC systems, particularly ductless mini-splits, is that they do not require ductwork. This makes them an ideal choice for retrofitting older buildings or extending air conditioning to rooms without existing ducts.

Q5: How much does it cost to install a split AC system?
A5: Installation costs for split AC systems can vary widely depending on the type of system, the number of indoor and outdoor units, and the complexity of the installation. Generally, mini-split systems are less expensive to install than traditional central air systems because they do not require ductwork.

Q6: Can I install a split AC system myself?
A6: While some DIY enthusiasts may attempt to install a mini-split AC themselves, professional installation is strongly recommended to ensure optimal performance, efficiency, and safety. Improper installation can lead to inefficiencies, increased energy costs, and even system failure.

Q7: How do I choose the right size split AC system for my space?
A7: Choosing the right size involves calculating the cooling load of the space, which depends on factors like room size, insulation levels, window size, and occupancy. An HVAC professional can perform a detailed assessment to recommend the most appropriate size for your needs.

Q8: Are there any maintenance tasks I can perform myself?
A8: Yes, homeowners can perform basic maintenance tasks such as cleaning or replacing the air filters, ensuring indoor and outdoor units are free from obstructions, and checking that the drainage system is clear. More complex servicing should be left to professionals.