Table Of Contents
The Different Types of Air Conditioners
The Pros and Cons of Central Air Conditioning Systems
Pros and Cons of Multi-Split Air Conditioning
Ducted Air Conditioning or Ductless Air Conditioning?
What Air Conditioning Is Best Suited For The UK?
What To Remember When Choosing Your Central Air Conditioner
Why Should I Seek Professional Advice?
With so many different air conditioning systems available, it can be confusing toying between the options that are on offer. Without inside knowledge of the air conditioning industry, it can all be a bit overwhelming when you are faced with all the options. Fortunately, with our handy comparison guide, we will go into depth into two recommended air conditioning systems you can consider: the central air conditioning system and the multi-split air conditioning system.
The Different Types of Air Conditioners
There are plenty of different air conditioners to investigate when you are considering implementing a system in your UK home. As some systems, such as HVAC, are more suitable for commercial buildings, we have streamlined your options based on the best air conditioning systems for a residential space. Therefore, we believe there are two main systems to choose from: a central air conditioning system and a multi-split air conditioning system.
Read on to discover how both systems work and the positives and negatives of each. The most important thing to keep in mind when considering your options is what air conditioning system best suits your needs, situation and location.
Central Air Conditioning
Often referred to as a ducted system, a central air conditioning system is used to regulate your home’s air temperature, similar to a large refrigerator; however, some models can provide heat. This climate control system is used to circulate cooler or warmer air throughout your home. To disperse cooled air from the central unit, this air conditioning system uses ducts and grills – conduits that provide a passageway for the temperature-controlled air to flow through.
The central air conditioning system consists of an indoor unit and an outdoor unit. The external unit is where you will find the air conditioner’s condenser and compressor. For commercial buildings, this tends to be housed on the roof; however, while residential properties can also locate this unit on the roof, most find space down the side or at the back of their property. Moreover, the ducting is often housed within the property’s loft space, should there be room.
The Pros and Cons of Central Air Conditioning Systems
The biggest negative of central systems is that they require ducting to function. Due to the need for an insulated passageway throughout a property, they are quite bulky and time-consuming to install. Moreover, if you are simply looking to add an air conditioning system to your decorated home, the installation process will often leave your property requiring some cosmetic jobs. With all of this taking more time, it also requires more money.
The ducting can also cause additional issues if it were ever to require repairing or replacing. Carrying out maintenance work on ducting often requires plaster to be removed, which in turn causes a lot of mess and disruption to a domestic home. Once the necessary work has been carried out, there is often additional work that needs to be arranged to return the room to its original condition.
However, central air conditioning systems are the best option to provide a property with a constant temperature. There is no need to preset the temperature of each individual room; a central air conditioning system will instead heat the whole house to the same climatic conditions through one thermostat. If you are considering a renovation or building your own house, this may be worth your consideration.
Multi-Split Air Conditioning
A multi-split air conditioning system uses a Variable Refrigerant Flow (VRF) process. What this means is that even though a multi-split system is installed within your whole property, you can set different areas independently from others.
With a multi-split system, one external air conditioning unit can support 2-5 internal units. These differ from split systems, where each internal unit needs a corresponding external unit. When compared to a central air conditioning system, there are some similarities. For example, the compressor will be found in the outdoor units, and then the internal and external units will be connected by wires and refrigerant piping.
Pros and Cons of Multi-Split Air Conditioning
It is down to the fact that multi-split air conditioners can support different rooms, heated or cooled to different temperatures simultaneously, which makes them a popular choice. Using a heat pump, these systems have more heating and cooling functions, another popular feature with the seasonality of the UK. In addition, as selected air conditioner units can be turned off, while others are on, you are more in control of how much it is costing you.
What multi-split air conditioning systems also allow is a choice over which rooms are installed with an internal unit. Unlike central air conditioning systems, multi-split systems can be installed in the rooms that will be used most, without compromising any function. As an outdoor device that can run on as little as 2 units, you have the flexibility to install more if you wish.
These systems are also much easier to access with minimal hassle. Therefore, if there is ever a need for maintenance repairs to be carried out, or a part required to be replaced, your unit can be worked upon without undoing and causing excessive disruption to your home’s interior. In addition, the units are easy to manoeuvre if you are designed to reconfigure your home.
Ducted Air Conditioning or Ductless Air Conditioning?
Sometimes the terms ‘ducted’ and ‘ductless’ are used to determine what type of air conditioning systems you have chosen. As we have previously mentioned, ducted air conditioning systems require the installation of these ducts throughout your home to provide a passageway for cooled/heated air to travel along. Ductless air conditioning systems, quite simply, do not require a designated channel to disperse their cooled/heated air.
Ducts come in two different forms: flexible and rigid. Flexible ducting can be recognised by its corrugated, silver appearance; however, these will be screened off from view. Rigid ducting is also boxed off, but can often be seen running along with ceilings or down walls. All the ducting will feed into vents in the walls or ceilings of the room, allowing the cooled/heated air to filter in.
As ductless air conditioning systems do not require ductwork to distribute air, instead, they blow cooled/heated air directly into the chosen rooms through a unit attached to the wall. As the units heat or cool the room directly, these systems are more efficient than ducted systems. It consists of two main parts, the indoor air-handling unit and the outdoor unit. The indoor unit is where you will find the evaporator coil and fan. These two components are then linked together using refrigerant and suction tubing, as well as a copper conduit and condensate drain.
Central Air Conditioning vs Multi-Split Systems
When deciding between central air conditioning (AC) and multi-split systems, understanding how each system works and what it offers can help you make an informed choice. Both options have their advantages, depending on your home’s layout, size, and specific cooling needs. Here’s a detailed comparison to guide you.
| Feature | Central Air | Multi-Split |
| Installation | Complex, requires ductwork | Simpler, no ductwork needed |
| Cost | £8,000 – £15,000+ | £3,000 – £8,000 |
| Efficiency | Best for large homes | Better for partial cooling or small spaces |
| Control | Single thermostat for entire home | Individual room control for each unit |
| Aesthetics | Hidden system, no visible units | Visible wall-mounted units in each room |
| Maintenance | Complex duct cleaning required | Simple unit servicing and cleaning |
Central Air Conditioning is ideal for larger homes or those needing consistent cooling/heating throughout, while Multi-Split Systems are more suitable for homes or areas that need cooling in individual rooms without the need for ducts.
Your Selection Criteria with Central Air Conditioning
When selecting a central AC system, several factors need to be considered:
- Home Size: For UK homes, typically 1-2 tonnes of cooling capacity are needed for every 1,000 square feet. Larger homes will require more capacity to ensure efficient cooling or heating.
- Ductwork Requirements: If you have existing ducts, your costs may be lower. However, for homes without ducts, you’ll need to consider the installation of new ductwork, which can add to the cost and complexity.
- Energy Efficiency: Look for systems with high SEER (Seasonal Energy Efficiency Ratio) ratings of 16 or above. Systems with variable speed technology are also more energy-efficient than single-speed units.
- Installation Complexity: Installing central air typically requires professional expertise, and the process can take 3-5 days, depending on the size of the property and the complexity of the ductwork.
- Zoning Capabilities: Many modern systems offer multi-zone capabilities, allowing different areas of your home to be cooled or heated to different temperatures. This can improve efficiency and comfort.
- Heat Pump Integration: Some central AC systems also function as heat pumps, providing both cooling and heating, making them a year-round solution.
The Costs of Central Air Conditioning
The cost of installing central air conditioning in the UK can vary widely depending on factors such as the size of your home, the complexity of the installation, and whether you’re starting with existing ductwork.
- System Only: £8,000 – £15,000 (depending on home size)
- Installation Costs: £3,000 – £8,000 (including ductwork)
- Ductwork Installation: £2,000 – £5,000 (new builds)
- Existing Duct Modification: £1,000 – £3,000 (if modifying existing ducts)
- Annual Running Costs: £400 – £800 (for an average 3-bed home)
- Maintenance Costs: £150 – £300 annually
These figures cover installation and running costs for an average UK home and will vary depending on factors such as energy efficiency and specific system features.
A Sizing Guide
To ensure that your central AC system is properly sized, it’s important to choose the correct tonnage based on the size of your property. Here’s a general sizing guide:
- 2-Bed House (800-1,200 sq ft): 1.5-2 tonnes (18,000-24,000 BTU)
- 3-Bed House (1,200-1,800 sq ft): 2-2.5 tonnes (24,000-30,000 BTU)
- 4-Bed House (1,800-2,500 sq ft): 2.5-3.5 tonnes (30,000-42,000 BTU)
- Large House (2,500+ sq ft): 3.5+ tonnes (42,000+ BTU)
Proper sizing ensures the system will meet the cooling or heating demands of the space without wasting energy.
Energy Efficiency
Efficiency is a crucial consideration for both initial investment and long-term running costs. Modern central AC systems are designed with high-efficiency ratings to reduce energy consumption.
- SEER 16+: High-efficiency systems that offer the lowest running costs.
- SEER 14-16: Standard efficiency, with moderate running costs.
- Variable Speed: Systems with variable-speed technology are 30-40% more efficient than single-speed units, as they adjust their speed to match the cooling or heating needs.
- Inverter Technology: This technology allows the system to run continuously rather than cycling on and off, which improves energy efficiency and reduces wear on the components.
- SCOP 4.0+: For heat pump systems, this rating ensures high seasonal heating performance.
- ERP A++ Rating: An EU classification that indicates superior energy efficiency.
For homeowners looking to lower energy consumption, opting for high-efficiency models with these technologies will pay off in the long run.
UK Installation Requirements for Central Air Conditioning
In the UK, central air conditioning systems must comply with specific regulations and standards for installation:
- F-Gas Certification: Installers must be certified to handle refrigerants under the EU F-Gas regulations.
- Building Regulations: Compliance with Part L of the building regulations (conservation of fuel and power) is required to ensure the system meets energy efficiency standards.
- Planning Permission: If the installation is in a listed building or conservation area, you may need planning permission.
- Electrical Compliance: The system must comply with Part P electrical regulations to ensure safe installation and operation.
- Noise Regulations: The system should not exceed 42dB at 3.5m from a neighbouring property, ensuring minimal disruption.
- Ductwork Standards: Ductwork must be properly insulated and sealed to avoid energy loss and ensure optimal system performance.
Compliance with these standards ensures that your system operates efficiently and legally.
What Air Conditioning Is Best Suited For The UK?
In the UK, when considering which air conditioning system is suitable for your home, the multi-split system often comes out more favourable. And, there are a few reasons why it is the preferred choice of climate control.
The first factor is efficiency. Multi-split air conditioners are more energy-efficient than the central air conditioning system, and this all stems from the multi-split air conditioning using a ductless system. Air conditioners that rely on transporting cooled or heated air through ducts are often at risk of temperature variations; for example, on a particularly cold day, the heated air within the ducts can end up losing heat and vice versa on hot days. As your system will need to work harder to maintain your preferred temperature, this reduces its efficiency, costing you more money too.
Multi-split systems, or split air conditioning systems, allow different areas of your house to be set at varying temperatures. Therefore, a spare bedroom can only be heated or cooled when necessary. But with a central air conditioning system, you have less control, and all rooms are set to the same constant climate. In the example of a spare bedroom, you would be paying to heat/cool a space that is only occasionally used.
However, there are occasions when a central air conditioning system is preferred in the UK. If you are looking to completely renovate a property, or you are looking to design and build your own, a central air conditioning system can be worked into your planning. Another reason why multi-split systems are preferred is due to their ductless installation. But if space is reserved for ducting within the planning stage of a build or project, a central air conditioning system can be accommodated to meet your needs.
Another reason multi-split and split systems are preferred in residential homes is due to the extensive choice this air conditioning system offers. With a wide range of makes and models, there is a broad choice of colours to help your unit blend in, whatever your interior.
Another property that can benefit from a central air conditioning system is UK bungalows, especially if the ground floor and loft space are all open plan. The only hesitation with this option is the lengthy installation process. When compared to multi-split systems, these are much quicker, easier and cheaper to install. This is particularly significant if the central air conditioning system requires solid ducts.
What To Remember When Choosing Your Central Air Conditioner
Whichever air conditioning system you decide on in your UK home, there are a few things to consider before committing. Your air conditioning engineer should encourage you to evaluate these factors before they begin the installation process. Make sure you take into account:
- Your Indoor Space: All air conditioning systems will require some space for the installation, maintenance checks and services and occasional repairs of the system. While different air conditioners will need different amounts of space, you will need to ensure you can adequately accommodate your chosen system.
- The Number of Registers: Your air conditioning system will contain supply registers and return registers. Supply registers deliver cool air to a room, and return air registers remove the warm air, taking this back to the air conditioning unit. When settling on a system, your engineer will be able to help you ensure you have enough of each register.
- Duct Installation: It is recommended to install your ductwork within the rooms you wish to condition, rather than placing them in the loft, as heat rises, your loft space becomes extremely warm. On installation, all your ducts must be sealed with duct mastic and heavily insulated ducts. A professional air conditioning specialist will take care of this during installation.
- The Location of the Condensing Unit: A condensing unit can be noisy; therefore, you need to decide on where it can be installed and where it will not disturb you or your neighbours. Also, it cannot be situated where its airflow will be blocked or obstructed.
- The Placement of the Thermostat: All thermostats must be positioned away from heat sources, including windows and supply registers.
Why Should I Seek Professional Advice?
If you’re still unsure about which air conditioning system, a ducted or ductless system, is most appropriate for your house, do not worry. Our air conditioning experts at PRA Air Conditioning will be happy to help you explore the options in more detail. With their inside knowledge of the industry, they are highly qualified in both central air conditioning systems and multi-split air conditioning systems, as well as their installation, maintenance, servicing, and repairs.
For support in choosing and installing your air conditioning system, leave it to our experts. Get in touch with us today for a personal quote on air conditioning for your home.
FAQ
What is central air conditioning, and how does it work?
Central air conditioning is a whole-home cooling system that uses a single outdoor unit connected to an indoor air handler. Conditioned air is delivered through a network of ducts and vents to maintain an even temperature throughout the property. The system works by circulating refrigerant between the indoor and outdoor units: heat and humidity are absorbed from inside the home and released outdoors, leaving cooled, dehumidified air circulating indoors.
How much does central air conditioning cost in the UK?
For a typical UK home, central air conditioning installation costs £8,000-£15,000, which includes equipment and professional installation. If your home doesn’t already have ductwork, expect an additional £2,000-£5,000 for duct installation (more common in renovations than in new builds). Running costs typically range from £400-£800 per year, depending on usage and system efficiency. Many homeowners also see a 5-10% uplift in property value after installation.
Do I need planning permission for central air conditioning in the UK?
Most installations fall under permitted development and do not require planning permission. However, permission may be needed for:
- Listed buildings
- Conservation areas
- Flats or properties with restrictive covenants
External units must also meet local noise regulations, typically requiring sound levels below approximately 42 dB at 3.5 metres from the neighbouring property boundary.
Is central air conditioning worth it in the UK?
Central air conditioning is a strong investment for larger homes or properties where whole-house temperature control is desired. It’s especially beneficial in well-insulated modern homes and areas experiencing hotter UK summers. When integrated with heat-pump technology, these systems can also provide efficient heating, making them a versatile year-round solution.
How long does central air conditioning installation take?
A standard installation usually takes 3-5 days, covering outdoor unit placement, indoor air handler installation, duct connections or adjustments, electrical work, and system commissioning. If your home needs new ductwork, the installation may take 1-2 weeks.
What’s the difference between central air and ducted air conditioning?
There is no difference. Both terms describe the same system: a whole-home air conditioning setup that delivers cooled (or heated) air through ductwork. “Central air” is the common term in the US, while the UK typically uses “ducted air conditioning.”
Can central air conditioning heat my home too?
Yes. Most modern central air systems in the UK use heat pump technology, allowing them to provide both cooling and heating. Heat pumps are highly efficient, often delivering 3-4 times more heat energy than the electricity they consume. They perform particularly well when outdoor temperatures are above -5°C.
What maintenance does central air conditioning need?
To keep your system running efficiently, plan for:
- Monthly filter cleaning or replacement
- Annual servicing by an F-Gas certified engineer
- Ductwork cleaning every 3-5 years
- Seasonal clearing of debris around the outdoor unit
- Annual refrigerant level checks
Regular maintenance improves performance, reduces running costs, and extends the system’s lifespan.
Is central air conditioning energy efficient?
Modern systems with SEER 16+ ratings are highly efficient and usually outperform multiple individual room units. Features such as variable-speed compressors and accurate system sizing further enhance energy efficiency. However, ducted systems can lose 20-30% efficiency if the ductwork is poorly sealed or inadequately insulated, so quality installation is essential.
What size central air conditioning do I need for my UK home?
Sizing depends on your home’s floor area, insulation levels, layout, ceiling height, and window orientation. As a guide, many UK homes require around 1.5-2 tonnes of cooling per 1,000 sq ft, though accurate sizing should always be calculated through a professional load assessment to ensure optimal performance and efficiency.