Air Conditioning for Three Rooms
- 3 days ago
- 6 min read
Air Conditioning for Three Rooms: A Recent Multi-Split Installation
When you want air conditioning in several rooms, you don't necessarily need a separate outdoor unit for every indoor unit. A multi-split air conditioning system can connect multiple indoor units to a single outdoor unit, providing independent temperature control across different areas of a property.
Cold Control recently completed a three-room multi-split air conditioning installation, using Daikin Perfera indoor units and a single outdoor unit. The installation also incorporated black external trunking, providing a modern finish to the exterior of the property.
Air conditioning for multiple rooms
For homeowners looking to air condition several rooms, there are two main approaches: installing separate split systems or using a multi-split system.
A multi-split system allows several indoor units to connect to one outdoor condenser. This can be particularly useful where space outside the property is limited or where the customer wants to minimise the number of external units.
In this installation, we installed an multi split system, with three indoor units providing air conditioning across three separate rooms.
Each room can be controlled independently when in heating or cooling mode, allowing occupants to adjust the temperature to suit the space and how it is being used.
Can three air conditioning units use one outdoor unit?
Yes. This is one of the main advantages of a multi-split system.
Rather than installing three separate outdoor units, a suitably sized multi-split system can connect three indoor units to a single outdoor unit.
The system needs to be correctly designed and sized according to the rooms being conditioned. Room size, heat gain, insulation, windows, orientation and how the rooms are used can all influence the required capacity.
A professional site survey is therefore important before selecting the equipment.
Why choose a multi-split system?
A multi-split installation can offer several practical advantages for a residential property.
One outdoor unit
Three individual split systems could require three outdoor units. A multi-split system can provide the same multi-room coverage using a single outdoor unit, subject to the system design.
This can help reduce the amount of equipment required outside the property, and also reduce maintenance costs.
Independent room control
Each indoor unit can be controlled separately. This means there is no need to cool every room to the same temperature simply because one room requires air conditioning.
For example, a bedroom can be set differently from a living area depending on individual comfort and use.
A more discreet installation
Reducing the number of outdoor units can also help create a cleaner appearance outside the property.
Careful planning of the pipework and trunking is also important, particularly where the installation is visible externally.
Daikin Perfera air conditioning
For this installation, Cold Control used Daikin Perfera indoor units.
Perfera is designed for residential applications where comfort, quiet operation and energy efficiency are important considerations. The indoor units have a modern, compact appearance, making them suitable for bedrooms, living areas and other rooms within the home.
The units provide both cooling and heating, allowing the system to be used throughout the year rather than only during periods of hot weather.
Why black air conditioning trunking?
One of the challenges with any air conditioning installation is deciding how to route the refrigerant pipework, electrical connections and drainage.
Where pipework needs to run externally, trunking provides protection and gives the installation a cleaner finished appearance.
For this project, black trunking was used externally.
Rather than treating the trunking as something to simply hide, the darker finish worked with the exterior of the property, matching the guttering.
Our three-room multi-split installation
For this project, Cold Control installed:
Three Daikin Perfera indoor units
A multi-split outdoor unit
Independent control for each room
External refrigerant pipework and associated services
Black external trunking to protect and conceal the pipework
The system was designed around the requirements of the individual rooms, with the indoor units positioned to provide effective air distribution while keeping the installation as discreet as possible.
The result is a single multi-split system providing heating and cooling across three rooms without requiring three separate outdoor units.
Full Capacity or Zonal Capacity: How is a Multi-Split System Sized?
When designing a multi-split air conditioning system, there are different ways the outdoor unit can be sized in relation to the combined capacity of the indoor units.
The right approach depends on how the rooms are expected to be used and whether maximum heating or cooling capacity is likely to be required in every room at the same time.
Full Capacity System
Think of this as a “no compromise” setup.
The outdoor unit is sized with enough capacity to run every indoor unit at 100% at the same time. This is
ideal where you expect every room to require maximum heating or cooling simultaneously.
For example, if three rooms are regularly occupied at the same time and all three need to reach their target temperature quickly, a full-capacity configuration provides the outdoor unit with enough capacity to meet the combined demand.
This approach can provide maximum available capacity across all zones, although the system may require a larger outdoor unit than a zonal configuration.
Zonal Capacity System
A zonal configuration takes a different approach.
The outdoor unit is sized slightly below the combined maximum capacity of all the indoor units, based on the assumption that it is unusual for every room to require maximum heating or cooling at exactly the same time.
For example, during the day you might primarily use the living room, while in the evening the bedrooms become the main areas requiring heating or cooling.
The system intelligently distributes the available capacity between the indoor units that are operating, directing more capacity towards the areas where it is needed.
Importantly, all of the indoor units can still operate at the same time. If all three rooms are switched on together, the system will not overload or simply shut down because the combined indoor capacity is greater than the outdoor unit's maximum output.
Instead, the outdoor unit operates at its maximum available capacity and the system manages how that capacity is distributed between the indoor units.
If every room is demanding maximum output simultaneously, each indoor unit may therefore receive less than its individual maximum capacity. As a result, it can take slightly longer for all rooms to reach their target temperatures.
Which approach is right?
Neither configuration is automatically better. The most suitable approach depends on the property, the rooms being conditioned and how the system will actually be used.
A full-capacity system provides maximum available output across all zones simultaneously, while a zonal-capacity system can be a more efficient way of sizing a multi-split system where rooms are unlikely to require maximum output at the same time.
This is one of the reasons professional system design is important. At Cold Control, we consider the size and characteristics of each room, how the spaces are likely to be used and the customer's heating and cooling requirements before recommending the appropriate system configuration.
For this particular three-room installation, we specified a full capacity system.
This means the outdoor unit was selected to provide sufficient capacity to run all three indoor units at their maximum output simultaneously. The system was designed without relying on the assumption that the rooms would be used at different times.
This approach gives the customer greater flexibility. If all three rooms need heating or cooling at the same time, the system has the capacity to meet that combined demand without having to share a limited outdoor capacity between the indoor units.
For this property, the full capacity configuration was selected to provide maximum flexibility and performance across all three rooms, ensuring that the system can respond to demand throughout the property, whether one room or all three are being used.
How much does air conditioning for three rooms cost?
The cost of installing air conditioning across three rooms can vary considerably depending on the property and the specification required.
Factors that can affect the cost include:
The size of each room
The required cooling and heating capacity
The number and type of indoor units
The location of the outdoor unit
The length and route of the pipework
Electrical requirements
Access to the property
Whether pipework needs to be installed externally
The type and finish of trunking required
For this reason, there isn't a single price that applies to every three-room installation.
Cold Control can assess the property and recommend a system based on the rooms being conditioned, the layout of the property and the customer's requirements.
Is a three-room multi-split system right for your home?
A multi-split system can be a practical solution if you want air conditioning in several rooms but don't want multiple outdoor units around the property.
The key is to design the system around the individual rooms rather than simply selecting equipment based on the number of rooms.
At Cold Control, we can advise on the most suitable system, indoor unit positions, outdoor unit location and pipework routing before installation.
If you're considering air conditioning for three rooms, multiple bedrooms or different areas of your home, contact Cold Control to arrange a site survey and discuss the options available, or complete a quote request form:
