Where should the indoor and outdoor units be located? Where should the pipework run? How should the condensate be drained? Are we considering conventional wall-mounted air conditioners, a multi-split system, or a partially concealed, ducted solution? If these questions are resolved at the appropriate stage of construction, the air-conditioning pipework and mechanical components can be integrated as part of the building structure.
When should you start planning the air-conditioning system for a newly built house?
Ideally, it is worth considering the issue of air conditioning at that stage, when the floor plan and the functions of the rooms have largely been finalised, but the details of the mechanical and electrical works have not yet been set in stone.
At this stage, it is already clear where the larger glass surfaces will be, what the orientation of the building will be, and roughly how the furniture will be arranged. All of these factors influence the air-conditioning system.
What sort of cooling system should we use for the new house?
One of the first decisions to make is what sort of system we’re thinking of. For a small family home, the obvious solution is the several conventional split-system air-conditioners. In this case, each indoor unit has its own outdoor unit. The advantage of this is the simple design and the ability to control each room independently; however, suitable space must be found for several outdoor units.
Multi-split system In such cases, several indoor units may be connected to a single outdoor unit. Whilst this may be advantageous from an aesthetic or space-saving perspective, the sizing and pipework of the system become a more complex task.
In the case of new builds, it is worth looking into ducted air conditioning this option as well. In this case, the indoor unit can remain concealed, whilst the treated air is distributed to the rooms via air ducts and vents.
The capacity of an air conditioning unit is not determined by square metres
The required cooling capacity, calculated on the basis of a given floor area, may serve as an initial estimate, but is insufficient for accurate sizing. The actual characteristics of the building must be taken into account: the floor area and internal height of the rooms, the thermal insulation, the size and orientation of the windows and doors, shading, the function of each room and the expected internal heat load.
A modern, well-insulated house may require little energy in winter, whilst a large south- or west-facing glazed area can cause a significant heat load in summer. For this reason, there can be a significant difference in the cooling requirements between two rooms of the same floor area.
Before making a precise selection, it is therefore advisable to carry out a technical assessment and sizing. The „Air-conditioning performance in practice – What should you expect during an on-site survey?” In our article entitled […], we explain in more detail what factors we take into account during such a survey.
Where should the indoor units be placed?
In the case of new builds, we have much greater freedom when it comes to positioning the indoor units, and it is worth making the most of this opportunity.
One of the most important aspects of good placement is the airflow. For example, it is not advisable to position the unit so that it blows air directly onto a person sitting on a bed, sofa or at a desk. The aim is for the indoor unit to distribute the air efficiently throughout the room.
A single high-capacity unit does not necessarily replace several smaller units positioned appropriately. Even if we install an air-conditioning unit in the corridor, the cool air may not reach every room through the open doors, and it cannot cool several rooms at once.
For more details on this topic, see the „Installing an air-conditioning unit in your flat – where should the indoor unit be placed?” is covered in our guide entitled […].
Air-conditioning ductwork during construction: things worth sorting out before the walls are closed up
In new-build projects, a major advantage is that the routes for refrigerant pipes and electrical cables can be planned in advance, meaning the finished system can look much neater, as there is no need to install cable ducts in the walls at a later stage.
Details of the correct method can be found in the „Rules for air-conditioning pipework – how to ensure your system is durable, safe and aesthetically pleasing” We present this in our article entitled […].
This applies not only to air-conditioning pipes, but to the entire pipework system: It is advisable to document the route of the cables before the walls are sealed – It can be useful when drilling a hole or assembling a new piece of furniture.
The drainage of condensation must also be planned in advance
Condensation is produced during cooling, and this must be safely drained away. Where possible, It is advisable to drain the condensate by gravity. However, this requires a suitable, continuous gradient. If the route does not allow for this, it may be necessary to use a condensate pump.
It also matters where we channel the water. We have summarised the possible solutions and key considerations for implementation in detail in the „Draining condensation from air conditioning units – how should it be done properly?” in our article entitled ….
Electrical connection for the air conditioning: consult both the air-conditioning engineer and the electrician
A common mistake in electrical preparation is that the electrician installs the necessary wiring for the air-conditioning unit before the exact system has been finalised. Yet not all units have the same electrical configuration.
For this reason, it is particularly useful in new-build projects for the air-conditioning specialist and the electrician to coordinate their work before the basic electrical installation takes place. This way, the air-conditioning system does not have to be adapted to the existing electrical system at a later stage.
Where should the outdoor unit be installed?
The outdoor unit moves a large volume of air whilst in operation, therefore He must be provided with adequate air circulation. A poorly ventilated area impairs operating conditions. We must also bear noise in mind: For example, it is not ideal to install the unit near the bedroom or directly next to the seating area on the terrace.
When designing a new house, it is possible to designate an area during the architectural planning stage where the outdoor unit will be less of an eyesore, whilst still being in a technically suitable location.
A serviceabilityNor should this be sacrificed for the sake of aesthetics. A skilfully concealed outdoor unit is of little use if it later proves difficult to access for simple maintenance.
The detailed criteria can be found in the „Installing an outdoor air-conditioning unit in a detached house – technical considerations and common mistakes” We have compiled this information in our article entitled [...].
Suspended ceilings and concealed air conditioning: we have more options in new-build projects
A ducted system allows for partial or fully concealed air conditioning. In this case, the air is supplied through appropriately designed air outlets, for which space must be provided when installing the suspended ceiling – this has an impact on the design of the internal ceiling height.
Air conditioning, heat pumps and ventilation: let’s not think of them as separate systems
In a detached house, air conditioning is just one part of the overall building services system: a heat pump, underfloor heating, domestic hot water production and even heat-recovery ventilation may form part of the system, and it is worth considering these together. The air conditioning system may also be used to provide supplementary cooling or heating.
So, when building a new house, the starting point is: what kind of building services system ensures the building remains comfortable all year round?
Air conditioning during building works: what decisions need to be made and when?
The ideal timing for each decision is influenced by the progress of the building works and the chosen system, but the following order can serve as a good starting point:
| Construction phase | Climate-related task |
|---|---|
| Floor plans, architectural design | Cooling concept; determining possible locations for indoor and outdoor units |
| Mechanical engineering design | System type, estimated power requirements, and the design of pipework and condensate drainage |
| Electrical design | Power supply, coordination of necessary circuits and wiring |
| Structural Engineering | Design of necessary wall penetrations and service routes |
| Basic mechanical engineering installation | Preparing air conditioning ducts, cabling and condensate drainage |
| Before plastering and fitting plasterboard | Checking and documenting routes and overhangs |
| Once the interior work has been completed | Installation of indoor and outdoor units |
| Before handover | Commissioning, inspection and trial run |
There is no need to purchase the actual appliances right at the start of the building project, but decisions that would later involve demolition or major alterations must be taken in good time.
7 common mistakes when designing air-conditioning systems for new builds
Even with careful planning, it can happen that air conditioning is considered too late in the process. Many of the most common mistakes can be avoided with simple planning:
- Planning for the air-conditioning system only begins once the painting and tiling have been completed.
- The locations of the indoor units are chosen solely on the basis of aesthetic considerations.
- There is no adequate condensation drainage.
- The electrical preparations are not compatible with the selected air-conditioning system.
- There is no suitable location for the outdoor unit, either from a technical or an aesthetic point of view.
- The air conditioning system is designed to be completely independent of the heating and ventilation system.
- The exact locations of pipes and cables running through the walls are not documented before the structures are sealed off.
When should an air-conditioning specialist be involved in a new-build project?
In a newly built house, the ideal time to involve an air-conditioning specialist is during the mechanical and electrical design phase. At this stage, it is still possible to coordinate the pipework, condensate drainage, electrical connections, outdoor units and even the design of the suspended ceiling.
Frequently asked questions about new-build projects and air-conditioning design
When should the air-conditioning pipework be installed in a new build?
It is advisable to determine the route of the pipework during the mechanical engineering design phase, and the preparatory work itself should be carried out before the walls are finally sealed, plastered or fitted with plasterboard. The exact timing must always be adapted to the construction methods used.
Do you have to choose the specific air-conditioning system whilst the building is still under construction?
A sufficiently precise system design is required for the preparatory work. As the technical requirements of different devices may vary, it is not a good idea to install pipework and electrical connections at random for a future system that is as yet completely unknown.
Where should the power socket for the air conditioner be fitted?
This depends on the design of the chosen unit and system. For this reason, it is advisable for the air-conditioning engineer and the electrician to consult with each other regarding the required power supply, cabling and protection measures before the electrical installation work begins.
Can the air-conditioning be completely concealed in a newly built house?
It depends on which system you choose. With a ducted system, the air ducts can be installed in the suspended ceiling or in a plant room, whilst the supply and extract air vents are visible in the rooms.
Is it worth installing a separate air-conditioning unit in every room?
Not necessarily. The need for separate cooling must be determined on the basis of the thermal load on the rooms, their use, and the mechanical systems in place. A well-designed system is one that ensures the required level of comfort through adequate capacity and a sensible design.