On a a renovation site for a single-family home, we often encounter the same blockage: the client wants their air conditioning operational before summer, but no one has explained that drilling the wall, electrical connections, and commissioning follow specific technical constraints. Installing air conditioning in a house is not just about fixing two units and plugging them in. Each step affects the system’s performance for the years to come.
Wall passage and condensate drainage: the detail that no one sizes correctly
When preparing to drill between the inside and outside, the reflex is to drill straight. The problem is that the condensate must drain by gravity. The wall passage requires a slight slope towards the outside so that condensates do not stagnate in the connection.
The diameter of the hole varies between 60 and 80 mm depending on the model of the split air conditioner. On a 20 cm concrete block wall, it passes without difficulty with an appropriate hole saw. On a stone wall of 40 cm or more, sometimes core drilling is required, which changes the budget and necessary equipment.
Before knowing how to install home air conditioning, one must first know the exact composition of their walls and plan the right drilling tool. A PVC sleeve inserted into the passage protects the refrigerant connections and the electrical cable from friction against the masonry.
Electrical connection dedicated to the panel: circuit breaker and cable section
This point remains discreet in most guides, yet it conditions the safety of the entire installation. A split air conditioner requires a dedicated electrical line from the panel, protected by a circuit breaker of 16 A or 20 A depending on the power of the outdoor unit.
An air conditioner should not be connected to an existing outlet shared with other devices. The cable section (generally 2.5 mm²) must correspond to the maximum current drawn by the compressor at startup. A 30 mA differential at the head of the line protects against current leaks.
Verification before powering up
Before powering the system, three points are checked at the panel:
- The dedicated circuit breaker is well-calibrated according to the power of the air conditioner (the manufacturer’s manual indicates the maximum absorbed current)
- The line has no branches between the panel and the outdoor unit
- The interconnection cable between the indoor and outdoor units passes through the wall sleeve without bends that could damage the sheath
If the housing has an old panel without free slots, it is necessary to plan for the addition of a module. Feedback varies on this point, but in houses built before the 1990s, an undersized panel is often observed.
Vacuuming the refrigerant connections: the step that conditions the lifespan
Once the indoor and outdoor units are fixed and the refrigerant connections are made, vacuuming eliminates air and moisture from the circuit. This operation requires a vacuum pump and a manifold (set of pressure gauges). Without it, residual moisture circulates in the refrigerant circuit and degrades the compressor within a few seasons.
The vacuum is maintained for at least fifteen to thirty minutes, then the stability of the pressure on the gauges is monitored. If the pressure rises, there is a leak at a connection that must be located and tightened before proceeding.
Handling refrigerant and capacity certificate
Regulations require a capacity certificate to handle refrigerants. Specifically, opening the valves of the outdoor unit (which releases the pre-charged refrigerant into the circuit) falls under this obligation. A private individual can install the units and pull the connections, but this final step requires the intervention of a certified professional.
Positioning the outdoor unit: noise, ventilation, and future access
The choice of the outdoor location goes beyond the simple question of ventilation. Noise nuisance for the neighbors represents a constraint often underestimated that can lead to conflicts, or even an obligation to relocate the device after installation.
Avoid placing the outdoor unit directly against a shared wall or under the window of a neighboring room. A clearance of at least 30 cm around the device ensures good air circulation and prevents overheating of the condenser.
- Choosing a shaded facade reduces the thermal load on the condenser and improves the efficiency of the reversible air conditioner
- Plan for easy access for the annual cleaning of the outdoor filter and the leak check of the circuit
- A floor support with vibration dampers limits the transmission of vibrations to the building structure, especially on a terrace or balcony
Commissioning the split air conditioner: first start-up checks
After vacuuming and opening the valves, the first cycle is started in cooling mode. We check that the indoor unit blows air that is significantly cooler than the ambient temperature after a few minutes of operation. The difference between the blowing temperature and the return temperature gives a direct indication of proper functioning.
We also check the drainage of the condensates: water should flow freely through the drainage pipe. If nothing comes out after twenty minutes of continuous operation, the connection of the condensate tray likely has a slope issue.
The professional who carries out the commissioning normally provides a leak-tightness certificate and a refrigerant tracking slip. These documents condition the validity of the manufacturer’s warranty and must be kept for the entire lifespan of the device. Without them, a failure covered by the warranty may be denied by the manufacturer.