Reversible air conditioning: heating & cooling

Understanding reversible air conditioning (air-to-air heat pump) and its uses

Difference between air conditioning, an air-to-air heat pump and a reversible system

Air conditioning mainly refers to cooling a dwelling. An air-to-air heat pump is a heat pump that captures heat from the outdoor air and transfers it indoors via an outdoor unit and one or more indoor splits. When it's described as reversible, the same equipment can also produce cooling. In practice, people often say "reversible AC", but the key point remains the heat transfer, not the cooling production.

Heating and cooling modes: simple operation to explain to the client

In heating mode, the machine draws energy from the outdoor air, even in cool weather, and releases it into the room. In cooling mode, the reversed cycle removes heat from the room to the outside. The client can keep one simple idea in mind: heat is moved from one side to the other, controlled by a thermostat and remote control.

Mono-split, multi-split, ducted: choosing the right configuration for the dwelling

A mono-split heats or cools a single zone, practical for a living room or one floor. A multi-split feeds several rooms, useful when needs differ from bedroom to bedroom. Ducted systems are discreet, with ceiling grilles and a duct network. They need space in the false ceiling and careful sizing, to aim for the right output without over-equipping. To go further, also see choosing between an air-to-air and an air-to-water heat pump.

Properly sizing air conditioning to avoid discomfort and overconsumption

On-site criteria: floor area, insulation, exposure, internal gains and number of rooms

Before choosing the output, start from the site. Floor area and ceiling height, insulation quality, airtightness, exposure, solar protection, internal gains (kitchen, IT equipment) and number of rooms. A fully glazed south-facing living room is not treated like a north-facing bedroom. In renovation, an improvement to insulation or shutters can significantly reduce the cooling need.

Output, airflow, unit placement: points of vigilance in renovation

Aim for air conditioning able to cover the summer load without cycling erratically. Favour a well-tuned Inverter unit. Check the airflow and diffusion to avoid direct draughts. On the installation side, plan ahead for the placement of the indoor units, the routing of the lines, condensate drainage, acoustics and maintenance access.

Common mistakes (oversizing, poor placement) and corrective solutions

Oversizing makes the machine cycle, dehumidifies poorly, and can lead to overconsumption. Poor placement creates cold zones and hot zones. Solutions. Recalculate room by room, adjust the setpoint, add solar protection, balance the shutters, or use finer zoning. Have it validated by an RGE-certified professional.

Installation and commissioning: the key steps for reliable, quiet air conditioning

Site preparation: support, condensate drainage, penetrations and sealing

Before installing air conditioning, everything hinges on placement. The outdoor unit is fixed on anti-vibration mounts and a sound wall, with proper distances kept for airflow and noise. Condensate drainage is planned from the start. A continuous slope, a trap if needed, and controlled discharge. Wall penetrations are made with a sleeve, then careful air and water sealing to prevent infiltration.

Connections, vacuum pull-down, leak testing: what makes the difference

Fittings torqued correctly, insulated refrigerant lines, and clean brazing. The vacuum pull-down is done with a vacuum gauge, not "by feel", to remove moisture. Then a dry-nitrogen leak test before opening the valves and releasing the refrigerant. This is also the moment to check compliance related to refrigerants.

Settings, tests and usage explanations: handing over a system that delivers on its promises

Finish with fine-tuning. Test heating and cooling modes, check temperatures, airflow, condensate and noise level. Then move to the practical side. Filter cleaning, instructions, night mode, and a reminder about maintenance. A clear handover avoids 80% of the "it's making noise" callbacks.

Regulation, maintenance and best practices in 2026

Handling refrigerants: obligations, certificates and traceability

On an air conditioning system, any intervention on the refrigerant circuit (recovery, charging, evacuation) remains reserved for certified professionals. The company must hold a capability certificate. The technician, a competency certificate. Keep a refrigerant log (quantities, sources, recoveries) and retain the supporting documents. In the event of a leak, finding and fixing it takes priority over any top-up.

Maintenance, cleaning, performance checks: a recommended schedule for your clients

Simple advice. Dust off filters every 1 to 2 months during the season. Clean the heat exchangers and check the condensate at least once a year. For many systems, biennial maintenance is required between 4 and 70 kW, and every 5 years above that. Use the visit to check tightness, airflow and controls.

Optimising service life: usage tips (temperatures, scheduling, humidity management)

Aim for a reasonable gap between indoor and outdoor temperatures, rather than a big blast of cold. Schedule the time slots, avoid repeated on/off cycling, and keep the grilles clear. In the shoulder seasons, dehumidification mode limits discomfort and eases the load on the compressor.

Selling and quoting reversible air conditioning without wasting time

The right arguments: summer/winter comfort, savings, improved energy performance of the dwelling

Reversible air conditioning is a single piece of equipment that cools in summer and heats in winter. Sell the immediate comfort and room-by-room control. On the bill side, emphasise the air-to-air heat pump principle, often more efficient than direct electric heating. And on the DPE, a controllable, efficient system can boost the dwelling's rating, provided it is properly sized (see the base outdoor design temperature).

A clear quote: essential line items (supply, lines, accessories, commissioning, options)

A readable quote avoids 3 rounds of back-and-forth. Clearly distinguish:

• Supply (outdoor unit, indoor units, remote controls).
• Refrigerant lines, wiring, condensate drainage, drilling and patching.
• Accessories (mounts, trunking, anti-vibration mounts, electrical protection).
• Vacuum pull-down, charging if needed, commissioning and checks.
• Options (multi-split, ducted, condensate lift pump, Wi-Fi module, maintenance contract).

Typical client cases: apartment, older house, converted loft (what to propose and why)

Apartment. Often a mono-split, with care over noise, placement and co-ownership approval. Older house. Propose a multi-split or ducted system, linking the sizing to the insulation and usage. Converted loft. Favour even distribution (ducted or console unit), and secure maintenance access. A tailored proposal gets quoted faster, and gets signed with more confidence.