Reversible air conditioning: what is it?

Why choose a reversible air conditioning system?

Reversible air conditioning is becoming an increasingly popular solution for ensuring thermal comfort throughout the year. Indeed, this system offers numerous advantages that explain its growing success in the energy renovation market.

One device for two functions

The main advantage of reversible air conditioning is its versatility. Contrary to popular belief, this equipment is not limited to cooling your home during the summer. Thanks to its cycle reversal system, it also provides efficient heating during the winter. This 2-in-1 operation is based on a simple but ingenious principle: in air conditioning mode, the unit extracts heat from the interior and releases it outside, while in heating mode, it captures the calories present in the outside air and distributes them throughout your home.

This dual functionality provides a comprehensive solution for maintaining the ideal temperature in all seasons. Even when the outside temperature drops significantly, your reversible air conditioning system continues to produce heat efficiently. However, in very cold weather (below 14°F), some models may require auxiliary heating to maintain optimal comfort.

Space saving and ease of use

Installing a reversible air conditioning system saves a considerable amount of space in your home. By replacing two separate systems (heating and air conditioning) with a single piece of equipment, you free up valuable space. This solution is ideal for all types of homes, whether apartments or detached houses.

In addition, the modern technologies integrated into reversible air conditioners offer remarkable user comfort. Most models now allow precise temperature control to within a tenth of a degree, ensuring constant thermal comfort. In addition, many units are equipped with advanced filters that purify indoor air by capturing particles and allergens, helping to improve the quality of the air you breathe.

Ease of use is also a major advantage. Modern reversible air conditioning systems can be controlled remotely via smartphone or tablet, allowing you to adjust the temperature to suit your specific needs, even when you are not at home.

Reducing your energy bill

Reversible air conditioning stands out for its exceptional energy efficiency. For every 1 kWh of electricity consumed, it produces between 3 and 5 kWh of heat or approximately 3 kWh of cooling. This remarkable performance is due to the fact that the device does not generate energy directly but transfers it from one environment to another.

Compared to a traditional electric heating system, reversible air conditioning can deliver significant savings of up to 75% on your electricity bill. For a home equipped with a reversible air-to-air heat pump.

The efficiency of a reversible air conditioning system is measured using two main indicators: SCOP (seasonal coefficient of performance for heating) and SEER (seasonal energy efficiency ratio for cooling). The higher these values, the more energy-efficient the unit. For example, an A+++ rated air conditioner has a SCOP greater than 5.1 and a SEER greater than 8.5.

This energy saving, coupled with the use of a renewable and free energy source—air—makes reversible air conditioning an ecological and economically advantageous solution for your daily thermal comfort.

How reversible air conditioning works

Reversible air conditioning works on an ingenious physical principle that allows you to adjust the temperature of your home according to the season. Unlike traditional heating or cooling systems, this versatile system changes the direction of the heat flow to meet your needs throughout the year.

Principle of reversibility

A reversible air conditioning system is essentially a heat pump capable of reversing its cycle. It operates using a closed circuit containing a refrigerant that changes state (liquid/gas) to transport thermal energy. This system comprises four essential components:

• A compressor that pressurizes the refrigerant
• A condenser where the fluid liquefies, releasing heat
• A pressure reducer that reduces the pressure of the liquid
• An evaporator where the fluid evaporates by absorbing heat

The key component that enables reversibility is the cycle reversal valve, also known as a 4-way valve. This device changes the direction of refrigerant flow, thereby transforming the condenser into an evaporator and vice versa. As a result, the indoor unit can either heat or cool the living space, depending on the need.

Differences between summer and winter

In air conditioning mode (summer), the system extracts heat from the interior and releases it outside. The refrigerant absorbs heat from the indoor air at the evaporator (indoor unit) and then releases it outside via the condenser (outdoor unit).

In contrast, in heating mode (winter), the process is reversed. The outdoor unit captures the calories present in the outside air—even in cold weather—and transfers them indoors. Thus, the condenser becomes the indoor unit that distributes heat throughout your home, while the evaporator becomes the outdoor unit that draws thermal energy.

Interestingly, reversible air conditioning can operate effectively even when outdoor temperatures drop to -15°C, although its efficiency gradually decreases below -7°C. At these extreme temperatures, some models automatically activate an auxiliary electric heater to maintain thermal comfort.

In addition, modern systems incorporate a defrost function that prevents ice from forming on the outdoor unit during cold periods, ensuring optimal operation in all circumstances.

Energy consumption by season

The energy efficiency of a reversible air conditioning system varies considerably depending on the season and outdoor conditions. This efficiency is measured by two main indicators: the COP (Coefficient of Performance) for heating and the EER (Energy Efficiency Ratio) for cooling.

In heating mode, a reversible air conditioner generally offers a COP of between 3 and 5. This means that for every 1 kWh of electricity consumed, the device produces between 3 and 5 kWh of heat. This exceptional efficiency is due to the fact that the device does not generate heat directly, but transfers it from the outside air.

During the summer, in cooling mode, the EER typically ranges between 2.5 and 4, meaning that the unit produces 2.5 to 4 times more cooling than the electrical energy consumed.

However, these performances vary depending on climatic conditions. When outdoor temperatures are extreme (very low in winter or very high in summer), efficiency decreases because the device must work harder to maintain the desired temperature.

Systems equipped with inverter technology further optimize this consumption. Instead of operating in an all-or-nothing mode, they continuously adapt their power to actual needs, enabling additional energy savings of up to 30% compared to traditional models.

Finally, it is important to note that the average annual consumption of a reversible air conditioning system for a 100m² house is between 500 and 1000 kWh for summer cooling, and between 2500 and 4500 kWh for winter heating, depending on the insulation of the building and usage habits.

Models available on the market

Today's reversible air conditioning market offers a wide variety of models suited to all needs and home configurations. Each system has specific characteristics that make it more or less suitable depending on your project and constraints.

Reversible air conditioning without outdoor unit

Monobloc air conditioning without an outdoor unit is an ideal solution for urban apartments or buildings where it is impossible to install an external unit. This compact system works in a similar way to other reversible air conditioners, but all its components are housed in a single unit placed inside the home, on a wall in contact with the outside. Two holes in the wall allow hot air to be expelled and outside air to be drawn in.

However, the absence of an outdoor unit has an impact on performance: these models are generally less powerful and noisier than traditional split systems. Their price ranges from $500 to $3,000, including installation.

Monosplit et multisplit

The monosplit system consists of a single outdoor unit connected to a single indoor unit. This solution is ideal for cooling a single room such as a living room or bedroom. 

On the other hand, multisplit systems allow several indoor units (up to 5) to be connected to a single outdoor unit. This system is particularly suitable when you want to air condition several rooms without increasing the number of outdoor units. 

Ductable and cassette

The ducted air conditioner is installed in the attic or a false ceiling. Air is distributed via a network of ducts to discreet grilles in the ceiling. Only these grilles are visible, making ducted air conditioning the most aesthetically pleasing solution. 

The cassette, meanwhile, fits into the ceiling and distributes air in four directions. It is particularly suitable for offices and commercial premises. There are two main formats: 4-way 600x600 and 900x900 cassettes.

Inverter models

Inverter technology is now featured in most reversible air conditioners. Unlike traditional models that operate on an "all or nothing" basis, inverter air conditioners continuously adjust their power output to actual needs. The compressor never stops completely but operates at variable speeds.

This intelligent control system allows the desired temperature to be reached more quickly and maintained at a stable level, without the unpleasant fluctuations associated with conventional systems. Inverter models consume up to 30% less energy and offer a longer compressor life thanks to reduced start/stop cycles.

Although more expensive to purchase (approximately 10 to 20% more expensive), these devices offer significant savings in the long term while ensuring optimal thermal comfort.

Installation and maintenance of reversible air conditioning

To ensure the performance and longevity of your reversible air conditioning system, professional installation and regular maintenance are essential. These two factors determine not only the energy efficiency of your unit, but also the quality of the air you breathe every day.

Installation by an RGE-certified professional

It is strongly recommended that you use a certified RGE (Reconnu Garant de l'Environnement) professional to install your reversible air conditioning system. This label guarantees that the installer has the necessary skills to handle refrigerant, which is potentially harmful to the environment. In addition to the mandatory certificate of competence for handling fluids, the professional must have ten-year insurance that protects you for 10 years against any damage related to the work.

Regular filter maintenance

Filters are the most important component to maintain regularly. During periods of intensive use, they should be cleaned at least twice a month. The process is simple: after turning off the power supply, remove the filters, vacuum them to remove dust, then wash them with soapy water. Make sure they are completely dry before replacing them in the appliance.

Also remember to clean the condensate tray to prevent water stagnation, which promotes bacterial growth.

Risks associated with poor maintenance

A poorly maintained air conditioner poses many risks. First, it can lose up to 50% of its efficiency and consume up to 30% more electricity.

In terms of health, the consequences are potentially serious. A dirty air conditioner promotes the development of Legionnaires' disease, a respiratory illness that can sometimes be fatal. The accumulation of bacteria, mold, and allergens in filters can also cause allergies, asthma attacks, and respiratory irritation.

In addition, neglected maintenance can lead to noise pollution, unpleasant odors, and environmental risks in the event of a leak of refrigerant, a powerful greenhouse gas.

How much does a reversible air conditioning system cost?

Investing in a reversible air conditioning system represents a significant budget item that should be carefully analyzed. According to industry experts, the total cost depends on several factors, including the type of unit, the area to be cooled, and the complexity of the installation.

Price according to model type

The purchase price of a reversible air conditioning system varies considerably depending on the technology chosen:

• Mobile monobloc air conditioning: $350 to $1,200, ideal as a backup solution
• Fixed monobloc air conditioning: $1,000 to $3,000, for small spaces
• Single-split air conditioning: $1,600 to $3,600 for a single room
• Multi-split air conditioning: €3,000 to €6,000 for two indoor units, suitable for multi-room homes
• Ducted air conditioning: between €100 and €200 per square meter, or approximately €10,000 for a 100-square-meter space.

For a standard 75 m² apartment, you should budget around €5,700 on average, while a 120 m² house will require nearly €9,300, including installation.

Installation cost

Installation represents a significant portion of the overall budget. This cost varies depending on the complexity of the project and the number of units to be installed:

• Installation of a single split system: $700 to $1,000
• Installation of a multi-split system: $1,000 to $2,200
• Installation of a reversible heat pump air conditioning system: €2,000 to €3,000

In addition, additional costs may apply depending on the configuration of your home: specific drilling, upgrading the electrical panel to current standards (€500 to €1,000), or installing a lift pump (approximately €150).

Summary of the advantages of reversible air conditioning

Reversible air conditioning is undoubtedly an effective solution for ensuring thermal comfort throughout the year. Thanks to its ingenious principle based on heat pump technology, this equipment provides both heating and cooling with a single device.

Admittedly, the initial investment may seem substantial, ranging from €2,000 for a simple model to €18,000 for a complete installation in a large house. However, the long-term energy savings more than justify this expense. For every kilowatt-hour of electricity consumed, your system produces between 3 and 5 kWh of heat, which significantly reduces your energy bill.

Furthermore, choosing the right model for your home is crucial. Whether you opt for a single split, multi-split, ducted, or cassette system, the key is to size the installation correctly according to your specific needs. In this regard, calling on a certified RGE professional is essential, especially since this certification gives you access to certain financial assistance programs.

Regular maintenance, although sometimes neglected, remains essential to ensuring the longevity and efficiency of your air conditioning system. Cleaning the filters every two months and having annual maintenance carried out by a qualified technician will not only prevent costly breakdowns but also potential health risks.

Beyond the economic aspects, reversible air conditioning is also part of an ecological approach. Contrary to popular belief, these modern systems use air, a natural and renewable resource, as their main source of energy. In addition, the Inverter technology found on most recent models further optimizes consumption by continuously adapting power to actual needs.

Finally, even if not all regions offer the same financial assistance, CEE subsidies can reduce your initial investment. In the long term, improved thermal comfort, lower energy bills, and increased property value make reversible air conditioning a wise choice for your home.