How much does it cost to heat your home with an air conditioner?

More and more people are choosing to heat their homes with an air conditioner—and for good reason. An air conditioner that also provides heating is significantly more energy-efficient than traditional options. In this blog, we discuss the costs of heating with an air conditioner and compare it to other heating methods. We also explain why combining an air conditioner with solar panels is a smart choice and provide practical tips for energy-efficient heating with an air conditioner.

Summary:

• Air conditioners heat quickly, are cheaper than gas heating, and also offer cooling in the summer.
• In winter, an air conditioner extracts heat from the outside air and blows it inside; in summer, it works in reverse to cool the space.
• Heating is done per room, so multiple units are needed to heat the entire home. Air conditioners generate some noise and can dry the air.
• Costs depend on electricity consumption, the type of air conditioner, electricity rates, and usage.
• Set a stable temperature and use the air conditioner continuously at low power for more efficient heating, clean the filters monthly, and ensure proper insulation.
• Using solar panels makes heating with an air conditioner more sustainable and cost-effective since you generate your own electricity.

How does heating with an air conditioner work?

An air conditioner, also known as an air-to-air heat pump, has both cooling and heating capabilities. Its principle is similar to that of a heat pump. Most air conditioning systems consist of an indoor and outdoor unit. The system works based on pressure differences: during expansion, pressure and temperature drop, allowing the refrigerant to absorb heat (cooling). During compression, pressure and temperature rise, releasing heat (heating). This principle enables efficient heat transfer, even at low outdoor temperatures.

Advantages of heating with an air conditioner

There are several advantages to heating with an air conditioner. An air conditioner heats a room relatively quickly. Furthermore, heating with an air conditioner is cheaper than heating with gas. Finally, when it’s hot outside, an air conditioner can also provide cooling indoors.

Disadvantages of heating with an air conditioner

There are also some downsides:
An air conditioner can only heat individual rooms, so multiple units are needed to heat an entire home.
Both an indoor and outdoor unit are required.
Air conditioners produce some noise during operation.
Heating with an air conditioner can dry out the air.

How much does heating with an air conditioner cost?

Heating with an air conditioner (also called a heat pump air conditioner) can be energy-efficient and cost-effective, depending on various factors. Below is an overview of cost calculation and the main factors that affect it.

Cost calculation example

Costs depend on electricity consumption and energy rates. A general formula is:

• Formula: Consumption (kWh) × Electricity Price (€/kWh) = Heating Cost per Hour

Example:

A 3.5 kW air conditioner is typically suitable for a 40 m² space. If the SCOP efficiency in heating mode is 4, the unit produces 4 kWh of heat for every 1 kWh of electricity consumed. With an electricity price of €0.40 per kWh, consumption is 0.875 kWh per hour, resulting in a cost of €0.35 per hour (approximately €63 per month or €378 per year). This makes air conditioning a relatively inexpensive heating option, provided you use it efficiently, only heat one room, and consider electricity costs.

Can my air conditioner heat my space?

When installing an air conditioner, it is important to ensure that the unit has sufficient power to heat the intended space. You can calculate whether the unit is suitable for your room.

Example of calculating air conditioner power

To choose the right air conditioner, consider the volume of the room. Use a multiplication factor of 50, representing the average heat loss per cubic meter in a well-insulated home.

For example, if the room volume is 40 m³ (length × width × height: 4.5 × 3.7 × 2.4 m), the calculation is:
40 m³ × 50 = 2000 W
This means you need an air conditioner with a capacity of 2000 W (2 kW) to heat the room efficiently.

What else do the costs depend on?

Air conditioning costs can vary depending on:

• Type of air conditioner: Split units are generally more energy-efficient than portable units.
• SCOP value: Higher SCOP means higher efficiency.
• Temperature setting: Each degree increase raises energy use by roughly 6%.
• Usage time: The longer the air conditioner runs, the higher the cost.
• Electricity rate: Dynamic pricing or solar energy can reduce costs.
• Maintenance: Clean filters improve performance and efficiency.

Combining air conditioning with solar panels

If you have solar panels, you can heat your home with an air conditioner. The unit extracts heat from outside air and transfers it indoors efficiently. Running the air conditioner on self-generated solar power allows sustainable and cost-effective heating.

Benefits of Heating with Solar-Powered Air Conditioning

Heating with solar-powered air conditioning has several advantages:

• Sustainable & Eco-Friendly: Reduces reliance on fossil fuels and lowers CO₂ emissions.
• Lower Energy Costs: Using solar power can significantly reduce long-term energy expenses.
• Efficient Heat Generation: Modern air conditioners with heat pump technology provide more heat than the electricity they consume (COP 3–5).
• Heating & Cooling in One: The same unit can cool in summer.
• Rapid Heating: Heats spaces faster than traditional gas radiators.

Tips for energy-efficient heating with an air conditioner

To maximize efficiency, follow these tips:

1. Maintain a Stable Temperature: Keep it between 18–21°C for optimal efficiency.
2. Continuous Heating: Keep the unit running at low power during cold days rather than turning it off and on.
3. Clean Filters: Clean filters at least once a month to maintain performance. Annual maintenance is also recommended.
4. Combine with Solar Panels: Use solar energy for sustainable, cost-effective heating.
5. Ensure Good Insulation: Proper insulation keeps heat in, and closing windows and doors improves efficiency.

Conclusion

Heating with an air conditioner is an efficient and often cost-effective way to heat your home, especially when combined with solar panels. Air conditioners work like air-to-air heat pumps, heating rooms quickly while lowering energy costs and providing cooling in summer. Downsides include noise during operation and the need for multiple units to heat multiple rooms. However, with smart settings and good insulation, you can maximize your air conditioner’s performance and heat your home sustainably.