Heating with Air Conditioning Saves on Cost and Can Cut CO2
From Japan to China and the US to Scandinavia, heating with air conditioning has long been standard practice.
From Japan to China and the US to Scandinavia, heating with air conditioning has long been standard practice. But now warming homes with AC is catching on in other parts of the world.It's a sweltering summer afternoon. You step indoors, switch on the air conditioner, and within minutes the air begins to cool. What's happening behind that familiar hum is not the creation of cold, but the movement of heat.
In summer, heat is absorbed from indoor air and released outside via a refrigerant loop. But in winter most AC systems can run in reverse, extracting heat from the outdoor air and distributing it indoors to warm the space.
Also Read | Rahul Vaidya Reveals Ajit Pawar's Favourite Songs in Emotional Tribute After Deputy CM's Tragic Demise.
Now air conditioning systems and heat pumps for heating are becoming increasingly popular worldwide.
Some 2.3 million new heat pumps were installed in Europe in 2024, with 40% of these made up of air conditioning systems that can both cool and heat (air-to-air heat pumps), according to a European Heat Pump Association (EHPA) report.
Around 10% of building space worldwide is heated with AC systems and other heat pumps. According to forecasts by the International Energy Agency (IEA), this figure will rise to around 20% by 2030 and over 40% by 2050.
Air conditioners heat faster and cheaper than gas
Heat pumps and AC systems primarily use environmental heat from the surrounding area. This makes heating with them particularly efficient and inexpensive. And when powered by low-carbon electricity, they're also significantly more climate-friendly than fossil-fuel heating.
Most devices draw heat from outside air. However, warm exhaust from buildings, factories and data centers, as well as heat from rivers, groundwater, wastewater and soil, can also be harnessed.
As the technology has improved, air conditioners and heat pumps have become much more efficient. In relatively temperate climates such as Germany, modern systems now generate more than five kilowatt hours (kWh) of heat per kWh of electricity annually. That means they're around a third cheaper than heating with gas.
In warmer regions, higher outside temperatures allow AC units to heat more efficiently. In southern Europe, good air conditioners often deliver more than six kWh of heat per kWh of electricity on average over a year.
In Spain and Portugal, those using these systems can cut costs by about two-thirds compared with gas heating. This is helped by comparatively low electricity prices, with households paying around €0.25 ($0.29) per kilowatt-hour.
Special air conditioners can also operate in temperatures as low as minus 30 degrees Celsius (minus 22 degrees Fahrenheit). About 60% of buildings are heated this way in Norway, 40% in Finland and 25% in Sweden.
Oil and gas heating is rare in Scandinavian countries. In Norway, fossil fuel heating systems have been restricted since 2020 as part of efforts to reduce emissions.
Fewer emissions and direct heat
Heating with air conditioning systems is usually cheaper than oil, gas or electric resistance heating. Unlike coal and wood heaters, which emit soot and nitrogen oxides, AC systems produce no local air pollution and are particularly climate-friendly when run on renewable electricity.
Not all systems work the same way. In Central Europe, air-to-water heat pumps are more common. They heat water first, which is then sent through radiators or underfloor heating. This extra step makes them less efficient than air conditioners that warm the air in a room directly.
Air conditioning systems can significantly reduce oil and gas consumption
Climate change and rising temperatures are also driving up demand. According to the IEA, more than 140 million air conditioning units were sold worldwide in 2024. A simple unit in Germany costs between €1000 and €2000.
At the same time, more consumers are purchasing the systems for heating, primarily to save money.
New buildings can now do without water-based heating systems, removing the need for laying pipes and installing radiators. For well-insulated buildings that can be heated easily with air conditioning, this lowers both construction and long-term energy costs.
Air conditioning systems can also be used to heat older buildings, either fully replacing gas, coal and oil systems or operating alongside them to reduce their fuel use.
Because air conditioners heat using warm air, a room warms up within minutes, reducing the need for continuous operation. However, the airflow can feel uncomfortable, especially in very cold rooms. Modern systems address this with sensors that detect occupants and automatically reduce airflow.
Good information helps with installation
Air conditioning systems usually include an outdoor unit that can supply up to five indoor units with cooling and heating.
The outdoor units are often mounted on facades facing the street. However, it is more visually appealing to mount them on the back of the house, in the backyard or on the roof.
Compact air conditioners do not require an outdoor unit and need only two holes in the outer wall for air exchange.
Installing an air conditioning system and selecting the right technology for a building requires careful planning. Books, online resources, experienced neighbours, energy labels, consultants and specialist companies can help inform the decision and to compare costs with a heat pump, which can also cool.
This article was originally written in German
(The above story first appeared on LatestLY on Jan 29, 2026 03:10 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).