Is heating with air conditioning cheaper than gas?

What is in a cubic metre of gas

For energy tax, the law works with gas at 35.17 megajoules per cubic metre (Article 59, Wet belastingen op milieugrondslag, the Dutch environmental taxes act). One kWh is 3.6 megajoules, so a cubic metre of gas holds about 9.8 kWh of energy. No central heating boiler gets more heat out of it than that, and in practice a little less. So by using that 9.8 kWh, the sums below are generously in favour of gas.

What an air conditioner makes from a kWh of electricity

An air conditioner takes heat from the outside air and brings it indoors. How many kWh of heat it makes from 1 kWh of electricity, on average over a heating season, is called the SCOP. The energy label gives it for an average European climate. Under the European rules, an air conditioner with an A++ label for heating has a SCOP of at least 4.6.

Milieu Centraal, the Dutch environmental advice centre, recommends choosing an air conditioner with an A++ energy label or higher if you want to heat with it. A less efficient air conditioner uses a lot of electricity for heating.

How much electricity it takes to make the heat in a cubic metre of gas

Divide 9.8 kWh by the SCOP of the air conditioner. That tells you how much electricity it needs to make the heat in a cubic metre of gas, and so at what ratio between your rates it becomes cheaper.

On average, a cubic metre of gas cost more than five times as much as a kWh of electricity in September 2026 (CBS, Statistics Netherlands: supply rate plus energy tax, including VAT).

Do the sum with your own contract: divide your price per cubic metre of gas by your price per kWh of electricity, both including taxes and VAT.

When the advantage gets smaller

The sum is based on an average heating season. On some days and in some homes, it works out less well:

• when it freezes hard: the colder the outside air, the less heat the air conditioner delivers. In frost and damp weather, the outdoor unit defrosts now and then, and heating stops for 5 to 15 minutes
• when you want to heat more rooms: an air conditioner only heats the room with the indoor unit in it, and a multi split with several indoor units on one outdoor unit is less efficient
• when your rates change: if electricity gets more expensive or gas gets cheaper, the ratio drops

According to their manual, the Mitsubishi Heavy Industries SRK ZS wall-mounted units heat when it is between about minus 15 and plus 24 degrees outside. If it is colder still, the manufacturer recommends a second heat source.

That is what the unit can handle. We advise using the air conditioning as your main heating down to an outside temperature of about 0 degrees. When it gets colder outside, we advise additional heating. That does depend on how well your home is insulated and on the capacity of the installation.

What an air conditioner does not do

An air conditioner doesn't make hot water: you still need your central heating boiler for that. The warm air can also feel like a draught, unlike the warmth of a radiator. Using the air conditioning for extra heating does save gas, Milieu Centraal says.

If you'd like to know how heating with air conditioning works in practice, read Heating with air conditioning.