Skip to main content

Air conditioner running costs for heating your home

Changes in utility prices have led to more people wondering if they should be switching to alternative home heating solutions that have a reputation for high efficiency ratings and renewable energy usage. Switching from a traditional heating system to something more planet friendly like an air conditioner is a big decision so first it is important to consider all the facts and crunch some numbers.

Air conditioning vs. gas heating

Air conditioners are now being considered more for their heating ability and not only as a device for cooling. Gas heating uses combustion of non-renewable fossil fuels to heat water, which is then pumped to radiators around your home, whereas an air conditioner using primarily renewable heat energy, and consequently having a lower environmental impact. Modern air conditioners are known for being very energy efficient; Daikin has been developing and improving upon technical solutions such as inverter technology and systems to control the compressor, fan and expansion valve leading to further reduction in energy consumption.


Understanding heater efficiency

A new gas boiler is around 93% efficient. This means that for every unit of primary energy, in this case, natural gas, your boiler converts around 93% of it into heat. Over time efficiency goes down and a boiler over 10 years old may only have an efficiency of around 85%. This means your boiler needs to work harder and use more energy to create the same amount of heat and as a result will be costing you more to run.  

When it comes to air conditioners, SCOP and SEER ratings are used and can be found on the energy label to highlight the energy efficiency of the product.

  • SCOP is the Seasonal Coefficient of Performance. This is the ratio between the heat energy transferred into a room and the required power input. SCOP represents measured efficiency over an entire heating season (i.e. winter), to give a more realistic view of energy consumption due to changes in temperature and day to day use.
  • SEER is the Seasonal Energy Efficiency Ratio and is used as a rating for an air conditioner’s cooling ability, much like SCOP, representing cooling efficiency over the entire cooling season.
  • To understand what these numbers mean, an air conditioner with a SCOP of 4 will transfer around four times as much heat from the outside air into the house for every unit of electrical energy used. As with most rating systems, the higher the number, the greater the efficiency. When looking at air conditioners for heating, a rating of A+++ will have a SCOP greater than 5.10, while one with an A rating will have a SCOP between 3.40 and 4.00.

Here we consider using air conditioners for heating and look at some of the things that can affect air conditioner running costs to help you determine whether air conditioning really would be an economical and efficient alternative heating system for your home.


How much does air conditioning cost to run?

While efficiency ratings make comparing one air conditioner to another a relatively simple task,  answering the question ‘how much does an air conditioner cost to run?’ can be more difficult. A clearer way to understand costs is to compare the cost of running air conditioning to gas heating.


Based on average 2022 prices, the following table shows how much it would cost to replace a gas boiler with either a new boiler or a multi+ air conditioning system. If you have an old non-condensing boiler, then the savings are considerable if you install multi+ air conditioning, and you will continue to save on running costs every year. This is because newer, condensing gas boilers require a different chimney or flue gas system.  However, if you are replacing a condensing gas boiler then the initial investment for a multi+ system will be higher than for a new condensing boiler. The important consideration here is the ongoing running costs. For each subsequent year you will save significantly by using a multi+ air conditioner for heating, so it will eventually offset the original outlay and continue to save money.


Home Heating Appliance

Cost of unit & installation

(EUR, ex.VAT)

Running cost per year

(EUR, ex.VAT)

Total cost for first year

(EUR, ex.VAT)

Total cost for first 5 years

(EUR, ex.VAT)

Efficiency or SCOP

New condensing gas boiler (replacing a condensing boiler)






New condensing gas boiler (replacing a non-condensing boiler)






Multi+ air conditioning system







From the figures in this table, you can also compare the efficiency and SCOP rating of each type of heater, another indication of how it can save on your running costs. While a new condensing boiler will be around 93% efficient, converting 93% of the energy it uses into heat, a new multi+ air conditioning system as a SCOP rating of 4.63, so for each unit of energy used it will transfer over four times as much heat energy from the outside air into your home. 

What you need to consider when looking at air conditioner running costs

It is important to understand that the actual cost to install and run an air conditioner for heating will depend on many different factors which will vary for every person and every home.

  • The type of air conditioning unit you choose. Some air conditioners have higher energy efficiency ratings than others, but you also need to consider the features and functions that will be most beneficial to you and the comfort level you wish to achieve.
  • The size of the space to be heated. You need to choose an air conditioner that is a suitable size for your room. This is referred to as the air conditioner’s heating capacity. If an AC with has too high a capacity it is oversized, and while it may warm your room more quickly, it also uses more energy and cause larger oscillation of actual room temperature in comparison to the desired room temperature. On the other hand, an undersized AC might not heat up the room at all, so it is important to have the right size if you want it to be efficient.
  • The number of rooms you are heating. The more air conditioning units you install, the more they will cost to run. A multi-split system connects up to five indoor units to one outdoor unit, making it a more economical and efficient option if you need air conditioners in multiple locations. Another option is a multi+ system enabling you to connect up to three AC units and a hot water tank.
  • The temperature you want to achieve. Individual preferences vary, so if you like to keep your home at a balmy 25°C then your running costs will be considerably higher than if your thermostats are set to a cooler 20°C.
  • Where you live. The climate you live in will affect how often and how long the air conditioner runs in heating mode, as well as the amount of heat it needs to generate to maintain a comfortable temperature in your home. The type of home you live in can also have an effect. An apartment surrounded by other homes may require less heating than a single detached house.
  • The quality of your home insulation. A well-insulated home will help maintain the heat in your room so your AC unit doesn’t have to use so much energy. Keeping doors and windows closed will also help keep the warmth in.
  • Maintenance. Regular cleaning and annual services will ensure your air conditioner stays in top condition and running efficiently.

With energy costs at an all-time high and as we seek to more away from using fossil fuels for home heating, an air conditioning system is without doubt, a cost effective, planet friendly alternative to a traditional heating system.


For more information or to discuss your alternative heating options contact us. 

Not sure where to start? 

Let us help!

Complete the form today and one of our team of experts will be in touch with you to arrange a one-to-one customised consultation to discuss which heating, cooling or hot water system is best for your home and your needs.

Alternatively, take a look at our Home Solutions Hub to find out everything you need to know about heating, heating with air conditioners and heat pumps.

Find more information

Take a tour in our virtual showroom

Need help?

Read our news

Read our blog

Get inspired from references

Find more information

Need help?

Need help?