Air conditioning and other heat sources for heating single-family houses

Is it worth heating your home with air conditioning? Electricity prices, like other heat carriers, have increased significantly in 2023. So what does home heating look like? heat pump air-to-air? See a comparison of expenses in buildings with different heat energy requirements that are heated in different ways.

Annual heating expenses in 2023 can give any property owner a headache. More and more people are looking for solutions that will contribute to savings in this field. In any case, the reduction of heating costs without having to give up thermal comfort is associated with the need for investment. On the one hand, it is possible to reduce the building's demand for thermal energy through systemic insulation of the building and replacement of woodwork. On the other hand, it is worth considering changing the heating system. The best results are achieved by combining both investments.

The building is not equal to the building

The buildings differ in the technology used in construction, materials used for erecting the structure, as well as woodwork and insulation, which can be reduced to the degree of insulation of the building. From the point of view of the annual demand for thermal energy, 5 categories of buildings can be distinguished, as presented in the table below.

Tab. 1 Annual demand of buildings for thermal energy per 1 m2, taking into account the degree of insulation (in kWh/m2/year).

The table above shows how huge are the differences in the demand for thermal energy of houses with different insulation. These differences become even more pronounced when we assign the demand to buildings of different sizes.

Tab.2 Demand for thermal energy in buildings of various sizes (kWh/year). 

The degree of insulation of the house and the area that needs to be heated directly affects the amount of expenses related to heating. It is worth noting that a small house with an area of ​​100m2, which is not insulated, will generate twice as much heating costs as a large low-energy house with an area of ​​2m200. Low-energy buildings are a relative novelty in the domestic landscape. Most Polish houses are built in traditional technology. It is worth emphasizing, however, that in order to save heat energy, it is not necessary to build a new passive house right away - a well-insulated building will generate 2 times lower heating costs than a building without insulation.  

Heating buildings with different heat sources - comparison of heating costs

Coal

Until recently, it was said that Poland stands for coal. At the same time, black gold was the cheapest raw material used to heat houses. No wonder that most of the older buildings are heated with traditional coal boilers. However, black gold is getting more expensive every year. What's more, extraction in Polish mines is systematically decreasing, which are unable to meet the needs of industry and private individuals. Until 2022, the situation was saved by coal imports, but due to restrictions on imports of raw material from Russia, owners of coal-fired houses faced the risk of not having access to the raw material or buying it at exorbitant prices, as a result of which heating with coal became 3,5 times more expensive than in previous years. 

How much will it cost to heat houses with coal in 2023? Black gold has a relatively low calorific value - it gives about 8 kWh of heat from 1 kilogram of raw material. At the same time, the price for obtaining 1 kWh for hard coal of the walnut type is approx. PLN 0,3 and PLN 0,44 for eco-pea coal. The low efficiency of coal firing is also affected by boilers that generate relatively low efficiency - 60% for hard coal and 85% for eco-pea coal. As a result, this gives the cost of obtaining 1kWh in the amount of PLN 0,5/1kWh for nut type coal and PLN 0,52/1kWh for eco-pea coal. 

So how much will it cost to heat houses with coal in 2023? Owners of a small house with an area of ​​100 m2, which does not have thermal insulation, in order to achieve thermal comfort, must take into account the annual heating costs of PLN 7.500 (when heating with walnut coal) and PLN 7800 when heating with eco-pea coal. In the case of an uninsulated house with an area of ​​200 m2, these expenses increase dramatically to PLN 15000 (walnut) and PLN 15600 (eco-pea coal). What are the costs of heating a house with coal at different levels of insulation? Refer to the table below.

Tab.3 Estimated house heating expenses (in PLN) broken down by building area and degree of insulation.

Gas

Not only coal has become more expensive over the last year - gas prices have also increased significantly - both natural and propane-butane. As a result, heating with these fuels has also become much more expensive. However, this jump is not as drastic as in the case of coal. Currently, you have to pay PLN 1 for 0,32 kWh of natural gas, and PLN 0,10 for LPG. With the efficiency of natural gas boilers of 105%, you have to pay about PLN 0,30/1 kWh for heating with this raw material. In the case of liquefied gas boilers, the price for 1 kWh is PLN 0,10. 

How much do you have to pay annually when heating your house with natural gas and LPG? You will spend the most when you have a large house with an area of ​​200m2, which is not insulated and heated with natural gas - PLN 9.000. On the other hand, you will pay the least if you have a small low-energy house with an area of ​​100m2 heated with liquefied gas - only PLN 400. 

Tab.4 Estimated annual costs (in PLN) of heating a house with liquefied petroleum gas and natural gas, taking into account the area of ​​the building and the degree of its insulation. 

Heating oil and electric heating

For years, one of the most expensive raw materials used to heat buildings has been fuel oil. This has not changed in 2023. Currently, the cost of obtaining 1 kWh from an oil boiler is approx. PLN 0,68. It is no different in the case of electricity. Currently, the cost of generating 1 kWh of heat is PLN 0,80 for consumption up to 2000 kWh per year and PLN 1,24 for consumption exceeding 2000 kWh. It is worth noting that in the case of electric heating, each building to be heated (even the smallest and low-energy one) will exceed the threshold of 2000 kWh. 

What are the charges for electric and oil heating in houses of various sizes and with varying degrees of insulation? 

Tab.5 Estimated annual costs (in PLN) of heating a house with fuel oil and electricity, taking into account the building area and the degree of its insulation. 

Air conditioning

Poles increasingly often use air conditioning systems to heat their homes, or in other words, air-to-air pumps. Good quality devices are very energy-efficient, and their heating efficiency is often over 500% (for example for Toshiba air conditioner Daiseikai 9 SCOP is 5,2, which is 520% ​​efficient). What does air conditioning efficiency mean? It is the result of energy extraction from electricity and air - i.e. an air-to-air heat pump extracts 1 kWh of electricity, converts it to 1 kWh of heat and additionally produces 5,2 kWh of heat from the air. As a result, you pay for 1 kWh of electricity and receive 5,2 kWh of heat. This makes air conditioning an extremely efficient heat source. 

How will the annual expenses for heating with air conditioners be distributed?

Tab. 6 Estimated annual costs (in PLN) of heating a house with air conditioning, taking into account the area of ​​the building and the degree of its insulation. 

It is worth noting that the settlement includes the SCOP parameter, which is the seasonal coefficient of the air conditioner's efficiency in heating mode. It takes into account the fluctuations of the external temperature, which also means lower efficiency of the device in the event of a decrease in temperature. Importantly, modern, good-quality air conditioners dedicated to the temperate zone (mostly Poland is one of them, excluding mountainous and north-eastern areas) work efficiently down to an outdoor air temperature of -15 degrees Celsius. This means that they can be successfully used not only in the transitional season - autumn and spring, but also on most days in winter. 

Air conditioning - one of the most economical sources of heat

Let's summarize the previous considerations and calculations. Currently, air-conditioning is second only to liquefied gas in terms of the price for heating. Prices of liquefied propane-butane gas for heating purposes allow you to heat a standard, well-insulated house with an area of ​​140 m2 for less than PLN 1000 per year. However, as experts say, the situation with this raw material is dynamic and prices may start to rise quickly (if only because of the release of prices temporarily frozen by the government). What's more, when preparing for the heating season, you have to refuel the tank for the coming months by spending more cash at once.

A more stable solution in terms of price is air conditioning. Currently, for heating a well-insulated house with an area of ​​140 m2, you have to pay less than PLN 2000 per year (this price takes into account the user's consumption exceeding 2000 kWh per year). This year's scale of increases and the progressive increase in the share of energy from renewable energy sources in Poland's energy mix suggests that electricity increases will not be so drastic. It is also worth noting that the amount of PLN 2000 for heating with air conditioning is divided into monthly installments, so it is less annoying than a one-time purchase of gas (or other heating material). 

In terms of price and comfort, air conditioning is significantly ahead of other heating materials. It is not only cheaper than traditionally the most expensive heating with electricity (PLN 9500) and fuel oil (PLN 5700), but also natural gas (PLN 2500) and even coal, considered the cheapest heating material (walnut coal - PLN 4200 and eco-pea coal - PLN 4370). 

What's more, air conditioning is easy to install - its installation does not require a major renovation. It is often treated by users as an alternative source of heating, which in a way has become an additional advantage of the system in addition to the traditionally used cooling. 

Air conditioning - savings and comfort of use

The use of air conditioning to heat rooms is very beneficial in economic terms. In addition, it is rare that an economic option also provides other benefits that are not available with more expensive alternatives. Air conditioning in terms of heating is zero-emission, thanks to which it helps to protect the natural environment. This is particularly evident when the air-to-air heat pump is powered by electricity from renewable energy sources (e.g. photovoltaics). It is also worth emphasizing that renewable sources are becoming more and more important in the energy mix in Poland, which sometimes provide ⅓ of energy in the public power grid. 

Energy efficiency and eco-friendliness of air-conditioning systems are not the only benefits that the user obtains. Air conditioning, both during heating and cooling, thanks to the filter system, effectively cleans the air of pollutants such as allergens (pollen, dust, mold spores), viruses, bacteria, as well as unpleasant odors. A good air conditioner also guarantees even air distribution, thanks to which the temperature is the same in every part of the room. Air conditioning can also quickly (unlike underfloor heating or radiators) heat the room. Controlling the system is intuitive and extremely simple. It also does not require the supply of fuel to the tanks (which is necessary in the case of coal, pellets, as well as oil or liquefied gas). What's more, it allows you to maintain a constant set temperature, also when you are on holidays or holidays, while consuming minimal energy. 

Let's get back to the controls. Modern air conditioning can be controlled not only with a remote control, but also with Wi-Fi modules. This means that you can manage its work from anywhere in the world with Internet access.