Is the traditional heat pump a viable alternative to the HR boiler? Because the UK does not want to become dependent on foreign gas, buildings and houses must be heated in a different way. Climate change is also mentioned as an argument to stop gas and switch to a heat pump. A lot of things and figures about this subject are confusing. This makes it difficult to weigh up the facts and the reality of today. After all, a heat pump costs a lot of money and results in some renovations in your house. Moreover, a heat pump requires quite a lot of electricity. What is the influence of this on the environment and climate? Is it true that a heat pump is better than a HR boiler? In short, there are still plenty of questions about the miracle device. Let’s take a closer look at the heat pump.
What is a heat pump?
A heat pump is a reversed refrigerator system. A refrigerant (F gas) absorbs heat from the air, soil or water. This gas is then pressurised, making it liquid and hot, up to around 40 to 55 ° C, depending on the efficiency. This temperature is great to use for underfloor heating or low temperature radiators. The heat pump looks like a boiler. The heated refrigerant is brought in from outside through pipes, where the heat is transferred to the central heating water or a boiler.
The power consumption of the heat pump
A heat pump uses quite a lot of power to pressurise tubing and transport to the coolant. In many cases, the power consumption of households will double. For a 2-persons household, for example, the current electricity consumption is around 2,700 kWh. A heat pump needs about as much to work. Exactly how much a heat pump consumes electricity depends on many things. If the heat pump is installed correctly, the house is well insulated, what is the highest achievable yield, how large your house is and how much heat you need, are different factors to take into consideration. As a result, the actual consumption can always be higher or lower. The high power consumption of heat pumps has consequences for the power supply. A double amount of electricity must be transported through the country. This requires, for example, additional power cables that many people do not want to have in their backyards. This can cost billions, which ordinary people have to pay in taxes.
CO2 emissions: does the heat pump help with climate change?
The heat pump is often mentioned as the savior of climate change. CO2 is released during the combustion of gas. By living gas-free and purchasing a heat pump, you would therefore contribute to climate change. To what extent is this correct? What many people don’t know is that heat pumps also need fossil fuels to function. This is because a heat pump uses electricity, which for the most part (80%) currently comes from power stations that mainly use coal and gas. A small part of the electricity production comes from sustainable sources such as solar panels and wind turbines. Windmills and solar panels will be installed, but the share of renewable energy will not increase rapidly due to doubling the energy consumption. While we are encouraged to get rid of the gas, we cannot do without gas (or other fossil fuels) to produce enough electricity for the heat pump! During the production and combustion of gas, approximately 2.2 kg of CO2 per cubic meter is released (source). CO2 production is also emitted. During production, the electricity from our socket has emitted just over 65 grams of CO2 per kilowatt hour. The CO2 released during the production and installation of wind turbines and solar panels is included in this; the large amount of CO2 that is released during the incineration of biomass (waste and wood residues) is not included in the official figures.
How much does a heat pump save?
If you want to compare a heat pump with an HR boiler, you have to compare them fairly. Unfortunately that does not happen in practice. In most houses, high-efficiency boilers do not work at all as they should. As a result, they use 10-30% more gas than they actually need. In addition, many people have not yet applied radiator foil and other simple measures to make their central heating system work optimally. The national gas consumption is therefore actually higher than it should be. Nonetheless, organisations use the figures of this gas consumption from reality to compare them with heat pumps. The power consumption of the heat pump corresponds to a correctly installed and optimally functioning device.
Are refrigerants bad for the climate and the environment?
Heat pumps work with refrigerants. These refrigerants are also located in air conditioners, refrigerators and freezers. In the past, so-called CFCs, chlorofluorocarbons, were used for this. These were refrigerants that later became known to attack the ozone layer. A ban came on that. As a successor to the CFCs, the industry invented a new tool, namely HFCs (hydrofluorocarbons). These are made from petroleum and natural gas. Hydrocarbons are made in oil refineries where CO2 is released when pollution occurs. These substances are poorly biodegradable. Anyone who has a heat pump is therefore actually dependent on the chemical industry, which causes environmental pollution worldwide and makes a major contribution to global CO2 emissions. It is not known how much CO2 is released during the production of refrigerants. The effect on the environment if these substances end up in large sizes is also unknown.
Is the heat pump warming up the earth?
It is clear, however, that HFC gases are very bad for global warming. HFCs are generally 250 to 15,000 times stronger than CO2 and remain in the atmosphere for thousands of years. The HFC gases used in heat pumps (such as R-134A) are often 1000 to 4000 times stronger than CO2 per kilo. This is called the Global Warming Potential (GWP). How many kilos of refrigerant a heat pump contains depends on the capacity and length of the pipe through which the fluid flows. Low-heat heat pumps, suitable for a well-insulated terraced house, have around 1 to 3 kg of refrigerant. Suppose a heat pump needs 2 kg of refrigerant that has a GWP of 2000. Then this is comparable to 4000 kg of CO2! As long as the gas remains trapped there is nothing to worry about, but as soon as it is released into the air you will largely lose the small saving compared to the HR boiler! That is why heat pumps must be installed properly so that the chance of leakage is as small as possible. The gas is bad for your health and you don’t want to have it in a tightly insulated house! Moreover, nothing has eternal life. The refrigerants will someday have to be processed. If it is 99% pure, it can be reprocessed into a fully-fledged refrigerant. That also costs energy and CO2 emissions, but how much is unknown. Refrigerant that cannot be reused enters the incinerator and ends up in the air, partially or completely.