Disadvantage of Heat Pump Water Heater

Heat pump water heaters are becoming more and more successful. However, they are not necessarily the right choice for every situation. Here's a "true or false" to give you an idea of the downsides typically associated with this type of heating.

1. Installing a heat pump is expensive

Real. They cost significantly more than gas-fired units. However, grants can be used to reduce purchase costs, which is not the case for gas-fired units. However, even with such subsidies, heat pumps are still at least 20% more expensive.

On the other hand, a heat pump pays for itself over its life cycle due to its low operating costs. Especially when combined with solar panels. When investing, the bills are indeed higher.

Not suitable for every family

Real. If your home is poorly insulated and on a budget, start with insulation and forget about heat pumps for now. Doing this, even your old heater will give you some satisfaction by consuming less. The money you save will help you fund your heat pump installation in the future.

2. Heat pumps end up being more expensive because electricity is more expensive than natural gas

Mistake. Indeed, electricity (about 0.25 EUR/kWh) costs more than natural gas (about 0.06 EUR/kWh). However, at the end of the day, the difference disappears because the heat pump pays off 3 times more than the gas boiler:

When a boiler consumes 1 kWh of gas, it provides about 0.95 kWh of heat if its output is 95%.

When a heat pump consumes 1 kWh of electricity, it provides about 3 kWh of heat (less if it is cold).

Where does this difference come from? Heat pumps extract the sun's free heat from the environment (water, air, soil). A heat pump uses 3 times the energy of an air pump to generate the same amount of heat.

Consume more gray (hidden) energy

True and false. To generate the electricity required for heat pumps, thermal power stations consume approximately 2.5 to 3 times as much primary fossil energy (natural gas, gasoline, coal) as the primary energy source. In this case, electricity ends up producing more pollution than natural gas or gasoline.

However, there are two good news:

1. Increasing use of solar or wind or other renewable energy sources, as well as nuclear energy that does not produce CO2, to generate electricity

The basic principle of a heat pump is to generate the same amount of heat as a boiler, it consumes about 3 times less energy. This more or less compensates for the fossil energy consumed to generate electricity.

You can also limit your heat pump's power consumption by applying these tips.

2. Production drops in cold weather

Real. More precisely, it's the "coefficient of performance" that drops. 3 on average: 1 kWh of electricity is consumed for every 3 kWh of heat produced.

The colder the weather, the more the heat pump has to work, and therefore the more heat it consumes, in order to continue extracting heat from the increasingly colder source. This is an unavoidable fact of life.

If the outside temperature is between +°2C and -7°C, the power consumption will be doubled.

At temperatures below -20°C, heat pumps with air (air/water or air/air) exchangers cannot operate because the refrigerant they contain no longer evaporates. This is why the heat pump is equipped with an additional electric heater that takes over when the system cannot gather enough external energy to heat the water to the desired temperature.

However, it is important to put the problem in perspective:

The average annual temperature is 9.8°C (7.5°C in Hautes Fagnes and 11°C in Campine). This means that the heat pump operates under optimal conditions for most of the year.

Depending on the region, the lowest figures vary between -10 and -15°C for a total of 2 to 12 days a year. In our temperate oceanic climate region, arctic periods are very rare and very brief. Less common in urban areas.

An optional space heater is enough to ensure basic comfort during the cold, and remains an interesting addition throughout the season, such as a wood/pellet stove.

My electricity bill will double

Sometimes true. However, gas bills will be lower. Also, maintenance is cheaper. If you have solar panels, you can at least compensate for some extra consumption.

1. The radiator needs to be replaced

TRUE if you are replacing the boiler with a heat pump. In practice, this operates at lower temperatures (25 to 28°C compared to 45-55°C for gas condensing boilers) and requires a larger exchange surface.

Having said that, replacing boilers with heat pumps is not ideal with existing central heating.

2. Installation of heat pump during renovation: impossible

Mistake. This is usually possible as long as the house is well insulated and sealed (ventilated!). However, in this case it is not possible to use all types of heat pumps.

Floor or wall heating can be envisaged as a perfect complement to a heat pump when undertaking major renovations.

3. Heat pumps in apartments: impossible

Mistake. You just need to pay attention to some peculiarities of the situation to choose the most suitable solution.

4. The heat pump is noisy

Real. At least outdoors, this could annoy you or disturb your neighbors. This is the same annoying noise as an external unit in an air conditioning system.

5. This does not apply indoors: heat pump air/air (injected hot air) is no more noisy than mechanical ventilation.

Hope you fully understand its disadvantages when purchasing a heat pump water heater. Of course, heat pumps are still an excellent choice in many places. If you need to buy. Please contact us. We will provide you with free professional advice.