Vaillant Group
Vaillant Group

Gas-condensing boiler technology

Modern gas-condensing boiler technology makes efficient and cost-aware heating possible. Gas-fired condensing boilers can be combined with technologies based on renewable energies to form hybrid systems. The Vaillant Group’s current generation of appliances can already be operated with a hydrogen content of up to 30 per cent. The Vaillant Group has received initial certification for a gas-fired condensing boiler that can be powered with pure hydrogen.

Why gas-condensing boiler technology is worthwhile

energy savings*

% increase of energy efficiency*

% fuel efficiency*

* compared with condensing boilers

The technology is proven, efficient and economical

High energy use combined with economical consumption is a decisive advantage of the proven gas-condensing boiler technology, which can be used both in new buildings and in energy-efficient renovation. Property owners can save heating costs and reduce CO2 emissions by replacing a non-condensing boiler with a gas-fired condensing boiler.

A long-term pillar of the heating market

In the EU, 70 per cent of heat generators currently use gas as an energy source. Gas technologies will likely retain their important role in the supply of energy to buildings in the longer term. Modern condensing boilers can already use mixed climate-neutral gases such as green hydrogen or biomethane as energy sources.

Modern gas-fired condensing boilers are ready for new challenges

Vaillant Group
Vaillant Group

In addition to natural gas from different supplier countries, bio-natural gas and other gases are also fed into the national supply networks. As a result, the quality of the gas can fluctuate. The new generation of devices from the Vaillant Group reacts automatically to fluctuating gas qualities. The IoniDetect gas-adaptive combustion control system automatically compensates for different gas qualities. This ensures safe and efficient system operation at all times.

Vaillant Group
Vaillant Group

Ready for use in hybrid heating systems

Gas-fired condensing boilers can be easily combined with technologies such as solar thermal energy and heat pumps. This offers ecological and economic benefits. Most gas-fired condensing boilers are already prepared ex works for operation in hybrid systems in which gas-fired condensing boilers and technologies based on renewable energies are used.

How gas-condensing boiler technology works

Modern condensing boilers use the heat stored in the exhaust air and are thus considerably more efficient than non-condensing boilers. This not only creates a warm home, but also directly benefits the environment.

When natural gas burns, heat is generated. During this process, the hydrogen contained in natural gas combines with the oxygen from the combustion air and becomes energy-rich steam. This steam disappears up the chimney in conventional heating systems, but a condensing boiler uses the energy potential of steam. The steam is cooled via a heat exchanger until it condenses back into liquid water. The use of the thermal energy of the steam makes gas-fired condensing boilers particularly efficient. Energy costs can be reduced by lower gas consumption, while the solution also contributes to a reduction in CO2 emissions.

Vaillant Group
Vaillant Group

Gas-condensing boiler technology with hydrogen supports decarbonisation

According to plans by the European Union, no more CO2 should be produced in the buildings sector by 2050. In addition to the increased use of heat pump technology, a partial or complete substitution of fossil gas with green gases is a possible solution in this regard. The Vaillant Group already uses the necessary technology as standard in existing series of appliances.

The latest generation of gas-fired condensing boilers can work with a hydrogen content of up to 30 per cent in the gas mixture. In the future, hydrogen in its pure form produced from renewable energies will also be able to play a role in the energy transition in the buildings sector and thus make a significant contribution to climate protection.

What potential does hydrogen have in gas-condensing boiler technology?

Hydrogen can reduce CO2 emissions during heat generation in the buildings sector. The prerequisite for this is the synthetic production of “green” hydrogen through electrolysis processes that use electricity from renewable sources. Hydrogen can be used to heat real estate in two ways: in its pure form, which leads to a complete avoidance of CO2 emissions, or as an admixture to conventional natural gas – this can also significantly reduce greenhouse gas emissions.

Green, blue, grey – how is hydrogen produced?

There are three methods of producing hydrogen in large quantities – only one of which is completely emission-free.

Vaillant Group
Vaillant Group

“Green” hydrogen

Produced by the electrolysis of water. If only electricity from renewable sources is used in the process, the hydrogen produced is considered “green”, i.e. completely emission-free.

Vaillant Group
Vaillant Group

“Blue” hydrogen

Produced with carbon splitting from fossil fuels. “Blue” hydrogen is not completely emission-free, but is often considered CO2-neutral because the carbon dioxide does not enter the atmosphere, and instead is stored in tanks and underground caves.

Vaillant Group
Vaillant Group

“Grey” hydrogen

It is also extracted from fossil fuels, via a process called methane pyrolysis. The resulting CO2 is released unused into the atmosphere.