How oil condensing technology works briefly explained

Energy consumption reduced by up to 35 percent

In Germany alone, there are still around two million heating systems in use today that are more than 25 years old. Their owners are often completely unaware of how much money they are wasting unnecessarily on energy, which is pointlessly burned up and exits the chimney as unused heat. In addition, these old systems pollute the climate through unnecessary CO₂ emissions and contribute to global warming. By promptly replacing these systems with highly efficient oil condensing systems combined with solar technology, end users could reduce their energy consumption by up to 35 percent. This would translate into ten percent of Germany's total energy needs, with annual CO₂ emissions being reduced by 54 million tonnes at the same time.

A boiler generates heat by burning fuel and using the resulting hot flue gases to heat the heating water. With conventional boilers, this flue gas heat is discharged directly into the open air. This is necessary because the water vapour contained in the flue gases would otherwise condense as soon as the flue gases had cooled below their dew point temperature. However, components of this condensate are corrosive, which is why the hot flue gases were considered unusable for a long time.

Important information for the use of oil condensing technology

The deliberate condensation of the water vapour contained in the flue gases produces condensate. Although this has acidic components, it can normally still be discharged into the waste water system (not small sewerage treatment plants) – provided that the drainage system itself is acid-resistant. The pH value is important here. Water has a pH value of about seven. This value is considered neutral. Everything below this is acidic. The pH value of the condensate in crude oil is 1.5 to 3.5. A basis for calculation is provided in Code of Practice "DWA-A 251" of the German Association for Water, Wastewater and Waste (DWA). It is also advisable to enquire with the responsible municipal waste water association.

Other important factors for discharge into the normal waste water are the size of the oil condensing boiler and the type of fuel oil. As a rule, systems that use oil condensing technology and have a rated heating output of less than 200 kW are exempt from the obligation to neutralise. In some cases, the condensate must be diluted before discharge. Those who still use standard fuel oil must always neutralise the condensate before discharging it.

The chimney must also be suitable for oil condensing technology

Not only must the drainage system be designed for operating a condensing boiler, but it is also important to ensure that the flue system cannot be damaged by condensate. In addition, it must withstand a certain overpressure without leaking. This is necessary because during operation it is essential to use a fan, which actively blows out the cooled flue gases. Flue pipes made of stainless steel or special plastic are tried and tested.

A further point in favour of oil condensing technology is its variety of combinations. Combination with solar technology makes sense, both economically and ecologically. The free energy delivered by the sun is still not used enough for central heating backup and DHW heating. When modernising, homeowners should consider combining their new heating system or boiler with a solar thermal system.

With the help of solar technology, solar energy can be used for central heating backup or DHW heating. This is extremely economical, as it means that the oil condensing boiler does not have to work at all on some days. Since less oil is burned, system owners also reduce the burden on the environment and thus actively contribute to climate protection. Last but not least, this combination makes them a little less dependent on their fuel supplier.

Contrary to the assumption of many consumers, a hybrid heating system consisting of oil condensing technology and solar thermal can be used not only in older buildings, but also in new ones. Provided that a few factors are taken into account, the requirements of the German Buildings Energy Act (GEG) can be met.