Condensation Technology: Where and How to Use It Best?

When it comes to extracting maximum value from fuel and converting it into heat, condensing technology is essential. This term refers to the optimal use of the gross heating value. It differs from the term “net heating value,” which simply describes the measurable heat produced by burning the fuel.

The term “condensing technology” is explained

Until the 1970s, constant-temperature boilers were considered cutting-edge. They were later replaced by low-temperature boilers, which are still used in many homes today. Both types of boilers have one thing in common: they use only the heat released as a measurable temperature (net calorific value) during combustion of the fuel (natural gas or fuel oil). In contrast, flue gases, which can reach temperatures of up to 200 degrees Celsius, are deliberately diverted from the chimney to prevent condensation from forming in the heating system and chimneys. Flue gases contain valuable heat, which is then lost.

A unique feature of condensing technology is that it additionally utilizes the condensation heat (gross calorific value) contained in the flue gases, thereby significantly increasing the boiler’s standard seasonal efficiency [according to DIN]. The section “Operating Principle of Gas Condensing Technology” explains in detail how the gross calorific value is obtained using natural gas as a fuel.

Save money by upgrading to a Vitodens 300-W* gas condensing boiler.

Save money by upgrading to a Vitoladens 300-C* oil condensing boiler

Condensing technology in new buildings

Along with modernization projects, condensing technology is also used in new buildings. However, due to stricter legal requirements, it is often combined with renewable energy sources. Most Viessmann condensing boilers are designed for use with a solar system for backup central heating or hot water heating. This combination not only provides system owners with extremely efficient heating but also saves resources. Finally, the government supports the addition of solar thermal energy with attractive subsidies. However, these are only available for regenerative heat generators.