Condensing boilers are water heaters typically used for heating systems that are fueled by gas or oil. When operated in the correct circumstances, a heating system can achieve high efficiency by condensing water vapour found in the exhaust gases in a heat exchanger to preheat the circulating water. This recovers the latent heat of vaporisation, which would otherwise have been wasted. The condensate is sent to a drain. In many countries, the use of condensing boilers is compulsory or encouraged with financial incentives.
Condensing boiler
Condensing boiler exhaust vapour
Condensing boiler
Stainless steel exhaust with condensate
A central heating system provides warmth to a number of spaces within a building from one main source of heat. It is a component of heating, ventilation, and air conditioning systems, which can both cool and warm interior spaces.
A condensing boiler
Hot water central heating unit, using wood as fuel
Ruins of the hypocaust under the floor of a Roman villa at La Olmeda, Province of Palencia (Castile and León, Spain).
Sylvester's warm-air stove, 1819