The advantages of condensing boilers they mainly consist in reduced management costs, reliability and low polluting emissions. Consumption can also be 20-30% lower than a traditional boiler, provided that maintenance of the system is not neglected (connection circuits and variable flow adjustments) and that you can count on a well insulated building from a thermal point of view.
Starting with advantages of condensing boilers, it must be said right away that they are interesting. The first consists of the low polluting emissions made possible by a premix burner that allows to minimize gas consumption and the emission of harmful substances (in fact, the emissions of nitrogen oxides NOx and carbon monoxide CO are very low) .
Furthermore, the combustion system of the condensing boilers (in which the air-gas mixture is made completely inside the fan device, electronically controlled, which blows it directly onto the burner) guarantees constant efficiency throughout the operating range of the appliance, ensuring energy savings that are impossible to obtain with traditional atmospheric burners.
Another advantage of the condensing boilers it is structural. Those who install a system of this type may in fact have exemptions from the obligation to connect to chimneys, flues or evacuation systems above the roof. In order to speed up the replacement of old systems, the possibility of discharging the fumes directly on the façade has been envisaged through horizontal evacuation ducts which usually have a shorter length and are easier to make than roof flues.
Another point in favor of condensing boilers of the latest generation is that they can be combined with the action of a solar thermal system for the production of only domestic hot water. Experience indicates that the condensing boiler-solar thermal combination allows to reduce the overall energy requirement even more than 50% compared to the utilities of a house already thermally insulated.
As for incentives, the condensing boilers (both condominium and single-family) allow you to obtain white certificates (after verification by the Electricity and Gas Authority of the actual energy savings obtained) which are energy efficiency certificates with an economic value that can be traded on the market. This is in addition to the tax bonus for the energy requalification of buildings introduced for the first time with the Budget Law (now the Stability Law) of 2007.
Let's move on to disadvantages of condensing boilers. In the article 'Condensing boiler: is it always convenient?We stressed that the condensing boilers they have the characteristic of having a high efficiency at relatively low temperatures, which makes them particularly suitable in combination with radiant floor or wall heating systems and, as mentioned, in buildings with good thermal inertia. In the absence of these requirements it's not that they don't work, let's say they don't give the best.
Another requirement that contributes to making investment in one appreciable and economically justifiable condensing boiler (which costs more than a traditional one) is that the costs for heating are quite high, which happens in cold climatic zones. In fact, convenience depends on the intensive and continuous use of heating, while traditional boilers are preferable for occasional and discontinuous use (such as in second homes).
What about security? The condensing boilersdue to their characteristics, they are placed outside the usual classification of gas user appliances. However, since 2003 they must comply with the UNI 11071 standard for the design, installation, commissioning and maintenance, and the names UNI 7129 and Uni 7131 with regard to the design of the internal system and the ventilation of the premises.
Before being placed on the market, the condensing boilers they must be subjected to verification by a notified body and, after marketing, must be subjected to periodic production surveillance by the same body. In Italy IMQ takes care of it.
The condensing boilers they represent a green technology, but regular maintenance is required to preserve the environmental benefits over time. For this purpose, it is important to fill in the plant instruction booklet, which must be written in the language of the country where the boiler is sold and must be requested during the installation phase.
Perhaps you are also interested in our article: How a condensing boiler works