When is it advisable to replace the boiler? What are condensing boilers? What about modular generators? How do the 2020 tax bonuses work? All these questions are answered Aeneas (the National Agency for New Technologies, Energy and Sustainable Economic Development) e Isnova (the Institute for the promotion of technological innovation) in a publication entitled "Practical guide to the renovation and energy requalification of buildings".
Here are the key points.
1) WHEN SHOULD THE BOILER BE REPLACED?
Apart from the appliances that give signs of malfunctioning, it is always advisable to evaluate the replacement of boilers older than 15 years, because over time the risk of breakdowns increases and therefore the operation can be considered an intervention preventive maintenance. Furthermore, if the appliance is old, certainly many products on the market today would guarantee a much higher degree of energy efficiency.
2) WHAT ARE MODULAR GENERATOR SYSTEMS?
Instead of a high power generator, it is possible to install a modular generator, i.e. a system made up of several less powerful heat generators arranged in parallel, which are activated in a "cascade" based on the power required by the external conditions. The goal is to maximize system performance.
3) WHAT ARE CONDENSING BOILERS?
The technology installed on the condensing boilers is the one that guarantees the best energy performance ever. To understand how it works you have to start from the past.
In traditional generators, the heat produced was transferred to the heating system fluid via a heat exchanger: after heating the water in the pipes, the hot fumes (over 120 degrees) were expelled outside through the flue.
In condensing boilers, on the other hand, the heat of the fumes is recovered by the exchanger by cooling and therefore condensing the fumes themselves, which in this reverse process return more heat to be transferred to the liquid in the heating system. The additional energy thus produced reaches 11% of the overall generation in the case of methane gas combustion, while it stops at 6% with liquid fuels such as diesel.
4) WHAT ARE THE 2020 BOILER BONUSES?
As far as tax bonuses are concerned, they are not applicable to less efficient devices (energy class B). For class A condensing or biomass boilers, on the other hand, there is a 50% tax discount (Irpef or Ires deduction), which rises to 65% only for condensing boilers with advanced thermoregulation systems. This is the so-called eco-bonus, which must be divided into 10 equal annual installments. In all cases, the maximum deduction is equal to 30 thousand euros.
If replacing the boiler results in energy savings, the is also applicable mobile bonuses 50% (on a maximum cost of 10 euros, including money for transport and assembly). Also in this case the deduction must be divided into ten equal annual installments.
5) WHAT SHOULD BE ATTENTION TO?
To choose the size of the boiler, it is advisable to contact a qualified designer, remembering that old generators are almost always too large compared to current user needs. Before replacing, therefore, it is important to verify the thermal power actually required by means of an energy calculation of the entire building. Finally, the operation can be an opportunity to check the entire system linked to the generator, the compliance of the gas network, the water treatment and the flue.
