While town gas is in full development, gas heating is gradually supplanting oil heating. This is all the more the case since the latest generations of gas boilers, known as condensing boilers, constitute a very efficient means of heating. Particularly suitable for heated floors, they make it possible to obtain tax credits and to make significant savings on the heating bill.
Conventional gas boilers and their record efficiency
The operating principle of conventional gas boilers is very simple. The gas is burned, which creates smoke. The latter passes through an exchanger in which water circulates, which in turn feeds the heating circuit. These boilers have, as a rule, and depending on the quality of the boiler, an average efficiency of 93%. Some of them, called low temperature, and very often presented as a revolution, limit the starting temperature to 40 ° C in general. Amply sufficient for underfloor heating or low temperature radiators.
Gas condensing boilers: the new generation
Gas condensing boilers operate on the same principle as conventional boilers. However, they have the particularity of recovering the latent heat contained in the water vapor of the fumes created by burning the gas. Thanks to this phenomenon, it is now possible to reach 105% on the PCI (Lower Calorific Power). This system is certainly more expensive to buy, but it quickly pays for itself because it shows performance without comparison possible with a conventional gas boiler. So much so that today, when it comes to gas heating, condensing boilers have become the benchmark. To operate optimally, the heating return must be as cold as possible in order to obtain better condensation and therefore recover more heat. A gas condensing boiler will thus be more efficient on a heated floor than on a radiator circuit, which offers a warmer return of about twenty degrees.
Gas boilers: saving money
The ecological properties of gas condensing boilers are real. So much so that they are eligible for the energy transition tax credit. In addition, the gas price, even if it is indexed to the price of oil, remains particularly cheap and attractive since gas stocks remain sufficiently large for the time being. The gas condensing boiler also has the advantage of not having to store a cylinder if one is connected to town gas. Replacing an oil boiler with a gas condensing boiler does not require too much investment and makes it possible to significantly reduce the heating bill due to the performance recorded by this system.
A limited ecological scope for gas boilers
Heating with a gas boiler nevertheless has some drawbacks. Of course, the combustion of gas emits less CO2 than an oil boiler. However, it is not the most ecological solution for the environment. In the case of propane, this involves the installation of a cylinder located outside the building which should be recharged once or twice a year depending on the size of the house to be heated and the duration of use of the heating system. Propane also has a higher price than fuel oil and electricity. Finally, if the dependence of gas on petroleum does not reach that of fuel oil, it nevertheless remains significant.