Choosing a boiler is not always easy, it is an important investment and can not be done lightly.
In addition to the cost of the boiler, one must consider the impact on the energy bill and the savings opportunities offered by new technologies. How to proceed to choose the most responsive boiler for our needs? Let's see some issues.
Analyze your needs
The first step and perhaps the most important is a careful analysis of needs. We must keep in mind a number of variables:
- Location of the building. Depending on the climatic zone in which the building is located we can choose the boiler with the appropriate power.
- Requested services. We can use the boiler only for heating, or just to produce domestic hot water. If, on the other hand, the boiler is used for both functions, it is better to choose one with greater power.
- Type of fuel available. The availability of fuel is a determining factor for the choice of the boiler. If no gas is available, other solutions such as heat pumps or biomass boilers can be evaluated
- What will be the type of radiating bodies. The latter may influence or be influenced by interior design that we're going to heat the home. However the modern condensing boilers can ensure excellent functionality and energy saving and in case of floor heating systems or radiant panels, which in the case of classic radiators.
The sizing of the heating system depends on the climate of the area in which the building is located, more precisely the temperature difference between inside and outside. Based on this data we will have to choose the boiler that can produce the necessary amount of heat.
The law divides the Italian territory into climate zones, for each one defines the minimum external temperature, obtained on the basis of statistical observations of the minimum temperature that can actually be had and the behavior of the buildings. In the same way the law fixes the internal temperature, for the whole national territory. It can vary depending on the use of the building, in the case of residential housing is 20 degrees centigrade.
Depending on the climatic zone in which we are the minimum external temperature can vary from 5 to -20 degrees centigrade and the temperature range can vary from 15 to 40 degrees centigrade. So if in the hottest climatic zone I need a certain power to heat the rooms up to 20 °, in the coldest climatic zone I will need more than twice the power to get the same result.
- Dimension. The first feature of the building to be evaluated to choose the boiler is the magnitude of the environments of home. Obviously, the larger the environments are, the greater the energy required to heat them, but there are other aspects to be evaluated. For example, in the presence of large double-height mezzanine environments, it is preferable to provide a floor heating system to obtain a more uniform temperature. Underfloor heating requires low temperature water, so we can choose one condensing boiler, which in these conditions offers better energy efficiency.
- Construction period. If we are renovating an old building, built before the 1975, this will not have good thermal insulation. Unless they are planned, or have already been made interventions to improve energy performance. Due to the greater ease of heat dispersion we will have to oversize the heating system to achieve the desired thermal comfort.
- Exposure. If the rooms to be heated are exposed to the north, or in a position that causes low solar irradiation, more energy will be needed for heating, so we will have to choose a boiler with a higher output.
- Degree of thermal insulation. The buildings of recent construction are generally made of materials and technologies that determine a good thermal insulation. We will however have to evaluate the heat requirement for our case so as to correctly calibrate the boiler power.
heat pump or boiler?
In recent years, the technological evolution has made another technology, heat pumps, interesting for use in the domestic heating system. The heat pump can take heat from water, air or soil and make it usable for heating. The electricity consumed is not used directly to be transformed into heat, but to activate the mechanism that extracts heat from external sources.
In summer the heat direction can be reversed, so the heat pump can also be used to cool rooms.
There are three types of heat pumps: air-water, water-water, ground-water. The most common type of heat pump is that air-water, it is more simple and economical installation, extracts heat from the outside air, but this is precisely its limit, in fact when the outside temperature drops close to or below zero the performance undergoes a sharp decline.
The other two types extracting heat from elements that have a much more constant temperature are less affected by this problem. On the other hand, if you need deep-set pipes through soil drilling, they are more difficult and expensive to install.
Heat pumps produce water at low temperatures, they are suitable for systems with radiant panels or underfloor heating systems. They are well suited to operate in environments where the heating is on for many hours, without interruption.
Unlike the heat pump, the boiler is the component in which heat is transferred from a fuel in the combustion phase to a liquid. The liquid has the function of conveying the heat towards the radiating elements that will distribute it in the rooms to be heated.
The evolution of the boiler is closely linked to that of fuels. Starting from coal, fuel in the solid state, it is passed to liquid fuels, then the gas. Remarkable are the differences both in the mode of supply and storage, either in the combustion mode.
The condensing boiler is the most advanced type of gas boiler, choose condensing boiler means Also save up to 40% on your energy bill, if the boiler is combined with irradiation systems. The reason for saving is one greater energy efficiency. The condensing boiler via a component precisely said capacitor, is able to recover the residual heat of the exhaust fumes.
A condensing boiler generally has a higher price than a traditional one, it is around the 1000 - 2000 euro, installation excluded, but this initial cost is amortized by energy savings.
Parameters to be compared
The technological evolution has allowed to equip the boiler with many new functions that improve the management of the heating system. The ultimate goal of this evolution is the optimization of consumption, therefore of energy saving.
There are many technical aspects that must be evaluated when choosing the boiler, for example, the modulation ratio, the compatibility with the thermoregulation accessories, the possible areas of management for large environments, the use of an external boiler for the production hot water. These issues clearly affect both the complexity of the system that the price, so you have to make an optimization of price and benefits on the basis of what are the needs.
False myths to debunk
That being a condensing type of boiler appeared on the market recently, many do not know the characteristics in detail. This promotes the dissemination of statements but are not reflected in reality. Let the false myths.
- Conventional boilers are better.
In reality it is not so, condensing boilers provide higher performance, greater savings and less environmental impact. Their level of technology is much more advanced, this allows a much more detailed parameter control and the optimization of consumption. The characteristics of the condensing boiler, when combined with the external probe that allows you to anticipate any changes in temperature (also sudden) during the day, ensuring customers maximum savings in the bill.
- Condensing boilers cost much more.
This is partially true. Condensing boilers have a much higher technological value, which surely justifies a higher initial cost. During the course of their lives provide high bills long after that, in time, they provide a guaranteed and substantial investment.
- Condensing boilers are only saving with underfloor heating systems.
False. Even in the presence of old plants with radiators, the condensing boiler, combined with thermoregulation, allows to obtain a substantial saving in the bill (compared to an old traditional boiler), ensuring a greater environmental comfort.
- Condensing boilers are noisier compared to an old traditional boiler.
False. The noise level of condensing boilers, thanks to the technology, it is much lower compared to the old traditional boilers.
Hoping that these guidelines can help you select the most suitable boiler for your heating system, please also read insights on: room thermostat, Revision of the boiler and on New EU rules on energy efficiency standards.