What is the Standard that regulates the project design of underfloor heating systems?
The standard UNI EN 1264 in its four parts.
Why are insulating panels employed?
Because they act as a support for the loops, they are an excellent thermal insulation, and they reduce the thermal inertia of the system.
What is the thermal inertia of the system?
The thermal inertia of the system can be identified as the “speed” with which the system follows the variations in room temperature. The insulating panels allow a reduction of the thermal inertia and therefore speeds up the operation of the system.
What advantages do the PEXAL and MIXAL pipes offer in underfloor heating systems?
The PEXAL and MIXAL pipes, because they have an inner layer in aluminium, allow the loops to be easily installed. Once the pipe is bent it remains in the established position unlike plastic pipes made of PEX or PERT. The PEXAL and MIXAL pipes guarantee an absolute (100%) barrier to gas and in particular to oxygen. Furthermore, the layer in aluminium increases the thermal exchange coefficient of the pipe as compared with other plastic pipes.
Is it possible to use an underfloor heating system in an industrial building or in a building with a very high ceiling?
Underfloor heating systems are ideal in spaces where the ceilings are very high, in that the energy is produced at the height of a person and the distribution of the temperatures ensures real energy saving.
Is it true that underfloor heating generates circulation problems?
The problem which you refer to is a phenomenon of the past related to the poor project design and the installations carried out several decades ago. Today the project design and the installation must observe the requirements set by the standards in force. The standard UNI EN 1264 establishes that the maximum temperature of the tiles must not be greater than 29°C in rooms such as the bedroom and the living room. In bathrooms the maximum temperature is 33°C so that it is possible to create a warmer environment. Such temperatures are perfectly compatible with the body temperature and create absolutely no problems with blood circulation which could have happened in the past.
Does a standard exist that regulates the production of insulating panels?
Yes, the reference standard for polystyrene panels (EPS) is UNI EN ISO 13163 which sets the compressive strength, the flexural strength, the dimensional stability, and the thermal conductivity.
In comparing insulating panels is it correct to make reference to the density?
No, the fundamental parameter for a correct comparison is the compressive strength measured in kPa (Pascal kilos). This identifies the capacity of the panel to resist the loads which he floor will have to hold. This parameter is very important in the realisation of industrial underfloor heating systems.
How are the Valsir multi-layer pipes produced?
The multi-layer pipes produced by Valsir are made of five layers of material. The inner and the external layer are made of PEX (crosslinked polyethylene), the intermediate layer is butt-welded aluminium. To unite these materials two layers of adhesive are used.
What are the principal characteristics of the Valsir multi-layer pipes?
The multi-layer pipes produced by Valsir offer, on one side, the advantages of plastic pipes (in PEX) in that they are non toxic, lightweight, there are no incrustations, low pressure loss, and there are no corrosive effects. On the other hand we have the benefits of metal pipes such as it acting as a barrier to gas, low thermal expansion, dimensional stability, flexibility.
Which diameters are employed in underfloor heating systems?
In residential systems the multi-layer pipe MIXAL 16x2, while in industrial systems MIXAL 20x2. In renovations PEXAL 14x2 is used whereas in high power snowmelt systems the PEXAL 26x3 pipe is used.
What is an anti-snow/anti-freeze system?
An anti-snow/anti-freeze system is made up of a loop placed underneath the pavement of a road, car park, helipad, viaduct which when filled with hot water increases the temperature of the road surface thus eliminating ice and snow.
In this case the energy required is very elevated, and can reach 1400 W/m2.
How much can be saved as compared with traditional heating systems?
Le particolari caratteristiche degli impianti di riscaldamento a pavimento radiante c
The particular characteristics of underfloor radiant heating systems allow the achievement of reductions in consumption of combustible gas of at least 20-25%.
This is due to various reasons such as the distribution of the temperatures, the low temperature of the transporting fluid, the large heating surface, the presence of insulating panels, etc.
What type of boiler can be used?
It is possible to use any type of boiler; both traditional ones and also condensation boilers.
Is it possible to install a thermostat in each room?
Yes, it is possible to regulate the temperature in each room by acting on a suitable command station on each circuit by closing or opening it depending on the temperature conditions.
What space is necessary to install an underfloor heating system?
The minimum space required for an underfloor heating system is approximately 7,5 cm. These heights are reached with the system for renovations made up of an insulating panel of 2 cm and the 14x2 MIXAL pipe.
Are there limits to the thickness of the concrete poured over the loops?
Yes, the standard sets a minimum limit of 3 cm. In residential systems the thickness of the concrete is approximately 4,5 cm.
Is a radiant system noisy?
Absolutely not, noise is generated when the speed of the water is elevated. In underfloor heating systems the speed is very low (maximum 0,5 m/s) and therefore the noise which is typical of systems with high speed water flow is not generated.
Does underfloor heating create dust?
Heating systems do not generate dust. Dust is generated in a completely natural way; it is the distribution on floors and furniture that depends on the type of heating system.
A system with radiators and fan heaters creates movement of the air and therefore also the dust which then deposits on the furniture.
An underfloor heating system does not generate convective motions and therefore the dust remains on the floor.
Is it possible to use parquet flooring?
Any type of covering can be utilised. It is important to inform the project designer of the choice of flooring during the dimensioning phase. Every type of covering, and therefore also parquet, has a thermal insulation coefficient which must be taken into consideration during the dimensioning phase.
Does the underfloor heating system cause irritation of the air tract?
Absolutely not. The temperature of the floor remains at such low levels (27-29°C) that the air humidity conditions are not modified. For this type of system it is therefore not necessary to use humidifying containers that are usually adopted with radiator systems.
What is the temperature of the water that circulates in the loops?
The temperature of the water depends on various factors such as the type of floor covering, the temperature required in the rooms, the external climatic conditions, etc.
Generally the supply temperature ranges from 35°C to 45°C in the most extreme climatic conditions.