Underfloor heating
Is it floor heating or underfloor heating? Most likely just as much has been argued about the terminology as about the choice between underfloor heating versus radiator heating. Which is right, floor heating or underfloor heating – let the client be the one to decide. A lot has been talked about the advantages and disadvantages of one or another system but let us look at the matter from a different perspective and base our decisions on common sense and the foundation of all issues that we often tend to forget - physics.
Underfloor heating is more favourable!?
The main reason underfloor heating is more economical is that the sense of warmth, the sensed temperature, is created by a large surface. A human being perceives temperature not just as air temperature but also as thermal radiation. The wall of a fireplace or a sauna stove emitting heat could be the first examples to think about in this respect. The perceived temperature is the average value of the temperature of air and of the surfaces around us. The more of warm surfaces there are around us, the lower the importance of air temperature. In short, underfloor heating creates a better perceived temperature at lower room air temperatures. Hence, the possibility of economising.
Heating emission of underfloor heating!
Different theories speak of the diameter of piping of underfloor heating as something very important. All myths are usually related to a certain diameter. Here we dismantle these myths! The diameter of the pipes of the underfloor heating is not important; the surface area that is used for heating is important. Everything else is the self-fulfilment of engineers with an artistic soul. The diameter of pipes of underfloor heating systems is related only to the given construction or situation and nothing else. The pipes of underfloor heating start generally from 9.9 mm and end at 25 mm, other solutions are extreme and rarely used. The choice of a good underfloor heating system always starts from the analysis of the cross-section of the floor, supplemented by evaluation of limit values. The position of underfloor heating pipes in the construction, i.e. installation depth, is also important. If we want a cosy, warm floor that follows regulations, we have to keep in mind some restrictions: for example at room temperature of 21 degrees Celsius, the heating emission cannot be more than 88 W/m2 and with a more high-quality floor covering (wood parquet flooring) the calculation result is 66 W/m2. Generally new buildings correspond to such parameters and heating losses are compensated. The abovementioned values may not be sufficient in houses that are being renovated.
Automated underfloor heating?
It is a system supplement that has been considered expensive and not a very sensible choice, quite unnecessarily. Here it is important to look at the habits of users of the living space. A TV remote control unit could be a good comparison here. We can do without it but most likely there are no TV sets in our homeland that would come without a remote control unit. Automated underfloor heating system is certainly an extra comfort that according to myths saves energy. Generally that is not the case! Such a solution certainly consumes more energy and the saying – comfort costs extra, is true. The comfort comes from the temperature management of all rooms individually. By now, upgraded automation systems are offered where energy spent for comfort has been regained. That in the form of economising 8% of heating energy!
Advantages and disadvantages of underfloor heating:
- Lower water temperature and thus somewhat lower costs of heating (10 – 12 %).
- No circulating air flows, which is quite important for allergic people.
- Research has shown that in rooms with underfloor heating, the amount of dust mites considerably decreases since a floor with underfloor heating isn’t a suitable living environment for them.
- Thanks to the floor being the warmest part of the room, meaning that heat is where people are, the feeling of comfort can be achieved at air temperatures that are lower than usual (this means cutting heating costs).
- The space is free and there are no restrictions to placing furniture.
Requirements and recommendations on underfloor heating:
- Temperature of heating water has to be kept as low as possible. With concrete floors, the temperature of heating water should be 30-40 ºC and with floors on wooden joists up to 55 ºC.
- If the temperature of heating water is too high, the average room temperature also increases since the filling mechanisms used in the comfort automation systems of underfloor heating, which open and close heating circulation, are slow, and thus water with higher than needed temperature will continue to circulate in the floor for several minutes after the system is switched off, but that depends on the selected automation system too.
- The temperature of floors in rooms where people stay constantly should not be above 29 ºC (the ideal range is considered to be 24-25 ºC), in rooms that are being used for short periods of time (bathrooms) it should be up to 33 ºC.
- When the heating is not switched on, care should be taken to make sure that circulation pumps and valves of distribution collectors do not get caked; to avoid that, they should be periodically kick-started. An automated underfloor heating system of higher quality can do that job for you.