Advantages and Disadvantages Of Underfloor Heating
Almost every second builder now decides for a surface heating system. It is usually a floor heating system, but also wall and ceiling heating systems are very popular. Their great advantage is that the operating costs are about ten percent below those for radiator heating. There is a lot of talk about underfloor heating – and many prejudices prove to be pure everyday myths. Nevertheless, there are also some drawbacks.
According to a study conducted by the Freie Universität Berlin on behalf of the BVF in Hagen, floor heating is not necessarily more expensive than radiator heating. “Material and labor costs are almost the same,” says BVF Managing Director Joachim Plate. If there are additional costs, the builder should inquire how this is done.
Matthias Wagnitz from the Zentralverband Sanitärheizung Klima (ZVSHK) sees a similar situation: “The installation is somewhat more expensive, but it is not particularly important for new buildings.” The higher price for underfloor heating goes back to the insulation, which is included in the price. In the case of a radiator heater, for example, the latter is introduced into the calculation of the screed, which makes its work more expensive.
The plastic pipes of underfloor heating systems have a service life of 40 to 50 years, if properly operated, explains Wagnitz. Contrary to popular fears, they do not age so easily because the system is operated only at low temperatures and low pressure. “It is important to use material in which no oxygen diffuses,” adds Holfert. “Otherwise the mud can come to mud after a year or two.” That will be expensive. Therefore you should not orientate yourself with the material at the lowest prices. The expense for replacing the pipes is higher for the surface heating than for radiator heating.
The floor heating is not visible
There is no underfloor heating. Plate therefore advises on this type of heating for roomy windows. “Radiators have to be cleaned regularly, which is not necessary for underfloor heating,” adds Wagnitz. The view does not seem to bother most people. According to a ZVSHK survey, only about 10 percent of the respondents want smaller radiators. However, these can even be deliberate eye-catchers in the room. Infrared heaters can look like small works of art.
When installed, both systems are equilibrated
The boiler of a radiator heater occupies a relatively large space, but the installation is easy. This also applies to the installation of underfloor heating systems in the new building: a thermal and impact sound insulation is laid on the raw concrete, the pipes of the underfloor heating coming before the screed is applied, explains Plate.
Subsequent installation of floor heating is difficult
“It is possible to retrofit a floor heating system in an inhabited old building, but it is very expensive,” says Wagner. Either the floor structure has to be increased by several centimeters or appropriate ducts have to be milled into the floor, which receive the pipes. Here, it may be more appropriate to install a wall heating system, explains Plate.
Birgit Holfert from Verbraucherzentrale Energieberatung also advises whether a retrofit in the old building makes sense. “Whether one is worth depends on one’s own condition.” Because the effort is quite high, and both heating systems are justified. “Before laying a floor heating, you must also be aware of the flooring you choose,” explains the Exertin. If it is, for example, cork or wood, a special floor heating is necessary.
Against the installation in an old building, it often also means that a surface heating needs a well-insulated environment so that the heat stays in the house. In houses that do not comply with the provisions of the Energy Saving Ordinance (EnEV), they can not fully develop their qualities. “Because in most cases higher flow temperatures are required there, the heating needs more fuel and can not work as energy-efficient as in insulated buildings,” says Holfert. “However, there are solutions for every individual case,” emphasizes industry expert Plate.
Do not install both
Wagnitz advises not to mix both systems, ie to choose a radiator heater and to install pipes for floor heating in the bath. “This is not efficient, and the temperature is difficult to control and it may become too hot in the room,” he explains. If you absolutely want to install both systems, you should mix at least level.
Floor heating saves ten percent operating costs
Floor heating systems are more efficient than radiators. “In new buildings with heat pumps or solar collectors you can not miss them,” says Holfert. Area heating systems can be operated at low temperatures. They simply required a flow temperature of 30 to 35 degrees. “In order to produce the same heating power for radiators, a flow temperature of 50 to 60 degrees is required, since the surface area of the radiator is much smaller,” explains the expert. Accordingly, underfloor heating systems are ecologically beneficial and also good for your own purse. “Around ten percent operating costs can be saved,” says Plate.
In addition, the panel representative finds the thermal comfort of surface heating systems larger. “If the enclosure is warm, the air is generally warmer.” It could be up to two degrees cooler in the room, but it was equally comfortable. In addition, the room air flow is better in underfloor heating systems because they radiate the heat evenly over the floor. In the case of radiators, however, there are partial air movements.
Disadvantage of floor heating
“The advantage of radiators, however, is that they react much faster,” says Holfert. So it gets warmer. Since the floor heating has a large area and the screed several centimeters thick is a large storage tank, this type of heating is slow. But the industry is working to remedy this disadvantage. Modern heaters have a self-regulating effect. If the temperature in the room increases, for example due to intense solar radiation, the heat emission is automatically reduced. Conversely, the lowering of the room temperature results in an increase in the power output.
Which floor coverings are suitable for underfloor heating
Ceramic tiles and natural stones are ideally suited for their storage and thermal conductivity, explains the Initiative Wärme +. But also products from the groups laminate, parquet, linoleum and carpet can be laid over heating mats. The manufacturers, however, specify for each product exactly whether this is suitable – for example with the indication “Suitable for underfloor heating”. The experts also advise in the trade to ask specifically.
Carpets have a black and white symbol showing a heating coil and three arrows pointing upwards. These products have been tested according to standards EN 12667 or ISO 8302.