In modern construction, underfloor heating replaces standard radiators. In the case of underfloor heating, pipes hidden in the floor distribute heat evenly throughout all heating zones in the building, operating at low supply temperatures. This makes it possible to heat the house economically and ecologically. But what types of surface heating do we even have to choose from? Because, after all, it’s not just floor heating.
Plane heating is a type of heating system in which the entire room is heated using invisible-to-the-eye pipes with a spiral or meandering arrangement. They are hidden in the floor, but can also be installed in the ceiling or wall. The heat source (heating medium) here can be water, air or electricity.
This type of heating has a much larger surface area than radiators and gives off heat to the entire heating plane. It works on the principle of radiation, much less convection. As a result, it heats evenly and slowly – it also loses heat slowly. To maintain a comfortable temperature in the room (in the heating zone) (about 22-23°C), surface heating needs a low supply temperature (up to 30°C), which is not only environmentally friendly but also economical.
Why is this so? It’s pure physics. If we want to reduce the supply thermal parameter, we need to increase the heating surface. And this is what happens in surface heating.
Importantly, the low feed temperature of surface heating works well with eco-friendly heat pumps, which are gaining popularity among forward-thinking investors.
We have already discussed the advantages of surface heating many times (for example, here). To summarize, you should know that – compared to radiator heating – surface heating is more efficient and healthier. It is also more comfortable for the occupants because, with lower supply temperatures and gradual distribution of heat, the house is never overheated. The heat does not “hit you in the face” as is the case with radiators, which “dump” hot air rising to the ceiling. As a result, radiator heating often distributes heat unevenly – the farther we are from the radiator, the colder we are, and at the radiator itself we can hardly stand the heat. Another issue is air quality. Surface heating does not dry it out, while radiators do. Radiators also collect dust in their nooks and crannies. They cause air movement; they lift pollutants, forcing us to inhale them.
If we are determined to use surface heating, let’s briefly see what the options are.
Heating loops hidden in the floor
In the case of underfloor heating – the most popular version of surface heating – the manifold distributes the heating medium (e.g. water) through pipes or heating tubes hidden under the floor. This allows for the added comfort of stepping on a pleasantly warm floor, although in practice it boils down to the fact that – except in the bathroom, where the floor is perceptibly warm – in other rooms it is not simply cold. Of great importance here is what the floor is covered with. The best conductors of heat are ceramic tiles, laminated panels, waterproof vinyl, resin flooring, and wood (materials with low thermal resistance). Underfloor heating is the most efficient and unquestionably the most popular version of surface heating – it brings thermal comfort at the lowest supply temperatures.
Heating elements hidden in the ceiling
With ceiling heating (an installation placed behind a suspended ceiling, for example), heat radiates evenly from the ceiling to the structural elements of the building and objects inside. We feel the heat at head height, not at leg height. In this case, we will not benefit from the comfort of a warm floor. For many investors, this is a disadvantage of this solution, but there are also advantages: there is no risk of covering the heating surface with a carpet or violating the installation when hanging cabinets or home decorations (as with wall heating, as we will discuss in a moment). On the other hand, we must take diligent care of the insulation of the building. The supply temperature of ceiling heating is usually higher than with underfloor heating because the heat does not sink to the ground. For the heating effect to be satisfactory, it must be increased.
Heating loops hidden in the wall
Wall heating is the least common form of surface heating. Heating elements are permanently embedded in the walls and emit heat through them, warming the interior. As with underfloor and ceiling heating, the heat spreads gradually, without overheating or raising breath-irritating dust. There are no additional layers here to reduce efficiency (e.g., panels, carpets). However, you should be aware that with this solution the usable area of the room is reduced – it becomes smaller by the thickness of the installation built into the wall (this is especially noticeable with air heating). With this type of surface heating you also need to set a higher supply temperature than with underfloor heating (up to 45℃). However, it is still economical and low enough not to cause damage or burns if possibly touched.
Where to install the heating elements is one thing, but the key is the heating medium you ultimately decide on – water, air, or electricity. This important choice will depend on the cost of using surface heating, and therefore the entire house.
The water system heats the building thanks to plastic or metal pipes through which hot water flows. The installation is insulated and protected against leaks or moisture buildup. This is important to prevent corrosion, rusting, or rotting of heating elements.
Air heating is characterized by the fact that specially hollowed channels run in the ground or wall, in which heated air circulates – it is set in motion by an internal fan.
Electric surface heating is based entirely on heat conducted through heating cables or foils. Its main advantage is the ease and “cleanliness” of installation and convenient operation, while the obvious disadvantage is the price of heating fuel. Electricity is expensive, especially with such increased use.
In Poland they are still a kind of market “freshness”, so it is worth mentioning that they exist and is an interesting variant, or rather alternative to the installation of surface heating. We are talking about the so-called capillary mats, that is – laid under the plaster or floor – light and thin networks of polypropylene tubes, through which the heating medium (water) flows.
Before laying the plaster, they are mounted with screws to the surface (to the floor, wall, ceiling). Capillaries are flexible and subject to molding, which means that they can be placed on architectural elements of different shapes and different cross-sections – for example, on a semicircular wall, a suspended ceiling, or in the attic (bevels). Capillary mats are not only lightweight but also work quietly (quieter than surface heating) and do not reduce the usable area of the room.
When choosing capillary mats, however, you need to remember to install them in walls about which you have no long-term plans for decorating or renovation. Accidental drilling of plastic tubes (for example, when hanging a painting) can cause damage and expose us to unnecessary repair costs. Such a wall must not be covered by a piece of furniture – then the action of the mats misses the point. However, these are limitations that also apply to wall surface heating.
At this point, the biggest disadvantage of capillary mats is the high price of installation. When buying them, pay attention to the quality of the materials used and the soundness of the welds.
Each room in a building has an individual need for heat. Rooms may lose it at different rates, but they also perform different functions, so they should have different temperatures. That’s why it’s important to introduce zone control, which involves installing controllers separately for each heating zone. Then each room will have its temperature, set by us.
Of course, in the case of air heating (radiators), this is also important and necessary, but the underfloor especially needs precise control. This is due to what we consider an advantage of this installation – it is slow to heat up and slow to give off heat. With such a mechanism of operation, the heating schedule must be logically thought out, planned, and watched over by the automatic controllers.