Warm floor

The Roman Empire

Archaeological excavations and written sources indicate that attempts to equip the floor heating system have been undertaken since ancient times. Floor heating, for example, was used in ancient Rome . At the initial stage, warm floors were the privilege of wealthy citizens, but gradually spread everywhere in public institutions (primarily baths), especially in the cold regions of the Roman Empire . The floor heating system in Roman baths included special furnaces and channels located under the floor. When wood was burned in the stoves, hot gases formed, which spread through the channel system. One furnace was used to heat several rooms. The custom of floor heating disappeared after the fall of the Roman Empire.

Similar heating systems were previously widely distributed in the modern territory of central and southern Russia, namely in ( Volga region , Don region ), as well as in the south of Ukraine , Moldova , Romania , and in the Crimea in the 13th – 15th centuries.

Korea

Unlike the Roman Empire , where floor heating was lost over time, the underfloor heating system has been used in Korea for thousands of years and was called the ondol. This word in translation from Chinese means "warm cavity." It is assumed that this system was invented during the three Korean states ( I century B.C. - VII century A.D. ). The principle of its work was as follows. There was an oven in the kitchen or in the outer wall of the room. Horizontal cavities (tunnels) were laid under the floor of the room for smoke and hot air that passed through the cavities during the burning of wood in the stove. The special device of the floor heating system helped to retain heat for a long time. Today, heating the floor with the ondol system is a typical feature of a traditional Korean home. However, in modern homes, the ondol system in its original form is practically not used, it is replaced by an improved system of water and electric floor heating. Almost all houses in South Korea are equipped with underfloor heating systems. At the moment, South Korea is one of the main manufacturing countries and exporters of heating film for underfloor heating.

Electric underfloor heating

The most common floor heating option. Electric heated floors, depending on the version, are cable (both in the form of separate electric cables, and in the form of heating mats with a thin cable on the grid), film, rod and based on an amorphous metal tape. And by the principle of heating - convection and infrared. All types of underfloor heating have a number of environmental advantages compared to radiator heating: anti-allergenic effect, uniform distribution of air temperature and its heat exchange throughout the volume of the room, the absence of convection flows associated with the temperature difference on one horizontal plane in different parts of the room.

Liquid electric heated floors (electric-water heated floor, with heating cable inside the pipe)

One of the latest developments in the market of underfloor heating. Installation of these systems is carried out directly in a cement-sand screed. They are used under almost all known floor coverings: tiles, laminate , linoleum , pvc tiles. The exceptions are cork and natural parquet : with these floor coverings, it is necessary to limit floor heating to 28 degrees, or use a special engineering parquet, which is designed to work with warm floors. The appearance of such novelties expands the use of underfloor heating, since before, underfloor heating often only served as a comfortable additional heating of rooms, now warm floors can already be a complete heating system for a modern building.

The likelihood of failure of such a warm floor is somewhat lower, since the cable is in a special heat-conducting fluid. Repair is carried out as in classic water heated floors: replacing the damaged section of the pipe with a new one and coupling on 2 sides.

Mobile underfloor heating

Mobile infrared film underfloor heating. It is a closed system that can be used in any room.

The design is powered by an electrical network, but it cannot be used safely in rooms with high humidity. Stacked under the carpet, which is an important safety point.

Cable underfloor heating

Warm floor based on amorphous metal tape

The floor is based on a thin (20-25 microns ) amorphous alloy tape.

Usually, an amorphous metal tape-based warm floor is presented in the form of heating mats that are directly laid under the floor covering — tiles, tiles, parquet, laminate, carpet, etc. Screed is not required.

Film underfloor heating

A relatively young (from around the 2010s) type of electric underfloor heating is a film underfloor heating ^[2] , where a special film is used as a heating element. Often it is also called infrared, which is not entirely correct, since any heat is the result of infrared radiation. At the moment, the main countries for the production of heating film is South Korea. South Korea is the main supplier of heating film to the CIS countries. There are film models that can be used under tile glue for masonry.

There are 2 types of film floor: carbon (it is also erroneously called graphite ) and bimetal.

• Carbon: This film is a resistive element laid between two layers of mylar film ( parallel connection of carbon heat elements). The heating film can be used for heating rooms of all types as primary or secondary heating, as well as for heating outdoor areas. Thermal film can be placed on the floor, walls and ceiling of the room.
• Carbon are divided into 2 types:
• 1. Film floors for laminate, linoleum and carpet.
• 2. Film perforated floor for tiles, porcelain tiles and screed.

The film makes it possible to install a warm floor quickly and easily. At any time after installation, it can be assembled and put into another room, if necessary.

• Bimetallic: There is a bimetallic film, which is a thin film of polyurethane, inside which there is a patented compound of 2 layers: the bottom is an aluminum alloy with additives, the top is a copper alloy with additives. The shape of the film is a continuous roll, divided into square sections, sizes 0.585 × 0.545, which can be cut into these sections. Section structure: along the edges there is an open current-carrying bus, which is connected by a zigzag conductor (1 mm thick with a step of 1 mm). This film is designed for laying under decorative flooring, such as laminate, linoleum, carpet, not suitable for tiles. The recommended maximum temperature on the thermostat is +27 ° C, this is due to the features of decorative coatings. (A striking example is the behavior of a tree during heating. The maximum temperature at which a tree feels comfortable: +28 ° C. When this temperature is exceeded, a tree (eg parquet) will begin to dry out over time.) Due to the lack of grounding , connection via an RCD or via differential automatic (for this, the film floor must be covered with a grounding layer, which is purchased separately).

Film floors should not be installed in wet rooms, since GOST requires a device protection class of at least IP21.

Water heated floor

There are 2 types:

• Electro-water (heating cable is inside the pipes)
• Classic (boiler + pipes)

1. Electro-water underfloor heating is different in that they do not connect to the boiler. The heating element is inside, along the entire pipe. For their work, there is also no need for a circulation pump, since the liquid warms up evenly along the entire length of the pipe. Such warm floors are delivered ready-made, with liquid inside the pipes and a heating element. It is enough to connect them to the network (220V) through a thermostat, which automatically controls the temperature of the floor or air in the room. Systems for each room are selected in length, based on the area of ​​the room. If we compare such systems with pipes that are connected to an electric boiler, this system has several advantages: 1. less volume of heated liquid; 2. uniform heating of the pipe along the entire length (in contrast to the classical water, in which the liquid cools downstream); 3. the possibility of local heating of individual rooms, without heating the liquid in the entire system (since each circuit is closed). The electro-water floor (also called "liquid") can be used as the main heating of cottages and loggias.

They can be installed in apartments (unlike ordinary water floors, which are prohibited to be installed in apartments, since there is a risk of flooding of neighbors and because of increased load on heating systems), since they are not connected to the central heating system.

2. In classic warm water floors, heat is supplied to the floor structure using pipes with circulating liquid heat carrier (water or ethylene glycol ). Heating of the heat carrier is carried out using a gas boiler or from a central heating system ^[3] .

Floor heating systems today are actively used in almost all areas of construction: multi-storey buildings , cottages , individual apartments , shops and shopping malls , sports and cultural facilities, places of worship, in the heating of stadium fields, sports fields, roads and access roads, hangars , runways , etc.

The universality of the systems allows them to be mounted both during construction and at an already erected facility. It is possible to connect both to the heating plant, and the inclusion of fully autonomous heating systems.

Modern design solutions allow the use of a water heated floor for any type of building. In apartments, the use of underfloor heating is permissible when connected through heat-exchange nodes, which are specially calculated so as not to violate the hydraulic integrity of the centralized heating system.

This heated floor (as well as an electric-water heated floor) can be made under most types of furniture without causing it to dry out, which in turn allows you to make the necessary changes to the interior at any time.

Pipes for a water floor heating are made of cross-linked polyethylene or metal plastic . They are not subject to corrosion and the inner layer of such pipes does not contribute to the accumulation of deposits, since the diameter of their bore is maintained.

Types of water floor heating:

• Concrete system. The most common water heated floor system today, in which the pipes of the circuits are poured with concrete and additional heat distributors are not required.
• Flooring (polystyrene) system. The basis of this system is polystyrene plates with grooves in which aluminum plates are inserted, and then the pipe. The thickness of polystyrene can vary from 12 to 30 mm. Today, there are also developments of thin systems for areas of small diameter, 8 mm high.

This system is recommended for use when:

1. The height of the premises is limited.

2. The design or regulatory load on the floor is limited.

3. The installation of concrete screed is organizationally impossible (it is impossible to deliver concrete in the time necessary for construction)

4. When reconstructing an old heating system.

• Wooden system of modular or rack type. The system is mounted directly on the logs. thermal insulation layer is laid between the lags.

Water floor heating can be used with almost any floor coverings (even parquet), subject to certain rules and automation of the system.

On the basis of the water heated floor system, it is possible to implement a snow melting system, which has a wide scope: pedestrian paths, courtyards, parking lots, airport complexes, roofs, stairs.

Flooring

As a rule, electric underfloor heating systems are laid under the tile, because the surface of the tile is perceived by a person as cold, and also because the tile provides excellent heat transfer and is insensitive to prolonged exposure to heat. Also, the warm floor is laid under marble , granite , basalt and porcelain stoneware . Wooden floors and carpets have significantly lower thermal conductivity , so they usually do not need heating. If heating is organized by means of the “warm floor” system, then wood and carpets are not suitable due to the fact that heat is poorly transferred from the heating element to the room and negative effects can occur (drying of the wood, emission of harmful substances by synthetic carpets). In apartments and private houses, underfloor heating is arranged in kitchens, in bathrooms and toilets, in corridors and on balconies.

Since water heated floors are most often used as a heating system, it is used with almost any kind of finish coating, with the exception of heat-insulating materials such as cork, carpet and insulated linoleum, but with low heating loads, the above materials can also be used.

Distinctive features of the warm floor is a large heating area and low location of the heating surface. This contributes to a more even distribution of temperature horizontally and vertically compared to radiator heat sources concentrated in small areas above the floor. The uniform distribution of heat vertically allows the use of lower coolant temperatures. Room temperature can be reduced by 2 ° C compared to traditional radiators without changing the way a person feels heat. A temperature reduction of 2 ° C provides a 12% reduction in energy consumption.

The disadvantage of a warm floor can be high thermal inertia (a long time for heating and cooling the thermal surface). The rate of change of temperature of a warm floor, for example, for a concrete system of a water heated floor, may be less than the rate of a daily change in the temperature of the outdoor air, which leads to temperature overflows indoors.

• Kozin V. Warm water floor with your own hands. - 2013.
• Pisarev E. Underfloor heating: water or electric. - Robur, 2012.

•   Wikimedia Commons has media related to Warm Floor