Heated floating floor

An inappropriately used heating element placed under a wooden or laminate floating floor can have a strong negative impact on the lifespan of the floor.
During the development of our ECOFILM 60 and 80 W/m² heating films, we cooperated with leading European producers of laminate and wooden floating floors. According to their requirements and the results of measurements and tests, we introduced a product to the market more than ten years ago which had, already at the time of its appearance, a technical base and level of quality which had been tested over many years in installations of ECOFILM 140-300 W/m² film in mounted constructions - mainly from plasterboard.

The requirements of the producers of floating floors were:

• uniform distribution of temperatures within the whole surface of the laminate and wooden parquetry, so that that spot overheating doesn't take place, as this causes changes in shine and colour in the location of overheating, and uneven expansion of the parquetry due to heat, which in multi-layered materials such as these can create raised areas at spots which are overheated, and the tearing-off of one layer from another at cooler spots.
• even temperature increase throughout the whole thickness of the parquetry, so that there are no distinct differences between the temperatures of the lower and upper layer of the parquetry which could cause general bending of the parquetry and the opening of the joints between the parquetry blocks (the lower part expands faster then the upper part which is walked on).
• perfect straightness of the heating element, which becomes important during the loading of the floor e.g. by a foot, when the cable gets squeezed into the base. The floor sinks at this location and the locks of the parquetry are loaded excessively, which leads to their total degradation and snapping over the course of time.
• surface temperatures up to 28°C, in order to preserve colour and shine, and prevent the opening of the joints between the parquetry blocks.

At first, we used ECOFLOOR heating mats, which have been our product for many years. We attached 30μm - thick aluminium foil to both sides of the heating cable and we assumed that the aluminium would distribute the heat perfectly and the meanders of the cables would sink into the base of the impact insulation, made from MIRELON foam polyethylene.

Heating cable in aluminium foil.

However, we soon found out that this is not the correct method, even when we tried to increase the thickness of the aluminium foil for better heat distribution, or to decrease the wattage of the heating cable.

One of the test products

With the heating cable installed in the aluminium foil there was spot overheating of the laminate floor in the location of the cable, and also, in between the meanders of the cable the temperature was significantly lower, as you can see in the picture captured by an infrared camera.

In the picture, there is a cable in aluminium foil under a floating floor.
The spacing between the meanders of the heating cable in the aluminium distribution layer 50 mm and the length wattage of the cable 5 W/m²
(the photo was taken during testing and therefore the temperature sensor can be seen)

The temperature in the location of the cable was so intense that the difference between the temperatures of the lower and upper part of the parquetry was more than 10°C, and when we wanted to decrease this temperature to an optimal level, the spacing between the meanders of the heating cables was so small that it started to remind us of an almost continuous heating surface which resembled ECOFILM heating film. Not only the mutual distance between the heating cables, but also the length wattage of the cable began to be similar to the carbon heating strips which were used in the ECOFILM film supplied to us by Flexel International Ltd. As a matter of fact, we bought this company in 2004. With the heating film, the problem with the base being not perfectly even due to the presence of the cable was solved, as well as the problem with the uneven distribution of temperatures and the significantly different temperatures of the bottom and top parts of the parquetry.

In the picture, there is an Ecofilm heating film under a floating floor.
The temperature is s spread perfectly.

The result of the above-mentioned cooperation with Flexel and the leading European producers of laminate and wooden floating floors were two types of heating film with their output differentiated according to the material used:

• for laminate floors, Ecofilm heating film with an output of 80 W/m² and
• for wooden floating floors, Ecofilm heating film with an output of 60 W/m²

These films have continued to be functional throughout a long-term lifespan test as well as in many applications all over the world, without defects. With regards to the widespread use of the heating films in what are known as low-energy houses, we are considering launching the production of film with an output of 40 W/m².

Today, with the use of laminate and wooden floating floors becoming massively more widespread, competing producers of heating cables and mats are trying to produce heating elements for use under laminate floors made from a heating cable in aluminium foil, just as we did some time ago. However, as the pictures from the infrared camera show, they cannot reach the quality of ECOFILM heating film.

We have made another test of a competitive product in October 2008, based on dealings between our business representative and the owner of an electrical-engineering company that has been using heating wire in aluminium packaging under laminated floating floors and under carpets.
Having heard our experience with similar products, the owner of the company was very surprised and asked us to test the product used by his company.

The technical finish of the product suggested that the service life and safety of the product are not going to be very high.

As you can see in the picture, two resistant conductors have been used; the conductors were not fixed in meander bends to the aluminium foil which is to carry away and spread heat in order to prevent conductors from overheating and to prevent flooring from spot heat load. Resistant conductor crossing is also risky upon a weight load from current operation in the room, from the perspective of possible narrowing or breaking of electrical insulation and contingent short-circuit.

We were very surprised by heat foil grounding where a copper conductor was used in contact with an aluminium foil. These materials are directly forbidden to be in contact in electrical engineering to prevent the creation of an electrical link between these two metals and to prevent them from degrading.

As infracamera measurement shows, our truth concerning heat spot load of the floor in meanders and uneven distribution of temperatures on the floor has been proven again.

In the end, I would like to point out two facts, besides manufacturer’s recommendations:

1. The resistant conductor is only insulated by means of one insulation and in the meander bend the product can be considered product of protection class 0 that has to be supplemented by further insulation upon floor laying. However, I have not read anything about this anywhere although the application can be life-dangerous without additional insulation.
2. 2. Although the manufacturer indicates that the product can be used directly under the carpet, this is contrary to safe operation of the product and I consider it to be a life-threatening application.

After the client studied test results and read this article, we won another applicant for the ECOFILM system.