Fenix LDTS - Manual (Page 11)

11
2. Using mats for moderately accumulating and direct floor heating
a) Dimensioning

If the floor heating is intended to be used to warm the floor surface for short intervals, we recommend
that the heating mat be installed close to the floor’s surface.

If the floor heating is to be used to heat a room, it is necessary to know the thermal loss value for the
building in order to select the most suitable heating system. The installed output should correspond to
a multiple of 1.1 to 1.3 times the calculated thermal loss for the building. If it is impossible to install
the calculated output into the entire floor area, an additional heating device must be used (for example,
direct heating convectors).

For short-term heating and for bathrooms, we recommend using the LDTS 160W/m 2 . For rooms
occupied for long time periods, we recommend using the LDTS 80, 100 and 120W/m 2 .
b) Installation – moderately accumulating system
INSTALLATION INTO CONCRETE
(self-leveling materials)

First read Clause 1 in the General Terms and Conditions.

The concrete mixture must be sufficiently compact so that the layer contains no air bubbles, cavities
and the like and ensures full contact with the heating cable. Compacting must be done carefully, by
hand, to prevent damaging the cable. In no case may immersion vibrators be used.

The concrete mixture must contain so-called plasticizers (for example, MAPEI- DYNAMONSR or
PLANICRETE).

When concreting, it is necessary to bear in mind that in case of a break in work longer than 60 minutes
the concreted areas do not join fully. Therefore, in case of a longer break, it is necessary to create an
adhesive connecting bridge (e.g., by penetrating or in another manner).

The areas where the heating mat is to be placed must be insulated thermally using polystyrene
(expanded polystyrene of at least 25kg/m
3
or, even better, extruded polystyrene with a long-term
thermal resistance of 75°C) or mineral floor board 70–80mm thick. In case of a moderately
accumulating system, the heating mat may be placed directly on the thermal insulation (LDTS 80, 100
and 120W/m
2 – expanded polystyrene, LDTS 160W/m 2 – extruded polystyrene).
When installing the reinforcing steel, you must pay close attention to avoid damaging the cable’s
insulation.