WO2009019595A2

WO2009019595A2 - Loose radiant layer for floor radiant heating and cooling

Info

Publication number: WO2009019595A2
Application number: PCT/IB2008/002122
Authority: WO
Inventors: Gianluca Tolin; Andrea Cavaleri; Carlo Caldera
Original assignee: Politecnico Di Torino
Priority date: 2007-08-09
Filing date: 2008-07-31
Publication date: 2009-02-12
Also published as: WO2009019595A3; ITTO20070593A1

Abstract

A radiant floor comprising a series of heating pipes (3) combined to a radiant layer (2). Such radiant layer is essentially made of siliceous sand.

Description

"Loose radiant layer for floor radiant heating and cooling" ***

TEXT OF THE DESCRIPTION The present invention generally relates to radiant floors. More particularly, the present invention relates to radiant layers usable in radiant floors.

Radiant floors are composed in their essential elements by a radiant layer inside which there are the heating pipes where the thermal carrier fluid passes through and an underlying insulation layer to limit the downward heat flows. Radiant floors can moreover be provided with an insulating perimetrical band that aims to contain horizontal heat flows. The radiant layer is ^orrverϊtϊόhally realised in conglomerate of concrete, to which additives can be added also to improve the heat exchange performances.

The use of a concrete conglomerate entails relatively long time of work for the realisation due to the necessity to harden of such conglomerate.

The present invention proposes to realise the radiant layer using technologies that solve inconveniences related to the use of concrete conglomerates . According to the present invention, this purpose is reached thanks to the solution specifically displayed in the following claims. The claims are integral part of the technical teaching here supplied with relation to the invention. The present invention concerns a radiant layer for radiant floors essentially constituted by siliceous sand.

Some benefits resulting from the use of siliceous sand for the realisation of the radiant layer of a radiant floor can be summarized as follows. In the first place, the use of siliceous sand as radiant layer reaches an initial energy saving in terms of energy construction costs, related to the absence of cement binders that need baking at high temperatures. Still, it is obtained a reduction of the work finishing times since the sand radiant layer does not need waiting times for the hardening of the conglomerates.

In addition, the use of siliceous sand as radiant layer limits the formation of dust in the construction site. This is due to the absence of fine granulometries in the proposed invention, which instead are easily generated with conglomerates as concrete.

The use of a radiant layer made of sand allows easier inspection of the partition, better dismantling and increased capabilities of recycling and reuse.

Furthermore, the use of siliceous sand as radiant layer involves the absence of scrap production because the remaining material from one construction site may be moved and reused in a next one, then it eliminates some collateral operational phases such as the necessity to clean the tools at the end of the day of work when humid construction techniques are used, and finally, the use of radiant layer made of sand limits the need of specific equipment. Moreover, the use of sand with grain-size-mix inside the limits shown in Figure 4 (or in Table 1) , allows to get an unexpected efficacy in terms of thermal performances together wilh limiLed production of dust in the construction site (due to the absence of fine granulometries) .

The invention will be now detailed with reference to the annexed figures. The description is not limited to the analyzed examples, in which: o Figures 1 to 3 show three configurations of radiant floors; o Figure 4 show the grain-size of a preferred mix of siliceous sand. X-axis shows the grain size diameter in millimetres of the sieve. Y-axis shows the mass percentage of sand passing through the sieve. The curve with triangles and the curve with squares limit the grain-size mix of the preferred siliceous sand.

With reference to Figure 1, a radiant floor A, is realized in accordance to the EN 1264-1 with a floor coating 1, a radiant layer (support layer) 2, a protection layer 4, an insulation layer 5 and a structural layer 6. Heating pipes 3 are placed inside the radiant layer 2 and provide the necessary heat exchange to warm up the floor. Then the radiative heat transfer that is emitted from the floor superior surface obtains the room heating.

Vice versa it is possible to obtain a cooling effect on the room using cooled liquid in the heating pipes 3. Figures 2 and 3 show two other configuration of radiant floor. In figure 2 the heating pipes 2 are embedded in at least one conductive element with laminar shape 7. The element 7 has high thermal conductivity and supplies the function of increasing the thermal distribution of the heating pipes 3 plased below and possibly with direct contact with the same element 7. Both the conductive element 7 and the heating pipes 3 arc placed below the protection layer 4, partially inside the insulation layer 5. In Figure 3 between the radiant layer (support layer) 2 and the protection layer 4 there are two additional layers: a separation layer 8 and a levelling layer 9, with the heating pipes located in the levelling layer 9. The solution here described use radiant layer (support layer) made of siliceous sand in the configuration illustrated in Figure 1.

At a glance loose material like sand looks not suitable for making radiant layer. The grain nature of the sand involves the presence of interstitial spaces that can limit the thermal transmission performance of the radiant layer.

The use of siliceous sand with spherical grain and dimension such as the grain-size-mix reported in Table 1 allows, by the way, to reach the radiative performance obtained using conventional radiant layer made of conglomerates, reducing the disadvantages coming from the use of such conglomerates. The siliceous sand that is composing the radiant layer has humidity level preferably inferior to the 15% in terms of mass.

Table 1

Experimental evaluations showed that the thermal performance offered by solution with radiant layer made of sand, realized as above described, are comparable to the performance offered by solution with radiant layer made of conglomerate and are compatible with the conventional systems for the radiant heating.

Naturally, the details of realization and the execution shapes can be widely modified with respect to what described and illustrated above, without that the protection area covered by this invention is invalidated, as defined in the annexed claims.

Claims

1. Radiant layer (2) for radiant floors (A) heating and cooling, characterized in that said radiant layer (2) consists of siliceous sand.

2. Radiant layer according to claim 1, wherein the siliceous sand consists of spherical grains.

3. Radiant layer according to claim 1, wherein the siliceous sand presents grains having grain size lower than 10 mm.

4. Radiant layer according to claim 1, wherein the siliceous sand presents grains having grain size in the range of 0.05 to 10 mm.

5. Radiant layer according to claim 1, wherein the siliceous sand presents grains having grain size in the range of 0.25 to 10 mm.

6. Radiant layer according to claim 1, wherein the siliceous sand presents grains having grain size in the range of 2 to 10 mm.

7. Radiant layer according to claim 1, wherein the siliceous sand presents a moisture content lower than 15% of mass.

8. Radiant floor comprising a radiant layer according to any one of claims 1 to 7.