Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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~UPPORTING PLATE FOR UNDERFLOOR HEATING
The present invention generally relates to the installa-
tion of underfloor heating, and more specifically relates
to a supporting plate for underfloor heating, for suppor-
ting underfloor heating pipes, which consists of a plate
of a material having good thermal conductivity and being
provided with at least one upwardly open groove extended
in the longitudinal direction of the plate and being
intended for receiving said underfloor heating pipes.
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Underfloor heating is presently installed above all in
residential buildings, offices, hotels and sports facili-
ties etc, but will in the future also be installed to an
ever increasing extent in industrial plants. Among the
advantages of employing underfloor heating complementary
to conventional heating, it may above all be mentioned
that underfloor heating is ideal for the comfort of a
room, since it provides optimum temperature distribution
in the room, i.e. the temperature is slightly higher at
the feet than on a level with a person's head. Underfloor
heating is also advantageous in the aspect of consumed
energy, since the energy consumption for the conventional
heating may be lowered essentially when the floor is
warm. The reason for this is that a person finds the room
warmer if his feet are warm, which means that the air
temperature in the room may be lowered thanks to the
underfloor heating.
In an underfloor heating system low temperature water
(having a temperature ofl30-45C depending upon the type
of floor) is allowed to circulate through pipes laid in
loops in the floor. Thereby the laying of the pipes is
more or less complicated depending upon the type of floor
structure. In connection with casting the underfloor
heating loops into a concrete floor, the pipes are simply
tied to the reinforcement, whereupon the floor is cast
and is provided with a suitable type of flooring. When
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installing underfloor heating in connection with the
laying of so called floating floors, i.e. on concrete,
particle board or wooden floors, underfloor heating
sheets of cellular plastic, for instance Styrolit, are
laid out over the floor. These sheets are provided with
grooves in which a corresponding groove of a heat
-emitting plate, for instance of aluminum and of the kind
indicated in the introduction, is pushed down, whereupon
the pipes are laid in loops in these grooves and the sub-
floor, such as parquet or particle board, is finally
laid.
When installing underfloor heating in connection with the
above described types of floor structures the actual
installation of the underfloor heating or the laying of
the flooring presents no problem, since all work is
carried out against a structural or bearing base or
bedding. However, when installing underfloor heating in
connection with floor structures with joist frame it is
necessary to solve the problem of supporting the actual
underfloor heating installation and of providing a
bearing structure that may be employed as a working floor
during building. According to a first principle the
underfloor heating system may be installed on the joist
frame, whereby a secondary spaced boarding is laid across
the joist frame, whereupon the heat emitting plates are
positioned on the secondary spaced boarding and are
nailed thereto with the groove positioned between two
adjacent boards of the secondary spaced boarding.
The disadvantage of th'is' solution is that,it may only~be
employed in the case where the building structure permits
ithat the floor is raised from the joist frame, and more~
over it is obvious that this solution results in an un-
`35 acceptably high cost of material and cost of labour on
account of the secondary spaced boarding. In this connec-
tion it should also be mentioned that when the secondary
spaced boarding is laid it is necessary to nail every
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other pair of boards to the joist frame and to leave -
every other pair loose, the reason for this being that it
must be possible to lay out the loop of underfloor
heating pipe (which in many cases may be up to for -
instance 200 meter long) without passing the pipe under
the boards of the secondary spaced boarding.
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According to another principle the underfloor heating -
system may be installed in the joist frame whereby a
secondary spaced boarding is laid as in the previous
case, but in this case along the joist frame and on a
level therewith. However, this solution suffers from the
- drawback that further work has to be carried out since
bearing rails or so called nogging pieces will first have ` j~
to be nailed to the floor joists, extended between the
same, in order to serve as a base or support for the
secondary spaced boarding. ~ ~;
Thus, a general object of the invention is to provide a
supporting plate for underfloor heating of the kind indi~
cated in the introduction, by means of which the above
described disadvantages in connection with the installa-
tion of underfloor heating systems may be eliminated. ~ -
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A more specific object of the invention is to provide a
supporting plate for underfloor heating, which in itself
may~carry substantial load and which at the same time`~
provides an optimum heat distribution and heat emission.
.
30 These objects are achieved by means of a supporting plate ~ j
` for underfloor heating comprising the fea~tures indicated
in the characterizing portion of the enclosed claim 1.
~ Advantageous further developments of the supporting plate
- 35 for underfloor heating according to the invention are -~
indicated in the dependent subclaims.
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The invention is described more closely below, with refe-
rence to an exemplifying embodiment thereof which is
illustrated in the enclosed drawings, on which:
Figs. la and b illustrate the supporting plate for under-
floor heating according to the inventionj in a perspec-
tive view as viewed obliquely from above and obliquely
from below, respectively,
-
Fig. 2 is a perspective view as viewed obliquely from
below, of the supporting plate for underfloor heating
according to Figs. la and b, but with the load distribu-
ting plate removed, ' '~;'''
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15 Fig. 3 is a perspective view as viewed obliquely from ' ~ -
above, of the removed load distributing plate, ' ''
Fig. 4 is a partial perspective view of an underfloor - -
heating installation employing the supporting plate for
20 underfloor heating according to the invention, and ~'
Fig. S is a partial perspective view of a prior art '~
underfloor heating installation. '
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As illustrated especially in Figs. la and lb the suppor-
ting plate 1 for underfloor heating according to the
invention basically consists of a plate which is substan-
tially rectangular in a plan view and which in the illu-
strated embodiment is provided with three groves 3, 4, 5
extending along the full length of the plate 2, at mutual
' distances'from"e'ach other. The two outer grooves 3, 4 are~ ' -
intended for receiving underfloor heating pipes 15 (see
Fig. 4) which during the installation are pressed down
into the grooves, and the middle groove 5 is an expansion
groove, the function of which will be described more
closely below.
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Z003637
A basic object of the plate 2 is to provide an optimum
heat emission with the heat as uniformly distributed over
the surface of the plate as possible, and accordingly the
plate 2 consists, in a manner known per se, of a material
having good thermal conductivity, preferably aluminum. In
order to obtain the good heat emission and heat distribu-
tion the different parameters plate thickness, material
and number of grooves for receiving underfloor heating
pipes ~ay be varied, but the experience is that the best
result, generally speaking, is achieved with an aluminum
plate having a thickness of 0,6 mm and being provided
with two grooves 3, 4 for underfloor heating pipes and an
- expansion groove 5 provided therebetween. Moreover the
outer dimension of the plate 2 is preferably approximate-
15 ly 60 x 120 cm, whereby the width is determined by the
space between the floor joists.
Regarding the above-mentioned plate thickness of 0,6 mm
it should also be mentioned that this thickness is
preferable in another respect, since the plate must be
sufficiently soft or flexible to permit that the under-
floor heating pipes 15 are pressed down into the grooves
- 3, 4 which are slightly narrower than the outer dimension
of the pipes in order to securely retain the pipes there-
in.
From the figures it is also clear that the plate 2 i8
curved or crowned in an upward direction towards the open
side of the grooves 3, 4, 5, and the purpose of this is
to guarantee a good preloaded engagement between the
plate~and-the flooringlto be laid on top of it. This good
engagement between the plate and the flooring is of vital
importance for obtaining good conduction of heat to the
sub-floor, since air pockets between the plate and the
sub-fIoor immediately impairs the efficiency of the
. .
system. In this connection it should also be pointed out
that the above given width of the plate, as well as the ;
width mentioned later on in the specification, refers to
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2003637
the dimension of the plate before it is curved or
crowned.
As mentioned above the plate 2 is provided with at least
one expansion groove 5, the purpose of which is to take
up the lateral expansion of the plate 2, on the one hand
when the underfloor heating pipes 15 are pre~sed into the
grooves 3, 4 and on the other hand when the curvature or
crowning of the plate is pressed down in connection with
laying the sub-floor or flooring. Without this expansion
groove the material would have nowhere to go when this
lateral expansion takes place, which would cause the
flooring to rise or would put the plate 2 in such a state
of strain that it would produce a banging plate sound
when the sub-floor or flooring is loaded. Moreover the
expansion groove 5 takes up the lateral expansion occur~
ring when the heat is turned on in the system. To
summarize, this means that the expansion groove 5 enables
all lateral expansion to be taken up therein such that
the conctact between the plate and the sub-floor is as
close and even as possible, which essentially improves
the efficiency of the system.
A second basic object is that the supporting plate 1 for
underfloor heating shall be bearing, i.e. it shall at
least be able to take up the load of a person standing on
it, and for this purpose the plate 2 is provided with a
number of load carrying members 6 at its bottom or under-
side. In the illustrated embodiment these load carrying
members 6 consist of strips provided at mutual distances
from each otherlalongithè length of the p1ate 2. Thelends
of the strips 6 are attached to the respective long side
of the plate 2. Thus, the strips 6 are extended transver-
sely across the plate. The number of strips may vary, but
for a plate 2 having a length of approximately 120 cm it
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has proven to be adequate to employ four or preferably
five strips. The strips 6 are preferably manufactured
from an appropriate steel quality and are attached to the
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Z003637
long sides of the plate 2 for instance by stamping out
lugs 6a at the ends of the strips, which lugs are brought
up through corresponding apertures, not illustrated in
detail, in the plate and are bent down against the plate.
Although it has proven to be preferable to employ steel
strips, specifically with regard to the attachment of the
strips to ~he plate 2, it should be emphasized that any
other material (such as plastic) may be employed which in
a corresponding manner provides the load carrying func-
tion without being elongated or stretched to any essen-
tial extent. In such cases the attachment of the strips
is carried out in a manner suitable for the respective
material.
As illustrated especially in Fig. 2 the strips 6 are of a
length slightly exceeding the width of the plate, whereby
the strips 6 will hang down in a curve from the underside
of the plate 2 so as to act as a hammock in carrying a
load distributing member 7 positioned between the strips
6 and the plate 2. In the illustrated and described
embodiment the strips are approximately 8 mm longer than
the width of the plate 2.
The load distributing member which in the preferred
embodiment consists of a plate or sheet 7, i8 basically
provided for distributing a load applied to the suppor-
ting plate 1 for underfloor heating, between the load
carrying strips 6,-but also improves the efficiency of
the underfloor heating system since it insulates the
plate 2 downwards.
The load distributing sheet 7 preferably consists of
cellular plastic, such as Styrolit, and has a generally
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rectangular shape in a plan view. The length of the sheet
35 7 is substantially the same as that of the plate 2, but ; ;~
the width of the sheet 7 is slightly smaller (for
instance approximately 55 cm) in order to leave a portion ;~
of the long side of the plate 2 free. This portion of the - ; -
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200~637
long side of the plate 2 is intended to be placed on the
floor joists and to be nailed thereto. In the illustrated
embodiment the maximum thickness of the sheet 7 is
approxiamtely 50 mm.
As illustrated in Figs. lb and 3 the sheet 7 is provided
with longitudinal grooves 8 which in the assembled condi-
tion coincide with the grooves 3, 4, 5 of the plate 2 and
receive the latter, and transversal grooves 9 which in
the assembled condition coincide with and receive the
strips 6. As partly illustrated in Fig. lb the transver-
sal grooves 9 are curved corresponding to the curvature
of the strips 6, i.e. the grooves 9 have their smallest
depth in the middle of the sheet and are deepest at the
long sides of the sheet. The purpose of this is naturally
to provide an even contact for the load carrying strips 6
against the sheet 7 and thus an even distribution of the
load. Fig. 3 also illustrates that at its upper side the
sheet 7 is provided with a number of cavities 10 intended
to reduce the consumption of material and thereby the
~ost of the sheet 7. The cavities 10 are arranged such
that they do not critically impair the strength of the
sheet, which means that they are not provided directly
adjacent the grooves 9.
In order to prevent transport damage caused by the sharp
edges and corners of the plate 2 it may be preferable to
m~ke the sheet 7 approximately 5-10 mm longer than the
plate such that the sheet extends somewhat past the short
sides of the plate.
Through the combination of the plate 2, the strips 6 and
the sheet 7 a unit is provided which at least carries ~he
weight of a person although the plate 2 is dimensioned to
provide optimum heat emission and heat distribution and
accordingly is not bearing in itself. Instead the load is
carried by the strips 6 acting as a kind of hammock due
to the fact that the load applied to the plate 2 is
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evenly distributed between the strips by means of the
load distributing sheet 7 positioned between the plate 2
and the strips 6.
The use of the supporting plate for underfloor heating
according to the invention in connection with installing
an underfloor heating system will now be described, and
as a comparison a conventional underfloor heating in~tal-
lation will initially be briefly described. Fig. 5
partially illustrates an underfloor heating installation
of the kind mentioned in the introduction to the specifi-
cation, i.e. with the underfloor heating installed in a
- joist frame.
Fig. 5 illustrates that in this case bearing rails 11
will initially h'ave to be provided between the floor
joists 12, and said bearing rails are attached by means
of special clamps or supports 13. A Recondary spaced
boarding 14 is then laid on the bear-ing rails 11 on a
level with the floor joists 12. In order to provide an
opening for the return loops of the underfloor heating
pipes 15 every other pair of boards in the secondary
spaced boarding are made shorter and moreover recesses 16
are provided in the floor joists at the location where
the pipes 15 pass said floor joists.
When the secondary spaced boarding has been laid the heat
emitting plates 17 are laid out, and as illustrated in
Fig. 5 these plates ronsist of a flat, rectangular plate
which in its center is provided with a longitudinal
groove in which the' underfloor heating~ pipes 15 are
secured.
In comparison to this prior art method the use of the
supporting plate 1 for underfloor heating according to
the invention makes it possible to install the underfloor
heating system directly without all the previously
required preparatory work such as the nailing of the
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, 10
bearing rails and the laying of the secondary spaced
boarding. With reference to Fig. 4 it is obvious that the
supporting plates 1 for underfloor heating are simply
laid out one after the other between the floor joi~ts 12
and nailed thereto at the above mentioned, free portions
of the longitudinal edges of the plate. This completes
the installation of the supporting plate for underfloor
heating and the plates may without any problem be loaded
in connection with the laying of the underfloor heating
pipes 15 in loops. As illustrated in Fig. 4 a free space
must be left for the return loop of the underfloor
heating pipe, i.e. so that the plates do not completely
cover the floor, and partly for this reason the insula-
tion obtained by means of the load distributing sheet 7
is supplemented with a conventional isolation 18 in the
same manner as in connection with the prior art method
according to Fig. 5.
:
In the light of the above description it is now clear
that the objects of the present invention as stated in
the introduction, are achieved by means of the described
supporting plate for underfloor heating, namely: ~
- that the heat distribution and the efficiency of the - ``i
system are optimized by employing the comparatively
thin, crowned aluminum plate which contributes to an
even, close contact without any space between the plate
and the sub-floor, and also by using the insulating
distribution sheet;
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- that the supporting~piate for underfloor heating is ;--
made bearing by employing the load carrying strips
being attached to the plate and the load distributing
sheet installed between the plate and the strips; and ~ -
- that the material cost as well as the installation cost -
may be essentially reduced due to the fact that the
supporting plate for underfloor heating is bearing in
200~6"7
1 1
itself so that there is no need for the secondary
spaced boarding for carrying the underfloor heating
system.
Although the invention has been described above with
specific reference to a preferred embodiment thereof, it
should be obvious that the invention also comprises such
alterations and modifications of the illustrated embodi-
ment that are obvious to a man skilled in the art.
Examples of such modifications are the choice of other
materials having similar properties as those materials -
given as examples herein, altered dimensions for the
plate and/or the sheet and different numbers of expansion
grooves, grooves for receiving underfloor heating pipes
and load carrying members. The invention is likewise not
restricted to those examples of load carrying and load
distributing members used in the illustrated, preferred - :-~
embodiment, but also comprises variants thereof which ~ -
serve the same purpose. Thus, it is possible to provide
the load carrying member in the shape of rods, a net or
as a thin plate/foil having substantially the same dimen-
sion as the plate 2, whereby the load distributing member
is modified in accordance therewith. Accordinyly, the
in~ention shall only be restricted by the enclosed patent
claims.
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