EP1157172A1

EP1157172A1 - Arrangement for heat distribution in cavities at floor structure

Info

Publication number: EP1157172A1
Application number: EP00906838A
Authority: EP
Inventors: Sven-Hugo Thorstensson
Original assignee: Insurance Technical Services I Goterborg AB
Current assignee: Insurance Technical Services I Goterborg AB
Priority date: 1999-02-03
Filing date: 2000-02-03
Publication date: 2001-11-28
Also published as: SE9900359D0; WO2000046457A1; AU2839500A; JP2002536615A

Abstract

The invention relates to a method of building in an airborne floor heating system in a floor structure, constructed so that warm air can circulate in closed cavities (4) between a heat-insulating material (10) at the lower portion of the floor structure and a heat-conducting and heat-distributing layer (14) at the upper side of the floor structure. The closed cavities (4) is divided with vertical insulations (17) with the same partition as the rooms in the upper floor where individual temperature is desired. The warm air that has been heated in a special designed heating unit (5) built-in the floor structure, is blown out via ducts (16) to said cavities (4) where the warm air emits warmth to the heat-conducting and heat-distributing layer (14). In the opposite section of the cavities from which the inflate via ducts (16) is made, there are ducts (18) connected for extortion and reheating of the air in the heating unit (5). The air temperature and thereby the emitting of heat to the upper floor is regulated by room thermostats placed in the upper room or rooms where an individual temperature is desired.

Description

ARRANGEMENT FOR HEAT DISTRIBUTION IN CAVITIES AT FLOOR STRUCTURE

The invention relates to an arrangement according to the preamble of claim 1.

When arranging floor structures, the arrangement can be made either by mounting prefabricated whole plates of concrete or other suitable material, or by building the floor structure plate at the building site.

In those cases where floor heat should be used for warming up the upper floor, the material on top of the floor structure should have good heat-conducting and heat-distributing characteristics, to obtain a good function and heat distribution.

When using prefabricated concrete plates or prefabricated elements of other material in floor structures, this should be arranged in or on a relatively thin layer of heat-conducting material on top of the floor structure, if floor heat is to be used. This results in that the heat mediums that exist today and can be used for this purpose is either warm water in tubes or electric cable.

When using these two floor heat alternatives, there is a very large risk for damages and therefore water leakage and rupture of the electric cable respectively when work is performed on top of the floor structure.

To obtain a good function, even when using floor structures of concrete or other material built in site, the two floor heat alternatives mentioned above, tubes and electric cables respectively, should be mounted with a relatively small covering layer on top of the floor structure with the same risk for damages as mentioned above. If the risk for damages on said tubes and electric cables respectively should be reduced, these ducts should be mounted with a larger distance from the top of the floor structure and downwards in the floor structure plate.

This implies that to mount these tubes and electric cables, respectively, further inside, in the construction, site built floor structures will be the only realistic alternative where floor heat should be used.

When raising larger buildings, floor structures made of concrete are substantially used, which are often provided with some type of sound insulation on the top to achieve an acceptable sound level between the floors.

Normally, floor structures of concrete have relative good air sound insulating characteristics, but relatively unsatisfactory step sound insulating characteristics.

To fulfil the demands on air sound insulation in other floor structures than those of concrete, extensive and cost raising actions are often required.

Before casting, a mould should be mounted at the underside of the future concrete plate at site built floor structures. This mould must be supported underneath with so called braces and ledgers, which is a time consuming and expensive work and hinders passage.

Tubes for ventilation, drain and water, which should be placed horizontally in connection to the floor structure, must often be arranged or built-in under the floor structure in site built as well as in prefabricated floor structures. This is a cost raising action which also results in that the building height between the different floors in a building is negatively affected.

THE OBJECT OF THE INVENTION

The object of the invention is to solve the above mentioned problem in an effective way regarding economy and function, by making it possible to, in a site built floor structure, build in a floor heating system with air as heat carrier, where the risk of damages in the heating system through mechanical damage from the top and bottom respectively of the floor structure is eliminated, at the same time as a good heat distribution is achieved through that the top of the floor structure is provided with a concrete layer or other similar heat-conducting and heat-distributing material.

Furthermore, the object is to make the heated air circulate in a closed cavity inside the floor structure, between a heat-insulating layer at the bottom of the floor structure and the heat-conducting layer at the top of the floor structure and to provide adaption to different sound demands between upper and lower floors will be adjusted by variation of the building height of the floor structure and the comprised material.

Owing to that the cavity between these both layers is closed, particles and other contaminations from this closed cavity in the floor structure, can be prevented from being transported to spaces where people resides with risk for allergies and other injuries, or that air can be brought into the closed cavity inside the floor structure, which prevent spores and bacteria to be brought into this cavity.

The cavity between the bottom and top layer is divided by heat-insulating vertical insulations, which can correspond to the room partition in the upper floor.

The air which is blown into the different insulated cavities in the floor structure, could if desired, be heated to different temperatures by a simple adjustment via thermostats in the different upper rooms. This enables that desired temperature can be provided in these different rooms.

Moreover, the floor structure should be able to be built with a large span, similar to beam systems and prefabricated floor structure plates of concrete or other material that exist today, without using cost raising so called braces and ledgers.

Furthermore, the object is also to be able to arrange the tubes for ventilation, drain and water inside the floor structure, between the heat-insulating layer at the bottom and the heat-conducting layer on top of the floor structure, with the same possibilities to easy reach for service and reparation as a separate substructure below the floor structure provides. This results in savings in material as well as in work cost.

The solution of the problems appears from the characterising part of the claim 1.

DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a length section of a site built floor structure with supporting beam elements of steel, comprising a framework beam with flange 1 of angle iron and web of spar 2 and 3 of U-formed steel profile, which at its underside is provided with insulating material against heat, sound and fire 10 and 13, which is provided against a secondary beam of plate 11.

Fig. 1 also shows a heat-conducting and heat-distributing material 14 on top of the floor structure.

Fig. 2 shows a cross section of the supporting beam of the floor structure in Fig. 1, and how secondary beams 11 for the heat, sound and fire-insulating material 10 and 13 are arranged against the supporting framework beam by being rested on a vibration-absorbing and sound-insulating material 12.

Fig. 3 shows a horizontal cut through the U-formed web of spars 2 and 3 between the heat- conducting material provided on top of the floor structure and the insulating material provided at the bottom of the floor structure.

Fig. 4 shows a cross section of a special designed heating unit 5 which is built-in the floor structure and in which heating of air is made, which air is adapted to circulate in a closed cavity 4 in the floor structure.

Fig. 5 shows a horizontal cut through the floor structure, with the special designed heating unit 5 and ducts 16 and 18 connected to it for air circulation in delimited sections of the floor structure. Fig. 6 shows a cross section in a larger scale of the lower portion of the framework beam in Fig. 2, where secondary beams 11 in an angle of 90° is connected and rested on the lower flanges 1 of the framework beam on a vibration and sound-insulating material 12.

Fig. 7 shows a cross section of secondary beams 11 and fastening by means of screws of the underlying fire and sound-insulating material 13.

Fig. 8 shows a cross section of the floor structure where it is provided with a vertical heat- insulation 17 to make individual regulation of the temperature within different insulated cavities possible.

Fig. 9 is a diagram that shows the result of air sound measurement in a floor structure according to the invention, with in this case a 400 mm high framework beam and where the and sound insulating material at the bottom of the floor structure comprises 2 x 13 mm gypsum boards.

Fig. 10 is a diagram that shows the result of a step sound measurement in a floor structure according to the invention, with in this case a 400 mm high framework beam, complemented with 18 mm plywood and 3 mm decibel mat on top of the floor structure and where the fire and sound-insulating material at the bottom of the floor structure comprises 2 x 13 mm gypsum boards.

DESCRIPTION OF PREFERRED EMBODIMENTS

The invention relates to a site built floor structure with supporting beam elements and web of spar with an integrated heating system, with air as heat carrier, where the risk for damages on the heating system or damages from the heating system on adjacent sections of the building by mechanical effect from the underside as well as the upside of the floor structure is eliminated.

In Fig. 1, the supporting portion of the floor structure is shown where the beam element in this example comprises a framework beam with flange of angle iron 1 and a web of spar of U-formed steel profiles 2 and 3, arranged so that the upper and lower portions of the beam comprise two flanges 1 , which are held in a distance and in connection with each other by several U-formed web of spars 2 and 3. See also Fig. 2, 3 and 6.

The two flanges 1 at the upper and lower portion of the beam are made of angle iron, arranged and attached to both sides of the U-formed web of spars 2 and 3 according to Fig. 1-3 and 6.

The fastening is done in such a way that the flanges 1 at the ends of the web of spar 2 constitute an angle of 90° in direction away from each other and turned so that the extending part of the flanges lies at the same level as the ends of the web of spars 2 according to Fig. 2.

In the longitudinal direction of the framework beam, the U-formed web of spars (2) are arranged diagonally according to Fig. 1 and meets each other between the upper and lower according to Fig. 1. Where these web of spars 2 meets each other and are attached between the lower flanges 1 further U- formed web of spars 3 are arranged and attached between these lower and upper flanges 1 in such a way that they constitute an angle of 90° against the lower and upper flanges 1.

Above described supporting portion of the floor structure can comprise of other suitable material and design suitable for the supporting function, provided in such a way that air can freely circulate in a cavity between the bottom and top portion of the beam element, which is held in a distance and in connection with each other through a web of spar.

Support for the supporting framework beams according to Fig. 1, or other type of beam element or stiffening beam, during building process as well as after completion of the building, should only be those walls or other building elements which are intended as stationary element in the building after its completion, without using cost raising so called braces and ledgers during building.

The air which is intended to circulate in the described cavity 4 according to Fig. 1, 2, 4 and 8 between the lower and upper beam elements, is heated in a purpose built heating unit 5 according to Fig. 4 and 5. This heating unit is built-in in a plate box provided with double caps 6 on the top, between which a heat and sound insulated material 7 is provided. The plate box is mounted so that the upper cap lies in level with the finished floor surface on top of the floor structure according to Fig. 4.

The sides of the plate box are provided with holes in the sides 8 and 9 and can be designed according to Fig. 4 and 5 for connection of the ducts 16 and 18 for transport of the air heated by the heating unit 5.

The exhaust of warm air from the heating unit 5 out to the floor structure is performed by four of the total amount of eight holes 8 according to Fig. 4 and 5 and intake of air for reheating after having emitted heat to the floor structure is sucked in through the remaining four holes 9.

To obtain a good function with respect to heat and sound insulation, the lower portion of the floor structure is provided with a suitable insulation material 10 according to Fig. 1, 2, 4, 6 and 8 which is arranged on the secondary beams of plate 11 according to Fig. 1-4 and 6-8 or other suitable material and that these secondary beams 11 in turn are supported and connected in an angle of 90° according to Fig. 3 on the lower flanges 1 of the supporting framework beams or other suitable type of beam element on a layer of vibration and sound insulating material 12 according to Fig. 2 and 6.

In the preferred embodiment, the secondary beams 11 are made of plate and are mounted at a c/c distance of 400 mm. They are formed with a vertical web and in their lower part provided with horizontal flanges according to Fig. 7 for support of the insulating material 10, which in this case consists of a 120 mm mineral wool with a density of 28 kg/m³.

Furthermore, the bottom of the floor structure is provided with a fire and sound insulating material 13 according to Fig. 1, 2, 4 and 6-8 which is screwed into the secondary beams 11 according to Fig. 7, which results in that these secondary beams 11 including the insulating material, with respect to heat and sound 10, as well as said material underneath against fire and sound 13, will only be applied to the supporting floor structure construction by resting on the vibration and sound-insulating material 12 according to Fig. 2 and 6. The upper portion of the floor structure is provided with a heat-conducting and heat-distributing material 14 according to Fig. 1, 2, 4 and 8. Together with the heat-insulating material 10 in the lower portion of the floor structure, this leads to that heat from the circulating warm air from the heating unit 5 according to Fig. 4 and 5 is guided upwards and equally distributed through the heat- conducting and heat-distributing material 14 to the upper floor.

In the preferred embodiment, the heat-conducting and heat-distributing material 14 consist of a thin layer of concrete which is casted on top of a 0,85 mm profiled steel plate 15 according to Fig. 1, 2, 4 and 8 which is mounted with the profiles perpendicular on top of the supporting framework beams and which is dimensioned both as supporting part during the casting process and as bottom reinforcement after completion of the floor structure. Where it is needed for the static dimensioning, it is complemented by top reinforcement.

Exhaust of warm air from the heating unit 5 out to the floor structure is made through that ducts 16 according to Fig. 1, 2, 4, 5, and 8 connected to the four holes 8 on the heating unit 5 are arranged in the cavity of the floor structure between the heat-insulating material 10 at the bottom and the heat- conducting and heat-distributing material 14 at the top.

The length of the ducts are adjusted according to the partition of rooms in the upper floor where individual temperatures are desired. One or several of the four ducts 16 for exhaust of warm air according to Fig. 5, may be arranged below the respective room in the cavity of the floor structure between the heat-insulating material 10 at the bottom and the heat-conducting material 14 at the top, depending on size and calculated need of capacity in the upper rooms. Thus, each heating unit 5 can cover the capacity needed in one or several rooms in the upper floor.

To achieve an individual temperature in the different rooms in the upper floor, the cavity is divided between the heat-insulating material 10 at the bottom and the heat-conducting and heat-distributing material 14 at the top of the floor structure with vertical insulations 17 according to Fig. 8 of a heat- insulating material with the same partition as the rooms in the upper floor where individual temperature is desired. The duct or ducts 16 aimed for blowing warm air into the cavities in the floor structure divided by insulations, are drawn from the heating unit 5 according to Fig. 4 and 5 up to and through the vertical heat-insulations 17 according to Fig. 8.

In the opposite section of the insulated cavity in the floor structure, a duct or ducts 18, according to Fig. 5 for exhausting the air that has been blown into the cavity, have been drawn from the heating unit 5 and through the vertical insulations to the cavities in the floor structure, in the same way as exemplified in Fig. 8.

The free circulating air that moves from the inlet duct or inlet ducts 16 through the insulated cavity to the outlet duct or outlet ducts 18 and reheating in the heating unit 5. During this transport, heat has been emitted to the heat-conducting and heat-distributing material 14 at the upper portion of the floor structure.

The system is totally closed, which means that no air exchange with new air exists. This considerably reduces the risk for forming bacteria cultures or unhealthy particles and spores where humans reside.

In those cases where ducts for ventilation 19, drain 20 and water 21 according to Fig. 1 or other type of ducts exist in connection with the floor structure, these are aπanged in the closed cavity between the heat-insulating layer at the bottom of the floor structure and the heat-conducting and heat- distributing layer at the top.

Because the secondary support 11 of insulating material with respect to heat and sound 10 as well as the material underneath against fire and sound 13 will only be applied to the supporting frame construction by resting on the vibration and sound- insulating material 12 in combination with that variation of the height of the web of spar and therefore the height between the heat-insulating material 10 at the lower portion of the beam element or the stiffening beam and the heat-distributing material 14 at the upper portion of the beam element or stiffening beam can be adjusted, very good air and step-insulating values can be obtained and adjusted to the different demands in floor structures in buildings for different purposes. According to Fig. 9 it is clear that the measured value of the air sound-insulation for the preferred embodiment with in this case a 400 mm high framework beam and where the fire and sound- insulating material at the bottom of the floor structure consists of 2 x 13 mm gypsum boards, gave a value of R'w + C_50.315O equal to 58 dB, where C = - 1 dB. This value of 58 dB is only 2 dB from the best sound class A according to the Swedish standard SS 02 52 67, regarding the cavity between apartment and space outside the apartment. The measurements regard a reference area of 10,9 m² and a room volume of 27,5 m³. The thinner curve shows the measured values according to the columns to the right in the diagram, while the thicker curve is a reference curve for air sounds. The air sound measurement is made according to ISO 140-4. The summarized reduction number R'w and the adjustment term C₅₀.₃₁₅₀ are defined according SS-EN ISO 717-1.

According to Fig. 10 it is clear that measured value of the step sound level of the preferred embodiment with the same height of the framework beam as above, complemented with 18 mm plywood and 3 mm decibel mat on top of the floor structure and where the fire and sound-insulating material on the underside of the floor structure consist of 2 x 13 mm gypsum boards, gave a L'n,w + C₅₀.₂₅oo equal to 56 dB, where C, - 2 dB. This value fulfils the demands on step sound-insulation class C, in space in housing room from another space outside according to the Swedish standard SS 02 52 67. The sound class C corresponds to sound conditions which act as minimum demands in Swedish buildings. The measurements regard a room volume of 24,4 m³. In conformity with Fig. 6, the thinner curve in the diagram shows the measured values according to the columns to the right in the diagram, while the thicker curve is a reference curve for air sounds. Normalized step sound level L'n,w and the adjustment term C_{1 50}_₂₅₀₀ are defined according SS-EN ISO 717-2.

Within the scope of the invention, the invention may also be used in other types of floor structure constructions than the one described here for exemplification of the invention.

Claims

1. Method for arrangement of floor structure with beam element or stiffening beam (1), where the beam element or stiffening beam is held at a distance from and in connection with each other with means of a web of spar-unit (2) and (3), which design provides for adaption to different demands in sound insulation between upper and lower floors, respectively, and that warm air can circulate in one or several closed cavities (4) in the portion of the floor structure which is connected by the web of spar-unit (2) and (3) and that the form provides the heat in the warm air to be transferred to upper floor, c h a r a c t e r i z e d i n, that the beam element or stiffening beam (1) and the web of spar-unit (2) and (3) is made of steel or other material suitable for the static construction and that the beam element or stiffening beam at its lower portion is provided with a heat-insulating material (10) to control the heat brought to the floor structure from the air to the upper floor by providing a layer of heat-conducting and heat- distributing material (14) in connection with the upper portion of the beam element or stiffening beam and that a varying sound-insulation can be achieved by adaption of the height of the web of spar-unit.

2. Method according to claim 1, c h a r a c t e r i z e d i n, that the warm air is transported in a duct or ducts (16) from a heating unit (5) to a cavity or cavities in the floor structure insulated with heat-insulating material, adapted to correspond to the room partition in the upper floor in which an individual temperature is desired.

3. Method according to claim 1, c h a r a c t e r i z e d i n, that the air, from the moment when it leaves the duct or ducts in any section of the delimited closed cavity or cavities (4) in the floor structure, is sucked back to the heating unit (5), by a duct or ducts (18) connected to the heating unit and provided in the opposite end of the delimited closed cavity or cavities.

4. Method according to claim 1, characterized in, that the heat and sound insulating material (10) at the lower portion of the beam element or stiffening beam (1) is joined with a fire resistant and sound-absorbing material (13), which materials together are attached to the beam element or stiffening beam (1) by being rested on a vibration-absorbing and sound-insulating material (12).

5. Method according to claim 1, characterized in, that adaption to different sound demands between upper or lower floors can be achieved by varying the height of the web of spar-unit and thereby the height between the heat-insulating material (10) at the lower portion of the beam element or stiffening beam (1) and the heat-distributing material (14) at the upper portion of the beam element or stiffening beam (1).

6. Method according to claim 1-3, characterized in, that a heat-distributing heating unit (5) for distribution of warm air to the delimited or closed cavity or cavities (4), in the section of the floor structure that is connected by the web of spar-unit (2) or (3), is built-in the closed cavity or cavities and forms a closed system by connection to the closed cavity or cavities (4) via a duct or ducts (16) and (18).