Patent Publication Number: US-3874441-A

Title: Thermal and acoustical protection of a light construction

Description:
United States Patent [1 1 [111 3,874,441  
 Duehene Apr. 1, 1975 15 THERMAL AND ACOUSTICAL 3,450,192 6/1969 Hay 165/49 PROTECTION OF A LIGHT CONSTRUCTION [76] inventor: George Duchene, 40 Avenue Victor Cresson, 92 lssy Les Moulineaux, France [22] Filed: July 27, 1972 [21] Appl. No.: 275,826  
 [30] Foreign Application Priority Data July 29, 1971 France 71.27905 [52] US. Cl. 165/1, 165/50 [5 1] Int. Cl F24f 3/00 [58] Field of Search 165/48, 49, 50, 22, 1  
 [56] References Cited UNITED STATES PATENTS 3.143.637 8/1964 Rifenbcrgn 165/49 Primary Examiner-Charles Sukalo Attorney, Agent, or Firml-lolman &amp; Stern [57] ABSTRACT A light construction comprising walls, a roof panel, ceiling and a partition wall or partition walls. A porous layer is inserted in the walls, the roof panel, the ceiling and the partition wall or walls. Water from a source of cold water flows through the porous layers in a capillary network and returns to the source after having received the heat given off by the premises within the construction. The porous layer may be constituted by a nonwoven web of material.  
 19 Claims, 8 Drawing Figures PAIEMEM H915 SEEEET 2 BF 2 .kW -ZEfi A 5 l EEE W/ 4 L l LEEEI 31&#39;&#34; rill dill/I114 It! 1111/ THERMAL AND ACOUSTICAL PROTECTION OF A LIGHT CONSTRUCTION BACKGROUND OF THE lNVENTlON A light construction of buildings whether it concerns the outside walls. partition walls, floors. ceilings or roofs affords well-known advantages:  
  economy as concerns the foundations. materials. skilled labour and time.  
  possibility of industrialisation to meet the increased demand for housing. offices. schools. hospitals. etc.  
  Thermal comfort in winter can be ensured by the conventional methods of heating and by the use of modern insulating materials such as glass wool. synthetic foams. etc. Howe ver, a light construction has two drawbacks compared to a heavy or traditional construction with the use of masonry or concrete. which appear intrinsically related to the low mass of the materials employed. namely:  
  insufficient thermal inertia which has an adverse effect on the comfort mainly in summer and a secondary adverse effect in winter;  
 insufficient acoustical insulation.  
 SUMMARY OF THE INVENTION An object of the present invention is to impart to light constructions qualities which are equal or superior to those of heavy constructions.  
  The invention provides a method for the thermal and acoustical protection of a light construction in which one or more compartments are defined by walls. pan els, llagstones, etc. comprising creating from a source whose temperature is different from the natural temperature within the construction. a bidimensional flow of water through a porous layer the two surfaces of which are in contact with fluidtight surfaces and which is disposed in one or more of the walls. panels or flagstones so as to be in a state of heat exchange with the compartments to be protected while being protected. if desired. from the exterior medium by a thermal insulator. the structure ofthe layer being such that the flow is of a capillary type. that is to say. the water in motion is practically without pressure.  
  According to this method, the idea is basically to leave outside the construction. for example in the ground. the mass considered necessary for the thermal protection and to expose in elevation or above the ground only a small part thereof which is at each instant flowing in the porous layers.  
  During a warm period. whereas the thermal inertia of a heavy wall retards the change in temperature of the internal surface of a premises when there is a variation in the surrounding temperature because the heat received is diffused by conduction in the inner layers of the wall. the present invention resides in receiving the heat received from the interior in the water flowing by capillary action through the porous layers and diffusing it by causing it to flow in a large mass maintained for example in contact with the ground. the flowing water also receives possibly a small amount of heat which has passed through the insulator, which perfects the efficiency of the latter.  
  The heat-to-weight ratio of a heavy wall and even a very heavy wall may be easily equalled by the heat-toweight ratio of the reserve of water employed. to which is possibly added the hcat-to-wcight ratio ofthe ground in thermal contact with this reserve. It is indeed known that at a depth of one metre the ground has a remarkable temperature stability.  
  The method according to the invention can be can ried out in two ways. namely by recycling the water and by the use of discarded water.  
  ln the first case. a mass of water contained in one or more cisterns or flexible vessels is buried outside or inside the building, for example in the basement. A suitable raising apparatus. for example a low-flow electric pump. draws off the fresh water from the bottom of the reservoir and conducts it to the roof top whence it is distributed in the porous layers of the roof. the ceilings. floors, partition walls or supporting walls. At the downstream end of the layers the water is returned to the reservoir by the effect of gravity.  
  Calculation shows that. for temperate climates. a total mass of water sufficient to ensure the comfort in summer is sometimes a very small fraction of the mass that the building would have bad if it had been constructed of masonry. For example. 80 m of water is sufficient for a Youth Club of I50 m area whose superstructure would weigh 200 metric tons for a traditional construction as against about It) metric tons for a light construction.  
  The manner of carrying out the method according to the invention by utilisation of subsequently discharged water is somewhat similar to the foregoing case. considering that the notion of a reserve of water is applied to the upstream end ofthe water circuit. in this case. there is employed either the water of the water mains of the town which is supplied under pressure to the top of the roof so that there is no need to install a pump. or water from a river. pond or lake in the vicinity. The water is discharged by way ofthe rain water discharge circuit of the building.  
  Calculation shows that in respect of temperate climates. there is required only a very small amount of water to ensure thermal comfort in the summer. For example. in the case of a Youth Club on the ground floor having area of ISO m&#39;-. the underroof of which alone is treated. at the hottest hour of the day (32C outside temperature) and for an occupation of the premises by 50 persons. if the mains water has a temperature of 20C. a temperature of 26C is maintained within the premises by a flow of water not exceeding l t /hi.  
  The method according to the invention also permits affording a thermal protection in the winter in addition to. or instead of. a traditional heating system by the use of a reserve of heat-insulated hot water brought to the required temperature for example by electric heating.  
  The water can be not only heated in winter but cooled in summer by passage through a forced evaporation cooling means. This arrangement would be employed when there is neither sufficient space for housing a buried reservoir nor an abundant supply of water for the application of the method employing water which is subsequently discharged.  
  It is known that owing to their low mass. light walls cannot have good acoustical insulating properties at usual frequencies unless they have a structure comprising assembled sheets or webs whose materials differ as to their type and thickness and which are maintained by non-vibrating devices. The frequency specific to each sheet which acoustics engineers term holes overlap in such manner that transmission of all of the usual frequencies is substantially stopped.  
  The present invention affords the acoustics engineer a sheet of a new type constituted by a porous layer through which water flows without pressure the features of which may be advantageous in the stopping of certain disturbing frequencies. Furthermore. has not nature provided the maximum comfort for the foetus in placing it the bag of waters.  
  The method just described differs fundamentally from prior methods which employ a flow of heating or cooling fluid in the following respects:  
  a. As opposed to radiators and convcctors. the porous layers are of large size to the extent of the major part of the visible surfaces of the premises. Correspondingly. the difference between their surface temperature and the ambient temperature of the premises is very small.  
  b. As opposed to heating or cooling floors or ceilings constituted by a network of pipes which convey by conduction their supply of heat to a concrete slab or to metal plates. the porous layers according to the present invention, which are integrated in the walls of the premises. have in every respect an exceptional evenness of temperature since the temperature is practically that of the thermal fluid. Thus. in summer. the danger of condensation noticed in the region of the cooled pipes and. in winter. the unpleasant hot lines on the floor are avoided.  
  c. As opposed to systems in which the fluid is caused to flow by means of a pump or by means of a thermosiphon the rate of flow of fluid in the porous layers is very low. The flow occurs in laminar conditions and consequently any vibration or noise is avoided.  
  d. The most original aspect ofthe invention on which the three foregoing features depend is the flow of the thermal fluid without pressure in unsaturated porous layers. This means that the pores of the layer are open and that the fluid is maintained below the threshold of the filling of these pores. The material of the layer and the nature of the fluid are so chosen that the fluid has a tendency to flow in the layer rather than escape therefrom under the effect ofcapillarity. A point perforation of the fluidtight skin of the layer does not result in a flow of the fluid therethrough. Thus a light partition wall containing a porous layer may be traversed by nails with no adverse effect. A radiator. a convector and a heating or cooling battery are far from possessing this feature.  
  If the water supplied to the porous layers carries particles in suspension there is a danger that it rapidly clog the capillary layers. Consequently. there must be provided a filter at the head of the supply system. No particular precaution has to be taken as concerns the hardness of the water and the dissolved salts. Indeed. the water in the layers undergoes no sudden change of temperature or pressure liable to produce precipitations.  
  Each porous layer is normally supplied with water by a distributing pipe provided with jets. It might occur that foreign bodies. grains of sand or tartar clog some of the orifices of the distributing pipes. It is therefore desirable to dispose these pipes in compartments to which access is easy by merely removing a cover. In this way it would be possible to remove the distributing pipes for cleaning.  
  As concerns the risk of the growth of algae and fungii in the porous layers this may be precluded by the addition to the circuit of commercially-available algicide and fungicide chemical products.  
  The material of the porous layers may be of very diverse types. There maybe employed a cellular material or foam ha ing open pores or a fibrous material delining intcrcommunicating pore-like cavities constituting a capillary network such as a felt or a nonwoven web. for example in the form of strips having a thickness of 3 to It) mm and a width to suit the supports. each ofthe surfaces of the layer being provided with a fluidtight film. for example a thin sheet of polyethylene. polyvinyl or aluminium The lateral edges of the strip are closed by a welding or an adhesion of the edge portions of the fluidtight sheets. In the case of a fibrous material. the fibres may be synthetic (for example polyester). mineral (for example glass or rock wool). metallic (for example aluminium). plant or animal fibres. They must be capable of conserving their characteristics during a long period of immersion in the thermal fluid at ambient temperature.  
  The fibres are interconnected by their shape (for ex ample wavy fibres). by mechanical treatment (for example lashing for the nonwoven materials) or by the addition of a resin so that there is no danger that they be carried along by the current of fluid.  
  The nonwoven webs manufactured and sold by the Company RHONE&#39;POULENC under the trade name BIDIM seem to be particularly suitable for the pt rous layers according to the invention.  
  If the fluid does not et the fibres. each putting into operation of the system will be preceded by the addition to the fluid of a non-foaming wetting product (for example that known under the trade name TENATEX&#34;) so that the front&#39; of the fluid progresscs by eapillarity from the supply end to the fluid collector.  
  The fluidtight sheets may be secured to the felt by high&#39;frequency spotwelding (synthetic fibres) or by adhesion (mineral fibres connected to the resin) or by clips or fasteners. In the latter case. the fluidtight sheet is reinforced by a metal netting some of the wires of which are cut and inserted into the felt. Such a reinforced sheet is manufactured by the company BEKA- ERT.  
  The order of magnitude of the How through the porous layers is l.5 litre of liquid per minute for a strip having a width of one metre.  
  The order of magnitude of the rate of flow of liquid is 0.5 litre per minute. Thus the order of magnitude of the thickness of liquid flowing is 3 mm and its weight is of the order of 3 kg/rn&#34;.  
 BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described merely by way of example in the ensuing description.  
  In the accompanying drawings given solely by way of example:  
  FIG. I is a diagrammatic sectional view of a light construction comprising porous layers affording a thermal and acoustical protection in summer;  
  FIG. 2 is a sectional view. to an enlarged scale. of a sloping side of a roof of the construction shown in FIG. 1&#39;.  
  FIG. 3 is a sectional view in the region of a purlin shown in FIG. 2.  
  FIG. 4 is a perspective view of the connection between a pipe supplying water under pressure and the upstream end of a porous layer:  
  FIG. 5 is a sectional view of an interior partition wall of the construction shown in FIG. I;  
  FIG. 6 is a partial diagrammatic view of a modification of the structure shown in FIG. 2;  
  FIG. 7 is a diagrammatic view similar to FIG. I of porous layers provided to ensure comfort in winter, and  
  FIG. 8 is a sectional view of a composite material of utility in the construction of the porous layers.  
 DETAILED DESCRIPTION OF THE EMBODIMENTS The light construction shown in FIG. I rests on a foundation comprising walls I on which bear floor slabs or flagstones 2 and walls 3. 4 which support the roofing 6 having a double slope. In the right part, an interior partition wall 7 and a ceiling 8 define a premises A. The premises B in the left part is defined by the partition wall 7. the exterior wall 3 and one of the sloping sides 6a of the roof under which an insulating panel 9 is disposed. The panel 9, the exterior walls 3, 4 and the ceiling 8 are provided, on the side thereof exposed to the exterior medium, with a layer of a thermal insulator constituted for example by glass wool. The partition wall 7 comprises two juxtaposed panels of agglomerated particles 12, I3.  
  Between the panels 12 and I3 and between the insulator l] and the inner surface of the elements 3.4,83 and in contact with this surface there are disposed porous layers a which are integrated in a cooling water circuit so as to maintain a temperature in the premises A and B during a hot period which is lower than that of the exterior medium.  
  This circuit comprises a reserve supply of relatively cold water I6 which occupies a large part of the basement or an excavation sheltered from the sun in the vicinity of the building. It is of large size. its volume being of the order of 0.5 m per square metre of occupied floor. This reserve is constituted by two bags or vessels [7. I8 of plastics material or waterproofed fabric which are assembled by a thermopneumatic process and which are disposed between the walls I and intercommunicate by way of pipes I9. One of the vessels I8 comprises a pipe 2] which is connected to a feed pump 22 which supplies fluid to the pipings 23. 24. 26 of the wall 4, the ceiling 8 and the roof panel 9. Another piping (not shown) supplies water to the distributing pipes on the upstream side of the porous layer a of the wall 3 and partition wall 7.  
  Pipings. such as 27. 28. 29 3I. connect the downstream end of the porous layers a of the wall 4, the partition wall 7 and the wall 3 respectively, to pipes 32 which return the water to the vessels [7 and I8. Taps. such as the tap 30. provided in suitable places complete the cooling water circuit.  
  As can be seen in FIG. 4. the porous layer a which is the centre of a bidimensional capillary flow, is preferably provided with lluidtight sheets h. c, for example of plastics material or aluminium. on both sides of the layer.  
  FIGS. 2 and 3 show the arrangement pertaining to the roof panel 9 which is suspended. together with the roof sheet 6a by means ofpurlins, such as the purlin 33. against which an undcrroof pan bears. the porous layer a being applied against this pan. Hooks 34 support by a screwed connection the pans 35 and the wood battens 36 to which the root sheets 6a are nailed.  
  The upstream end of the roof panel 9 is supplied with water by way of one or more distributing pipes 37 which are connected to the piping 24 and provided with orifices 38 constituting jets. The distributing pipe 37 is overlaid by the upper rolled end portion 39 of the upper t&#39;luidtight sheet h while it is spaced from this sheet by a collar 4]. A resiliently yieldable clip 42 holding the end portion 39 of the sheet h in contact with the collar 41 detach-ably maintains the connection between the sheet [1 and the pipe 38. Thus the orifices 37 are always clear of obstruction and a reserve supply of water of a few centimetres is thus provided.  
  A detachable casing 44 permits access to the distributing pipes 37.  
  At the downstream end of the porous layers a. such as the layer of the roof panel 9. there is provided a U- shaped collector 43 to which the connecting piping, for example 27, is connected. The two covering sheets 11, c&#39; are immersed in this collector which has sufficient height to accommodate a depth of water of a few cen timetres.  
  The collectors are horizontal or slightly inclined so a free flow at a low rate occurs without noise.  
  FIG. 5 shows the interior partition wall 7. The two panels of agglomerated material l2. l3 hear. one, I2. against the ceiling 8 owing to the action of a jack 60 provided in a recess 61 between the floor 2 and the lower end of the partition wall. and the other. 13. against the floor 2. the upper end of the panel I3 being spaced from the ceiling 8 and defining a recess 62 in which is disposed a branch connection 23a of the piping 23 which supplies water by way of a tap 63 to the distributing pipe 37 which is identical in its operation to the distributing pipe shown in FIG. 4 and is disposed in similar manner with respect to the l&#39;luidtight covering sheets h. c of the porous layer a, the lower end of which is connected by the engagement of extensions of the sheets h. v in a collector 64 in the form of a section member connected to the piping 29. The two recesses 6|, 62 are covered by a detachable board 66 provided with apertures for the introduction of a squaresectioned key for operating the taps 63.  
  FIG. 6 shows a modification of the structure shown in FIG. I in which the circuit supplying water to the po rous layers a is connected to the water mains of the town so that the utilization of cisterns buried in the ground or otherwise arranged is unnecessary. The water which has flowed through the other porous layers a is received by pipes (not shown) which discharge the water for example into a trench or a drain 69 (FIG. I l.  
  FIG. 7 shows a light construction equipped to ensure comfort in the winter by a heating effect. The porous layers a having a capillary flow of heated water are provided. as seen in FIG. 7, in the floor slabs or flagstones 2. the walls 3. 4 exposed to the exterior medium and the interior partition wall 7. There has been shown a single vessel or bag SI buried in the ground between two foundation walls I and protected thermally from the ground by an insulating layer 52. The water of the vessel 5] is heated for example by an electric heating device 53 which operates preferably during the night. the temperature of the reserve of water being maintainctl constant in the course of heating by an aquastat. The temperature in the inhabited premises or rooms is regulated either by a mixing valve which modulates the take-off from the reserve of water in accordance with the desired temperature or by a number of electric radiators provided with thermostats. The radiators con sume little power since they merely have to compen sate for the temperature drop in the water from the vessel 51.  
  As in the structure shown in FIG. I. the pipings 23. 24. 2h. supply heated water by means of the pump 22 to the various porous layers a. the return to the vessel 5| being by way of pipings Z8. 3!.  
  H6. 8 shows a composite material which is particularly suitable for the construction of the porous layers a. This material consists of a nonwoven web 71. such as the known product sold under the trade mark BlDlM&#34; which is covered by a sheet of plastics material. for example polyethylene. which is folded onto itself so as to cover the web 7] in two thicknesses 72. 73. The sheet is secured to the web for example by welding superimposed free edge portions 72a. 73a of this sheet so as to form a lip portion. This product in strip form may be inserted. after having been cut to the required length. in the required places in the panels. walls. partition walls etc. of the light construction to be protected.  
  Having now described my invention what l claim as new and desire to secure by letters patent is:  
  1. Method for thermally and acoustically protecting a construction in which a space is defined by a plurality of wall means. comprising, providing a substantially planar porous fluid conduit layer having intercommunieating pore-like cavities distributed substantially throughout the entire mass of the layer and two opposed surfaces in at least one of said wall means so as to be in a state of heat exchange with said space. directing water from a source of water whose temperature is different from the temperature naturally prevailing within the construction to undergo a bidimensional flow through said fluid conduit layer of intercommunicatirig pore-like cavities of the porous layer and substantially throughout the entire mass of the layer while maintaining said two surfaces of said layer in contact with means defining fluidtight surfaces. said flow of said water through said pore-like cavities being substantially without pressure and achieved by capillarity and thermally conditioning the space covered by the layer through which water flows.  
  2. A method as claimed in claim I. wherein in the wall means which are exposed to the exterior medium the porous layer is protected by a thermal insulating means.  
 (iii  
  3. A method as claimed in claim I. wherein the porous layer is supplied with said water by pumping the water from a \essel containing the water to a first part of the layer. allowing the water to ilovv through the layer to a second part of the layer. and allowing the water to return to the vessel from said second part of the layer under the effect of gravity.  
  4. A method as claimed in claim 3. wherein the vessel is embedded in the ground.  
  5. A method as claimed in claim 1. wherein the porous layer is supplied with said water from an exterior mains water supply under pressure.  
  6. A method as claimed in claim 3. wherein said water is cooled in the vessel by cooling means.  
  7. A method as claimed in claim 3. wherein said water is heated in the vessel by heating means.  
  8. A method as claimed in claim 1. wherein the porous layer comprises a cellular material having open pores.  
  9. A method as claimed in claim 1. wherein the porous layer comprises a foam material having open pores.  
  10. A method as claimed in claim I. wherein the porous layer comprises a fibrous material.  
  11. A method as claimed in claim l0. wherein said material is felt.  
  [2. A method as claimed in claim 10, wherein said material is a nonwovcn web.  
  [3. A method as claimed in claim 10. wherein the fibres of the fibrous material are selected from the group consisting of synthetic. mineral. metallic. plant and animal fibres.  
  14. A method as claimed in claim 10. wherein the fibres are interconnected by the effect of the shape of the fibres.  
  IS. A method as claimed in claim [0. wherein the fibres are interconnected by mechanical means.  
  16. A method as claimed in claim 10. wherein the fibres are interconnected by a binder.  
  17. A method as claimed in claim I. wherein said means defining lluidtight surfaces comprise a watertight sheetv 18. A method as claimed in claim 17. wherein the watertight sheet is a sheet of plastics material.  
 19. A method as claimed in claim 17. wherein the watertight sheet is a sheet of aluminium.  
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