AN ARRANGEMENT IN INTERNAL PANELS FOR ELIMINATING COLD RADIATING SURFACES ON WALLS, CEILINGS AND FLOORS

Abstract: Arrangement in an interior panel (2) or the like having a rearwardly located space through which air which has been heated is arranged to flow, to eliminate the radiation of cold from a wall, a floor or the like. In accordance with the invention, the space is confined and divided into at least two thin air cavities (4, 5), by means of an intermediate plate (3) which extends parallel to the interior panel (2) and which comprises a material having good heat-insulating properties. The heated air is arranged to be circulated in the air cavities, around the intermediate plate. Means (9) are provided for heating the air passing to the air cavity (4) adjoining the interior panel, to a temperature of at most some few degrees above the room temperature.

Description: COLD RADIATING SURFACES ON WALLS ,CEILINGS AND FLOORS The present invention relates to an arrangement in internal panels or the like having rearwardly thereof a space through which warmed air is arranged to flow, there¬ by to eliminate the radiation of cold from a room surface , such as the surface of a wall, floor and/or ceiling. The comfort criterion of a heated room is the so- called directive operative temperature. The value of this temperature is determined by the radiation climate and the air temperature at selected points in the room. The radiation climate is affected negatively by room sur¬ faces which are cold due to transmission losses, i.e. which radiate cold into the room. An improvement can be achieved, by flushing the space behind the panel with air which has been heated, suitably supply air or exhaust air. Because of the heat lost to the external surroundings , it is necessary for the air to flow at a high rate, so as to prevent the temperature of the air stream, and therewith also the temperature of the internal panel, from falling beneath room temperature on the outlet side. The heat losses and difficulties in achieving requisite flow rates in a confined space have meant that solutions of this kind are not totally realistic. It is , however, highly desirable to find a solution to the problem of bringing the internal panel to a suffi¬ ciently high surface temperature, uniformly over the whole of said surface, since tests have shown that the room temperature can be lowered one or two degrees while main¬ taining a comfortable room-climate, if cold-radiation from walls, floors and ceilings can be totally eliminated, by bringing these surfaces to a temperature which is substan¬ tially equal to the temperature of the room, or slightly higher. In this latter case, the surface which was pre¬ viously a cold-radiating surface is now a heat-emitting surface. This enables the number of other heat-emitters in the room to be reduced, or renders the need for such further heat-emitters unnecessary. O PI so u on o e a oresa pro em s a or e y the invention, by providing an arrangement of the kind described in the introduction with the characterizing features set forth in the following claims. The tem¬ perature curve followed by the air circulating around the intermediate plate, the surface temperature of the interior panel, and the total transmission loss are de¬ termined by a number of parameters. Among these are included the original K-value of the wall, the internal radiation characteristics of the double cavity, the resistance to thermal transmission, air replacement, and the inlet temperature of the air. By passing -the air (either in total or in part) through the air gap which lies closest to the innermost cavity, subsequent to said air having passed the innermost air gap, the inter¬ mediate plate is held at a higher temperature than in the case when the air is passed solely through the inner¬ most gap (in the case of a single cavity) . This means that when the air passes through the innermost cavity, it is not cooled as greatly as when passed through a single cavity. This enables the air-flow to be lowered, or the inlet temperature to be lowered, while still main¬ taining the panel at the " same temperature level as in the single-cavity case. The invention will now be described in more detail with reference to two different embodiments of arrange¬ ments according to the invention illustrated schematically in the accompanying drawing, in which Figure 1 is a cross-sectional view of a wall pro¬ vided with a double cavity in accordance with the in¬ vention, and Figure 2 is a cross-sectional view of a wall having two double cavities connected in series, in accordance with another embodiment of the invention. Figure 1 illustrates an outer wall 1 constructed in a conventional manner. Extending parallel with the inside of the wall, at a distance of, for example, 5cm therefrom, is an interior panel 2. The space defined in this manner is divided by means of an intermediate plate 3 of suitable high-insulating material extending parallel with the interior panel 2 into an inner air- cavity 4 and . n . e en s between a floor 6 and a ceiling 7 in a room 8, while the intermediate plate 3 , on the other hand, is arranged to leave a free opening at the top and bottom of said plate. Arranged in the lower part of the cavity 4 is an elongate heating means 9 , the affect of which is such that the air in the double cavity 4 , 5 strives to flow in the circulation direction shown by the arrows, as a result of the cooling effect of the outer wall 1 on the air in the cavity 5, and as a result of heating the air flowing into the cavity 4 by the heating means 9. For the purpose of guiding the air flow in the flow • circuit, a fan means 10 is arranged beneath the heating means 9. In addition, a narrow passage 11 is arranged to connect the double cavity 4, 5 with the outside of the wall 1, so that the same dew-point prevails as that outside, thereby to prevent condensation in the double cavity 4 , 5. The heating means 9 is preferably of the counter- flow type, and is connected to a hot water line and a return line (not shown) , whereby a substantially con¬ stant temperature can be maintained along the whole length of the heating means 9 , along the lower part of the cavity . Heating of the air is so adapted that when the air enters the cavity , it has a temperature which is only a few degrees higher than the intended room temperature. The air flow is set by means of the fan means 10, so that in the transition region from the upper part of the cavity 4 to the cavity 5, the air temperature is substantially equal to the intended room temperature, which can also mean a temperature which is about 0.5-1.0°C lower than said temperature The temperature of the interior-panel surface is then practically constant over the whole of said sur¬ face, and, for example, equal to the intended room temperature. With an outside temperature of, for example, -20°C, cooling of. the air in the cavity 5 may be so great that the temperature of the air entering the heating means 9 reaches to only about 11°C. -With an effective counter-flow_ heat-exchanger in the heating means 9, the temperature of the water supplied need only be about 25°C, and the temperature of the return water about 13°C. With a temperature difference between the incoming and outgoing circulation water of about 12°C, the water flow may be equally as large as that employed in current practice in existing buildings. This means that when additionally insulating existing buildings , the radiator-serving pipelines present therein can be used for connecting the heating means 9. A still greater advantage afforded by the arrangement according to the invention is that a heating system with a water temperature of 25/13°C can be supplied with low-grade energy, particularly solar energy with low-temperature solar collectors of the simplest construction having a high degree of efficiency at these low temperatures. Figure 2 illustrates a variant of the arrangement illustrated in Figure 1, provided with a further double cavity 21, 22 on both sides of an intermediate plate 23 y in a space which is separated from the double cavity 4, 5 by a partition 24. The partition is arranged to leave a free opening at the bottom thereof, to connect the cavities 5, 21 and cavities 4 , 22 through connecting passages 25 and 26 respectively, which are divided by a guide plate 27, which connects the lower edges of the intermediate plates 3, 23. In this embodiment, the temperature in the outer¬ most cavity 22 is even lower than is the case in the embodiment according to Figure 1 at low surface tempera¬ tures, which means that the temperature of the return water will be still lower. Consequently, the outer wall 1 can be designed so as to enable solar energy to be . readily taken up by the air flowing in the cavity 22, during the Spring and Autumn periods. As beforementioned, the arrangement according to the invention can be also applied to floor and ceiling surfaces, which border onto unheated spaces. Instead of a water-carried heating system, there may be used a hot-air system with central heating and a central fan means. , innermost cavity 4 may be released into the room 8 , through a valve 30, for ventilating the room with warm, fresh air. Cold fresh air will then flow in through the passage 11.

Claims: 1. An arrangement in interior panels or the like having a rearwardly lying space through which heated air is arranged to flow, to eliminate the radiation of cold from the interior panel, said panel forming a room surface, such as a wall surface, floor surface and/or ceiling surface in a building, characterized in that the space (4, 5) is confined and is divided into at least two thin air cavities (4, 5) by means of an intermediate plate C3) which extends parallel to the interior panel (2) and which comprises a material having good heat-insulating properties, in which cavities (4, 5) the heated air is arranged to circulate forwardly over the air cavity (4) adjoining the interior panel (2), around the edge of the intermediate plate (3) and back through the other air cavity (5) , and then back to the beginning of the air cavity (4) adjoining said interior panel (2), and in that means (9) are arranged for heating the air upon entry to the air cavity adjoining said interior panel (2), to a tempera¬ ture of at most some few degrees above the intended room temperature. 2. An arrangement according to Claim 1, characterized in that the confined cavity (4, 5) is ventilated to the ambient air, by means of one or more fine passages (11). 3. An arrangement accordi ng to Claim 1 or Claim 2, characterized by means (10) for guiding the circulation air in a manner such that subsequent to the passage of the heated air over the whole of the air cavity (4) ad ¬ joining the interior panel (2), the air temperature is substantially equal to the intended room temperature. 4. An arrangement according to any one of Claims 1 -3, characterized in that one or more of the surfaces facing the air cavities (4, 5;21, 22) reflect radiation. liUl-U-A^ O PI

Inventors: PLATELL OVE BERTIL, PLATELL, OVE, BERTIL
Applicants: SUNSTORE KB
Application year: 1983
Main classification: E04B1
IPC codes: E04B1