AN ARRANGEMENT IN WINDOWS

Abstract: Arrangement in windows for bringing the innermost window-pane (11) to a surface temperature suitable from a comfort aspect, the innermost window-pane (11) and a further window-pane (5) being arranged to define a substantially closed space. The novel features of the invention consist in means (19) for causing the air in the aforementioned space to flow from an inlet (15) to an outlet (16) around an intermediate window-pane (8) arranged in the space, for attemperating the air prior to entering the cavity (10) between the innermost window-pane and the intermediate window-pane.

Description: AN ARRANGEMENT IN WINDOWS The present invention relates to an arrangement in windows for brirging the surface of an innermost window- pane to a suitable temperature from a comfort aspect, said window-pane together with a further window-pane being arranged to define a substantially closed space. 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 referance points in the room. The radiation climate is affected negatively by room surfaces which are cold due to transmission losses, especially windows since such surfaces obtain temperatures which are lower than the desired room temperature. By means of an arrangement of one or more hermetically sealed spaces, i.e. one or more so-called thermo-glasε panes , it has been possible to slightly raise the temperature of the inner window-pane in relation to conventional, coupled double-glazed windows. The temperature of the inner window-pane, however, will be re¬ latively low and the pane will have a cooling effect, if only such passive measures are taken. A better result is obtained when the space between the innermost panes is flushed with warm air, 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 that the temperature of the flowing air, and there¬ with also the temperature of the innermost window-pane ,does not fall beneath room temperature on the outlet side. The heat losses and the difficulties of achieving requisite flow rates in the confined space available in a window structure, which window must also be capable of being opened and has coupled frames to enable the surfaces of the glass contacted by the air to be cleaned, have meant that solutions of this kind are not totally realistic. It is highly desirable to find a solution to the prob¬ lem of maintaining the inner window-pane at a sufficiently high temperature, since tests have shown that the ro.om tem¬ perature can be lowered one or two degrees while maintaining ISUREAIT a comfortable climate, if the radiation of co3d from the window can be totally eliminated, by bringing the tem¬ perature of the inner window-pane to the same temperature as the room, or slightly higher. In this latter case, the cold-generating inner window-pane has become a heat emitter. This enables other heat-emitters in the room to be reduced in number, or to be totally omitted. A solution to this problem is afforded by means of the present invention, which relates to an arrangement of the kind described in the introduction having the charac¬ terizing features set forth in the following claims. The temperature curve followed by the air circulating around the intermediate window-pane, the surface temperature of the -inner window-pane and the total transmission loss are determined by a number of different parameters. Among these parameters can be mentioned the original K-value of the win¬ dow, the internal radiation characteristics of the double cavity, the resistance to thermal transmission, air re¬ placement, and the inlet temperature of the air. By passing r the air (either in total or in part) through the air gap lying nearest the innermost cavity , subsequent to said air havin passed the innermost air gap, the pane lying between the two cavities is held at a higher temperature than is the case when air is passed solely through the innermost cavity (in the case of a single cavity) . This means that when the air passes through the innermost cavity, said air is not cooled as greatly as it would be in the case of a single cavity. Consequently the air flow can be lowered, or alternatively the inlet temperature can be lowered, while still maintain¬ ing the temperature of the innermost pane at the same level as in the single-cavity case. At an external temperature of, for example, -20°C and a desired room temperature of, for example 20°C, the temperature of the air at the inlet to the substantially closed space need only be about 23°C, to fall to about 20°C subsequent to passing the inside of the intermediate pane. Subsequent to passing the outside of the intermediate pane, i.e. at the outlet of the space, the air temperature will have fallen to about 11°C. In order to re-heat the air to 23°C, for example by means of hot water in an effective heat exchanger, the temperature of the water entering the heat exchanger need, ideally, only be in the region of 23*5°C, the temperature of the water exiting from the heat exchanger being, ideally, for example 11-5°C J i.e. the temperature of the return water lies far beneath the room temperature, des¬ pite the fact that the whole of the inner pane has been brought to a temperature which does not lie beneath the room temperature of 20°C. As will readily be understood, this provides unsuspec¬ ted possibilities- of utilizing low-grade energy, such as low-temperature waste heat, solar energy, heat from storage batteries etc. A solar-energy collector, which may operate with an inlet temperature or outlet temperature of the cir¬ culating heat carrier of only 11-15°C or 23-27°C respectively obtains a much higher efficiency than is normally usual. When the arrangement according to the invention is used in a building having low K-valueε in the walls, and optionally a heat-exchanger for the input/output-air of the building, it is thought that in many cases no further heat-emitting appara¬ tus would be required for heating the building, in addition to the aforementioned approximately 23-27/ll-15°C-water system. With a temperature differential between the ingoing and out¬ going circulation-water of about 12°C, an equally large water flow can be used as is normal practice in existing buildings . Thus, when renovating such buildings, the arrangement accord¬ ing to the invention can be connected directly to the pipe- lineε of the exiεting heating system, with or without existing radiators . The invention will now be described in more detail with reference to a number of embodiments of arrangements accord¬ ing to the invention illustrated schematically in the accom¬ panying drawings , in which Figure 1 is a crosε-εectional view of a window with a heat-exchanger incorporated in the window frame , Figure 2 is a cross-sectional view of a window with the heat-exchanger and a fan incorporated in a window sill , Figure 3 is a cross-sectional view of a window which is provided with two subεtantially εealed spaces and which is connected to a warm-air line and a return line, the return line being connected to a heating plant , and Figure 4 is a diagram illustrating the temperature conditions in, for example, the embodiment illustrated in Figure 1. In Figure 1 there is shown an outer wall 1 having a window opening 2, in which a window frame 3 is fitted. Hung in the window frame 3 is an outer casement 4 having a conventional ther opane 5 comprising two panes of glass. Inwardly hereof are arranged two further casements 6 , 7 , of which the casement 6 carries a thermopane 8 , comprising two glass panes, such as to form a cavity 9 between the thermopaneε 5 and 8 , and so as to form a cavity 10 between said thermopane 8 and an inner pane 11 fitted to the case¬ ment 7. Between the upper parts of the casements 4 and 6 and the casements 6 and 7 are arranged deep slots 12 , while channels 13 which connect the slots 12 are arranged in the upper part of the casement 6 , immediately above the upper edge of the thermopane 8. Arranged between the casements 4 , 6 and 7 are through- passing slots 14, which terminate in corresponding slots 15, 16 in the lower part of the frame 3 , in which frame there is also arranged a chamber 17 which connects the slots 15, 16 along practically the whole width of the window. Arranged in the chamber 17 is an elongate, highly effective counter- flow * heat-exchanger 18, having transversely extending, fine passages which connect the slots 15, 16, and optionally a fan means 19, which directs a relatively slow air flow up into the cavity 10, while drawing air from the cavity 9 via the heat-exchanger 18. The heat-exchanger 18 is provided, in a conventional manner, with a tube-coil 20, the ends of which are connected to a hot-water line 21 and to a return line 22 respectively. The air heated in the heat-exchanger 18 flows slowly upwards through the slot 15, and into the cavity 10, optionally with the back-up of fan 19. As the warm air leaves the cavity 10 it passes through the slots 12 and the passages 13 in the upper part of the window, and then flows down through the cavity 9 while being cooled somewhat by the relatively cold panes 5. The cooled air is drawn down through the slot 16 and passes through the heat-exchanger 18, where it is re-heated. As previously described, and as will be made more clear hereinafter with reference to Figure 4 , the inner window-pane 11 can be brought to a surface temperature which is almost equal to the intended room temperature of, for example, 20°C over the whole of the surface of said pane, while using a water temperature of 23-27°C in the input line, and a water temperature as low as 11-15°C in the return line . The embodiment illustrated in Figure 2 differs from the Figure 1 embodiment, in that a single window-pane 25 is used instead of the thermopane 8 in Figure 1 , and in that the heat-exchanger 18 has been moved out and placed in a chamber 26 located in a window sill 27. The embodiment illustrated in Figure 3 has a further double-cavity 31, 32 defined by two further window-panes 29, 30 and formed in the same manner as the cavities 9, 10. Slots and passages in casements and window frame are so arranged and so connected to a hot-air passage 33 and a return passage 34 that warm air will rise up through the innermost cavity 10, down through the cavity 9, through the cavity 31, and down through the outermost cavity 32. As will be understood, the temperature difference in this case is still greater than the difference of approximately 12°C assumed in the previously described embodiments. Figure 4 illustrates the temperature distribution from the outer window-pane 5 to the inner window-pane 11 and in the two air cavititieε 9 and 10 along the whole height (m) of the window. The outside temperature is assumed to be -20°C (T) and the inside temperature +20°C. The temperature of the air when flowing in to the cavity 10 is 23°C, and when exiting from the cavity 9 is only 11°C. Despite this low temperature of the inflowing air, the surface temperature of the bottom part of the inner window-pane will be 21.2°C and at the upper part of said pane 19.7°C, i.e. temperatures practically equal to the inεide temperature. With a window of this kind, so-called cold slide will not occur, and the window will not be considered as a cold surface. When the surface temperature is raised through about 1°C, the window may also be considered as a warm surface, and if such windows are arranged in a low-energy building, additional heat-emitting devices may be more or less super¬ fluous. In the event of powerful solar radiation, for example in the summertime, the water temperature may, of course, be lowered somewhat, in which case the window arrangement according to the invention can alternately be used to keep the room cool. In order to prevent condensation, the cavities are ventilated to ambient air through a fine paεεage, in a con¬ ventional manner. As will be understood, the fan and heat-exchanger need not be placed adjacent one another and, if so desired, the fan may be incorporated, for example, in the upper part of " the window rame. " BUREA OMPI A

Claims: C L A I M S 1. An arrangement in windows for bringing the surface of an innermost window-pane (11) to a suitable surface temperature rom a comfort aspect , said window-pane together with a further window-pane ( 5 ) being arranged to define a substantially closed space, characterized by means (19) for causing the air in said space to flow from an inlet (15) to an outlet (16) around an intermediate window-pane (8) arranged in said space; and by a means (18) for attemperating the air prior to its entry into the cavity (10) between the inner¬ most window-pane and the intermediate window-pane. 2. An arrangement according to Claim 1, characterized in that the inlet (15) and the outlet (16) extend over the whole width of the window. 3. An arrangement according to Claim 1 or Claim 2, charac¬ terized by a fan (19) which is active over the whole width • of the window. . An arrangement according to any one of Claims 1 - 3 , characterized by a counter-flow heat-exchanger (18) which is incorporated beneath a window sill (27) connected to the window-frame ( 3) . 5. An arrangement according to any one of Claims 1 - 4 , characterized in that the intermediate window-pane (8) com¬ prises a thermopane. 6. An arrangement according to any one of Claims 1 - 5, characterized by a further, outwardly lying space having two cavities (31, 32) separated by a further intermediate window- pane (29) , around which the air stream of the first cavity (9, 10) is arranged to flow. 7. An arrangement according to any one of Claims 1 - 6 , characterized in that the means (18) for attemperating the air is arranged to bring the air flowing into the cavity (10) between the innermost window-pane and the intermediate window-pane to a temperature which at most is. somefew degrees above the temperature of the room air on the inside of the window. y&vREA 8. An arrangement according to any one of Claims 1 - 7, characterized in that the means (19) for causing the air to move is arranged to control the rate of flow of said air, so that the attemperated air when exiting from the cavity (10) between the innermoεt window-pane and the intermediate window-pane haε a temperature substantially equal to the temperature of the room air on the inside of the window.

Inventors: PLATELL OVE BERTIL, PLATELL, OVE, BERTIL
Applicants: SUNSTORE KB
Application year: 1983
Main classification: E06B7
IPC codes: E06B7, F24F5