Radiant energy heat transfer device

Drawings

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Patented May 6, 1952

United states patent office

Application August 29, 1946, Serial No. 693,787

This invention relates to radiant energy heat 2 transfer devices and particularly to heat trans scribed with reference to the drawings, in which: fer devices including a heat absorbing cell con Fig. 1 is a sectional view taken through the taining a heat storage and transfer medium per side of a building, the wall of the building in mitting compact construction of a cell having cluding a solar heating panel in accordance with relatively high heat capacity. the invention, and

An object of the invention is to provide a Fig. 2 is a sectional view of a solar hot water radiant energy heat transfer device in the form heater embodying the principles of the invention. of a cellular panel having at least one radiant In Fig. 1 of the drawings, the building shown in section has a floor 0 and a ceiling partly energy transferring face, a heat storage medium () defining in the cell, and means for indirect heat ex a room or apartment 2. The outer wall change, by radiation, conduction or convection 3, preferably a south Wall in buildings situated with a space, the temperature of which is to be in the northern hemisphere, is a composite Wall controlled. and has an outer transparent glass plate 4 and Another object, is to provide a radiant. energy an inner transparent glass plate 5 spaced there s from providing a dead-air space 6 between the heat transfer device in the form of a cellular plates. The pair of glass plates readily transmits panel adapted to form an integral part of the inwardly of the building radiant heat energy outside wall, or roof, of a building, and having at least one radiant energy transferring face from the Sun but, due to the included dead-air space is, acts as an effective heat insulator sub adapted to absorb incident solar energy in the 20 stantially form of heat or to radiate heat to the night, by preventing the outward escape of heat sky, and having a heat. Storage medium in heat conduction and convection. By using instead transfer relation with a space the temperature of6,glass, especially for the inner transparent panel transparent sheets of organic plastic mate of which is to be controlled.

Another object is to provide a solar heater in rials, such ascellulose, cellulosic materials for example cluding a radiation absorbing cell containing a 25 regenerated of transmission of having a larger coefficient higher frequency infrared material having a substantial heat of fusión at a temperature above about 50° F. - radiation than of lower frequencies, a still greater Another object of the invention is to provide retention of absorbed energy may be effected. a space cooling device including a heat radiating More than two transparent plates may be used. cell containing a material having a substantial The main panel of the wall 3 takes the form heat of fusion at a temperature above about of a hollow metallic cell 7 which may extend, 50° F. as ShoWn, from floor to ceiling. The Outer face Another object is to provide a solar hot water 8 of the cell, which is exposed to the sun, is heater having such high storage capacity that finished to absorb a substantial range of the the Ordinary hot Water storage tank may be 35 sun's radiation. The outer face 8 may be roughened and finished with a coating of dull eliminated.

Another object is to provide cells of the type black paint to provide an excellent absorbing described wherein the temperature of the heat. Surface. The interior face 9 of the cell forms the interior wall of the room 2 and may be storage medium may be held accurately at a preselected temperature during long periods of 40 decoratively finished as desired. heat absorption and dissipation. The hollow interior of the cell is Substan A further object is to provide in a solar heater tially filled with a Substance that has a fusion an improved construction of screen or shutter point at or about the temperature at which it which may be automatically responsive to is desired to maintain the wall and also having changes in solar radiation incident at the absorb 45 a relatively high latent heat of fusion. I have found that the Substance known as Glauber's ing element of the heater. Salt, the deca-hydrate of Sodium sulfate, is par Typically, the solar heater of the present in vention includes a cell having a high absorptive ticularly suited for use in the heating of houses; capacity for a substantial range of Solar radia ithigh has a melting point of 90° F., and a relatively heat of fusion of 103 B.t. u, per pound. The tion, a material in the cell having a substantial 50 cell is substantially completely filled with Glau heat of fusion at a temperature above about 50° ber's salt 20.

F., and means for indirect heat exchange be-, The cell may be built from a number of tween said material and a zone to be heated. prefabricated units of convenient size, some of The invention will be more particularly de 55 which may be provided with window openings or 4 the units may be so grouped as to provide Window narily exceed the fusion temperature of the ma openings. In general, cells having a thickness terial.

of six to eight inches will be found to be satis By way of illustration, Some of the materials factory for most applications of the invention. suitable for use in heater cells are listed in the The cell units are preferably made structurally 5 following table together with some of the physical strong enough to provide a self-sustaining wall, constants of the materials and the quantities needed for calculated cell thicknesses. The basis and may, in some instances, even support the of the table is one Square foot of cell Surface overhead structure of the building. absorbing solar energy in the amount of 1400 Between the Outer face 8 of the cell and the B. t. u, per day, which amount may be considered inner glass plate 5 is hung a curtain or Shutter 10 as the maximum solar energy available on a clear 2 having a highly reflecting inner surface. The winter day from a vertical Surface facing South shutter may be of the Wenetian-blind type and is in the area of Boston, Massachusetts. The figures opened when the Sun is shining and closed on are based on a room temperature and basis tem dark days or at night.

The blind may be manually operable, or, as li; perature of 70 F.

Needed for storing et- Heat

Libs. Cell thickness

(Inches)

CaCl2.6H2O-...------------ 90 103 .40 91 1. 12.6 1.66 shown, automatic means may be provided for From the foregoing description, it will be seen that there has been provided a Solar apartment opening and closing the blind in response to the heater including a cell containing a heat Storage condition of solar radiation incident upon the and transfer material and adapted to absorb solar heater. Such automatic means may include an 35 energy at one surface and radiate heat at another electric motor 22 having an arm 23 connected surface. Instead of radiating heat from the in by a link 24 to the blind, the motor being SO ner face of the cell to the space to be heated, Wired and the arm and link assembly So con heat may be transferred to Such a space, par nected and arranged that when the blind is closed and the motor is initially energized it will 40 ticularly if remotely located, by the circulation of air or water between the cell and the space run for half a revolution of the arm 23 to open to be heated.

the blind and will then automatically stop. An The principles of the invention may be also other initial energization will cause similar func embodied in a Solar hot Water heater such as that tioning to close the blind. Since motors of this shown by Way of example in Fig. 2. Referring to type are well known in the art, further detailed 45 this figure, it will be seen that the heater is in description is believed to be unnecessary. clined to face the Sun at its zenith and is Sup The naotor is controlled by a radiant energy ported at the desired angle by a framework 27. sensitive element 25 placed outside of the build ing, the element being adjusted to initiate ac The 28, heater includes an open-faced shallow box covered by a pair of spaced parallel transpar tion of the motor 22 to open the blind when the ent plates 29 and 29a, and containing a cell 30 solar energy level exceeds a predetermined value 0 Substantially filled with a material like those re and to close the blind when the solar energy level ferred to in connection with the wall heater falls below the predetermined point. hereinbefore described. In the case of hot water A Second Venetian blind 26 or other curtain heaters, it may be desirable to use a latent heat may be provided to selectively cover and uncover 55 storing material having a higher melting point the inner face 9 of the cell to control the tem than the materials used in Wall heaters, and pref perature of the room 2. This curtain may be manually operated or automatically operated in erably from about 90° to about 150 F. For this purpose I have found the penta-hydrate of SO response to room temperature by conventional means (not shown). The inner blind may ad 60 dium be thiosulfate, commonly known as hypo, to admirably suited. From the foregoing table, vantageously be constructed to provide air cir it Will be seen that hypo has a melting point or culation from the room across the inner face of phase transformation temperature of 120 F., a the Cell. high enough temperature for most domestic uses. In operation, When the Sun is Shining, its It Will also be seen that it has a relatively high rays fall upon the absorptive surface f8 of the 65 heat of fusion of 86 B. t. u. per pound. cell and heat the material within the cell to its . Within the cell 30 there is disposed in contact melting point. Additional heat imparted to the with the heat storing substance a pipe coil 32 cell is absorbed in the material at its fusion tem through which is circulated water to be heated. perature, the material being selected with regard to the temperature desired in the wall. The cell 70 The

Water may be led to the coil through inlet and drawn from the coil through outlet 34 thickness is preferably so chosen, keeping in mind to be passed to a domestic hot water system or the rate of heat dissipation from the cell and other pertinent factors, that the cell will absorb the like. As in the Wall heater, the hot water heater of Fig. 2 may have an adjustable shutter all of the average daily incident solar radiation 35 which may be manually or automatically op without melting the last increment of material; 75 erable.

thus, the desired wall temperature will not ordi

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Due to the high latent heat storage capacity of the material 3 filling the cell 30, the usual hot an outer panel transmitting a substantial range water storage tank may be dispensed With. of solar radiation, and an inner panel spaced By providing a cell of the general construction from said outer panel comprising a hollow cell of the cell of Fig. 2 in a wall or roof having a having an extended surface adapted to absorb northern aspect, the cell may be effectively used a Substantial range of Solar radiation facing said for cooling purposes. In this use heat is radi Outer panel and positioned to intercept radiation ated to the night sky thereby cooling the heat face transmitted thereby and a second extended sur facing inwardly of the building and posi storage medium below its solidification tempera tioned to dissipate heat thereinto, and a material ture. During the daytime, louvers or other shad 0. in said cell having a substantial heat of fusion ing devices, preferably automatic actuated, shade and a, meting point in the temperature range the cell from the sun, and heat from a space to from about 50 F. to about 150 F. be cooled is transferred to the heat storage medi 2. Wall construction as defined in claim 1 in um, by the circulation of liquid as shown in Fig. cluding a curtain positioned in the Space between 2, by the circulation of air from the space to be 5 cooled over the cell, or by transfer directly said panels and means for actuating said curtain through the inner face of the cell. to selectively cover and uncover the extended Sur When the cell is used for cooling purposes a face of said cell facing said outer panel. heat storage medium having a relatively low 3. Wall construction as defined in claim 2 in cluding power means for actuating said curtain solidification point, for example, from 50° to 65 20 and

F., is desirable. Such a medium can be provided light-sensitive means exposed to solar radi by the admixture of 10 to 25% of Sodium chloride ation for controlling said power means in ac with Glauber’s Salt. cordance with the magnitude of Solar radiation incident thereon.

The addition of borax to the Glauber's Salt with or without the addition of Sodium chloride, MARIA TELKES. is generally desirable as it prevents Supercooling 25 REFERENCES CITED of the Glauber’s Salt and also inhibits corrosion.

Cells containing a heat storage medium solidi The following references are of record in the fying at 50° to 65° F. may also advantageously file of this patent:

be used in maintaining the temperature of green 30 UNITED STATES PATENTS houses and other plant growing spaces. For Such Number Nanne Date purposes the cells may be positioned in or under 224,507 Ancelin ------------- Feb. 7, 1880 the roof of the greenhouse, for example, to absorb 246,626 Morse -------------- Sept. 6, 1881 Solar radiation during the day and thereafter 247,393 Nieske ------------ Sept. 20, 1881 maintain or aid in maintaining the desired tem 35 412,725 Calver ------------ Oct. 15, 1889 perature during the night by the radiation, con 780,352 Kafka -------------- Jan. 17, 1905 duction or convection of heat from the storage 1,081,098 De La Garza -------- Dec. 9, 1913 medium.

It will be seen from the foregoing description 1,673,429 Vinson ------------ June 12, 1928 that wide variation in details of construction and 40 1,887,618 arrangement is possible without departing from Bell ---------------- Nov. 15, 1932 the principles of the invention. 1951,403 Goddard --------- Mar. 20, 1934 By the term 'zone to be heated,' as used in the 2,191,198 Gould -------------- Feb. 20, 1940 description and in the appended claims, I mean 2,271,648 Kleist -------------- Feb. 3, 1942 to include broadly any Zone such as the room 45 2,388,940 Newton ------------ Feb. 22, 1944 space of a building, the point of use of domestic Taylor ------------- Nov. 13, 1945 hot water, or the like, and the term "outer wall' 2,428,876 Hawkins------------ Oct. 14, 1947 is intended to include the roof of a structure. FOREIGN PATENTS I claim: Number Country Date 1. Wall construction for a building comprising 19,560 Great Britain ------ Sept. 8, 1914