US2588723A - Method of converting air conditioning systems - Google Patents

Description

March 11, 1952 H. H. HERMAN METHOD OF CONVERTING AIR CONDITIONING SYSTEMS Filed Dec. 24, 1945 INVENTOR.

ATTO EV Patented Mar. 11, 1952 METHOD OF CONVERTING AIR CONDITION- ING SYSTEMS Harry H. Herman, Denver, Colo.

Application December 24, 1945, Serial No. 637,132

Claims.

This invention relates to a method of producing a cooling system, which may also be utilized for heating purposes, and more particularly to a method of producing a cooling system for a building, or the like, which comprises the conversion of a conventional two-pipe steam heating system.

A conventional two-pipe steam heating system consists of a steam supply main provided with steam by a boiler or the like, and a plurality of radiators connected with the steam main by branch pipes, risers and the like, and also similarly connected with a return or condensate main for conducting condensate back to the boiler. Such a heating system, however, cannot be utilized in.the summer or other warm periods of the year for cooling purposes. Also, if a cooling medium is circulated through the supply main to the radiators, moisture tends to condense on the radiators and produce pools of water between Furthermore, a heat radiator is dethe same. signed primarily for heating, and is relatively inefiicient for cooling purposes,

Among the objects of this invention are to provide a novel method of producing a cooling system for buildings and the like; to provide such a method which produces a cooling system which efficiently and effectively cools the rooms or enclosed spaces of a building or the like; to provide such a method which comprises the conversion of a conventional two-pipe steam heating system; to provide such a method whereby the conversion is simple and economical; and to provide such a method which produces a cooling system which also may be utilized for heating purposes. I

The above and other objects, and the novel features of this invention, will become apparent from the accompanying drawing, in which:

Fig. 1 is a partially diagrammatic elevation illustrating a conventional two-pipe steam heating system;

Fig. 2 is a partially diagrammatic elevation illustrating a preferred embodiment of this invention; and

Fig. 3 is a vertical cross section taken through a special shunt valve utilized in the system of Fig. 2.

A conventional two-pipe steam heating system as in Fig. 1, includes a steam supply main 9 to which steam may be supplied by a boiler or the like, normally installed in a basement of the building, and from which one or a plurality of risers l0 carry steam to various portions of the building. From each riser l0, steam branch lines ll lead to radiators R at the various floor levels,

each steam branch line H being connected with the inlet of a radiator, and the flow therethrough being controlled by a valve 12. The steam condenses in the radiator R, and the condensate is returned through a branch line l3 to a return pipe M, a suitable thermostatic valve l5 normally being installed at the outlet of the radiator R to insure that only condensate will pass out of the radiator. A plurality of return pipes !4 may lead to a return main for returning the condensate to the boiler. Return pipe 14 is smaller in site than riser l0, since steam occupies a considerably greater volume than condensate from the steam. The above system is conventionally used in heating buildings, each radiator thus being placed in a suitable position, as upon a floor IS in a room, hallway, or other portion of the building.

It will be understood, of course, that main 9 may extend to the upper portion of the building, and the upper ends of risers I0 may be connected therewith, the inlet of such a riser being at the upper end and the outlet at the lower end. Such risers are termed down risers, since the radiators supplied thereby are successively lower in the building. Thus, as used in the appended claims, the term riser includes both up risers and down risers, unless obviously inappropriate,

and the term supply main may include also one or more risers or other pipes supplying cooling or heating units.

In accordance with the method of this invention, as in Fig. 2, an eifective cooling system, which also may be used for heating purposes if desired, is produced by a few relatively simple changes in the conventional heating system of Fig. 1. These changes include merely the substitution of cooling (and heating) units U for radiators R; the addition of a single linea return main l1, preferably connected to the outlet end of each riser I0; and the installation of suitable shunt means, such as a shunt valve V, in riser ill at each floor level or other desired position, such as just above each branch line H.

Each cooling unit U includes a heat transfer element, such as a coil l9, disposed within a housing 20 and adapted to cool air passing thereover to be circulated into and through the room, as by fans 2| driven by a motor 22. The air may be taken into the housing through a'grill-work or louvres at the ends or sides of the housing 20 and discharged into the room through a grillwork or louvres 23 in the top of housing an, al-

though any other suitable position for the same may be selected for cooling and air condition 66 ing the room or enclosure. The method of this invention further includes the installation of a drip pan 25 beneath coil 19 of each cooling unit U, for receiving moisture condensing on coil 19, and connecting each drip pan with return pipe It by a branch pipe 26. Return pipe !4 is thereby utilized in the system of Fig. 2 as a drain line, and therefore leads to a suitable main connected with a drain, sewer, or the like.

A cooled heat transfer liquid, normally water, is supplied main 9 by a cooling or refrigeration apparatus 2'], preferably located in the basement, or at any other convenient location. Cooling apparatus 2'! may be conventional, and as such may operate in any one of several different ways, such as a compression refrigeration cycle wherein the motive power is supplied by an electric or other motor, or an absorption refrigeration cycle wherein the motivating energy is supplied by a gas flame or the like. In apparatus 21, the water to be circulated through the units U is passed in heat transfer relationship with a cooling medium, such as brine, expanded refrigerant gas or the like.

From cooling apparatus 21, the cooled liquid passes through a pipe 28 to main 9 in which is installed a pump 29 to insure an adequate circulation of the cold water through the main 9, risers l0, and individual units U. As the cold water passes upwardly in riser It), usually to the first of a series of units U, a portion thereof is shunted by valve V through branch pipe I I which may supply one or more units U, each through an inlet pipe 30 connected with coil 13. A hand valve 32 and a thermostatic valve 33 may be installed in each inlet pipe 30, to provide additional regulation of flow through the units U. r, either of valves 32 or 33 may be installed alone. After passing through the coil, the water is returned to riser i ll by an outlet pipe 3|, connected to riser adjacent the outlet side of valve V, such as just above the valve. As will be evident, each branch pipe II is connected to riser I0 adjacent the inlet of a valve V.

It will be understood, of course, that risers l0 may be down risers, in which event main 9 is connected thereto at their upper ends and return main I! at their lower ends. Or, a combination of up risers and down risers may be utilized.

The valve V may be constructed, as in Fig. 3, with a globular body 35 and a disc or butterfly valve 36, pivoted on a longitudinal pin 31. Disc 36 is operable by turning from outside the valve body to force any desired portion of the cold water through inlet pipe. 30. For units closer to the cooling apparatus 21, the shunt valve V will usually be set so as to offer less resistance to the flow of water through riser Ill, and thereby divert less cold water through inlet 30, since a smaller rate of flow through the unit is required, due to the lower temperature of the cold water. After effecting cooling and air conditioning in the room or other portion of the building in which the unit U is installed, the water, now warmer, is returned to riser ill through outlet pipe 3|.

After all of the units U have been supplied with cooled water in the above manner, the warmed water passes from the upper end of riser ill to return main I! and then downwardly through return main l! to the cooling apparatus 21. A valve 39 may be installed in each riser l0 adjacent return main H, to regulate the flow through the individual risers, so as to insure an adequate flow to each unit U.

The system produced by this invention may also be adapted for heating purposes, a boiler 40 being utilized instead of the cooling apparatus 21 to supply hot water to main 9 through pump 29. Boiler 40 is connected by a pipe 4| with return main I1 and by a pipe 42 with supply main 9, and is adapted to heat water to a desired tem-- perature, for circulation through units U, valves V functioning as before to divert portions of the hot water through the units U, and the used water being returned to the boiler through return main l1. Pump 29 is preferably utilized during heating, to insure an adequate flow of hot Water to all units U. Valves 43 are installed in return main l1 and main 9, respectively, for shutting off the flow through cooling apparatus 21 when boiler 40 is in use, and valves 4:2 are installed in pipes M and 42, respectively, for a similar purpose.

From the foregoing, it will be apparent that the method of producing a cooling system in accordance with this invention, which system also may be utilized for heating purposes, fulfills to a marked degree the objects and requirements hereinbefore set forth. A valuable feature of this invention is the low cost of installation and the simplicity of change-over, as well as the effectiveness in operation of the units U, both for cooling and heating. Furthermore, the method of this invention utilizes a maximum of piping already installed, and does not require the elimination of any such piping. Due to'the use of a maximum amount of piping already installed, the cost of the change-over is only a fraction of that which would be required for the installation of new piping for a cooling, or cooling and heating system. Also, the cost of additional equipment is relatively low, when compared with the greatly increased facilities for comfort afforded the occupants of the building.

It will be evident that the units U may be varied, both in design and in manner of operation, and that different means for insuring the flow of cold liquid through the coils is may be utilized, and further that different heat transfer elements, such as finned tube-type elements, may be utilized in lieu of coils 19. It will also be evident that return main I! may be installed so as to be connected to outlet lines 3!, thus eliminating shunt valves V. However, the former return pipe I4 will still be utilized as a drain line, since it is not large enough to handle the volume of liquid passing through units U for cooling purposes.

What is claimed is:

l. A method of converting a two-pipe steam heating system into a cooling or heating system for a building, said two-pipe steam heating system including a steam supply main having one or more risers, branch lines leading to steam radiators at various floor levels, at least one condensate return pipe, and branch return pipes leading from each radiator to a condensate return pipe, said method comprising the steps of installing cooling means for a heat transfer liquid and connecting the same with said supply main; substituting cooling units for said radiators, each said cooling unit including a heat transfer element; installing a drip pan beneath each heat transfer element for collecting moisture condens ing on said heat transfer element; connecting each said drip pan with a former condensate return line, thereby converting the former condensate return line into a drain line; connecting said drain line to a sewer or the like; installing a shunt valve in a riser at a point adjacent each cooling unit; connecting the inlet of the heat transfer element of each said cooling unit with a riser at one side of a shunt valve; connecting the outlet of each said heat transfer unit with said riser at the opposite side of said shunt valve; and installing a return line for conveying said heat transfer liquid from the ends of said risers to said cooling means.

2. A method of converting a two-pipe steam heating system into a cooling or heating system for a building, said two-pipe steam heating system including a steam supply main having one or more risers, branch lines leading to steam radiators at various floor levels, at least one condensate return pipe, and branch return pipes leading from each radiator to a condensate return pipe, said method comprising the steps of installing cooling means for a heat transfer liquid and connecting the same with said supply main; substituting cooling units for said radiators, each said cooling unit including a heat transfer element; installing drip pans for collecting moisture condensing on said heat transfer elements; connecting each said drip pan with a former condensate branch line, thereby converting the former condensate return line into a drain line; in-

stalling a shunt valve in a riser at each floor level; connecting the inlet of the heat transfer element of each said cooling unit with a riser at one side of a shunt valve; connecting the outlet of each said heat transfer unit with said riser at the opposite side of said shunt valve; and installing a return line for conveying said heat transfer liquid from the ends of said risers to said cooling means.

3. In the production of a cooling or heating system for a building, such system having a plurality of cooling units, each including a heat transfer element and a drip pan for collecting moisture condensing on said heat transfer element, the improvement which comprises converting a two-pipe steam heating system which includes a steam supply main having one or more risers, branch lines leading to steam radiators at various floor levels, at least one condensate return pipe, and branch return pipes leading from each radiator to a condensate return pipe; said conversion including the installation of cooling means for a heat transfer liquid and connecting the same with said supply main; substituting said cooling units for said radiators, said substitution including the installation of said drip pans; installing shunt means in a riser at least at each floor level; connecting the inlet of the heat transfer element of each said cooling unit with a riser at one side of a shunt means;

connecting the outlet of each said heat transfer unit with said riser at the opposite side of said shunt means; connecting each said drip pan with a former condensate return line, thereby converting the former condensate return line into a drain line; and installing a return line for conveying said heat transfer liquid from the ends of said risers back to said cooling means.

4. In the production of a cooling and air conditioning system for a building, also usable for heating purposes, such system having a plurality of cooling and heating units, each including a heat transfer element and a drip pan for collecting moisture condensing on said heat transfer element, the improvement which comprises converting a two-pipe steam heating system which includes a steam supply main having one or more risers, steam branch lines leading to steam radiators at various floor levels, at least one condensate return pipe, and branch return pipes leading from each radiator to a condensate return pipe; said conversion including the installation of cooling means for a heat transfer liquid and connecting the same with said supply main; installing heating means for said heat exchange liquid and connectable alternatively to said supply main; substituting said cooling and heating units for said radiators; installing shunt means in a riser at least at each floor level; connecting the inlet of the heat transfer element of each said cooling and heating unit with a riser below said shunt means; connecting the outlet of each said heat transfer unit with said riser above said shunt means; connecting each said drip pan with a former condensate return line, thereby converting the former condensate return line into a drain line; and installing a return line for conveying said heat transfer liquid from the ends of said risers to said cooling means, and alternatively to said heating means.

5. In the production of a cooling system for a building, such system having a plurality of cooling units at each floor level, each cooling unit including a heat transfer element, and a drip pan for collecting moisture condensing on said heat transfer element, the improvement which comprises converting a two-pipe steam heating system which includes a steam supply main having one or more risers, branch lines leading to steam radiators at various floor levels,

at least one condensate return pipe, and branch return pipes leading from said radiators to a condensate return pipe; said conversion including the installation of cooling means for a heat transfer liquid and connecting the same with said supply main; substituting said cooling units for said radiators, including the installation of said drip pans; installing shunt valves in a riser at points adjacent said cooling units and at the different floor levels; connecting the inlet of the heat transfer element of each said cooling unit with a riser below a shunt valve; connecting the outlet of each said heat transfer unit with said riser above said shunt valve; connecting each said drip pan with a former condensate return line, thereby converting the former condensate return line into a drain line; and installing a return line for conveying said heat transfer liquid from the ends of said risers to said cooling means.

HARRY H. HERMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,065,415 Wild et al. June 24, 1913 1,315,766 Feldman Sept. 9, 1919 1,979,941 Jewell Nov. 6, 1934 2,078,295 Thatcher Apr. 27, 1937 2,307,422 Richards Jan. 5, 1943

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