Patent Publication Number: US-7712161-B2

Title: Combination spa system with water chilling assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/684,674, filed 26 May 2005. 

   FIELD OF THE INVENTION 
   The present invention relates to spas and hot tubs. 
   BACKGROUND OF THE INVENTION 
   For many years, hot tubs and home spas were the exclusive luxuries of the wealthy. They were expensive to buy, expensive to operate, and not entirely reliable. With the onset of better manufacturing techniques, improved materials, and lower prices, however, the popularity of hot tubs and home spas has soared, particularly throughout the last decade. 
   History provides many examples of hot tubs or spas. For instance, the Romans were known to have used bathhouses, which became centers of social life and a common daily activity for the elite classes. Other cultures made use of spa-like hot baths as well, including the ancient peoples of China and Japan. 
   Some of the earliest spa enthusiasts appreciated the health benefits of using hot water to relax the body, open the pores of the skin, and generally promote better health. Cleanliness was considered healthful and a sign of prosperity. As medical science has advanced, there has been an increased awareness of the benefits of hot tub hydrotherapy. Many medical conditions, injuries and other health problems can be eased or improved with regular hydrotherapy treatments. For example, people with arthritis, multiple sclerosis, paralysis and other conditions that involve deteriorating range of motion benefit from time spent in a hot tub. The warm water helps ease aches and pains, while loosening joints and making them easier to move and keep mobile. Joint problems, chronic back pain and other painful conditions resulting from injuries are also helped with regular hot tub hydrotherapy. Those seeking stress relief, general relaxation, and quiet opportunities for conversation commonly experience significant hot tub benefits as well. 
   Modern technology, materials and production processes make it possible to design and build home spas and hot tubs with highly specialized hydrotherapy features. These features are typically based on a combination of seating position, jet position and jet function. 
   Traditional hot tub seating was bench-style, typically in a round shape and at a uniform depth so that everyone sat at the same level in the tub. This made it challenging for people of different heights to fully benefit from hot tub therapy. With the development of molded fiberglass spa shells came the development of different shapes and sizes of seats. Manufacturers began to include lounge seats, where the bather reclines in the water, as well as seats to accommodate bathers of different heights. Some also included deeper seats, designed to fully immerse the bather and allow placement of jets in specific positions for specific benefits. 
   Moldable shell manufacturing made it possible for the first time to place jets in nearly any position within the tub. Manufacturers began experimenting with placing jets in places where they would focus on specific areas of the body, such as the back, neck, shoulders, arms and legs. 
   The earliest jets were single-action nozzles with limited ability to adjust where they were aimed or the intensity of the jet action. This made it difficult to use them in positions where they would affect more tender areas of the body, such as wrists, forearms, ankles, feet and knees. As manufacturers developed more advanced jets with a wider variety of functionality, though, the technology of hydrotherapy advanced significantly. Modern hot tubs and spas can be customized with a surprising variety of jets that range from multi-purpose to highly specialized. Buyers often are able to select exactly which jets to install in specific locations within their hot tub or home spa. The benefits of different jet types have grown substantially with the development of independent seating control. In older spas and hot tubs, one set of controls ran all of the therapy jets, but independent seating control allows each bather to control the strength and intensity of therapy in their own individual seat. 
   Spas and hot tubs have been around in one form or another for centuries, but only in the last few decades have technology, materials and manufacturing improved to the point where a home spa is affordable enough and reliable enough to be within reach of most people. Although the field of spas and hot tubs has enjoyed considerable innovation throughout much of the last decade, much of the improvements have been directed toward improving the hydrotherapy systems, the jets, and the construction materials, particularly the construction materials relating to the tubs, with little effort directed toward improving their overall usefulness. As a result, the art suffers in that spas and hot tubs are not versatile in terms of providing users with the ability to not only enjoy the benefits of hot water, but also the benefits of chilled water. 
   Accordingly, it is an object of the invention to provide a spa system incorporating a tub and heating and cooling devices operatively associated with a circulating system for providing the ability to provide the tub with hot water and also with cold water. 
   It is another purpose of the invention to provide new and improved spa system that is easy to construct. 
   It is still another purpose of the invention to provide new and improved spa system that is inexpensive. 
   It is yet another purpose of the invention to provide a spa system that is easy to use, and that incorporates a tub held by a chassis that is specifically adapted to accommodate a water cooling device to be operatively plumbed with a circulating system for the tub that is concurrently operatively plumbed to a water heating device. 
   It is a further provision of the invention to increase the usefulness of spa systems. 
   SUMMARY OF THE INVENTION 
   According to the principle of the invention, a spa system is provided which is low in cost, which is simple in structure, which is safe, which incorporates a single tub, and which incorporates a circulating system adapted to withdraw and return water relative to the tub together with heating and cooling devices operatively coupled in series to the circulating system for chilling and heating the water circulating therethrough from the tub. 
   According to the invention, there is provided a spa system including a tub, water heating and cooling devices operatively coupled in series to a circulating system adapted to withdraw and return water relative to the tub, and a thermostat operatively coupled to the heating and cooling devices, in accordance with the principle of the invention. A chassis supports the tub, and there is a cooling device receiving area formed in the chassis, in which the cooling device is disposed at the cooling device receiving area. Opposed first and second rails are carried by the chassis, and are disposed on either side of the cooling device receiving area. A platform has opposed first and second sides received against the first and second rails, respectively, thereby supporting the platform at the cooling device receiving area. The cooling device is supported atop the platform. An access opening is formed through the chassis and leads to the cooling device receiving area. A closure is provided, which is adapted to be secured to the chassis for enclosing the access opening. 
   According to the invention, there is provided a tub supported by a chassis, a substantially enclosed space formed between the tub and the chassis, and first and second vents through the chassis leading to the enclosed space. Water heating and cooling devices are operatively coupled in series to a circulating system adapted to withdraw and return water relative to the tub, and a thermostat is operatively coupled to the heating and cooling devices. The cooling device incorporates a fan operative for drawing air into the enclosed space through the first vent in response to activation of the cooling device to cool the cooling device. The spa system incorporates a blower, which is operative for expelling air from the enclosed space through the second vent currently with the operation of the fan of the cooling device. A cooling device receiving area is formed in the enclosed space, and the cooling device is disposed at the cooling device receiving area. Opposed first and second rails are carried by the chassis, and are disposed on either side of the cooling device receiving area. A platform has opposed first and second sides received against the first and second rails, respectively, thereby supporting the platform at the cooling device receiving area. The cooling device is supported atop the platform. An access opening is formed through the chassis and leads to the cooling device receiving area. A closure is provided, which is adapted to be secured to the chassis for enclosing the access opening forming part of the chassis. In a preferred embodiment, the first vent is formed in the closure. 
   According to the invention, there is provided a spa system including a tub supported by a chassis, a substantially enclosed space formed between the tub and the chassis, and first and second vents through the chassis leading to the enclosed space. Water heating and cooling devices are operatively coupled in series to a circulating system adapted to withdraw and return water relative to the tub. According to the invention, the cooling device is operatively coupled to a blower, and a thermostat is operatively coupled to the heating and cooling devices. The cooling device incorporates a fan operative for drawing air into the enclosed space through the first vent in response to activation of the cooling device to cool the cooling device. The blower is activated by the cooling device in response to the activation thereof for expelling air from the enclosed space through the second vent. A cooling device receiving area is formed in the enclosed space, and the cooling device is disposed at the cooling device receiving area. Opposed first and second rails are carried by the chassis, and are disposed on either side of the cooling device receiving area. A platform has opposed first and second sides received against the first and second rails, respectively, thereby supporting the platform at the cooling device receiving area. The cooling device is supported atop the platform. An access opening is formed through the chassis and leads to the cooling device receiving area. A closure is provided, which is adapted to be secured to the chassis for enclosing the access opening forming part of the chassis. In a preferred embodiment, the first vent is formed in the closure. 
   In a spa system including a tub supported by a chassis, a substantially enclosed space formed between the tub and the chassis, and a water heater operatively coupled to a circulating system adapted to withdraw and return water relative to the tub, improvements therein according to the principle of the invention including a water cooling device operatively coupled to the circulating system in series with the water heater, and a thermostat operatively coupled to the heating and cooling devices. The improvements according to the present embodiment further include first and second vents through the chassis leading to the enclosed space, the cooling device incorporating a fan operative for drawing air into the enclosed space through the first vent in response to activation of the cooling device, and a blower operative for expelling air from the enclosed space through the second vent currently with the operation of the fan of the cooling device. A cooling device receiving area is formed in the enclosed space, and the cooling device is disposed at the cooling device receiving area. Still further the improvements incorporate opposed first and second rails, carried by the chassis, disposed on either side of the cooling device receiving area, and a platform having opposed first and second sides received against the first and second rails, respectively, thereby supporting the platform at the cooling device receiving area, wherein the cooling device is supported atop the platform. The improvements also include an access opening through the chassis leading to the cooling device receiving area, and a closure adapted to be removably secured to the chassis for enclosing the access opening forming part of the chassis, in which the first vent is formed in the closure. 
   Consistent with the foregoing summary of preferred embodiments, and the ensuing detailed description, which are to be taken together, the invention also contemplates associated apparatus and method embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring to the drawings: 
       FIG. 1  is perspective view of a spa system constructed and arranged in accordance with the principle of the invention; 
       FIG. 2  is a schematic plan view of the spa system of  FIG. 1 ; 
       FIG. 3  is a simplified, partially schematic side elevational view of the spa system of  FIG. 1 ; 
       FIG. 4  is a partially exploded perspective view of the spa system of  FIG. 1  illustrating a chiller disposed adjacent to a chiller receiving area formed in a chassis supporting a tub; 
       FIG. 5  is a view very similar to the view of  FIG. 4  showing the chiller positioned in the chiller receiving area, and a chiller cover detached from the chassis; 
       FIG. 6  is a perspective view of the chiller of  FIG. 4 ; 
       FIG. 7  is a fragmented perspective view of the chiller of  FIG. 4  shown coupled in fluid communication to inflow and outflow conduits; 
       FIG. 8  is a fragmented perspective view of a fluid pump of the spa system of  FIG. 1 ; 
       FIG. 9  is a fragmented perspective view of the chiller of  FIG. 4  showing a plugged electrical interconnection adapted to be coupled to a controller of the spa system of  FIG. 1 ; 
       FIG. 10  is a perspective view of a controller of the spa system of  FIG. 1 ; 
       FIG. 11  is a perspective view of a chassis of the spa system of  FIG. 1 ; 
       FIG. 12  is an enlarged fragmented perspective view of the chassis of  FIG. 11  illustrating opposed rails forming part of a chiller receiving area of the spa system of  FIG. 1 ; and 
       FIG. 13  is a perspective view of one of the rails of  FIG. 12 . 
   

   DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
   Referring now to the drawings, in which like reference characters indicate corresponding elements throughout the several views, attention is first directed to  FIG. 1  in which there is seen a spa system  20  including a chassis  21  supporting a tub  22  for holding a volume of water. Referring to  FIG. 4 , tub  22  includes an upstanding continuous sidewall  23  having an outer surface  24 , an inner surface  25 , a closed bottom  26 , and an open top  27  leading into a chamber  28  for holding a volume of water. Chamber  28  is bound and defined by inner surface  25 , and closed bottom  26  opposing open top  27 . 
   Tub  22  is generally square in shape. However, tub  22  may be of any suitable or desired configuration, such as round, rectangular, kidney, or other selected shape, and is preferably an integral tub structure. Tub  22  is constructed of any suitable material or combination of materials generally used in swimming pool and hot tub construction, such as fiberglass, acrylic, concrete, or other combinations of artificial and/or synthetic materials. It has been found convenient for the tub  12  to have a size approximately equivalent to a circle having a 6 to 12 foot diameter, in which chamber  28  has a capacity of approximately 400 to 2000 gallons. A spa system constructed and arranged in accordance with the principle of the invention may be configured with any desired volume capacity. Furthermore, although not specifically shown tub  22  may be formed with one or more seats for providing one or more seating areas within chamber  28 , and also one or more lounge seats for providing one or more lounging areas within chamber  28 . Any suitable configuration of spa tub may be used with spa system  20  without departing from the invention. 
   Spa system  20  may include a hydrotherapy system incorporating specialized hydrotherapy pumps associated with a hydrotherapy circulating system adapted to withdraw water from chamber  28  and return it to chamber  28  through a variety of jets thereby introducing jets of water into the volume of water disposed in chamber  28 . According to conventional practice, those having regard for the art will readily appreciate that spa system  20  can be customized with any variety and arrangement of jets that range from multi-purpose jets to highly specialized jets. 
   As a matter of example,  FIG. 3  illustrates a conventional hydrotherapy system generally indicated by the reference character  29 , which is coupled to tub  22  chamber  28  in fluid communication with a series of conduits (not shown). When activated, hydrotherapy system  29  withdraws water from tub  22  chamber  28  and then returns the water back into tub  22  chamber  28  through a series of jets at tub  22 , which eject water into the water in tub  22  chamber  28  in the form of jets of water. The jets of water agitate the water held by tub  22  chamber  28  thereby ensuring a relatively even temperature of the water throughout tub  22  chamber  28 , and provide a water massaging affect to users in the water held by tub  22  chamber  28 , which promotes muscle relaxation. The series of conduits coupling hydrotherapy system  29  to tub  22  chamber  28  forming a part thereof will normally include an outflow conduit through which water is drawn from tub  22  chamber  28  and a network of outflow conduits for receiving water from the inflow conduit and directing the water to the jets at tub  22 . Hydrotherapy system  29  is conventional and well-known to those having regard for the art, further details of which will readily occur to the skilled artisan and need not be described in further detail. Although desirable, hydrotherapy system  29  can be omitted, if desired. 
   Referring to  FIG. 2 , tub  22  chamber  28  is associated with a water circulating system  30  that, when operational, withdraws and returns water relative to tub  22  chamber  28 . According to the principle of the invention, water heating and cooling devices  31  and  32  are operatively coupled in series to circulating system  30 . Circulating system  30  withdraws water from chamber  28  through a drain port  34  formed in tub  22  at a predetermined flow rate, filters the water for particulate matter, and conducts the water first through heating device  31  and then through cooling device  32  before returning the water to tub  22  chamber  28  through an inlet port  35 . In this embodiment, drain port  34  is formed in closed bottom  26 , and it can be formed elsewhere, if desired. Circulating system  30  couples water heating and cooling devices  31  and  32  in fluid communication with the water held by tub  22  chamber  28 . According to the principle of the invention, water heating and cooling devices  31  and  32  are operatively coupled/plumbed in series to circulating system  30  thereby allowing heating device  31 , when activated, to heat the water passing therethrough, and allowing cooling device  32 , when activated, to chill the water passing therethrough. With respect to heating device  31 , the term “operatively coupled” describing its coupling to circulating system  30  means that heating device  31  functions to heat the water passing through circulating system  30  when heating device  31  is activated. With respect to cooling device  32 , the term “operatively coupled” describing its coupling to circulating system  30  means that cooling device  32  functions to chill/cool the water passing through circulating system  30  when cooling device  32  is activated. 
   In this preferred embodiment, circulating system  30  includes a water pump  40  for withdrawing water from tub  22  chamber  28  through drain port  34  into a conduit  41  and to the inlet port of a conventional large capacity filter unit  43  that filters out sediment and particulate matter from the water stream. The filtered water is applied through the outlet port of filter unit  43  through a conduit  42  to pump  40 , which in turn discharges the water under pressure through a conduit  44  to heating device  31 , which is a conventional spa or swimming pool water heater well-known to those having regard for the art, further details of which will readily occur to the skilled artisan. Heating device  31  is operated by electricity from a power source (not shown), such as a dedicated power source, a battery power source, a generator, etc., and is operatively coupled to a thermostat  45 , and when operational functions to heat the water passing through circulating system  30  for ultimately heating the water held by tub  22  chamber  28  to a predetermined temperature. The selection of heating device  31  is based on the desire to heat the water in tub  22  chamber  28  up to a nominal 106 degrees Fahrenheit. 
   From heating device  31  the water is then applied through the outlet port of heating device  31  through a conduit  46  to an inlet port of cooling device  32 . Cooling device  32  is operated by electricity from a power source (not shown), such as a dedicated power source, a battery power source, a generator, etc., and is operatively coupled to thermostat  45 , and when operational functions to cool/chill the water passing through circulating system  30  for ultimately cooling/chilling the water held by tub  22  chamber  28  to a predetermined temperature. From cooling device  32  the water is then applied through the outlet port of cooling device  32  through a conduit  47  to inlet port  35 , which conducts the water back into tub  22  chamber  28 . As a matter of illustration,  FIGS. 7 and 9  illustrates conduit  46  plumbed to the inlet port of cooling device  32 , and conduit  47  plumbed to the outlet port of cooling device  32 . 
   Pump  40  is a conventional spa or swimming pool water circulating pump on the order of a 0.05 to 2 horsepower unit that delivers the water at a flow rate of approximately 3 to 120 gallons per minute. Filter unit  43  is a conventional and well-known spa filter unit, which is sized to accommodate the maximum flow rate of pump  40 . 
   With momentary attention directed to  FIG. 6 , in the preferred embodiment herein disclosed cooling device  32  is a conventional inline water chiller, designated generally at  60 , provided under the exemplary trademark DELTA STAR, the specific details of which will not be discussed as they are known in the art. Chiller  60  incorporates a fan  61 , which activates concurrently with the activation of chiller  60  blowing cooling air over chiller  60  in the direction indicated by the arrowed line A thereby keeping chiller  60  cool during its operation and preventing it from overheating, which may cause it to operate inefficiently or fail. Although the chiller provided under the trademark DELTA STAR is preferred, other forms of chillers can be used. 
   The selection of cooling device  32 , such as chiller  60 , is based on the desire to chill the water in tub  22  chamber  28  to a nominal 62 degrees Fahrenheit, plus or minus 10 degrees Fahrenheit. And so chiller  60  is sufficiently powerful to adjust the temperature of the water flowing through circulating system  30  to the desired chilled temperature. Consistent with the teachings of the invention, any suitable chiller, refrigeration unit, or like device capable of removing heat from water in order to chill or cool it according to the teachings set forth herein can be used without departing from the invention. Chiller  60  is light in weight and not bulky, and is easy to install and incorporate with circulating system  30  allowing spa system  20  to be prefabricated at a manufacturing site and easily transported for installation at specified site. An example of another suitable chiller that may be use with the invention include the chiller offered by Schreiber Engineering Corp. under the trademark TRUETON. 
   Referring back to  FIG. 2 , thermostat  45  is operatively coupled to water heating device  31  and to water cooling device  32 , which was mentioned previously in this specification. Thermostat  45  is mounted to tub  22  at the top edge thereof forming part of open top  27  of tub  22 , which allows it to be easily accessed from within tub  22  chamber  28 . Thermostat  45  can be mounted elsewhere, if desired. Thermostat  45  is used in conjunction with heating device  31  and cooling device  32  to take water held in tub  22  chamber  28  to a predetermined temperature, and to maintain the water in tub  22  chamber  28  at the predetermined temperature. Thermostat  45  is operatively coupled to heating and cooling devices  31  and  32  with a controller  70 , which is coupled to thermostat  45  and to heating and cooling devices  31  and  32  with conventional electrical interconnections. All of the components of spa system  20 , including pump  40 , heating device  31 , cooling device  32 , thermostat  45 , and also hydrotherapy system  29 , plug into controller  70  providing easy installation with no confusing wiring, or miss-wiring. 
   The temperature of the water in tub  22  chamber  28  is managed by circulating system  30 , heating and cooling devices  31  and  32 , thermostat  45  and controller  70 , in accordance with the principle of the invention. In operation, thermostat  45  functions to sense the temperature of water held in tub  22  chamber  28 , which is monitored or otherwise “seen” by controller  70 . Thermostat  45  is used to set the water in tub  22  chamber  28  to a predetermined temperature from a starting temperature. If the predetermined temperature set by thermostat  45  is greater than the starting temperature of the water in tub  22  chamber  28 , controller  70  is responsive and concurrently activates pump  40  and heating device  31  thereby heating the water as it is circulated through circulating system  30  relative to tub  22  chamber  28 . Pump  40  and heating device  31  operate concurrently until the temperature of the water in tub  22  chamber  28  as sensed by thermostat  45  reaches the predetermined heated temperature, at which point controller  70  is responsive and concurrently deactivates pump  40  and heating device  31 . The thermostat  45  being set at the predetermined heated temperature, controller  70  will continue to periodically activate pump  40  and heating device  31  as needed in order to maintain the temperature of the water in tub  22  chamber  28  at or near the predetermined heated temperature set by thermostat  45 . Preferably, controller  70  is configured to activate pump  40  and heating device  31  when the temperature of the water in tub  22  chamber  28  as sensed by thermostat  45  falls approximately 2-4 degrees Fahrenheit below the predetermined heated temperature set by thermostat  45 . The operation of heating device  31  to heat and maintain the water in tub  22  chamber  28  to a predetermined heated temperature constitutes a heating mode of operation of spa system  20 . If desired, pump  40  can be configured to operate constantly to provide continuous water circulation through circulating system  30 , in which the operation of the remaining components of circulating system  30  remains the same as herein specifically described. 
   If the predetermined temperature set by thermostat  45  is lesser than the starting temperature of the water in tub  22  chamber  28 , controller  70  is responsive and concurrently activates pump  40  and cooling device  32  thereby cooling the water as it is circulated through circulating system  30  relative to tub  22  chamber  28 . Pump  40  and cooling device  32  operate concurrently until the temperature of the water in tub  22  chamber  28  as sensed by thermostat  45  reaches the predetermined chilled temperature, at which point controller  70  is responsive and deactivates pump  40  and cooling device  32 . The thermostat  45  being set at the predetermined chilled temperature, controller  70  will continue to periodically activate pump  40  and cooling device  32  as needed in order to maintain the temperature of the water in tub  22  chamber  28  at or near the predetermined chilled temperature set by thermostat  45 . Preferably, controller  70  is configured to activate pump  40  and cooling device  32  when the temperature of the water in tub  22  chamber  28  as sensed by thermostat  45  rises approximately 2-4 degrees Fahrenheit above the predetermined chilled temperature set by thermostat  45 . The operation of cooling device  32  to cool and maintain the water in tub  22  chamber  28  to a predetermined chilled temperature constitutes a chilling mode of operation of spa system  20 . 
   Accordingly, by using thermostat  45  the temperature of the water in tub  22  chamber  28  can be increased for providing hot water in tub  22  chamber  28 , and can be decreased for providing cold water in tub  22  chamber  28 . This provision allows users to, for instance, enjoy a hot water spa during the cold months of the year, and a cold water spa during the hot months of the year, all conveniently and efficiently in a single tub  22  chamber  28  utilizing heating and cooling devices  31  and  32  operatively coupled in series to circulating system  30 . It is to be understood that controller  70  activates heating device  31  and pump  40  to heat the water from tub  22  chamber  28  passing through circulating system  30  in order to bring the temperature of the water in tub  22  chamber  28  up to a desired temperature as set by thermostat  45 . Similarly, controller  70  activates cooling device  32  to chill or cool the water from tub  22  chamber  28  passing through circulating system  30  in order to bring the temperature of the water in tub  22  chamber  28  down to a desired temperature as set by thermostat  45 . And so the selective activation of heating device  31  and cooling device  32  is made by controller  70  in response to the temperature set by thermostat  45 , in which the selective activation of heating device  31  and cooling device  32  is dependent on the temperature of the water and the selected desired temperature which is set at thermostat  45 . 
   In sum, circulating system  30  is adapted to withdraw and return water relative to tub  22  chamber  28 , in which water heating and cooling devices  31  and  32  are operatively coupled to thermostat whereby the temperature of the water in tub  22  chamber  28  is set and maintained by the selective operation of heating and cooling devices  31  and  32  in response to operation of thermostat  45 . According to the principle of the invention, the water in tub  22  chamber  28  can be heated to a desired hot temperature for providing heated spa water, and can be cooled to a desired chilled temperature for providing chilled spa water, all in a single tub  22  chamber  28  and by using a single circulating system  30  incorporating heating and cooling devices  31  and  32  operatively coupled thereto in series. 
   Referring to  FIGS. 3 and 4 , chassis  21  will now be discussed. Other than the improvements made to chassis  21  to accommodate cooling device  31 , chassis  21  is generally conventional in nature in that it supports tub  22  and encloses circulating system  30  including heating device  31  and cooling device  32  and the other workings and devices of spa system  20  not herein specifically addressed, such as speakers and sound systems, switches, water conduits, etc. Chassis  21  generally consists of a frame  80 , which is fashioned conventionally of wood and/or steel framing members, and decorative siding  81 , which is applied exteriorly to frame  80  for concealing frame  80  and thereby forming a substantially enclosed space  82  between outer surface  24  of tub  22  and chassis  21 , and for providing a desired decorative appearance. This arrangement of chassis  21  consisting of frame  80  and siding  81  is conventional and notoriously well-known to those having ordinary skill in the art, further details of which will not be discussed as they will readily occur to the skilled artisan. Circulating system  30 , heating and cooling devices  31  and  32 , controller  70 , pump  40 , hydrotherapy system  29 , and the various conduits and workings of spa system  20  are maintained in space  82  and preferably secured to chassis  21  in a conventional manner, such as with nut-and-bolt assemblies, mounting brackets, fixtures, etc. 
   According to the invention, chassis  21  is unique in structure in that it is specifically adapted and arranged to accommodate cooling device  32  permitting it, when desired, to operatively coupled to circulating system  30  in series with heating device  31 . The provision of operatively coupling water heating and cooling devices  31  and  32  to circulation system  30  allows heating and cooling devices  31  and  32  to quickly and efficiently heat and chill the water passing therethrough as needed, and eliminates the need for a separate circulation system for heating and chilling. Operatively coupling heating and cooling devices  31  and  32  to circulating system  30  produces a quite surprising result in that the temperature of the water in tub  22  chamber  28  can be very easily and efficiently controlled and managed. 
     FIGS. 3 ,  4 ,  5 ,  11 , and  12 , illustrate a cooling device receiving area  90  formed by frame  80  of chassis  21  in enclosed space  82 , which represents an improvement to chassis  21  according to the principle of the invention. Frame  80  also bounds an access opening  90 A leading to receiving area  90 . Cooling device  32  is situated in receiving area  90  through access opening  90 A as shown in  FIGS. 3 and 5 , and plumbed to circulating system  30  as previously described utilizing conventional spa plumbing techniques. Circulating system  30  passes into and through receiving area  90 , in accordance with the principle of the invention, so that cooling device  32  can be plumbed to circulating system  30  when cooling device  32  is positioned at receiving area  90 . 
   According to the principle of the invention, and with specific reference to  FIG. 12 , opposed rails  91  and  92  are carried by frame  80  of chassis  21 , and are disposed on either side of receiving area  90 . Rails  91  and  92  are spaced apart and substantially parallel relative to one another, and are fastened, such as with nails, screws, adhesive, or other suitable fasteners or combination of fasteners, to opposed parallel support members  93  and  94  forming part of frame  80 . Referring also to  FIG. 13 , rail  91  is fashioned of steel, aluminum, or other strong and substantially rigid material or combination of materials, is elongate, and includes opposed inner and outer ends  100  and  101 , an attachment plate  102  positioned atop, and secured to, support member  93 , a support plate  103  extending into receiving area  90 , and an abutment  104  formed at outer end  101 . Rail  92  is the mirror image of rail  91 , and like rail  91  is fashioned of steel, aluminum, or other strong and substantially rigid material or combination of materials, is elongate, and includes opposed inner and outer ends  110  and  111 , an attachment plate  112  positioned atop, and secured to, support member  94 , a support plate  113  extending into receiving area  90 , and an abutment  114  formed at outer end  111 . 
   Looking to  FIGS. 4 and 6 , cooling device  32  is supported by platform  120 . Cooling device  32  is situated atop platform  120 , which has opposing sides  121  and  122  and opposed inner and outer ends  123  and  124 , and is secured thereto with fasteners, such as screws, nut-and-bolt assemblies, rivets, etc. Fan  61  is situated at outer end  124  of platform  120 , and the inlet and outlet ports of cooling device  32  to which conduits  46  and  47  are plumbed are situated at inner end  123  of platform  120 . 
   To install cooling device  32 , it is taken up together with platform  120  and positioned into receiving area  90  through access opening  90 A inner end  123  of platform  120  first, in which inner end  123  of platform  120  is directed inwardly into space  82 . Platform  120  is positioned atop support plates  103  and  113  of rails  91  and  92  as best seen in  FIG. 3 , in which sides  121  and  122  are received atop and against support plates  103  and  113  of rails  91  and  92 , respectively.  FIG. 7  shows platform  120  situated onto rails  91  and  92 , in which side  121  is received atop and against support plate  103  of rail  91 , and side  122  is received atop and against support plate  113  of rail  92 . Platform  120  forced inwardly along rails  91  and  92  until its inner end  123  at sides  121  and  122  is received against abutments  104  and  114 , respectively. The length of platform  120  from inner end  123  to outer end  124  is substantially coextensive to the length of rails  91  and  92  from their inner ends to their outer ends. Abutments  104  and  114  together limit the inwardly movement of platform  120  into receiving area  90 . Properly positioned onto and supported by rails  91  and  92 , sides  121  and  122  rest entirely on support plates  103  and  113 , respectively, and inner end  123  is received against abutments  104  and  114 . With cooling device  32  situated atop and secured to platform  120  and platform  120  situated onto rails  91  and  92  as herein described, cooling device  32  situated atop platform  120  is thereby suitably disposed in receiving area, in accordance with the principle of the invention. At this point, the inlet and outlet ends of cooling device  32  may be plumbed to conduits  46  and  47 , respectively.  FIG. 12  shows cooling device  32  in phantom outline as it would appear situated in receiving area  90  with platform  120  situated against rails  91  and  92 . 
   Cooling device  32  is provided with a plugged electrical interconnection  130 . To complete the installation of cooling device  32 , it must be operatively coupled to thermostat  45 , which is accomplished by plugging the plugged end  131  of plugged electrical interconnection  130  to a corresponding port  132  formed in controller  70  as shown in  FIG. 10 . Plugging cooling device  32  into controller  70  is an easy and efficient way of operatively coupling cooling device  32  to thermostat  45 . However, cooling device  32  may be hard-wired to controller  70 , if desired. 
   Cooling device  32  is normally mounted in place to frame  80  of chassis  21  at receiving area  90  before the installation of siding  81  is completed. Siding  81  typically consists of a series of siding panels, which are secured in place to frame  80  at the near or final completion of the construction of spa system  20 . One of the siding panels constitutes a closure  135  ( FIG. 5 ) for access opening  90 A, which is secured to frame  80  with fasteners, such as screws or nails or the like, thereby enclosing access opening  90 A forming part of chassis  21 . A vent  136  is formed through closure  135 , which leads to space  82  and is situated opposite fan  61  of cooling device  32 . When fan  61  is activated concurrently with the activation of cooling device  32 , the situation of fan  61  opposite vent  136  allows fan to draw outside air into enclosed space  82  through vent  136  to cool cooling device  32  so that it may operate properly and efficiently and not overheat or fail. If desired, an annular boot, frame, or other form of seal, such as the one designated generally at  137  in  FIG. 5 , may be applied between fan  61  of vent  136  for isolating the airflow therebetween. 
   As fan draws air into space  82 , positive pressure can, however, build up in space  82 , which may prevent the inflow of air into space  82  through vent  136  and thereby prevent cooling device  32  from being properly cooled. To eliminate the buildup of positive pressure in space  82  during the operation of cooling device  32 , spa system  20  incorporates a blower  140 , which is depicted in  FIG. 2 . Looking to  FIG. 1 , a vent  141  is formed in siding  81  of chassis  21  leading to space  82 , and blower  140  is positioned opposite vent  141  as depicted schematically in  FIG. 2 . Blower  140  is coupled in electrical communication with controller  70 . When controller  70  activates cooling device  32  to chill water passing through circulating system  30 , in which case fan  61  is operational drawing air into space  82  through vent  136  across cooling device  32 , controller  70  concurrently activates blower  140 , which is then operative for blowing/expelling air from enclosed space  82  through vent  141  thereby preventing positive air pressure from building up in space  81 , in accordance with the principle of the invention. When controller  70  deactivates cooling device  32 , it concurrently deactivates blower  140 . 
   In another embodiment, blower  140  is coupled in electrical communication with cooling device  32  via electrical interconnection  150  ( FIGS. 4 and 6 ). In this embodiment, when controller  70  activates cooling device  32  to chill water passing through circulating system  30 , in which case fan  61  is operational drawing air into space  82  through vent  136  across cooling device  32 , cooling device  32  concurrently activates blower  140 , which is thereby operative for expelling air from enclosed space  82  through vent  141  preventing positive air pressure from building up in space  81 , in accordance with the principle of the invention. When cooling device  32  is deactivated, it concurrently deactivates blower  140 . Any desired number of vents can be incorporated with chassis  21 . 
   Although cooling device  32  is normally mounted in place to frame  80  of chassis  21  at receiving area  90  before the installation of siding  81  is complete, spa system  20  may be constructed and arranged leaving cooling device  32  out. In this respect, spa system  20  may be sold as unit without the provision of cooling device  32 . However, because chassis  21  is structured and arranged with a receiving area  90  to accommodate cooling device  32 , and because circulating system  30  passes into and through receiving area  90 , cooling device  32  may be incorporated with spa system  20  at any time, in accordance with the principle of the invention. In other words, spa system  20  is specifically constructed and arranged so that it may be retrofitted with cooling device  32  at any time, as may be desired. To retrofit spa system  20  with cooling device  32 , closure  135  is removed, cooling device  32  is taken up and set into receiving area  90  as previously described, plumbed to circulating system  30  passing through receiving area  90 , and then operatively coupled to controller  70  with conventional electrical interconnections or plugs so that controller  70  will operate cooling device  32  as herein described, after which closure  135  is reattached thereby completing the installation of cooling device  32 . 
   The present invention is described above with reference to a preferred embodiment. However, those skilled in the art will recognize that changes and modifications may be made in the described embodiment without departing from the nature and scope of the present invention. Various changes and modifications to the embodiment herein chosen for purposes of illustration will readily occur to those skilled in the art. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof. 
   Having fully described the invention in such clear and concise terms as to enable those skilled in the art to understand and practice the same, the invention claimed is: