Abstract:
A spa system comprising a tub, a circulation system and a controller is provided. The tub holds water and has an outlet port and an inlet port. The circulation system has a pump assembly, including a motor driving a pump, to circulate water from the outlet port to the inlet port. The speed of the motor can be set at different speeds by the controller in response to user inputs to adjust the flow rate of the water discharged into the tub through the inlet port. Alternatively, or in addition, the speed of the motor can be set at different speeds by the controller depending one whether a water heater positioned in fluid communication with the pump assembly is in a heating mode or in a non-heating mode. In some implementations, the motor used to drive the pump is a BLDC motor.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation claiming the benefit of priority under 35 USC §120 based on co-pending U.S. patent application Ser. No. 11/653,082, which was filed on Jan. 12, 2007. The contents of the above-noted application are incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to recreational or therapeutic water circulation system such as spas, hot tubs, whirlpools, and jetted baths. Particularly, it relates to an improved water circulation system where the flow of water that is discharged into a tub or basin is selectively variable and controllable by a user. 
       BACKGROUND 
       [0003]    For some time, consumers have enjoyed recreational and hydro-therapeutic benefits of spas, hot tubs, whirlpools, and jetted baths (all forms of the aforementioned and derivatives thereof are referred to hereinafter as “spa system”). Spa systems can serve as a retreat for relaxation or socialization. They can also provide therapeutic benefits by making use of circulating heated water to treat muscles and/or joints to improve physical well being. Generally, the circulating heated water is passed through a jet or nozzle to accelerate the flow of the water as it is discharged into a tub. This jetted flow or jetted water offers therapeutic massages to the user. 
         [0004]    At the present time, spa systems include one or more AC induction motors that operate at one, two or three fixed preset speeds to deliver jetted water. A problem with this arrangement is that these preset speeds are defined by the manufacturer and cannot be changed by the user. Consequently, the user is unable to adjust the flow of the jetted water to his preference, and the blast of jetted water produced by the pump may be too strong, too weak, or uncomfortable for the user. 
         [0005]    Current spa systems also typically include a circulating pump, separate from the jetting pump, for circulating water during “standby.” Generally, “standby” is the time period when the jetting pump is not operating or when the spa system is not occupied by a user. Typically, the circulating pump is a single-speed pump that is programmed to turn ON to filter, sanitize, and heat the water. In other prior art systems, a single two-speed pump may be used for both jetting and circulating. But even here, a single high speed is used for jetting, and a single low speed is used for filtering, sanitizing and heating the water during standby. A problem with these configurations is that the same speed is used to filter, sanitize and heat the spa system&#39;s water. In practice, however, the water flow that is needed to heat the water differs from the flow that is required to filter and/or sanitize the water. Typically, for example, the pump speed required for filtering and sanitizing is lower than the pump speed that is needed to heat the water. Therefore, the current spa systems waste energy because unnecessary power is expended during the filtering and/or sanitizing cycle. 
         [0006]    Accordingly, it is an object of the invention to provide improved methods and apparatus for controlling the speed of a pump to adjust the water flow through an inlet to a tub or basin to a user&#39;s preference. It is also an object of the invention to provide an improved spa system that can deliver new and different jetting modes to be enjoyed by the user. It is further an object of the invention to provide improved methods and apparatus for operating a pump to deliver optimum or near optimum speed for filtering, sanitizing and heating water. It is further an object of the invention to provide the above-identified objects in an energy efficient manner over current systems. 
       SUMMARY OF THE INVENTION 
       [0007]    According to one embodiment of the present invention, there is provided a spa system that includes a tub, a pump assembly and a controller. The tub is capable of retaining water, and has at least one outlet port and at least one inlet port. The pump assembly includes a pump driven by a BLDC pump and circulates water from the outlet port to the inlet port of the tub. The controller is coupled to the BLDC motor and controls the speed of the BLDC motor in response to a user&#39;s input. The speed of the BLDC motor can be set to any speed within the speed range of the BLDC motor to adjust the flow rate of the water that is discharged from the pump into the tub through the inlet port. 
         [0008]    The spa system may include a user interface control pad for the user to indicate the desired BLDC speed or the strength of water flow through the inlet port of the tub. The spa system may also produce at least one jetting mode in response to a user input. The jetting mode may be a pulse mode, a sinusoidal mode, a ramp mode, or a saw-tooth mode. One or more characteristic of a jetting mode may also be modified in response to input from a user. The BLDC motor of the pump assembly may be a 6 HP motor with a speed range of zero rpm to 4000 rpm. 
         [0009]    According to another embodiment of the invention, the spa system includes a tub, a first pump assembly, a filter, and a heater. The tub is capable of retaining water and has an outlet port and an inlet port. The first pump assembly includes a BLDC motor and a pump and circulates water from the tub&#39;s outlet port to the inlet port. The filter and heater are in fluid communication with the first pump assembly. The BLDC motor of the first pump assembly operates at a first speed when the heater is activated to heat the circulating water, and at a second speed when the heater is not activated. 
         [0010]    Optionally, this second embodiment may include a controller coupled to the BLDC motor of the first pump assembly to control the speed of the motor. The first and second speeds can be set to any speed within the speed range of said first BLDC motor to adjust the flow rate of the circulating water. The speeds of the BLDC motor of the first pump assembly may also be optimized to filter the circulating water, or to heat the circulating water. The first pump assembly may also be operated at a third speed, set to any speed within the speed range of the first BLDC motor, for jetting. 
         [0011]    The second embodiment may further include a second pump assembly that circulates water. The second pump assembly may also include a BLDC motor that can be set to any speed within the speed range of this BLDC motor to adjust the flow rate of the water discharged from the second pump assembly into the tub. 
         [0012]    According to another embodiment, a spa system includes a tub, a jetting pump assembly and a circulating pump assembly. The tub is capable of retaining water, and has first and second outlet ports, and first and second inlet ports. The jetting pump assembly includes a BLDC motor and a pump to circulate water from the first outlet port to the first inlet port. The BLDC motor of the jetting pump assembly can be set to any speed within the speed range of the BLDC motor to adjust the flow rate of the water discharged from the first pump into the tub through the first inlet port according to a user&#39;s preference. The circulating pump assembly includes a pump to circulate water from the second outlet port to the second inlet port. The circulating pump assembly operates at a first speed when a heater is activated to heat the circulating water, and at a second speed when the heater is not activated. Optionally, the circulating pump assembly may include a BLDC motor. Also, the first and second outlet ports may be the same port. Further, the first and second inlet ports may be the same port. 
         [0013]    In another embodiment, the spa system includes a tub and a circulating pump assembly. The circulating pump assembly operates to circulate water from an outlet port to an inlet port of a tub during standby. Where the circulating pump assembly operates at a first speed when a heater is activated to heat the circulating water, and at a second speed when the heater is not activated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Other objects and features will become apparent from the following detailed description taken in connection with the accompanying drawings. However, the drawings are provided for purpose of illustration only, and are not intended as a definition of the limits of the invention. 
           [0015]    In the drawings, wherein the same reference number indicates the same element throughout the several views: 
           [0016]      FIG. 1  is a block diagram of an embodiment of a spa system. 
           [0017]      FIG. 2  is side view of an embodiment of a jetting pump assembly. 
           [0018]      FIG. 3  is a block diagram of a second embodiment of a spa system. 
           [0019]      FIG. 4  is a block diagram of a third embodiment of a spa system. 
           [0020]      FIG. 5A-5D  are illustrative examples of various jetting modes that may be produced by a jetting pump assembly according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    Embodiments of the present invention will now be described with reference to the drawings. Referring to  FIGS. 1 ,  3  and  4 , spa systems  10 ,  50  and  60  are each an illustrative embodiment of present invention and incorporates various inventive features or combinations. These features are described in detail below and illustrated in the accompanying figures for the purpose of describing the preferred embodiments of the invention. It is to be expressly understood, however, that the present invention is not restricted to the spa systems described herein. Rather, the present invention includes a water recirculation system that incorporates one or more of the disclosed features or combinations. For example, a system may or may not include a filter, a sanitizer, a heater, or a jet. It is to be understood that the present invention is directed to each of the inventive features or combination of features of the systems described below. 
         [0022]    As used herein, the term “spa system” refers to a system which includes a tub or basin that is suitable to contain a fluid such as water and which includes one or more stations that may each be occupied by a person. In at least one station, one or more jets may be selectively located. As used herein, a “jet” refers to an orifice or nozzle through which a fluid may be pumped, discharged or dispensed into the tub. Jets may be provided in various shapes, and sizes as commonly known in the art. 
         [0023]    Turning now in detail to the drawings, as shown in  FIG. 1 , a first embodiment of a spa system  10  includes a tub  12 , jets  16   a  and  16   b , a pipe system  18 , a jetting pump assembly  22 , a controller  24 , a control pad  26 , a filter  28 , a heater  32 , a sanitizer  51 , and a circulating pump assembly  34 . The spa system  10  may also include temperature sensor  38 , and flow sensors  53 ,  54 , which may be located about the discharge end of the jetting pump assembly  22  and circulating pump assembly  34 , respectively. The tub  12  holds fluid, such as water  14 , and may be sized to be occupied by one or more users. The tub  12  is also preferably shaped to facilitate the user to be in a seated position. The pipe system  18  connects the various components of the spa system  10 . 
         [0024]    In the illustrative embodiment, the controller  24  controls the operation of the spa system  10  and is electrically coupled to the jetting pump assembly  22 , the heater  32 , the sanitizer  51 , the circulating pump assembly  34 , temperature sensor  38 , and flow sensors  53 ,  54 . Power to the controller  24  may be by commonly known means suitable for commercial or residential service. The controller  24  may regulate and control the voltage and current that are delivered to the various spa system  10  components. The controller  24  may include a microprocessor or discrete devices and amplifiers to establish and deliver the desired voltage/current to the system components. The controller  24  may also monitor spa system parameters such as, for example, water temperature, water flow rate, or motor parameters. 
         [0025]    The controller  24  is also electrically connected to one or more control pad  26 . The control pad  26  is located at a convenient location for easy access by the user and facilitates the user to enter input for operating the spa system  10 . 
         [0026]    In the illustrative embodiment of  FIG. 1 , the jetting pump assembly  22  controls the flow of jetted water that is returned to the tub  12 . Water is drawn from the tub  12  to the jetting pump assembly  22  through filter  28  and outlet port  36   a , and discharged back to the tub  12  through jets  16   a ,  16   b . The filter  28  may be a single filter element or a plurality of filter elements, and preferably contained in a filter compartment. Referring to  FIG. 2 , the jetting pump assembly  22  includes a brushless DC (“BLDC”) motor  42 , and a pump  44 . The BLDC motor  42  includes a base  45  and a shaft  46 . The shaft  46  is coupled to the pump  44 , which includes an inlet  48  and outlet  49 , and drives the impeller of the pump  44  to advance the water to the tub  12 . Generally, an increase in the speed of the BLDC motor  42  corresponds to an increase in the flow of water through the outlet  49  of the pump  44 . 
         [0027]    The preferred jetting pump assembly  22  includes a BLDC motor  42  because compared to an AC induction motor, as used in prior art spa systems, a BLDC motor has greater reliability, better efficiency, and longer life. Also, unlike an AC induction motor, a BLDC motor advantageously has the ability to operate at any speed between zero revolutions per minute (“rpm”) and its maximum speed. Accordingly, through control pad  26  and controller  24 , the user is able to adjust the speed of the BLDC motor  42  to any speed within its range, and thereby control the water flow through jets  16   a ,  16   b . Unlike prior art spa systems that provide one, two or three fixed speeds for jetting, the jetting pump assembly  22  as described herein facilitates the user to adjust the speed of the BLDC motor  42  to any value to achieve the desired flow rate. In this way, the user may set the strength of the jetted water to his exact preference and receive maximum therapeutic benefit from the spa system. 
         [0028]    In addition to providing the ability to vary the strength of the jetted water to the user, the jetting pump assembly  22  including the BLDC motor  42  provides the user or the manufacturer to set the upper and lower limit of available speed to a desired range. For example, the lower limit may be set at 600 rpm so as to indicate to the user that the jetting pump assembly  22  power is ON. This may be desirable because extremely low speeds may not produce a flow that the user can detect. By setting the lower limit to a speed which will produce a flow that is detectable by the user, he can avoid inadvertently leaving the jetting pump assembly  220 N and wasting energy. Also for example, the upper limit of the jetting pump assembly  22  may be set to 3000 rpm to prevent an uncomfortably high jetted flow to the user. This may be desirable, for example, where the spa system is used primarily by older bathers. By setting the upper limit to a lower speed, inadvertent injury to the user can be avoided. 
         [0029]    Also, the BLDC motor  42  may be programmed to any speed range and operate at any particular speed without a significant loss in efficiency. For example, the BLDC motor  42  can be programmed to have lower and upper limit speeds of 600 rpm to 2500 rpm; 600 rpm to 3500 rpm; 600 rpm to 4000 rpm; or 1200 rpm to 3500 rpm. However, regardless of the range limit selected, the BLDC motor  42  of the jetting pump assembly  22  allows the user to adjust the BLDC motor  42  to any speed within the range and to produce water flow through the jets  16   a ,  16   b  that he desires. 
         [0030]    In the illustrative embodiment shown in  FIG. 1 , the user may be prompted by a display screen  27  on the control pad  26  to input the lower and upper speed limits of the jetting pump assembly  22 . Once the limits are defined, a dial  29  on the control pad  26  may be maneuvered by the user to adjust the speed of the BLDC motor  42  and, consequently, adjust the strength of the water flow through jets  16   a ,  16   b  to his preference. Although the embodiment described employs a dial  29  to adjust the speed of the BLDC motor  42 , the present invention is not limited by such an arrangement. The speed of the BLDC motor  42  may be adjusted by other suitable means, such as for example, a touch pad switch labeled with up/down arrows and a digital LED indication of the speed of the BLDC motor  42  or strength of the jetted water. 
         [0031]    In a particular implementation of the jetting pump assembly  22 , the user may preset the strength of the jetted water to his preference and store the preset value in controller  24 . In this way, the user may simply recall the preset value instead of having to adjust the speed of the BLDC motor  42  or the strength of the jetted water each time he uses the spa system  10 . In a preferred embodiment, the user may define a plurality of preset values, each to his preference, and store the plurality of preset values in the controller  24  for later recall. 
         [0032]    The jetting pump assembly  22  including the BLDC motor  42  can also be controlled to operate in particular jetting modes. For example, through the controller  24 , operating routines can be employed to generate jetting modes as represented in  FIGS. 5A through 5G .  FIG. 5A  illustrates a pulse mode, where the jetting speed produced by the BLDC motor  42  cycles between a first speed (S 1 ) and a second speed (S 2 ) a number of times over a period of time (T). In the preferred embodiment, the user can select the pulse mode by inputting a command using the control pad  26 . Preferably, the user may also select or adjust the pulse mode parameters, i.e., the first speed (S 1 ), second speed (S 2 ) and period (T), to any value to control the pulsing action as desired. Alternatively, the pulse mode parameters may be preset and stored in controller  24 . 
         [0033]      FIG. 5B  illustrates a sinusoidal mode, where the jetting speed cycles between a first speed (S 1 ) and a second speed (S 2 ) over a period of time (T) in sinusoidal form. Similar to the pulse mode as described above, these parameters may be adjusted by the user to his preference. Alternatively, the sinusoidal mode parameters may also be preset and stored in controller  24 . 
         [0034]      FIG. 5C  illustrates a ramp mode, where the jetting speed increases and decreases in a linear slope (M) between a first speed (S 1 ) and a second speed (S 2 ) over a period of time (T). The slope (M) may be adjusted to make the jetting force intensity increase gradually or sharply. In a preferred embodiment, the speeds, the period and the slope is selected by the user to his preference. Alternatively, the ramp mode parameters may be preset and stored in controller  24 . 
         [0035]      FIG. 5D  illustrates a saw-tooth mode, where the jetting speed increases from a first speed (S 1 ) to a second speed (S 2 ) over time (T), then substantially instantaneously drops to the first speed (S 1 ), and repeats this cycle. Again, these parameters may be adjusted by the user or they may be preset and stored in controller  24 . 
         [0036]    The present invention is not limited to these specific jetting modes. The jetting pump assembly  24  including the BLDC motor  42  may operate under other jetting routines which may vary jetting over different speeds, frequencies, and/or speed versus time patterns. Advantageously, unlike AC motors, these jetting modes and other jetting routines can be employed by the BLDC motor  42  without a significant loss in efficiency. 
         [0037]    In yet another alternate embodiment, the controller  24  may be programmed to have default settings for the user to choose from. For example, the user may be given the option of adjusting the jetted water speed to his own preference, selecting a preset speed, selecting a preset jetting mode, or overriding jetting mode parameters as desired and storing the preferred jetting mode for later recall. In the preferred embodiment, the BLDC motor  42 , also called an electronically commutated motor, is a 6 HP continuous duty motor with a speed range of zero rpm to 4000 rpm. However, other HP and speed range combination may be implemented. 
         [0038]    In another alternate embodiment, the controller  24  can be used to monitor spa system performance. For example, the flow through the filter  28  will reduce over time as it traps debris and particles. The controller can detect this change in the resistance across the filter  28  by monitoring the speed and/or the current draw of the BLDC motor  42 . Alternatively, the controller  24  can detect this change by considering the water flow rate measured by a flow sensor  53 . Regardless of the means to detect the condition of the filter  28 , the controller  24  can compensate for the clogging filter  28  by adjusting the speed of the BLDC motor  42  to maintain the desired jetting speed and flow as desired by the user. 
         [0039]    In yet another embodiment, the jetting pump assembly  22  may deliver water to features such as waterfalls and/or fountains. Utilizing the capability of the BLDC motor to control the speed of the jetting pump, the water flow rate to these features can be optimized for effect and, if desired, modulated to vary in concert with an audio system of the spa. 
         [0040]    Turning to another aspect of the present invention, the spa system  10  also includes a circulating pump assembly  34  which draws water from the tub  12  through filter  28  and outlet port  36   b . The discharge from the circulating pump assembly  34  passes through a heater  32  and a sanitizer  51  before returning to the tub  12 . The circulating pump assembly  34  generally operates during the standby mode and controls the flow of water during the filtering, sanitizing and heating periods of the spa system  10 . In a preferred embodiment, the circulating pump assembly  34  is also powered and controlled by the controller  24 . Generally, the circulating pump assembly  34  operates at a lower speed range than the jetting pump assembly  22 . In the illustrative embodiment, the circulating pump assembly  34  includes a pump  42  that is driven by a motor  43 . In a preferred embodiment, the motor  43  is a BLDC motor programmed to operate at two-speeds. 
         [0041]    In a preferred embodiment, the heating cycle is triggered whenever the temperature sensor  38  detects that the spa system&#39;s water temperature falls below a specified range, and this information is processed by the controller  24 . As shown in  FIG. 1 , the temperature sensor  38  is located along the interior wall of the tub  12 . However, multiple temperature sensors may be used, and they may be disposed at various locations throughout the spa system  10 . 
         [0042]    Once the controller  24  determines to trigger the heating cycle, signals are sent to activate the circulating pump assembly  34  and the heater  32 . As the circulating pump assembly  34  advances water through the heater  32 , the water temperature in the spa system  10  is eventually returned to the desired range. Generally, the heater manufacturer defines the desired flow rate through the heater which will yield the most effective heat transfer to the passing water. The speed of the circulating pump needed to achieve this desired flow rate is affected by, among other things, the diameter and length of the pipes used in the piping system  18 , and the resistance of the filter  28  and the heater  32 . Therefore, the speed of the BLDC motor during the heating cycle varies according to the total resistance of the particular spa system. However, because the BLDC motor can operate at any speed, the circulating pump assembly  34  can produce the desired flow which will most effectively heat the circulating water. In this way, energy conservation is realized using the BLDC motor. Once the temperature is raised to the specified range, the controller  24  turns the heater  32  and the circulating pump assembly  34  to OFF. Alternatively, the controller  24  may only turn the heater  32  OFF and continue operating the circulating pump assembly  34  for additional filtering. Typically, the circulating pump assembly  34  operates at a speed between 1200 rpm and 1900 rpm during the heating cycle. 
         [0043]    The circulating pump assembly  34  also operates to filter and/or sanitize the water. However, the circulating pump assembly  34  need not operate at the speed needed to heat the water during the filtering and/or sanitizing operation. This is because the primary consideration for filtering and/or sanitizing the spa system water is to merely advance the water through filter  28 , and the pump speed required is lower than the speed needed to heat the water. For example, filtering may be performed at a rate needed to exchange or pass the water in the spa system through the filter every forty-eight hours. Preferably, water filtering and sanitizing is accomplished during off-peak hours of the day to save energy. In a preferred embodiment, the controller  24  is programmed to run the circulating pump assembly  34  from 1 am to 6 am. Alternatively, the controller  24  may be programmed to run the circulating pump assembly  34  at a very low speed to filter and/or sanitize the water in the spa system  10  continuously. Typically, the circulating pump assembly  34  operates at a speed between 700 rpm to 1100 rpm. 
         [0044]    Because the motor speed or the flow needed to heat and filter/sanitize the water in the spa system  10  differ, the circulating pump assembly  34  of the present invention operates in at least two different speeds: a first speed for heating and a second speed for filtering and/or sanitizing, i.e., conditioning, the water. In this first embodiment, the circulating pump assembly  34  includes a pump  42  that is driven by a motor  43  that is a BLDC motor. Advantageously, because the BLDC motor can operate at any speed, the pump  42  may be driven at any first and second speeds. For example, for a particular spa system  10 , the desired water flow rate for the heating cycle may be achieved by operating the motor  43  at 1400 rpm, and the desired flow rate for the filtering/sanitizing cycle may be achieved by operating the circulating pump assembly  34  at 850 rpm. The circulating pump assembly  34  with a BLDC motor may be programmed by the controller  24  to operate precisely at a first speed of 1400 rpm, and a second speed of 850 rpm. As discussed above, the controller may turn ON the circulating pump assembly  34  to a first speed in response to detecting that the water temperature has fallen outside a specified range. The circulating pump assembly  34  may further be programmed to turn ON at a second speed at a predetermined time schedule to filter and/or sanitize. In this way, the circulating pump assembly  34  is used at optimum speeds to achieve heating and filtering and/or sanitizing. Because no more than necessary energy is used to heat, sanitize, and/or filter the water, the spa system  10  is more efficient than the prior art systems that use a single-speed circulating pump to perform these operations. 
         [0045]    Also, as discussed above, flow through the spa system  10  will be affected over time as the filter  28  becomes clogged with debris and particles. As shown in  FIG. 1 , the controller  26  is connected to the circulating pump assembly  34  and a flow sensor  54 . Because the controller  24  monitors the BLDC motor and flow parameters, it can detect a change in the resistance across the filter  28 . Accordingly, the speed of the circulating pump assembly  34  can be adjusted to compensate for a clogged filter  28  and continue to deliver optimum flow rate to the heater  32 . Similarly, during the filtering or sanitizing period, the condition of the filter  28  may be compensated and the speed of the BLDC adjusted to achieve the desired filtering or sanitizing flow rate. Moreover, by monitoring the change in the speed of the BLDC motor needed to maintain the desired flow through the spa system, the controller  24  can determine the condition of the filter  28  and alert the user of the need to replace the filter by, for example, activating an alert light  33  on the control pad  26 . 
         [0046]    In an alternate circulating pump assembly embodiment, the motor  43  of the circulating pump assembly  34  may be a two-speed AC induction motor. Because a two-speed AC induction motor is restricted in the available speeds it may generate, optimum speeds to heat and filter and/or sanitize the water may not be achieved. However, the two-speed AC induction motor may be designed to achieve greater energy efficiency over the prior art single-speed motor application. For example, the minimum conditioning speed for a particular spa system may be 900 rpm, and the minimum heating speed may be 1750 rpm. A two-speed AC motor may be designed to produce a first speed of 1050 rpm and a second speed of 1750 rpm. Although the two speeds may not match each of the desired speeds, a substantial energy saving is still achieved over a single-speed pump by running the filtering and/or sanitizing cycle at the reduced speed of 1050 rpm. 
         [0047]    Thus, a novel and improved spa system  10  has been shown and described. The variable and controllable jetting flow produced by the jetting pump assembly  22  as described herein has not heretofore been combined for use in a spa system. The current spa systems include AC motors to drive the jetting pump which cannot provide variable speed control over a range of speeds to the user. The jetting pump assembly  22 , including a BLDC motor  42 , is more energy efficient than AC motors used in prior art spa systems. This is because AC motors are optimal at only one speed, and their efficiency drops significantly at other speeds. In contrast, the BLDC has a relatively flat efficiency curve over the operating speed range. Therefore, regardless of the jetting flow the user chooses, the efficiency of the BLDC motor is generally maintained. In this way, the BLDC motor facilitates energy efficient operation of the jetting pump assembly  22  over many operating speeds. 
         [0048]    Other variable speed motors, such as a three-speed AC induction motor, a single speed AC induction motor or a permanent magnet rotor motor powered by a variable frequency electronic drive may be contemplated. However, these motors are less efficient than a BLDC motor, more expensive than a BLDC motor, or both. A universal type brush motor may also provide variable speed. However, universal type motors tend to be noisy and have a relatively short life as compared to a BLDC motor. 
         [0049]    Moreover, the jetting pump assembly  22  as disclosed herein can advantageously operate in the pulse mode, sinusoidal mode, ramp mode, and saw-tooth mode, among other jetting routines, with no detrimental effect on the jetting pump assembly. An AC induction motor, on the other hand, would generate significant heat when used in these modes and result in a shortened life or a failure to operate. 
         [0050]    The efficiency of the BLDC motor, over its AC based counterparts, used in either the jetting pump assembly or the circulating pump assembly  34  also facilitates the spa system  10  to operate the heater  32  concurrently with the pump assemblies. In prior known spa systems, the jetting pump and the heater typically could not be operated at the same time without overloading the system&#39;s electrical capacity, or the commercial or residential electrical service capacity. As a result, the water in the spa system may cool down while the jetting pumps are operating. In contrast, the pump assemblies including a BLDC motor as disclosed herein have lower energy consumption and facilitates a spa system to be designed whereby the heater and the jetting pump can be operated at the same time. In this way, the user can enjoy the benefit of heated hydrotherapeutic massages. 
         [0051]    In a second embodiment, as shown in  FIG. 3 , a spa system  50  includes all the features and components of the spa system  10  illustrated in  FIG. 1 . However, spa system  50  includes a plurality of jetting pump assemblies  22   a ,  22   b  to provide individual flow control to a plurality of user stations. In this way, jetting preference of individual users may be satisfied. 
         [0052]    In a third embodiment, as shown in  FIG. 4 , a spa system  60  includes a tub  12 , jets  16   a ,  16   b , a pipe system  18 , a controller  24 , a control pad  26 , a filter  28 , a heater  32 , a sanitizer  51 , and a pump assembly  55 . The pump assembly  55 , includes a pump  57  and a BLDC motor  59 . Notably, the spa system  60  does not include a separate jetting pump assembly and a circulating pump assembly. Instead, the pump assembly  55  and the controller  24  is configured to employ the pump assembly  55  to perform the functions of jetting and circulating. That is, when a user desires to receive jetted water, a command is input to the control pad  26  and controllable high pressure jetted water is received by the user. As described in detail above, the speed of the BLDC motor, and consequently, the flow of the jetted water can be varied and adjusted by the user to his preference. 
         [0053]    During the standby mode, the spa system  60  makes use of the pump assembly  55  for the circulating function. That is, if the temperature of the spa water is detected by the controller  24  to fall below a specified range, signals are sent to the pump assembly  55  and the heater  32  to turn ON. Particularly, the pump assembly  55  is activated to operate at a first speed, which is the desired speed to achieve the desired flow rate through the heater  32 . Once the temperature rises to the specified range, the controller  24  signals the pump assembly  55  and the heater  32  to turn OFF. 
         [0054]    Also in spa system  60 , to perform the filtering and/or sanitizing function, the controller  24  may be programmed to turn on the pump assembly  55  to a second speed for a period of time. This second speed is selected according to the filtering and/or sanitizing requirement. As described above, the second speed to filter and/or sanitize is less than the first speed to heat the water. In this way, energy efficiency is achieved. 
         [0055]    The pump assembly  55  of the spa system  60  advantageously utilizes a single assembly to perform the function of jetting and circulating. Having such an arrangement facilitates minimizing the number of components needed for a spa system and provides a way for users to enjoy hydro-therapeutic benefits in situations where space is limited. 
         [0056]    Referring to  FIG. 2 , in another application of the pump assembly  22 , the variable speed capability of the pump assembly  22  may be used to create a continuous current in a tub or basin to facilitate a user to swim in place. Swimming provides good aerobic exercise without the high impact and joint stress of running or jogging. But the cost and space required may limit the user&#39;s ability to acquire a pool at his residence. A continuous current tub facilitates the user to realize the health benefits of swimming without the need for a full size pool. The pump assembly  22  with a BLDC motor  42  may be configured to operate at any speed. In this way, the pump assembly  22  facilitates the user to adjust the current of the water flow according to his swimming ability or preference. Similarly, the pump assembly  22  including a BLDC motor  42  may be used in a swim spa system, which is a system that includes a continuous current feature for swimming and a jetting feature for hydrotherapy. 
         [0057]    Various embodiments of spa systems and their respective components have been presented in the foregoing disclosure. As already discussed, the improved spa system as described herein is not limited by the illustrative embodiments shown in the figures. While preferred embodiments of the herein invention have been described, numerous modifications, alterations, alternate embodiments, and alternate materials may be contemplated by those skilled in the art and may be utilized in accomplishing the various aspects of the present invention. For example, the spa system according to this invention may include three, four or more jetting pump assemblies, each arranged for each station in the tub  12 . Also, while each spa system disclosed herein employ a heater, filter, and a sanitizer, the particulars of the present invention may be practiced with any or none of these components. It is envisioned that all such alternate embodiments are considered to be within the scope of the present invention as described by the appended claims.