Abstract: An improved spa control system is disclosed. The invention describes a spa control system which calculates the time required to heat the water in the spa system to a desired temperature. From that information, the heating rate of the spa system can be determined, and the heating element of the spa system can be activated at the proper time to raise the temperature of the water to a selected temperature by a desired time. The spa system also monitors information which might show errors in the operation of the spa system such as a blockage in the flow of water over the heating element in the spa system.

Abstract: An improved spa control system is disclosed. The invention describes a spa control system which calculates the time required to heat the water in the spa system to a desired temperature. From that information, the heating rate of the spa system can be determined, and the heating element of the spa system can be activated at the proper time to raise the temperature of the water to a selected temperature by a desired time. The spa system also monitors information which might show errors in the operation of the spa system such as a blockage in the flow of water over the heating element in the spa system.

Abstract: A pool insulation system including storage means 2 for storing a plurality of buoyant articles 50, first transfer means 30 for transferring the buoyant articles from the storage means 2 to a pool 1 and second transfer means 3,4 for transferring the buoyant articles from the pool to the storage means 2. The second storage means comprises a flexible boom 3 and a motorised craft 4 manoeuvrable around the pool with the boom attached thereto so that the buoyant articles 50 on the surface of the pool are contained in an enclosure defined by the flexible boom. Means are provided to change the length of the flexible boom on the surface of the pool 1. The invention also relates to a method of removing buoyant articles from the surface of a pool 1, an automatic boom deployment system for a pool, pool apparatus and a pool docking system.

Abstract: Forms for building and assembling water containment holders such as but not limited to inground spas, pools, manmade ponds and fountains. The forms can have an L-shape with downwardly protruding members for allowing the forms to be placed about a base foundation having receiving openings for the protruding members. Lower walls, seats and backrests can be placed about the forms to assemble the water containment holder. All the components including the base, the forms, the seats, lower walls, and backrests can be modular components that are easily transported and assembled by an individual installer.

Abstract: An apparatus for melting paraffin wax is provided. It includes an integral plastic inner tub attached to an integral aluminum plate holder, each of which has a flat bottom and a sloped wall. A positive temperature coefficient heating element is attached to the flat bottom of the aluminum plate holder for self regulating to a preset temperature by autonomously varying the positive temperature coefficient heating element electrical resistance in response to the temperature of the positive temperature coefficient heating element thereby varying a power dissipation of the positive temperature coefficient heating element in order to maintain the positive temperature coefficient heating element at the preset temperature. Heat from the positive temperature coefficient heating element is transferred from the integral aluminum plate holder to the integral plastic inner tub via the flat bottoms and the sloped walls thereby melting any wax inside the integral plastic inner tub.

Abstract: A control system for a pool and spa. Main line voltage is provided through a single line voltage service and a single ground fault circuit interrupter circuit, facilitating a ground fault test and simplifying installation. The control system acts as a power distribution system for controlling the pool and spa equipment, with a circuit board assembly including individual fuse protection devices and switching circuits. A test algorithm is included, wherein the control system is disabled from normal operation if the GFCI test fails. The pool operator manually enters a water fill command, and the controller system automatically opens the fill valve for a predetermined time interval, and then automatically closes the valve. An emergency disconnect switch is mounted near the bathing area, connected by low voltage wiring to the controller system cabinet. The controller system senses the emergency switch closure and disconnects line voltage to the line voltage loads.

Abstract: A fitting for connecting to an end of tubing. The fitting includes a fitting body having a generally tubular construction with a first end adapted for leakproof connection to another component. A second end has a socket connector with tapered interior sidewall portions forming a truncated conical shape such that an end of a tube can be inserted into the socket connector and tightly wedged therein to form a leakproof seal. At least a portion of the fitting body is made of a light-transmitting material such that material lodged within the fitting body is visible from the exterior of the fitting body.

Abstract: A process of electrically heating a spa having electrically operated devices connected to the spa, such as one or more water pumps, lights, and at least two heaters, in an environment in which there is not enough current to operate all spa devices simultaneously. The process includes the steps of providing a control system with data as to which devices are connected to the spa and how much current each device requires, and how much current is available to the spa. Next, the amount of current that is being used by the devices currently operating, other than the two heaters, is calculated. This provides the amount of the residual current available. If the spa water temperature is below a desired temperature, a determination is made as to whether there is enough current to operate one or both spa heaters and either one heater or both heaters are turned on based upon this calculation.

Abstract: A warm/cold double-circulation water filter system and swimming pool arrangement comprises, a swimming pool, a double-circulation water filter system, a water pipe system, a heater. The present invention concentrated the valves in order to convenient management and control, to reduce valves amount and to offer a multiform elevated temperature manner.

Abstract: A solar pool heating system for providing a foldable floating frame and heat absorbent cover to permit selective heating of a pool of water. The solar pool heating system includes a floating frame and a cover member of heat absorent material. The frame positions the cover in spaced relationship to a surface of the water in a pool to permit heating of the pool as solar energy is absorbed by the cover. The frame assembly is foldable in half and the cover member is used as a way of carrying and storing the frame assembly in the folded position. In an embodiment, handles are provided on the cover member to facilitate handling and storage of the device.

Abstract: A floating bath assembly in which the user gets into an open tank in which he rests floating in a slightly heated high-density saline solution in a decubitus dorsal position. The tank has an electrical means for heating the solution, and in the lower part of the tank, there is a connection to an extraction tube of the liquid. The liquid is taken to a reservoir that has an electric resistance, which, at the same time, is connected to a filling tube that uses a valve to allow the tank to be filled again so the user may fill the tank with the high-density saline solution each time it takes a bath.

Abstract: Presented is an improved insulation device which, in multiple numbers, forms a swimming pool cover, or cover for other types of liquid containers. A complete cover is formed of multiple independent floatation insulation devices that collectively cover the entire surface of the water or liquid on which they float, yet enable dispersion thereof as a safety feature from below the surface of the water or liquid by a person in the water so that the person may extend his or her head through the cover to breath air. Structurally, the insulation device is hexagonal so as to cooperatively abut adjacent insulation devices to form a complete cover. The insulation device is injection molded-from plastic in two mirror image half-shells each of which is formed with a circular recess centrally disposed within the hexagonal outer periphery.

Abstract: Solar swimming pool heater panels which are rectangular or circular, black, plastic, floatable, corrugated, connectable, and rollable in bundles for placing on outdoor swimming pools for warming up and covering the water when not in use.

Abstract: A method and apparatus for heating an outdoor swimming pool. The apparatus includes a substantially buoyant web having a first end, a second end, a first exterior surface and a second exterior surface. A water distributor is attached to the first end of the web for flowing pool water longitudinally adjacent the first exterior surface of the web. A conduit in flow communication with the distributor provides a flow of water from a swimming pool pump to the water distributor. The water distributor is disposed to distribute the flow of water adjacent the first exterior surface of the web. The invention provides a pool heating device that is effective to heat pool water without using water flow conduits along the length of the web and is simply constructed for low cost, portability and case of manufacturing.

Abstract: A fitting for connecting to an end of tubing. The fitting includes a fitting body having a generally tubular construction with a first end adapted for leakproof connection to another component. A second end has a socket connector with tapered interior sidewall portions forming a truncated conical shape such that an end of a tube can be inserted into the socket connector and tightly wedged therein to form a leakproof seal. At least a portion of the fitting body is made of a light-transmitting material such that material lodged within the fitting body is visible from the exterior of the fitting body.

Abstract: A warm/cold double-circulation water filter system and swimming pool arrangement includes a swimming pool separated into two pools, each pool having a water outlet and a plurality of water inlets, a double-circulation water filter system adapted to treat water circulated through the pools of the swimming pool, the double-circulation water filter system including a first filter unit, a second filter unit, and a heater, and a water pipe system adapted to deliver water from the water outlet of each of the pools of the swimming pool to the water inlets of each of the pools of the swimming pool through the double-circulation water filter system, the water pipe system having valve means selectively controlled to let water pass from the first filter unit and second filter unit of the double-circulation water filter system to the water inlets of the pools of the swimming pool via the heater.

Abstract: An improved water heater for use in spas, hot tubs, pools, hydrotherapy pools, bath tubs, and similar bodies of water used indoors, outdoors, or both indoors and outdoors are used for both therapeutic and recreational purposes. The water heater uses heating element technology know as thick film on substrate comprising resistive elements bonded to the outer dry surface of a pipe to heat the pipe which in turn heats the water flowing therethrough. The heater is highly efficient due to the direct contact of the wet heating surface with the water and provides a smooth seamless inner heating surface by eliminating the need to pass electrical leads into the wet region of the heater. This virtually eliminates the risk of leaks in the water heater due to bulkhead fittings. The invention further eliminates the need for a heating element to be contained in the inner wet region of a spa heater, thereby reducing the risk of corrosion.

Abstract: A jet reactor pump as used to circulate heated water into a swimming pool at near sonic velocity to heat the swimming pool water.

Abstract: A method for adjusting the temperature of a swimming pool having a filter system and a waterfall, comprising running the filter system at times of the day such that heat transfer with ambient air is optimized by the action of swimming pool water falling through the ambient air, and further comprising positioning and substantially fixing the position of a movable surface below the water fall to help maximize the heat transfer with the ambient air. For pools without waterfalls, it is further disclosed to utilize a conduit from a submerged water return opening to the movable surface which could be a raft.

Abstract: A method for adjusting the temperature of a swimming pool having a filter system and a waterfall, comprising running the filter system at times of the day such that heat transfer with ambient air is optimized by the action of swimming pool water falling through the ambient air, and further comprising positioning and substantially fixing the position of a movable surface below the water fall to help maximize the heat transfer with the ambient air. For pools without waterfalls, it is further disclosed to utilize a conduit from a submerged water return opening to the movable surface which could be a raft.

Abstract: Multilayer polymeric shells for spas, bathtubs and shower enclosures having a textured and marbled surface layer. The shells are produced by forming by extrusion a multilayer polymeric sheet having a marbled appearing top layer, passing the sheet between rollers to impart a textured surface to the marbled top layer of the sheet, and thermoforming the sheets into the structural shells for spas, bathtubs and shower enclosures.

Abstract: A pump which is designed to be mounted within a recirculating water system where a portion of the recirculating water is diverted (bypass water) and cause to flow through the motor chamber with this recirculating water to absorb heat that is produced during the operation of the motor. The heated bypass water is then added back to the recirculating water. The pump includes an electric motor which is mounted within a pump motor chamber of a motor housing and is completely enclosed therein. The pump motor chamber is filled with oil thereby submerging of the electric motor in oil. A water conducting tube is mounted within the pump motor chamber and surrounds the electric motor. The tube inlets water from the pressure side of the pump impeller, conducts this bypass water entirely through the tube and then discharges the bypass water into the inlet of the recirculating water to the pump impeller.

Abstract: An improved swimming pool/spa water heating system whereby a portion of the water flow into the main heater unit (3), is preheated, thereby decreasing the time of operation of the main heater unit (3), to raise the pool water temperature to the desired temperature. The system improvement includes an arrangement wherein pool water is drawn from the pool by the water pump (22), and a portion of the water is diverted through a supplementary heater unit (27), which is located in the combustion exhaust stream of the main heating unit (3). The diverted water is thus preheated in the supplementary heater unit (27), by the residual heat in the main heater unit exhaust and is then directed back into the water system, at a point prior to the inlet of the main heater unit (3), and mixes with the remaining water in the system, thereby increasing the temperature of water into the main heater unit (3).

Abstract: To be used with a pool assembly of the type including a swimming pool, and a pool pump, a self regulating pool heater unit having a refrigeration unit structured and disposed to emit heat in order to heat a quantity of water cycled therethrough by the pool pump. Further, a power source is included and connected to the refrigeration unit, and to the pool pump through a timer. The timer has an on mode which sets a predetermined time period during which the power supplied by the power source flows therethrough to the pool pump so that it will function, and an off mode wherein no power flows through the timer to the pool pump. Additionally, an automatic timer bypass is included and connected in line between the power source and the pool pump.

Abstract: A spa has (a) a bath having an upstanding wall; and (b) a pump assembly removably mounted to the wall of the bath. The pump assembly comprises (i) a U-shaped cover having a dry leg, a wet leg, and a mounting groove formed therebetween, the wet leg of the cover having an inlet port and an outlet port extending therethrough; (ii) a pump disposed within the dry leg of the cover; (iii) an inlet conduit extending from the inlet port to the pump; and (iv) an outlet conduit extending from the outlet port to the pump.

Abstract: A pool monitoring and control system is provided including a pool having a plurality of inputs and a plurality outputs. Also included is a pump for suctioning fluid from the outputs of the pool only during the activation thereof. A control assembly is connected between the pump and the pool. The control assembly includes at least one sensor adapted to generate an activation signal upon a parameter of the pool falling out of a predetermined range. Further, at least one dispenser is included for dispensing a parameter correction fluid upon the actuation thereof. In use, the control assembly, when the pump is activated, is adapted to actuate the dispenser if the activation signal is received.

Abstract: A pump which is designed to be mounted within a recirculating water system where a portion of the recirculating water is diverted and caused to flow through the pump with this recirculating water to absorb heat that is produced during the operation of the motor. The heated diverted water is then added back to the recirculating water system. The pump includes an electric motor which is mounted within a motor housing and is completely enclosed therein. An electrically insulative mounting arrangement mounts the motor relative to the motor housing preventing the conductance of electricity therebetween. The motor housing is filled with oil thereby submerging of the electric motor in oil. The motor housing is enclosed within a seal plate. Surrounding the motor housing is an annular chamber through which the liquid is caused to flow. A baffle arrangement is located within the annular chamber to direct the flow of the liquid so that all area across the surface of the pump housing has liquid flowing thereacross.

Abstract: A spa is maintained at a ready-to-use temperature by a daily heating cycle that is initiated by a filter cycle clock, which traditionally has been used only for programming the circulation of the spa water through a filter. Once a daily heating cycle has been initiated, it normally concludes only when the temperature of the spa water reaches a desired temperature that the user has preset into a thermostat. However, for safety the heating cycle is terminated immediately in the event the heater temperature becomes excessive, since this event could result from lack of water or inadequate circulation.

Abstract: A temperature regulated manicure bowl is provided having a temperature control channel and an heating channel. The heating channel is provided to heat water to a preset temperature level. The temperature control channel is provided to control the heating channel, thereby regulating the temperature of the water. The temperature regulated bowl is also provided with a monitoring channel that monitor's the temperature control channel and the heating channel to insure proper operation. Additionally, a disposable sheath is provided to fit over the bowl. The disposable sheath is a means to prevent the spreading of hand born infections.

Abstract: A jet bath designed to use minimum water, to use a formed in place low cost waterfall type water inlet, to have pulsating and massaging air-water jets appropriately located in the tub, to allow user adjustment of water temperature, to prevent heating the water above 122 degrees Fahrenheit and prevent tripping of a manually resettable high temperature limit switch with initial filling of the tub with overheated water.

Abstract: A pool and spa water heater has a base and an enclosure coupled to the base. The enclosure includes a pair of curved, "shell-like" enclosure components coupled to the base by an overlapping attachment device, e.g., a tongue-and-groove device. The enclosure components may be removed from and attached to the base by moving each component laterally away from or toward the base. The new heater has a platform atop the enclosure for mounting a control panel. The platform and the support device to which the platform is mounted are cooperatively configured so that the platform may be indexed to any one of several positions with respect to the support device and the enclosure. Thus, after placing the base during installation, the control panel may be optimally and independently positioned with respect to the base.

Abstract: To be used with a pool assembly of the type including a swimming pool, and a pool pump, a self regulating pool heater unit having a refrigeration unit structured and disposed to emit heat in order to heat a quantity of water cycled therethrough by the pool pump. Further, a power source is included and connected to the refrigeration unit, and to the pool pump through a timer. The timer has an on mode which sets a predetermined time period during which the power supplied by the power source flows therethrough to the pool pump so that it will function, and an off mode wherein no power flows through the timer to the pool pump. Additionally, an automatic timer bypass is included and connected in line between the power source and the pool pump.

Abstract: A heated therapeutic spa which comprises a spa tub containing water and having plumbing attached thereto, the tub having a wall which is a relatively good thermal conductor; a thermally efficient, insulating container comprising a load bearing outer wall, and a bottom wall; a plenum chamber formed between the tub wall and the container wall and extending about the tub wall; a motor and pump supplying circulating water to the tub and extending in the plenum chamber; a fan located to circulate air that converts heat from the motor into hot air exhausted into the plenum chamber; the fan operating to force the hot exhaust air to circulate around the tub wall, whereby the temperature of the air drops in flowing about the tub wall before returning to the motor.

Abstract: The present invention relates to a flexible insulating panel for an out-of-ground swimming pool, the latter comprising vertical structural ribs that radially outwardly protrude therefrom. The panel comprises a substantially rectangular insulating foam liner encased in a protective jacket. The panel defines an inner surface abutting on the outer surface of the pool peripheral wall and a water-resistant outer surface. The panel is correctly dimensioned and adapted to fit between two consecutive ribs, a plurality of panels thus being installed in a peripheral consecutive manner along the peripheral wall of the pool. The jacket of the panel has two flanges that extend tangentially, relative to the pool peripheral wall, each flange straddling the flange of the next panel, adjacent to and over the rib between the two of them.

Abstract: The invention relates to an automatic solar heating system for open-air swimming pools with a basin (2) for holding the bathing water, including a solar heating means with a walkable basin boundary (4, 22) incorporating a circulation path and having an inlet (6) for bathing water to be heated arranged beneath the level of the bathing water and an outlet (8) for heated bathing water, and a heat-insulated, evacuatable warm water tank (10) for the heated bathing water, the inlet (12) of the warm water tank (10) being arranged beneath the level of the outlet (8) of the basin boundary (4, 22) and connected with this outlet (8), and the outlet (14) of the warm water tank (10) being in communication via a pump-filter unit (16) with a basin inlet opening (18) for the heated and filtered bathing water.

Abstract: A water circulation and heating system for spas which exhibits low power consumption for continuous circulation of the spa water while avoiding air entrapment in the water heating unit comprises a low speed water pump, and a heater that is configured so that water flows through it generally vertically. The low speed pump circulates spa water through the heater at a low flow rate that would cause air entrapment in the heater if it were configured so that water flowed through it horizontally. In a preferred embodiment, a high speed water pump is also provided for operating the spa's high speed jets when the spa is in use. The low and high speed pumps preferably form part of an interconnected water circulation system, so that the water flow rate through the heater is increased when the high speed jet pump is activated.

Abstract: A system for controlling water flow and heat exchange is connected between a central air conditioning system and a swimming pool.

Abstract: The present invention is a hot tub heater system. The hot tub heater system is comprised of a hot tub having water within. The hot tub heater system is also comprised of means for heating the water within the hot tub. The heating means comprises a hot water heater which heats a body of water within a tank and means for transferring heat from the water within the tank to the water of the hot tub without any intermixing. Preferably, the heat transferring means comprises a piping assembly which acts as a heat exchanger. The piping assembly can be a variety of different forms. The present invention allows a hot tub to be heated inexpensively with a domestic hot water heater.

Abstract: An immersible solar heater comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

Abstract: An auto switching swimming pool/spa heater system, to be utilized with a pool and a spa, including a pool pump, a spa pump, and a single heater unit, the heater unit adapted to receive water flow from the pool pump and spa pump into an internal pool/spa flow control apparatus which directs water received from both the pool pump and the spa pump through a coiled heat exchange conduit of the heater unit, for subsequent heating thereof. The flow control apparatus including a bypass conduit with a spring loaded flow regulator valve therein adapted to enable water to bypass the heat exchange conduit upon an increase pressure build up of water directed towards the heat exchange conduit, water exiting the bypass conduit and water exiting the heat exchange conduit being directed through a single water outlet of the heater unit into the spa where heated water overflow passes from the spa into the pool, accordingly heating the pool.

Abstract: An inexpensive, easy to use and to store, solar pool heater which comprises a flexible corrugated plastic sheet having one side thereof matte black and the other side thereof white in color and tubular plastic floats removeably secured to two edges of said sheet and suspending said sheet a short distance below the surface of the water of a pool when said sheet and floats are placed therein. During daylight hours, the sheet is positioned with the black, heat absorbing surface upwards and then, at night, the sheet may be reversed with the white surface uppermost to minimize heat loss from the water. The sheet is relatively small, e.g. 1 meter square, and in use, multiple sheets and floats are interconnected to give the desired coverage to the pool surface. Being small in area, the sheets may be removed from the pool and stored in a small space as by hanging from the wall of the pool enclosure.

Abstract: A time shared arrangement for delivering spa water and pool water to a water heater is disclosed in which check valves respond to the presence of spa water and pool water pressure. Water drawn from the pool is diverted into two streams, one passes through a check valve to a water heater and the other passes through a check valve to a return line. The flow of pool water to the heater is isolated by a further check valve forced to a close position by the pressure of the pool water. Water drawn from the spa is diverted into two streams, one passes through a check valve to a water heater and the other passes through a check valve to a return line. The flow of spa water to the heater is isolated by a check valve forced is closed by the pressure of spa water.

Abstract: A control for a spa and swimming pool pump and heater assembly with diverter valves, includes a selectively actuable pump and spa heater actuator or relay having a first latching circuit, and having a separate first unlatching switch or relay contact, a selectively actuable pump and pool heater actuator or relay having a second latching circuit including the first unlatching switch or relay contact, and having a second unlatching switch or relay contact in the first latching circuit. The control also includes a diverter valve actuator in parallel to one of the pump and spa heater actuator or relay and pump and pool heater actuator or relay.

Abstract: A modular seat unit to be incorporated into the perimeter wall of a swimming pool is provided. The modular seat is devised to afford a purchaser the option of incorporating the unit into a swimming pool by removing one or more modular wall panels which forming the perimeter of the swimming pool and substituting therefor and securing the seat unit into position in place of the omitted vertical wall panel or panels thereby integrating the seat into the perimeter of the swimming pool. The seat unit is provided with a console accessible to the seat occupant to locate controls such as for water flow from the swimming pool supply into the seat recess. The seating area is devised to include hydrotherapy air jets to produce therapeutic water turbulence. An adapter to hold the pole of an umbrella to shelter the seat occupant from the sun's rays and to function as a safety guard is also provided in the horizontal surface of the seat module. The construction provides a seat for an occupant to rest in the pool.

Abstract: A method and apparatus for heating water in a spa which has a plurality of venturi jets, a hosing which includes a plurality of venturi jets and a high speed pump which circulates water through the housing and the venturi jets in the spa and a water thermostat. The thermostat is positioned in the water of the spa and connected to the high speed pump such that the high speed pump is activated to propel water through the venturi jets at high speed and thus heat it whenever the water temperature falls below a preset level.

Abstract: An improved swimming pool water flow system for filtering in and intermittently heating the pool water, and for interrupting water flow through the heat exchanger when no heating is required. The system improvement includes an improved water flow arrangement wherein pool water is drawn from the pool and, encountering a filter or chlorinator, is selectively diverted at a predetermined pool water outlet temperature into the heat exchanger. The water pump is thus used to pull water through the heat exchanger in counter circulating fashion only when the thermostat sensing pool water outlet temperature opens a control valve in the water flow path between the heat exchanger and the pump.

Abstract: An above ground swimming pool rib structure including a lower plastic section, an upper plastic section, aligned tubular portions in the upper and lower sections, a wooden keying member joining the upper and lower sections, a second tubular portion in the lower section for receiving a wooden post for supporting the side of the water tank of the swimming pool, and third tubular portions with interspersed webs extending transversely to all of the foregoing tubular portions for rigidizing the rib structure, the wooden keying member receiving nails which extend through the tubular portion of the upper section for attaching fence members and a hand rail.

Abstract: A swimming pool with a convertible hot tub that may be easily installed or removed by a user. A barrier system, having a removable partition formed from a flexible sheet of material, is placed in the pool tank near an area that includes a hot water inlet nozzle. The partition has fasteners formed as peripheral ribs that slide into slotted channels secured to opposite sides of the tank. A water drain is located in the pool area. A water processing system, having a pump and a water heater, is connected between the drain and the inlet nozzle to remove warm water from the pool area, heat the water and supply hot water to the inlet nozzle to increase the temperature of the water in the hot tub. At equilibrium, the partition permits water to flow from the hot tub into the pool area at a rate substantially equal to the rate at which water is supplied to the hot tub via the inlet nozzle.

Abstract: Tubs are supplied with hot water through a water circulation system including a pump, an elongate electric flow-through heater, a water filter and piping connecting that pump, elongate flow-through heater and water filter in series in that water circulation system. The pump, elongate flow-through heater and piping are arranged in a horizontal plane so that water flow passages in that piping, in the elongate flow-through heater and in the pump are intersected by that horizontal plane extending along directions of water flow in the mentioned water flow passages. The pump may be provided with a water inlet and a water outlet both lying in the same horizontal plane as the elongate flow-through heater and piping. The pump also may be provided with an axis of rotation, and even with an electric drive motor, extending in that horizontal plane. The elongate flow-through heater may be provided with an elongate structure molded of an electrically insulating synthetic resin for housing an electric heating element.

Abstract: A system for providing heating air bubbles to a heated tub or spa positioned within a heated water circuit having heater and pump means. Included is an ambient air input conduit including a blower. Also included is a heat exchanger positioned within a fluid integral closet, the heat exchanger having a central fluid transfer coil and heat sink in thermal communication. The heat sink projects outwardly within the interior of the air closet, the air closet having as its input an output of said ambient air input conduit, the fluid transfer coil having as its input and output a by-pass of the hot water circuit. Further included in the system is an internal air conduit having as its input the output of said air closet and, as its output, the heated spa or tub.