Solar Pool Heater

The present application derives priority from U.S. Provisional Patent Application 63/645,203 filed 10 May 2024, and is a continuation-in-part of U.S. application Ser. No. 18/374,241 filed 28 Sep. 2023.

The present invention relates generally to pool heaters and, in particular, a floating solar pool heater that employs a solar-charged battery-powered immersion water heater and a wireless-enabled processor for remote pool temperature control.

Water heaters are often used in pools to maintain a comfortable water temperature. There are a variety of different types of pool water heaters. For example, flexible covers made of heat-absorbing materials are used to raise the temperature of the pool water. Unfortunately, pool covers restrict access to the water, are unwieldy and cumbersome to remove and replace, difficult to store, and often sink below the surface of the water.

Solar pool heaters are well-known. Solar heaters typically feed water to stationary solar panels installed nearby. The pool water may be pumped to the solar panels via electric pumps. However, most conventional solar pool heaters are very expensive, large and aesthetically unpleasant, and require substantial effort to install. They are also fairly inefficient due to heat loss in the return lines.

Consequently, there remains a need for a low cost modular high efficiency solar pool heater that can alleviate the disadvantages of the existing solar pool heating systems.

What is needed is a compact and efficient fully-automated and yet remotely controlled solar pool heater.

According to an embodiment of the invention, an automated wirelessly-controlled solar pool heater is disclosed that includes a floatation vessel carrying a water reservoir with internally-exposed immersion water-heating elements for DC-electric heating of pool water circulated there through, a pump assembly for intermittently pumping water through the water reservoir, and one or more temperature sensors for sensing temperature in the water reservoir and in the pool. A cover fits atop the water reservoir and a solar cell is mounted atop the cover for recharging a battery that powers the pump, heating elements and other electronics. A partition fits inside the flotation vessel, the cover/solar cell fits atop the flotation vessel, and the space between the cover and partition defines the water reservoir. In operation, heating of the water in the water reservoir occurs by exposure with the immersion heating elements. The water is intermittently pumped through the water reservoir by a pump assembly, both the pump assembly and heating elements being powered by a battery bank that is charged by the solar panel. The pool heater is controlled by a microcontroller module with wireless transceiver for remote monitoring and programmed operation. The pump assembly self-primes and automatically fills the entire water reservoir with pool water. Water in the water reservoir begins to heat via the heating elements. Initially it takes 4-6 minutes for the water in water reservoir to reach an optimal temperature, at which point the microcontroller module activates the pump assembly to intermittently expel the entire volume of the heated water residing therein back into the pool, simultaneously refilling the water reservoir with unheated pool water. The recirculation program continues until the water temperature of the entire pool reaches its desired temperature.

The present invention is described in greater detail in the detailed description of the invention, and the appended drawings. Additional features and advantages of the invention will be set forth in the description that follows, will be apparent from the description, or may be learned by using the invention.

Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

As seen in, the present invention is an automated wirelessly-controlled solar pool heatercomprising a floatation vessel, and an internal computer-controlled solar-powered pump assembly and battery (to be described) for periodically inducting pool water into an internal water reservoir, heating it via immersion heating elements, and intermittently expelling the heated water back into the pool and inducting new unheated water. An external ON/OFF button initiates one-touch operation.

is a bottom view of the solar pool heater,is a side view, andis a side cross-section taken along the line A-A of. With combined reference tothe floatation vesselcomprises a buoyant disc-shaped housing with interior circular partitionseated inside flotation vessel, a cover, and a solar cellseated atop cover. The area between the coverand partitiondefines a water reservoirfor active DC-electrical heating of water contained therein. The flotation vesselincludes a downwardly-protruding compartmentwith pull-down spoutthat when deployed protrudes well-beneath the water level for extended water intake and outlet. A separate water-proof housingdescribed below encloses a pump assembly, micro-controller chamber, and battery bank.

The partitionincludes a central hubthat extends a radial-array of immersion heating elementsfor active (DC electric) heating of the water in reservoir.

Referring back toa solar cellis mounted atop the cover. Solar cellis preferably a circular solar cell that substantially spans the coverfor maximum efficiency. The coveritself is a disc-shaped cover conforming to flotation vesseland configured for snap-fit or twist-lock insertion thereon, and preferably with a recessed top surface for seating solar cell.

illustrates the spout, which is an open-ended tubular member formed with hinge pinsat one end journaled into the walls of the bay. The spoutmay be seated flush inside bayor deployed to a downwardly extended position protruding 3-6″ beneath bay. Detent clipsmay be provided to prevent inadvertent deployment. The water intake tubeenters the spoutat the hinged end.also illustrates two opposing handlesmolded into the bottom of the floatation vesselto assist in carrying the solar pool heater.

With spoutextended, the pumpintermittently pumps water into the water reservoirthrough intake tube, where it travels past one of at least two temperature sensors,(one internal sensorfor sensing temperature in the water reservoirand one external sensorfor the temperature of the pool water). A battery bankis connected to the pump, to a plurality of immersion heating elementsradially-extending into water reservoir, to a solar panelfor maintaining battery bankcharge, and to a microcontroller modulewith processor, software and wireless transceiver for remote monitoring and programmed operation of solar pool heateras will be described. In operation, when first powered on via on/off buttonand placed in the pool the pump assemblyis self-priming and automatically fills the entire water reservoir. In addition to temperature sensors,, there is a water fill sensorthat indicates to microcontroller modulewhen the heating elementsare fully submerged in water (so as not to burn them out). Once full, the microcontroller moduleswitches off the pump assemblyand polls the water fill sensor. If water fill sensorconfirms that the heating elementsare fully submerged in water, the microcontroller moduleswitches on the heating elements, and active heating occurs as the water resident in the water-heating reservoiris exposed to the heating elementstherein. Given the active electric heating it initially takes only 4-6 minutes for the water in water reservoirto reach a maximum temperature (e.g., 150 degrees F., calculated as being just below a threshold that burns the skin). Microcontroller modulemonitors the internal temperature via internal temperature sensor, which is imbedded inside the water reservoir. Once the temperature of the water in the water reservoiris heated to a preset temperature apex, microcontroller moduleactivates the pump assemblyto expel the full volume of the heated water residing in water reservoirback into the pool, simultaneously refilling the water reservoirwith unheated pool water.

Water remaining in the water reservoirmixes with the incoming pool water and heats it, allowing the temperature of the preset water in the water reservoirto reach its apex more quickly. The recirculation program continues: each time the water in the water reservoirreaches the preset apex the pump assemblywill again flush the full volume of the water, and the cycle continues. Microcontroller modulemonitors the external temperature via external temperature sensor, which is outwardly exposed/embedded in the wall of the floatation vessel, and microcontroller modulecontinues to periodically recirculate the water in water reservoiruntil the water temperature of the pool water as measured at external sensorreaches its desired temperature. The microcontroller moduleis wirelessly enabled and remotely-programmable by a software application resident on a laptop, smart phone or the like.

Referring tothe solar cellis set into the disc-shaped one-part coverwhich is in turn affixed atop flotation vessel. The circular partitionis set inside flotation vessel, and the space between partitionand coverdefine the enclosed water reservoir. The water reservoiris further subdivided two concentric chambers by a raised annular hubthat rises up from partition. The area inside hubcomprises an active heating chamberand a plurality of heating elementsare suspended therein. The heating elementsare connected to contact terminalsthat protrude outside hub, and from there are connected on to the microcontroller moduleand battery bank. The entire partitionand hubmay be integrally formed of metal for heat conduction, so that heat from elementsis efficiently conducted into the water which fills the area outside hub. The microcontrollerselectively applies battery power to the heating elementsto actively heat the water inside water reservoir.

The circular partitionpreferably snap-fits or twist-locks inside flotation vessel, coversnap-fits or twist-locks atop flotation vessel, and solar cellsnap-fits or twist-locks inside cover, collectively presenting a″ diameter unit capable of easy lifting when filled with water. The flotation vesselleaves room at the center beneath partitionfor a separate water-proof housingcontaining pump assembly, battery bank, and microcontroller module. The pump assemblyincludes a pump, preferably a high-efficiency 12V solar water pump such as, for example, a Kamoer™ KLP02 micro diaphragm pump with 12V DC brushless motor calibrated to refill the entire water reservoirwithin a range of from 10-15 seconds, most preferably in ten seconds. The input of pumpis preferably connected to port, which is in turn connected to the water intake tubefor inducting water into the spoutat the distal-extended end below pool surface level. The output of pumpis preferably connected via portthrough the partition, and from there by a clear discharge tubeinto spout, which likewise discharges water below the floating waterline of floatation vessel.

The solar panelis calibrated to charge the battery banksufficiently each day to run pumpand heating elements. To this end the solar panelmay be a 100-watt solar panel capable of producing between 300 and 600 watt-hours (Wh) of solar energy per day. The heating elementsare mounted on the outside of huband extend radially therefrom. In a preferred embodiment, three immersion heating elementsextend radially at 120 degree increments and substantially traverse the water reservoir. The immersion heating elementsare electrically connected within hubto a switch controlled by microcontroller module. Heating elementsare collectively capable of drawing 300 watts and the pumpanother 50 W and so a 350 W hr lithium battery bankis recommended.

is a block diagram of the pump assembly, temperature sensor, temperature sensor, fill level sensor, battery bank, solar celland microcontroller module. The microcontroller moduleincludes a processor, on board non-transitory memory, and an on-board wireless transceiverfor remote communication. An external ON/OFF button initiates operation. The battery bankprovides power to the pumpthrough a first fuse block, to heating elementsthrough a second fuse block, and to microcontroller modulevia a third fuse block. Processoris in communication with temperature sensors,. As indicated above the temperature sensoris imbedded inside the water reservoirat or near the midpoint to provide a temperature measurement of the water inside the water reservoirto processor. In contrast, temperature sensoris preferably embedded in the bottom wall of flotation vessel. This way, processorcan also monitor the temperature of the pool water.

Fill level sensoris embedded in the wall of huband protects heating elementsby ensuring that they are fully immersed before activation. Microcontroller modulemay be any suitable low-power computer processor platform with on-board memoryand wireless communication capability by, for example, LA N and/or Bluetooth® connectivity via transceiver. A software application is stored in memoryfor execution by processor.

is a schematic diagram of an exemplary solar charging chamber for maintaining battery bankvia solar panel, which is based on a Texas Instrument™ MPPT BQ 25172 integrated 800-mA linear solar charge controller with solar input.

is a schematic diagram of an exemplary microcontroller modulewhich is based on an ST™ STM32WB5MMG wireless microcontroller incorporating an Arm® Cortex®-M 4 processor corerunning at 64 MHz (application processor) and an Arm Cortex-M0+ wireless core(wireless front end), with onboard 1 M byte Flash memoryand capable of wireless Bluetooth LE 5.4 and 802.15.4 protocols.

The internal temperature sensorand external temperature sensormay be any suitable temperature sensors capable of accurately sensing a range of from 55° C.˜130° C., such as Texas Instruments™ LM19CIZ/LFT4. Fill level sensormay be any suitable float switch or capacitive water level sensor.

is a flow diagram of the resident software application stored in memory.

At stepthe solar pool heateris powered up using on/off buttonand the software instantiates. The software requires several programmed parameter settings all of which initiate to default settings but may be user-customized by wireless transmission from a remote application running on a user's smartphone or other remote device.

At stepthe processorwaits a multiple of the Dwell Time (approx. 11 mins) to allow the user to place the solar pool heaterin their pool.

At stepthe processormeasures and compares the battery bankvoltage to the Low Volt Cut-Off to ensure that the battery bankhas an operational charge. If not, at stepa battery error L E D flashes. If the battery bankvoltage is greater than the Low Volt Cut-Off, then processoractivates the pump assemblyfor a Pump-time Duration sufficient to prime and automatically fill the entire water reservoir, e.g., a Pump-time Duration equals 10 seconds.

At step, the processorthen waits a predetermined delay period, the Dwell Time (e.g., one minute) for the water in water reservoirto warm fully. The initial delay period is calibrated to ensure that the water in water reservoirreaches its apex temperature, typically resulting in a temperature differential of twenty degrees between the pool water temperature versus the water temperature in the water reservoir. U se of an apex temperature differential maximizes the heating advantage of the water reservoirand minimizes the amount of time needed to raise the pool water temperature.

At stepthe processormeasures the apex temperature of the water in water reservoirTa at sensorand stores the measured apex Ta. Processorthen compares the temperature of the water in water reservoirTa at sensorto the pool water temperature Tp, and so long as Ta>Tp proceeds to step.

At stepthe processoragain measures and compares the battery bankvoltage to the Low Volt Cut-Off to ensure that the battery bankhas an operational charge. If not, flow returns to stepto await a full charge. If so, processoractivates the pump assemblyfor a single Pump-time Duration sufficient to refresh the water in water reservoir, e.g., one times a Pump-time Duration equals 10 seconds.

At stepprocessorpolls the water fill sensorto ensure that the heating elementsare fully submerged in water.

If the water fill sensoris fully submerged in water, then at stepprocessorthen activates the heating elementsto heat water inside active heating chamber.

Flow proceeds to stepand processorthen waits a predetermined delay period, e.g., a single Dwell Time (1 minute) for the new water inducted into water reservoirto warm fully by active heating inside water reservoir.

Next, at step, the processormeasures the apex temperature of the water in water reservoirTa at sensorand stores the measured apex Ta, and the pool water temperature Tp at sensor. Processorthe compares the temperature of the water in water reservoirTa at sensorto the pool water temperature Tp, and if Ta>Tp A N D the pool water temperature Tp is less than the desired pool temperature M ax Temp (F), flow proceeds to step.

At stepprocessoractivates the pump assemblyfor a Pump-time Duration sufficient to refresh the water in water reservoir, e.g., one times a Pump-time Duration equals 10 seconds.

At stepprocessorresets a cycle count and returns to step.

If at stepprocessorcompares the temperature of the water in water reservoirTa at sensorto the pool water temperature Tp, and either Ta<Tp OR the pool water temperature Tp equals or exceeds the desired pool temperature M ax Temp (F), flow proceeds to step.

At stepprocessorincrements the cycle count.

At stepprocessorcompares the current cycle count to the Count Limit (e.g., 5 sec). If the current cycle count is less than or equal to the Count Limit flow proceeds to step.

If the current cycle count exceeds the Count Limit flow returns to stepabove. The recirculation steps,,andrepeat as needed, flushing and inducting new water, until the water temperature of the entire pool reaches the desired preset maximum temperature M ax Temp. Use of the foregoing method and apparatus makes it possible to solar-heat an entire pool in approximately four hours. The foregoing disclosure of embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. M any variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims, and by their equivalents.