WATER HEATERS Field of the Invention:

The field of the invention is water heaters and in particular, the hot water tank of water heaters.

Background of the Invention:

Environment issues have captured the popular imagination. It is therefore imperative to direct Smart Home/Office design towards sustainable, environment-friendly practices. Resources and practices such as the sun, sky, gravity, and maintenance-freedom offer themselves with renewed vigour to the discerning audience. We teach here a globally optimal (solar) (centralized) water heater for a smart home and/or office with low energy costs that is luxurious, environment- friendly, inexpensive, and rugged or maintenance free to a large extent. We teach this using an exemplar deployment context, that is the smart home/office testbed for our operations, called the

Adbhut House, the residence address of the inventor, given above.

Minimality is an excellent design principle for minimizing maintenance. If a pressure pump can be eschewed, it is important to do so for low power consumption, as well as low maintenance and long life of plumbing. In our own space, we removed the pressure pump our space was originally architected with and within the head of about a (short) floor height, we have designed and installed high volume rain showers with no pressure pumping for either the hot water or the cold water. The overhead cold-water tank is shielded by our solar panels to ensure coolness, further improving water quality. Our plumbing recycles most of the shower and sink water through our rain-water-harvesting plant, to minimize our water footprint and to recover water at solar-friendly times for low power expense. It is not terribly hard to run water through a sediment filtered underground tank to arrive at sustainable low water-consumption houses with luxurious water-use quotient.

After initial construction, our Adbhut House started out in end- August 2010, with the inventor moving in and with a standard, solar water heater deployment using Racold equipment, a 500 litre tank on a high stand plus 4 south- facing solar panels, on a stand apiece, all on the top-roof called the concert garden stage (Fig. 3), with a pressure pump to run the configuration. By 2018, the tedious and expensive experience of pressure pump breakdowns (costing thousands of rupees apiece), costly repairs, repeated tank changes (each costing tens of thousands of rupees and a lot of headache), besides heating element/thermostat changes, and the fresh availability of money, from a January real-estate sale, the inventor decided to take this standard solution down. Venus, with a better-known tank was called in and again, a 1 tank solution, 200 litre, was deployed at a lower height, the larger tank in Fig. 4, with only one solar panel given the limited space and no pressure pump as the hot water tank was now below the cold water tank for the first time. Hot water pressure remained poor, given the narrow pipes, narrow inlets and outlets for the tank, in this standard solution. The first innovative step the inventor took was parallelizing this solution with another tank, a 100 litre second tank, seen in the figure, at a slightly higher height as shown. The parallelism doubled pipe and outlet thickness, substantially improving the water pressure in the house showers, faucets etc. A difficult experience the inventor had along the way with the first tank was a geyser explosion due to the use of a generic thermostat that did not work, leading to water overheating with pressure release malfunctioning resulting in tank blowup. Fortunately, this happened on the roof, so nobody was hurt. This was repaired upon Venus advice thereafter, by letting the damaged tank be as is, but replacing the defective pressure release with a pipe open above the cold water height, resulting in heat loss by radiation, but more importantly, providing little confidence in the ability of such a thin pipe surviving another overheating situation. All this experience and prior experiences of this nature that the inventor had seen (as a child growing up in IIT Delhi, the aftermath of a geyser explosion, where one of his neighbour’s 9 -inch thick brick wall had blown up along wiffi’thc indoor geyser, leaving a gaping hole one storey high in the building), motivated the inventor to arrive at the solution proposed herein, improving all the prior art with the problems as discussed above. The entire solution here eschews proprietary, difficult to obtain parts, in favour of inexpensive generic parts or easily made parts, used with such minimal load, as to ensure long, easily maintained, and successful life of the parts.

A search subcontracted by the inventor to his legal support for this disclosure located DE4114076A1, CN101851991A, WO20I3150525A1, US5823177A, CN201110647Y. None of these works solve or obviate any of the above-cited problems by the inventor, sufficiently, e.g. high pressure is reachable, whose containment thereafter including reliance on safety valves is still the approach, besides being expensive, underscoring the need for a new solution.

Buffnstaffs primary interest in smart home and office space is in designing low energy footprint, low maintenance buildings and systems with high sustainability (even at the micro level, including: [1] P. Varma, B. S. Panwar, andK.N. Ramganesh, "Cutting Metastability Using Aperture Transformation", IEEE Transactions on Computers, Vol. 53, No. 9, pp. 1200-1204, September 2004. [2] P. Varma, B. S. Panwar, A. Chakraborty, and D. Kapoor, "A MOS Approach to CMOS DET Flip-Flop Design", IEEE Transactions on Circuits and Systems - 1: Fundamental Theory and Applications, Vol. 49, No. 7, pp. 1013-1016, July '02. [3] P. Varma, B. S. Panwar, Arjun Singh, and S. Sriram, "Metastability Reduction by Aperture Transformation", IEE Electronics Letters, Vol. 36, No. 6, pp 501-503, March 16, 2000.). The building discussed here is intended to be applied to Buffnstaff-designed high-performance, low power software hosted on ordinary laptops comprising a sensitive information datacenter that cannot be outsourced due to information sensitivity. The water heater part of the system is described here.

Summary of the Invention:

Accordingly, the present invention provides a practically a no wish left unfulfilled, optimal geyser or water heater and tank system that is:

1. Cheap, safe (no explosions)

2. Has reduced part replacements (e.g. electrical heating element, optional thermostat), no tank replacements

3. Easy, cheap and occasional maintenance requirements only, e.g. tank cleaning, low electricity cost (e.g. using maintenance-free highly efficient solar water-heating panels, or excellent, layers of insulation)

4. And then provides high hot water pressure to users with no involvement of a pressure pump, using multiple pluggable options to heat water in parallel

5. And is highly scalable from few litres to mega litres.

The specific novel apparatus, arrangement, and functioning that realize the above benefits is detailed in the claims section below.

Brief Description of the Accompanying Drawings:

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: Fig. 1 is a schematic diagram of our water heater tank and pluggable heaters;

Fig. 2 is an exemplar deployment weather context that may be viewed optionally, depicting a hazy October sunrise that is looked upon by our east-facing photovoltaic solar panels; Fig. 3 is an exemplar deployment context that may be viewed optionally depicting the solar shielding of a cold-water tank on the rear boundary of our concert garden stage by south-facing solarpanels;

Fig. 4 is an exemplar deployment site dial may be viewed optionally, depicting poor art deployment at the site that may be upgraded by our teaching, showing our erstwhile hot water tanks pair, that operated in parallel to increase the water flow enough that hot water could be consumed in large volume, diluted to only some extent by the cold water, for more efficient lower temperature circulation and lower radiation loss and yet luxurious water pressure; Fig. 5 is an exemplar deployment context, that may be viewed optionally, comprising the smart home/office’s view from the front;

Fig. 6 is an exemplar deployment context, that may be viewed optionally depicting the solar panels and outlet side of an advantageously placed hot water tank as per our teaching; and

Fig. 7 is an exemplar deployment context, that may be viewed optionally, depicting the inlet and maintenance side of an advantageously placed hot water tank according to our teaching. Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help w improve understanding of aspects of the present invention. Furthermore, the one or more elements may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein. Detailed Description of the Invention:

It should be noted that the steps of a method may be providing only those specific details that are pertinent to understanding the embodiments of the present invention and so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention.

It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. Moreover, in interpreting the specification, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification refers to at least one of something selected from the group consisting of A, B, C .... and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

As Fig. 2 shows, in the local context of Adbhut House, the early winter solar is compromised by morning smog, and later winter solar by morning fog. Hence solar water heater panels can make best use of available solar by facing South or West, the latter of which is utilized by us, as shown in Fig. 4. This prior art deployment of Fig. 4 stands much improved in this teaching, by moving the single panel higher up the sloping roof, and utilizing the larger space there for additional panels, resulting in four total, in our preferred embodiment, which not only heat better, but serve an additional function of eliminating the function of the hemispherical plastic awnings shown in the figure by the overhang of the solar panels on the side of the slope. Such local optimizations for minimizing fixtures serve to significantly improve the cost-benefit ratio of Adbhut House. The four solar panels can be laid out on the sloping roof in a lower 2 and upper 2 pattern, with the hot water output of the lower right panel feeding the input of the upper left panel and the output of the lower left panel, feeding the input of the upper right panel. These two sequences flow in parallel, the upper two outputs combining into one to feed the hot water tank above the slope. The cold water (relatively), from a tank outlet above the slope feeds the inlets of the lower two panels. This crossed 4X pattern of connections provides an advantageous symmetric pattern with balanced solar exposure since each has one outer panel, getting more sunlight and one inner panel getting less sunlight. The entire solar panels system works by the principle of convection currents, with relatively cold water from the bottom of the hot water tank moving down and water heated by the solar panels moving up to the tank in an overall circular pattern of water flow. The solar system can be replaced, or added to in parallel by a similar water heating system, working again on convection, for example a fuel-burning heating system, or an alternative electric heating system, with no pumping needed of any kind for the purpose.

The hot water tank, schematized in Fig. 1 according to our teaching, is best placed at maximum head height, in parallel with the cold water tank, so that the hot water level and the cold water levels coincide maximally, the cold water tank providing the pressure head, to run the entire system gently, using gravity alone (no pumps). Our preferred advantageous hot water tank position is depicted in Fig. 6 and 7. Fig. 6 shows the view up the sloping roof, at the top end, where next to the photovoltaic panel supporting pillar and j ust under the steel ladder, the inlet and outlet of the hot water tank to solar can be made in a future implementation. The inlet- from-solar accepts heated water from the solar panels and is placed slightly higher than the outlet-to-solar. The inlet also shares the function of providing the hot water outlet of the system to the house. The hot water in the hot water tank therefore does not go lower than this level as this is the exit level of the system. The outlet of the hot water tank, to solar, carries relatively cooler water from the tank to the input of the panels at the bottom of the slope. This outlet. should be at the lowest level of the tank and can advantageously also serve as the tank emptying outlet, for m aintenance For this purpose the pipe from this outlet going down the slope can have a T junction, with control valves. Normally the exit to throw out water is blocked, so the water only flows to the panels’ input below. For maintenance, the valve for the flow down is turned off and the throw valve opened, so that the water is thrown. Later the reverse is carried out to return back to operational mode.

Fig. 7 shows the actual planned position of the hot water tank on the roof., under the photovoltaic panels, adjacent to the side opposite the cold water tank, whose demarcating boundary is the brick wall. Running along the opposite wall, from the comer solar panel pillar end to the edge of the raised platform on the metal step side, the hot water tank takes cold water input from the larger water pipe running at the bottom of the figure, which comes from the cold water tank. This cold water inlet has a non return valve, to separate the two tanks to ensure only one-way flow to the hot water tank.

Adding up, in this preferred embodiment, there are only 3 inlet/outlet openings in the tank, one on this side for cold water inlet, and two on the solar panels side for connecting to solar. This minimizes leakage risk and reduces maintenance work.

The hot water left below the hot water exit to house (i.e. the inlet from solar) comprises wasted heating. The advantage of this design is simplicity, as no automatic level monitoring of the cold water tank is mandatory. Upon the hot water running dry, there is immediate notice to the users that cold water needs to be pumped up to fill the hot water tank in turn. In the worst case, on continuous ignoring of this situation and continuous heating by an electrical element, the left hot water can evaporate, leading to burning out of the heating element. But this is a perverse situation, unlikely to arise and not meant for a disciplined manual system user, and further preventable by the use of thermostats (to cut off electrical heating) and/or automatic cold water monitoring that never lets the cold water level stay down. Left water heat loss can be reduced by lowering the height of the exit, but we emphasize instead a larger focus on insulation to make the left water a reserve resource by disallowing its heat to escape outside and to leave a large margin of safety against tank emptying. While this looks like a case of increasing the heat capacity of the system, it is not strictly so, as cold water, when added, recovers some of the investment for profitable use.

High pressure for the overall system users is obtained by the use of large inlets/ outlets and large pipes. A large pipe diameter also causes a larger amount of hot water to be left in the pipes after use, which needs to be traded off with a high pressure need. In our system the cold water pipes are larger diameter, and since water is normally mixed before use at the end, the cold water pipe diameter compensates for the smaller hot water pipe diameter, reducing such heat loss.

In case cold water level management is carried out manually, overflow by excess pumping is possible. The overflow from the cold water tank can either be piped back to the ground level tank from which cold water is pumped up to the roof, or else, as in our case, such piping can be eschewed in favour of the overflow going to rain water harvesting pipes, which are already there to recycle water.

The tank itself is an insulated hot water tank with one side open and unsealed, allowing repair and maintenance of the entire tank, including partial immersion of optional electric heating elements from the open side. The open side can be the top side of the tank. Insulation can be provided by air-separated second walls around the inner walls of the first tank, with the open side cover comprising loose tiles of calibrated weight sitting on a skeletal structure, in order to allow excess steam to escape while generally staying in place to maintain insulation. One or more further air-separated walls surrounding this arrangement can provide further insulation, with the open side being surrounded solely by supported loose tiles of calibrated weights at each wall level, the air separation in-between all the walls being calibrated from none to large, for calibrated insulation. Inside the tank, one or more electric heating elements, if so desired, can hang off a supporting rigid belt apiece, each element being screwed to its belt for easy removal and connection, each belt itself being screwed to the one or more surrounding sides comprising the perimeter of the open side, for easy removal and reconnection of belt itself to the tank. More than one electric elements can use and share a belt. Metal extenders can hold and support each partially immersed heating element and spread its heat over the entire floor of the tank, so that the element does not overheat. The tank can be a brickwork tank with large tile or stone cladding on the inner side to minimize the joints involved. An inlet and outlet in the tank allow the tank to be connected to heaters pluggable from the outside such as solar panels, gas/fuel-burning heaters, and any further electric heaters. The hot water tank, at its base level, has a one-way inlet from a cold water tank so that water level control for the hot water tank is obtained for free, the inflow of water into the hot water tank being capped by the maximum water level in the cold water tank. An overflow outlet in the cold water tank ensures the maximum water level in cold water tank, which in turn decides the maximum level in the hot water arrangement.

Finally, since large tiles on the inside of the main tank are proposed, waterproofing is kept out of the purview on the easily accessed outsides of the (inner) tank. The loose tiles cover on the tank ensures that even in the worst case of overheating, the water at most boils at about 1 atmospheric pressure, with the many loose tiles bouncing around randomly as multiple pressure releases. Maintenance of these easily observed and manipulated tiles is simply keeping them cleaned and unjammed, a task that requires no expertise.

The belts and attached electrical heating elements can be removed from the tank during off season, summer, for reduced immersion of the belt apparatus, for longer life. Before winter, the belts can be re-attached, any worn elements replaced apriori for convenience, the tank cleaned, and after winter, the belts removed.

An extender is any metal apparatus that sits on the tank floor, thereby not loading the heating element it connects to, but rather providing it additional support, and extends its metallic heat capacity and surface area connection to water to ensure larger faster, and longer-distance heat conduction from the element to water. An extender is optional, not needed, if the element is sufficiently dipped in water, the level of water being decided by the height of the water outlet, and the generally maintained level, by say automatic water-level maintenance described earlier.

An extender and a belt can be custom manufactured by common steel workers, preferably using stainless steel for rust-freedom. The rigid belt can have insulating rubber/other material at connection points to reduce a chance of current leakage. The water inside can be earthed further, by multiple metal conductors for safety, for example, as in our case by connecting it to the earthed solar pillars overhead.

The tank in our planned deployment is of a few hundred litre capacity. The concept herein however scales to mega-litre size tanks, a mega-litre, implying about a 30 meter by 30 meter pool, with 1 meter depth, or smaller surface pool, with larger depth. The large depths in this case require longer heating elements, which can be custom made for such purposes.

Multiple heaters can cooperate in heating water. All these heaters can be plugged in parallel with each other, just like the solar panels, with a lower-level outlet from the hot water tank feeding a heater input and the heater output looping back to the tank through a higher-level inlet in the tank. The system works on convection principles, whereby hot water rises and cold water sinks. In steady state, colder water at the base of the tank (lower-level outlet) sinks down to the input of a heater. The heater is arranged vertically, its input on the bottom and output on the top. The cold water enters the input and then rises to the heater top and on to the tank, after being heated. There is thus a temperature gradient on the rising side of the heater.

Consider two heaters rising in parallel, sharing a common input and a common output. From the common output to the tank, for a well-insulated pipe, there is no temperature gradient. If these are the only two heaters, then their output temperature is the highest in the system and the water current feeds the tank. Initially, among the two heaters, the hotter heater’s water flows unfettered, the cooler heater’s water stagnating completely, if it simply cannot reach close to the hotter heater’s temperature. But since the heater outputs are connected, some water from the cooler heater will move up due to mixing of waters and conduction heating. From the tank’ s perspective, the only water reaching it will be water hotter than the temperature at its high-level inlet. Anything less will simply sink down. In steady state, for heating rates q ₁ and q ₂ of the two heaters, in time Δt and a temperature difference ΔT between the tank outlet and inlet and heat capacity per litre of water C, the amount of hot water reaching the tank will be ((q ₁ + q ₂ )) Δt ) / (CAT) litres. This water is assumed to consumed at the same rate in steady state, so that the steady state tank temperatures are stable. The ratio of the hot water supplied by the two heaters is in proportion to their heat supplied, which reduces to their heating rates, q ₁ : q ₂

The heating rates, q ₁ and q ₂ in the above are assumed to be steady, regardless of the temperature of the water. Thus these heaters can hypothetically raise water temperature arbitrarily, given enough time. This is generally not true. On the other hand, water exists in liquid form only from 0 Celsius to 100 Celsius, so if the heaters can work in this range, it suffices for all purposes.

This is true for many heaters, such as electric heaters, gas/fuel burners etc. Solar operates in a narrower range but the range is still fairly large. Any plug-in can.be used, once the maximum temperature of the tank is specified and the heater can work up to or above that temperature.

The analysis above is the same if the two heaters don’t share a common pipe from the tank inlet/outlet. Now consider the 4 solar panels discussed earlier. 2 panels due to more sunlight have a heating rate q ₁ and two with Less sunlight have a heating rate q ₂ . Twice the heat of the analysis above is supplied. But since the volume supplied by a sequence, v, is the same for both its panels, the-temperature gain in the sequence due to its brighter panel is more than the other. So the midpoint of one sequence has a different temperature than the midpoint of the other sequence, the midpoint coming from a brighter panel being higher than the other . one'

Regardless, the 4 panels cooperate fully in supplying their entire heat to the tank. An important advantage of the X formation described in the preferred embodiment is that an equal flow rate is obtained among all the panels, which likely yields a balanced, long life for the system, besides requiring uniform piping everywhere, regardless of vagaries such as hardness of water. Extending the argument above, it is desirable for all the heater plug-ins to be loaded similarly, in the preferred embodiment, for a long balanced life of the system. While control is easy for electric, gas, and fuel heaters, the options are few for say a solar heater. It is a best practice to use the controllable options above disjointly with the solar heater, to balance the load, unless consumption demand dictates otherwise.

A notable feature of the pluggable heaters is that they are all submerged below the water level of the open-top tank. The outlet of a heater is below the water level as is the heater inlet. While it is possible to have an open-top heater, it makes little sense, as then the hot water (way) above the heater outlet is trapped and unusable to supply the main system.

A submerged heater is a closed system, with its entire interior volume filled by water compressed beyond a one atmosphere pressure by the additional water head from the water level of the open-top tank. While this is suitable for most purposes, it is not the best system for tank cleaning and electric element maintenance. In the present system, the submerged heaters are scaled down in size, significantly, compared to the main tank, so the entire replacement of such a heater is affordable, compared to the main tank replacement (which is obviated by the present invention). Solar panels have a very long life, so such heaters are mostly maintenance free. Electric elements, in the present system, are best used in the open top tank, directly, as described previously, or as a means to centralize, multiple (say indoor) geysers, with much increased safety. Safety of all such heaters is increased manifold by their being piped to the main open-top tank. Even if a heater boils water, the steam and hot water now have a path through the large outlet pipe to the main tank, and the safety, therefrom.

Normally, all the water flow in the system is highly efficient due to the use of large pipes and only streamlined, laminar flow. Turbulent flow is possible, if a heater goes out of control and generates steam and boiling water. This is a highly unlikely scenario, normally, but safely handled.

The interface for a plug-in heater to the open-top tank comprises piping in-between the heater and the tank. Piping to multiple heaters (e.g. solar panels) can be shared. Indeed, it is most sensible to reduce the number of openings in the main tank to reduce chance of leakage and other maintenance, capital costs. This is one reason for keeping electrical heating elements tied to the main tank’s belts, as then leakable openings for such periodically-replaced elements are totally avoided. An outlet from the main tank to heater needs to be lower than the corresponding inlet from heater to the main tank. It is best to separate the two horizontally, besides vertically, to reduce interference between convection currents and to strengthen them. Fig. 1 describes the teaching schematically, using mathematical induction. The inner cuboid, is the innermost container of the hot water tank, the top side of which is open with a belt, and another as shown. One of the belts has an electrical heating element connected to it, the line going down into the tank from the belt, with a metallic, conical extender holding the belt early on and going down further to the floor of the tank, regardless of whether the element goes that far or not. The cone can fan out further on the tank floor, which may be preferable, but not shown. The belts are above the cold-water maximum level, maintained by an overflow outlet in the cold-water tank. One of possibly many surrounding insulator boxes is shown, the top side of an insulator box being loose tiled. Four tiles are shown, not of homogeneous size, supported by a steel skeleton in a dashed grid pattern. This skeleton can well be implemented, by two belts one in the x direction and the second in the y direction, the surfacing of the tiles, /belts ensuring normally airtight fit for the four tiles in the four slots. The hot water tank is minimally completed with the inclusion of the one insulator box shown. This minimally complete tank is explained first, as the base case of the induction.

The outer cuboid can be moved around and resized vis-a-vis the inner container so that gap between the boxes on any of the six faces is unique. The gap contains air, and the absence of a gap implies the sides of the cuboids have merged into a fatter side. Although the top sides can be merged in this manner, this may not be preferred if one or more belts with electric elements have been deployed on the inner container, as then the tiles and/or their support may contact the electrical connections or interfere with their maintenance. In the preferred embodiment, the overflow ensures that the water in the inner cuboid does not reach up to the brim, so even if the top sides merge, there is still an air layer between the tiles and the top water surface. There is no requirement of homogeneity of the cuboid surfaces, so the air layer between two surfaces may not be of uniform thickness and merged sides may still have air pockets, in between, them. While a completely open top side of the inner cuboid is preferred, for maintenance, this top side may only be open in part, with the path to the sky from the opening being largely through removable tiles only in the above layer, in a large enough tank. As an example, since the gap between a surrounding box and the inner tank can be zero, th. is allows the reduction of the system to one fat-sided box, with the top side having a belt layer roofed further by loose tiles. A cuboid is a preferred shape for the tank, as it is easy to construct in brickwork/masonry, but this is not a requirement.

The tiles may be kept in place using the perimeter of the insulating cuboid directly for support. For a large tank, reliance on a skeletal structure like belts may be done, as discussed above, to keep tile sizes manageable. For maintenance, the skeletal structure may be removable from the perimeter of the cuboid, analogous to the inner cuboid case, along with the individually removable tiles resting on it. At this point, it may be noted that the air between the two cuboids is closed within the outer cuboid. The only way it can mix with outside air is for tiles to be raised (e.g. by steam release), else it remains contained within the system. It may be sub- partitioned into smaller closed chambers, depending on the layer mergings carried out. Another way to sub partition the air layers is to explicitly bridge the cuboids’ walls with ledges, e.g. horizontal, vertical, or diagonal, to reduce the air/moisture traffic within the tank and/or to waterproof it. Regardless, without tiles being raised, the insulation discussed here through closed air, deals largely with radiation transfer of heat, as opposed to convection or conduction transfer.

With the base case discussion of the tank completed here, we now carry out its inductive step. Hypothesize a tank constructed up to K insulation cuboids, K = 1 already having been considered in the base case above. This tank is now depicted by the inner cuboid, the belts in the inner cuboid being there for the tiles support of that tank. The (K+l) ^th cuboid is next constructed around the inner cuboid, exactly as discussed in the base case, with one difference. The top side, when merged now, comprises merging of two tile layers. This is a meaningful step, the merging implying their unification into one tile layer, not necessarily a fatter layer than the other tile layers. This straightforwardly generalizes the tank now to K+l insulation boxes. With the base case explained, the inductive step carried out, construction of an arbitrary tank may now be done in this manner. Inlets and outlets in this multi-layer tank go through all the layers to connect the water inside to the outsides of the tank, using generic galvanized steel plumbing preferably, for long life and high temperature compatibility. In the construction described, not all the non-air layers need be of rigid material. They may be comprised of soft insulation material, like wool. However, the perimeter of such a layer must then support its tiles differently, e.g. by merging its tile layer into a rigid layer’s tiles layer.

Since a target of preventing heat transfer is to stop radiation transfer, the tank may well be constructed of white body layers, as discussed in this disclosure later, including the tiles layers.

Relatively cold water moves in the direction down shown by an arrow, from the base of the hot water tank to any plugged heater by convection. It goes from the heater’s bottom to the top, and back to the hot water tank at a higher level (return shown in the direction up, shown by another arrow). Multiple heaters can be used in parallel, as shown by the dotted lines. No pumping is needed. All water flows allow bidirectionality, implying the system does not force one-way traffic anywhere, except at one place, the cold-water feed to the hot water tank from the cold-water tank. That is unidirectional, using a non-retum valve, to keep the waters separated. A particular heater plugin may impose its own directionality requirements, which the system allows, given that it is most general by itself (bi-directional).

A preferred, but not required non-retum valve technology from the perspective of this disclosure is as follows. It comprises a flap that shuts, when.hot-side.head is greaterthan coldside head. It may be a flap that is closed at 0 radians and opens maximum to K/4 radians on the hot side only, in the middle of a same-diameter (as the flap) pipe from hot-side to cold-side. This flap will shut when hot-side head is higher than cold side head. "When the heads are the same, the flap can open. When the cold-side head is higher, the flap will open fully. When the flap is operrpartially or 'fully- it "will permit balanced convection currents between the tanks. However, such currents will only permit the exchange of hot-tank’s bottom water with the cold water from the cold tank. The higher hot water will not exchange. So then, this provides additional safety to the system, against the bottom water boiling away due to continued electrical heating on an. emptied. hot water tank, discussed previously in this disclosure.- The hot water will never run dry pre-empting electric element burn out, a desirable goal. Electric element bum out in this scenario is now reduced to both the hot water tank and. the cold water tank getting emptied simultaneously, a rare and perverse scenario, wherein the user is insisting on using electrical heating past such behaviour. This is thus one preferred choice of non-retum valve technology for our system.

Now consider that the fate of heat loss is proportional io the temperature difference between a hot source and sink for both radiation and conduction. Placing an. air gap in layers has. two advantages: (a) reduction in heat capacity of the entire insulated tank, and (b). elimination of conduction across the gap. Air is a poor convector of heat, given its sparsity of matter content

(very low density). The constants of proportionality, for heat transfer, vary by material. The practical experience with Adbhut House, for its cold water tank, comprising walls with a single layer of brick work with porcelain and brick tiling on a wall’s interior and exterior respectively, leading up to a total thickness of just above 7 inches for the wall is that the cold water in it does heat up during hot sunny summer days unless solar shielding has been put in place, specifically here, by the overhead photovoltaic solar panels (Fig. 3). The roof of the tank has a similar thickness, which transfers heat to the tank by radiation, since there is a large air gap between the roof and water surfaces due to an overflow outlet. The roof heat transfer is the one that is largely shielded by the solar panels in place. While for the cold water tank, this heat transfer may be considered largely a nuisance, for a hot water tank, this can be a substantial energy cost.

In hot, sunny Delhi, the cold-water tank exterior surface temperature can get to be very hot, probably the highest setting of water temperature that may be sought from the hot water tank. The heat transfer problem of the two tanks is thus similar, the shielding stopping the problem of heat transfer from outside in and the insulation solution being proposed here trying to stop heat transfer from inside out, for the hot water tank. What the solar shielding achieves, is to stop direct sunlight from reaching parts of the cold-water tank exterior, reducing its exterior surface temperature to the outside air temperature range, which is at most in the 40s (Celsius). One way to reduce heat loss from the hot water tank thus is to not attain very high hot water temperatures, say keep them below 50 Celsius, which our solution, using fat piping everywhere does support — namely, let the fat piping supply lots of luke-warm water at high pressure to be able to use it largely undiluted with cold water.

Regardless, demanding better performance from insulation, we fall back on older solutions to the problem, from British India days, e.g. the inventor's grand-paternal home in Allahabad, India, of the use of very thick walls and high roofs in cooling homes. While this can be used directly, a difference is in the larger heat transfer via convection of air, water vapour mix to the roof - that occurs in the tank’s case — in the tank, the convection is upwards, aiding heat loss, while in the old homes, the upward convection reduced heat transfer.

Now comes the benefit of layering. For the normal case, the water vapour is stopped largely at the first tile layer, with the insides this layer being wet, and the tiles not bouncing and air pressure inside this layer being around 1 atmosphere. A multiplicity of tile layers does not increase the air pressure in any layer over 1 atmosphere. The tiles are supported by either the perimeter of a side, or a further perimeter-supported skeletal structure, like thin steelwork like a belt, to keep the tiles in place. The tiles therefore exert no pressure on the air inside. From the perspective of insulation, a layer of tiles forms a thin layer, with limited heat capacity, the air chamber below and above a tiles layer being largely independent. The chambers open to each other only when overheating creates enough steam in a lower layer to raise the pressure in that chamber above 1 atmosphere to 1 atmosphere + X, where X is the weight pressure of a tile (force/per unit area). Then the occasional bouncing of a tile begins and steam passes from one chamber to the next and so on. In the maximum pressure case, in a tank with K tile layers, the top chamber can have a pressure of 1 + X before it releases steam outside, the chamber below this has to lift its roof of pressure X with 1 + X above it, requiring a total pressure buildup of 1 + 2X and so on for a bottom chamber pressure of 1 + KX before the lowermost tiles lift. Thus the quantify KX has to be kept small, using the best choice of K and X. There is a clear pressure gradient from chamber to chamber in this case, allowing high-temperature use of the tank in this range, with steam and moisture rising largely only as far as the nth chamber, n < K for a pressure rise in the lowermost, Oth chamber of 1 + nX.

Perfectly machined tiles, perimeter, or belts are not asked for in this simple system. Nor is the uniformity of pressure in the chambers presupposed, for example in the bottom chamber, since steam generation near boiling point is highly turbulent. Thus an expectation of all-tiles rise together in a layer can be eliminated by the observation that this would comprise a highly unlikely unstable equilibrium, most unlikely, given the easy tolerances allowed to its machined parts and the relatively random edges implied. The maximum pressure of the tank would therefore be well below 1 + KX, before steam releases. Indeed, the operating principle P of the tank for a temperature range would be to heat it's water to its highest end, and check that moisture reaches only its lower chambers as a result, for a given tiles placement The remaining ensure tight insulation for its operation at that range. Juggling the tiles around would yield different results, given the imperfect tolerances allowed. Note that the scenario of perfection is actually the worst scenario, from a maximum pressure buildup perspective. That is the scenario of all tiles rise together. Any imperfections would release steam from its lightest point earlier than the others, at a pressure below the case of perfection

The tradeoff in going from perfection to imperfection then, is the cost of insulation, as in the worst case, at a high temperature a convection current wilfgo across all the the layers, through its lightest path, causing heat loss. The operating principle P described above will ensure avoidance of this scenario however. This scenario then becomes the insurance against further overheating, as the heat/steam loss by such overheating would cool the tank and periodic such releases will keep the tank operating safely even in its worst case. The safety is hugely magnified, compared to say safety valves, as the multiplicity of tiles, their large set of edges, the many layers, combine to ensure a very large combination of path alternatives, by which the steam can release well below 1 + KX pressure. Furthermore, a safety valve is terribly limited by the inability of a user to observe, understand, and maintain it, with only a blowup indicating a fault, as opposed to the system here, totally maintainable, cleanable, and adjustable by any user. A fault in this system can only occur if a user insists on gluing its tiles down one way or the other, avoiding the easily doable maintenance.

Finally, notice that 1 atmosphere pressure is equivalent to 10+ meters of water head. This is equivalent to meters and meters of tile-density head, way more than enough KX to work with in our low-pressure, combinatorially-huge-number-of-altemate-paths design for safe steam release.

Next, consider the following exercise on heat flux. Consider a spherical body of water of radius r, at AT temperature above distant surroundings. The body in steady state of fixed temperature radiates heat at a rate H. If this body is now surrounded by a perfect conductor increasing its radius to 2r, and the conductor radiates like water, then, as the surface area is quadrupled, the body will require a supply of 4H to maintain the same steady state temperature. If the body is surrounded by a perfect insulator of radius r, the body will require no heat supply, as nothing reaches from the interior to the surface and hence no heat is radiated as the surface acquires the temperature of the surroundings.

If the tank of thickness r (outside the hot water sphere of radius r) ensures the same heat radiation H from its outside, then its presumed water-like radiation requires a surface temperature of ΔT/4, given that the area is quadrupled, creating a temperature gradient of 3/4 ΔT from the tank interior to the outside. This tank may be considered as non-insulating, as its presence or absence makes no difference to the original body of water of radius r, as far as radiation loss is considered. This tank may be hypothesized as just a layer of isolated (i.e. non- convecting) air or vacuum, as that allows only radiation loss from the interior, whose flux is quartered by the time the radiation reaches the outside larger area of the tank, ensuring the above behaviour.

The air layers in our tank are a subset of the above hypothetical tank. The rest is the practical, containing material, which, is best comprised of a brickwork/masonry layer, one apiece on the tank interior and exterior sides, for repair and maintenance. In-between can be layers of the user's option, depending on his climate and requirements. In a windy, wet region, a large air layer isolates the tank interior further from the convection cooling of the outside, by allowing a larger temperature gradient to the outside than the 3/4 ΔT above, lowering the outside temperature, besides reducing the heat capacity of the tank. The choice of tiles in the different layers can be made similarly, the interior/ exterior ones being more robust than the rest.

Brickwork/masonry layers on the interior and exterior of the tank are therefore useful, as described above. For large parts of the world sharing the Delhi climate, it turns out that brickwork/masonry is likely the only kind of layering needed for the level of insulation required. A counter argument begins with the observation of sea breezes, where it is widely known that the daily cycle of breezes relies on the convection currents driven by land heating and cooling faster than the sea. This suggests that the thermal ..properties of common, land, structures, like brickwork are not conducive to the best insulation, at least the thermal inertial properties, namely speed of heating and cooling, which are also reflective of heat capacity, with water being known to have a high heat capacity. Regardless, the air layering among the brickwork layers now comes into play. A black body is known to be the best absorber and radiator of the electromagnetic speetnum. The transfer of heat across air layers occurs primarily by radiation. It is extremely important to remove the layers as far as possible from black body behaviour to hinder the propagation of heat among the layers. Just like any coatings in thermally insulating double glass layers ensure excellent insulation, a feature that is used across the cold climates in the globe, coatings, among the layers in the tank., system can insure excellent insulation of the tank — indeed, double glass itself can be a layer, though it is terribly expensive and an overkill (transparency is not needed, nor is it’s fragility). A cheap, easy coating is white paint, following the observation that a white body, in contrast to a black body, is an excellent reflector and bad absorber of radiation and conversely is a bad emitter of its own radiation (symmetric to bad absorber). Probably the best way to obtain robust, cheapest insulation is to have a lot of th in white body la yerswith air layers, in. between, the white bodyemission ensuring the best insulation properties, including among tile layers. The robustness, protection, and independence offered by layering, e.g. the enablement of widespread use o f brickwork, ensures that a tank once constructed only requires local repairs at most in maintenance, never full replacement, meeting one of the design goals of this system. The tank has a low heat capacity, given that air layers contribute almost nothing to its heat capacity.

Notice finally, that the entire insulation problem lies in a hot water temperature range of 0-100 Celsius. Water is in liquid form only in this range. Thus, the insulation problem is a contained problem, with more aggressive insulation layers needed only for very cold regions like the poles and mountains. The entire design here is based on minimality. Use the least amount of widely available material, cheaply, to get the environment-friendly work done. A large heat capacity tank is wasteful. The heat invested in the tank is wasted each time the tank is allowed to cool due to say non use, wasting more if the heat capacity is large. The capacity reduction is obtained by material reduction in conjunction with the work.

It is to be noted that no pumping requirement extends to the hot water tank and system only. The cold-water head drives this hot water system, without a pump. The cold-water level may be maintained by pumps, which is outside the purview of this system.

As a footnote, the purpose of engineering a system is to create an assembly of natural materials, such that the assembled behaviour yields the objectives from the system. We are able to create the assembly, because of our knowledge of Science, and Nature’s observed compliance with such knowledge. From an Information Technology perspective, the input output behaviour of a system can be dictated by a computer, a transformer in other words, that transforms the input into the specified output. The computer in such a system can be digital, or analog. Keeping the design principle of minimality and simplicity, our system generates its hot water output from cold water input, using multiple, modular, pluggable heating elements, the analog computer in this analog system being enshrined in the assembled system itself, implicitly, to yield its overall, highly robust, modular, safe, scalable, minimal-maintenance, parallel design. This becomes the subject of programming nature directly, of interest to Buffhstaff, immediately.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature.

While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person in the art, various working modifications may be made to the process in order to implement the inventive concept as taught herein.