Abstract:
A water processing system includes a water collector to deliver unpurified water to a first container, and a water purifier to purify the water in a second container. A thermal scavenging device extracts heat from a thermal source to heat the purified water, wherein the heated water is stored in a third container, and wherein the first, second, and third containers comprise identically sized containers.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is related by subject matter to the following three U.S. non-provisional patent applications, entitled: PASSIVE HEATING, COOLING, AND VENTILATION SYSTEM; INTEGRATED OFF-GRID THERMAL APPLIANCE; and MULTI-FUNCTION VENTILATION AND ELECTRICAL SYSTEM; which were all filed on Jul. 23, 2009, and which are incorporated by reference in their entirety. This application is further related by subject matter to PCT application entitled INTEGRATED INFRASTRUCTURE FOR SUSTAINABLE LIVING, filed on Jul. 23, 2009 and also incorporated by reference in its entirety. 
     
    
     BACKGROUND  
       [0002]    The lives of refugees, disaster victims, homeless and the poor throughout the world have been improved by low-cost mass-produced housing. Such housing may be rapidly deployed on a large scale, or on an individual basis such as at a campground, festival or as a personal living quarters. The developed world often takes for granted utilities and other infrastructures put in place to sustain its large population densities. When access to clean water, sanitation, cooking heat, electrical lighting, etc. is compromised by natural or man-made events, it can be difficult to restore these services without a massive scale effort. This can result in a significant delay for restoring these basic services for the individuals involved, with large health and safety impacts even if they have basic sheltering provided by low-cost mass-produced housing and community structures. 
         [0003]    In some developing world or rural regions, where access to utilities may be limited or unavailable, such structures may in fact become a permanent residence or other inhabitable structure, where a chronic lack of utilities may lead to exposure, disease, and mortality as well as conflict over scarce resources. Similarly, many people living in developed countries want to reduce their environmental footprint. 
         [0004]    Passive utility provisioning and waste disposal systems integrated into low-cost mass-produced housing would provide the ability to deliver a rapid response to these types of crises and situations, reduce the need for costly ongoing support of aid recipients, and reduce the environmental cost of temporary sheltering. The goal of low-cost mass-produced housing is to extract maximum human survival and comfort per dollar from the environment while producing as little waste or pollution as possible. The structures should require a low initial cost, low operating cost, low need for external resources, and be easily scalable to the user needs. 
         [0005]    By eliminating the complexity of modern urban infrastructures, we can strive to start with an empty expanse of unspoiled terrain, rapidly inhabit it for short or long term without the need for purchasing scarce resources, move away, and leave no trace on the land, air, or water. A complete solution that achieves all of these goals while enabling human survival and conveniences has so far proven elusive. 
         [0006]    The embodiments described herein address these and other concerns. 
       SUMMARY  
       [0007]    A water processing system is disclosed herein, comprising a water collector configured to deliver unpurified water to a first container, and a water purifier configured to purify the water in a second container. The system further comprises a thermal scavenging device configured to extract heat from a thermal source to heat the purified water, wherein the heated water is stored in a third container, and wherein the first, second, and third containers comprise identically sized containers. 
         [0008]    A method is disclosed herein, comprising collecting unpurified water in a first container purifying the water in a second container, and extracting heat from a thermal source to heat the purified water in a third container. The first, second, and third containers comprise identically sized containers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  illustrates a passive room and cooking ventilator used for a building. 
           [0010]      FIG. 2A  illustrates a turbine solar chimney trombe. 
           [0011]      FIG. 2B  illustrates an example heat exchanger used with the turbine solar chimney trombe of  FIG. 2A . 
           [0012]      FIG. 3A  illustrates an example solar concentrator. 
           [0013]      FIG. 3B  illustrates the solar concentrator of  FIG. 3A  secured to the top of a grill rack. 
           [0014]      FIG. 4A  illustrates an off-grid thermal appliance. 
           [0015]      FIG. 4B  illustrates an example solar collector. 
           [0016]      FIG. 4C  illustrates a further example of a solar collector. 
           [0017]      FIG. 5  illustrates a state table state diagram for an off-grid thermal appliance. 
           [0018]      FIG. 6  illustrates an example of a complete integrated cooking, heating, and ventilation subsystem. 
           [0019]      FIG. 7  illustrates an example electrified turbine ventilator. 
           [0020]      FIG. 8  illustrates an example integrated electrical subsystem operable with the electrified turbine ventilator of  FIG. 7 . 
           [0021]      FIG. 9  illustrates an example off-grid water subsystem. 
           [0022]      FIG. 10  illustrates an example water transporter operable with the off-grid water subsystem of  FIG. 9 . 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Described herein is an integrated set of passive natural resource subsystems that work together to provide a complete set of utilities for human survival and comfort using what nature provides. The resulting family-scale passive utility grid harnesses solar energy, wind, geo-cooling, gravity, convection, and rain or river water along with a minimized quantity of fossil fuel for additional thermal energy, and delivers ventilation, heating, cooling, cooking, fire ignition, exhaust ventilation, electric lighting and accessories, a complete subsystem for collecting, purifying, storing, dispensing, and reusing water, and human sanitation, in tightly integrated fashion. Novel aspects of each subsystem will be described, followed by its integration into preceding subsystems and novel features of such integration. 
         [0024]    Passive Room and Cooking Ventilator 
         [0025]      FIG. 1  shows passive room and cooking ventilator  1  used for a human shelter  2  or similar structure containing a sloped or peaked roof  5  and where air from the sheltered area can flow freely to inside the highest point of roof  5 . A ventilation turbine  10  containing multiple spinning blades  15  such as used for attic venting is located at or near the highest point on roof  5 . In one embodiment, the roof  5  is sloped down in all directions from one location, such as the center of a yurt as shown. A roof slope and wall below increase wind speed at the location of turbine  10 , while a directionally uniform slope yields similar wind response regardless of wind direction. 
         [0026]    Turbine  10  is held above the roof surface by chimney  20  and secured to chimney  20  by inserting screws  25  through cowl  30  on turbine  10  and into chimney  20 , or using any other convenient attachment means. Chimney  20  is positioned on roof  5  via a hole in roof  5 , and prevents water intrusion via flashing  35  which also distributes its weight about the roof. Chimney  20  is then secured to plenum  40  via additional screws, snap fit, or other fasteners inside the structure (not shown). Plenum  40  contains an air adjustment means such as a baffle  45  with a flow adjuster  50  to control it. A ceiling vent  55  cosmetically finishes the interior of plenum  40 , and ceiling vent  55  may contain an air/insect filter, which may also be located inside turbine  10  as will be later shown. Turbine  10  also may contain a mechanical brake  60 , which contains a control linkage  65  to enable limitation of rotation during high winds. Since turbine  10  is at the highest point on the roof, it contains a lightning rod  70  located above an upper bearing  75  and a cable (not shown) from stationary lightning rod  70  to earth ground. 
         [0027]    In operation, the wind spins turbine  10 , which creates reduced air pressure inside shelter  2  and pulls air  115  out of the highest point in the interior of the structure through plenum  40  via ceiling vent  55 . The ventilating flow can be quite significant even in light winds, and once spinning, turbine  10  acts as a flywheel, continuing to spin while buffering the effects of wind gusts, downdrafts, and calms. In addition, whenever air inside shelter  2  is warmer than the air outside turbine  10 , air  115  will also rise and exit via turbine  10 , increasing net air flow and additionally spinning turbine  10 , although temperature differences have less air flow impact than the wind does. In cold weather, baffle  45  may be closed to retain warm air inside the shelter  2 , while in warm weather baffle  45  may be opened to exhaust warm air. The warm air is replaced by cooler air from a window  120 , or from an inlet vent  125 , located near the cooler ground. 
         [0028]    Additional turbine motion and ventilation may be enhanced using the solar chimney effect, wherein turbine  10  and chimney  20 ) are made black and heat absorbent. Solar radiation  130  from the sun  135  impinges on turbine  10  and chimney  20  directly, as well as when reflected from roof  5 . This causes air inside chimney  20  to warm up, spinning turbine  10  and exhausting air  115  from shelter  2 . 
         [0029]    Where shelter  2  contains a basement  140  or other raised floor, increased cooling may be achieved using a floor inlet  145  combined with a basement inlet  150  on the shaded side of the structure, which cools incoming air as it flows over the permanently shaded ground under the shelter  2 . Where terrain permits, even greater air cooling may be achieved using a qanat inlet  155  that pulls air in from a shaded place near shelter  2 , cools air further underground, and releases it into basement  140  at underground inlet  160 . In many climates, a swamp cooling effect may also be achieved by adding moisture  165  at any air inlet  120 ,  125 ,  145 ,  150 ,  155 , or  160 . Ideally, such moisture  165  exists naturally underground between qanat inlet  155  and underground inlet  160 . 
         [0030]    A key element of passive room and cooking ventilator  1  is a secondary flue  80  that leads from a vent hood  85  above a cooking stove  90  and pot  95  or an open fire  100  to an outlet port  105  inside the spinning turbine  10 . As will be later described, outlet port  105  is configured to avoid fouling upper bearing  75  or other bearings within turbine  10  while opening within the low-pressure area generated by turbine  10 , which draws air or fumes up from vent hood  85  through flue  80  and out of the structure via turbine  10 . A flue controller  110  such as a baffle closes flue  80  when no heat is being produced. Hot fumes from flue  80  will additionally rotate turbine  10 , assisting air removal from shelter  2 . 
         [0031]    In addition to general room ventilation, the combination of turbine  10 , chimney  20 , plenum  40 , hood  85 , flue  80 , and outlet port  105  enable reduced fuel use, and comprise a natural solution to the problem of lung cancer in developing nations as a result of cooking over open fires inside structures. Typically, even with a flue and chimney, it can be challenging to get heat-driven exhaust of flame products moving soon enough and completely enough to achieve efficient fuel ignition or overcome smoke diffusion and subsequent inhalation. In  FIG. 1 , a low pressure zone from the combination turbine and chimney effects can be located immediately above a flame source and may begin operating prior to flame ignition, providing the functionality of a powered vent hood for users without electrical power This not only exhausts fire and cooking fumes efficiently, but also pulls fresh air into the combustion area where stove  90  or open fire  100  is operating. This harnesses the wind to provide a suction-driven bellows effect to ensure sufficient air for complete combustion in the manner of the rocket stove, which can reduce carbon fuel use 75% or more while using agricultural waste as fuel. The use of a wind-driven turbine to ventilate a living space and independently drive cooking air pressure and flows thus addresses multiple problems in off-grid survival in an integrated and passive manner. 
         [0032]    Turbine Solar Chimney Trombe and Solar Heating Integration 
         [0033]      FIG. 2A  illustrates several additional aspects that extend passive room and cooking ventilator  1  described in  FIG. 1  into turbine solar chimney trombe  170 , with previously described details such as the flue  80  and all other cooking-related aspects omitted for clarity. These additional aspects include integrating a trombe wall or solar ventilator with the turbine  10  and chimney  20  to provide additional ventilation benefits, novel solar collection features in the trombe wall approach that concentrate solar heat to enable heating and purifying water in addition to its air movement functions, and additional means to heat and cool the interior of shelter  2  using heated and cooled water. 
         [0034]    In  FIG. 2A , Plenum  40  is enhanced to contain three primary inlet/outlet directions for air rather than two as shown in  FIG. 1 . Ceiling vent  55  and opening to chimney  20  are as previously described, while a new trombe chimney  190  is added to connect a trombe wall  195  to the chimney  20 . Trombe chimney  190  is shown as a vent duct inside the shelter  2  in  FIG. 2A , and in such a configuration, trombe chimney  190  would be insulated from the interior space of shelter  2 , uninsulated at the roof  5  surface, and painted black on roof surface  5  to capture solar radiation  130 . Alternatively, trombe chimney  190  may be implemented as a blackened vent duct located on the exterior surface of roof  5  without any loss of generality. In either case, trombe chimney  190  captures additional heat into the air flowing upwards within it to assist rotation of turbine  10 . The trombe wall  195  may also be referred to as a solar ventilator. 
         [0035]    Trombe wall  195  may contain various elements of trombe walls and solar chimneys, including a transparent window  200 , a black painted heat absorbing surface  205  that absorbs heat from the sun  135  to serve as a heat bank and help heat the air contained within Trombe wall  195 , an adjustable lower room vent  210 , and an upper means for exhausting heated air or delivering it to the interior space, which means may be an opening, turbine  10 , or ceiling vent  55 . 
         [0036]    In a trombe wall used for heating an interior space on cold sunny days, trombe wall  195  is closed to the exterior environment at the bottom and at the top. Solar radiation  130  passing through transparent window  200  heats air inside the trombe wall  195 , which causes the air inside to rise. Air from inside shelter  2  is pulled into the trombe wall  195  via lower room vent  210 , is heated in trombe wall  195 , and re-enters shelter  2  via an upper room vent, in this case ceiling vent  55  after taking advantage of extra heating from trombe chimney  190  but no assistance from turbine  10 . This return air path is designated with airflow arrow  345 . 
         [0037]    In a trombe wall as used to provide cooling ventilation on hot sunny days, the solar chimney method is applied as follows: air from inside shelter  2  is similarly pulled into trombe wall  195  via lower room vent  210  and heated in trombe wall  195 , but instead of re-circulating the heated air into the interior space via an upper vent such as ceiling vent  55 , the heated air is released to the exterior environment via a vent at the roof, including turbine  10 , to provide additional assistance. As the heated air rises and exits, it creates low pressure inside the shelter  2 , which pulls cooler air from other openings, such as any air inlet  120 ,  125 ,  145 ,  150 ,  155 , or  160 . This integrates passive wind and sun powered ventilation, as designated by air flow arrow  350 . 
         [0038]    The addition of a passive turbine  10  and associated components previously described significantly improves air flow through trombe wall and solar chimney configurations such as the air heating elements here including trombe wall  195 , trombe chimney  190 , chimney  20 , and turbine  10 , without the need for an electrically powered air moving fan. 
         [0039]    The combination of turbine  10  with trombe wall  195  and the solar chimney effects of trombe wall  195 , trombe chimney  190 , chimney  20 , and turbine  10  enable additional 4-way functionality not known in trombe walls or solar chimneys. In a first mode of operation, Plenum  40  contains a baffle  45  that is in this case bifurcated so that the baffle  45  contains two sections, a room side baffle  215  and a chimney side baffle  220 . Each such baffle  215  and  220  may be independently controlled. With both baffles in the upwards positions as shown in  FIG. 2A , air from shelter  2  flows into trombe wall  195  via lower room vent  210 , is heated within trombe wall  195  and trombe chimney  190 , and is forced back into shelter  2  via ceiling vent  55  as depicted by airflow arrow  345 . This provides the trombe wall room heating effect on cold sunny winter days, and if chimney side baffle  220  allows a small amount of leakage between trombe chimney  190  and turbine  10 , then turbine  10  can still help drive air flow. This enables the wind and sun to combine in driving trombe wall operation. In addition, the same setting may be used to heat the room on cold nights when a stove  90  or open fire  100  is creating heat, as flue  80  from  FIG. 1  may be routed inside trombe chimney  190  to heat the air inside it and thus drive convective flow back into shelter  2 , while flue  80  exhausts to the exterior via outlet port  105  and turbine  10 . 
         [0040]    In a second mode of operation, if room side baffle  215  remains in the upward position shown and chimney side baffle  220  is adjusted downwards to open trombe chimney  190  to turbine  10  but close trombe chimney  190  to ceiling vent  55  ( FIG. 1 ), the effect is a wind-assisted solar chimney that provides cooling ventilation powered by the wind and the sun, removing air from shelter  2  via lower room vent  210  and pulling cool air into shelter  2  via any inlet  120 ,  125 ,  145 ,  150 ,  155 , or  160  ( FIG. 1 ) as depicted by airflow arrow  350 . 
         [0041]    In a third mode of operation, if room side baffle  215  is in the downwards position while chimney side baffle is in the upwards position, the wind-assisted room air exhaust functions described in  FIG. 1  are achieved as designated by air flow arrow  355 . In a fourth mode of operation, if both room side baffle  215  and chimney side baffle  220  are in the downward positions, rotation of turbine  10  will simultaneously provide the shelter ventilation functions of passive room and cooking ventilator  1 , wind-assisted trombe wall operation, and wind-assisted solar chimney operation as designated by air flow arrows  350  and  355  together. It should be understood that there are various intermediate adjustments of room side baffle  210  and chimney side baffle  215  that may be used to optimize operation of the various functions available, and that by integrating turbine  10  with trombe chimney  190  and trombe wall  195  as described, a useful ventilation, room heating, and room cooling method is enabled for a wide variety of climates and weather conditions. It should similarly be understood that a synergistic integration between these benefits and the cooking benefits of  FIG. 1  may be readily achieved. 
         [0042]    Water Heating, Thermal Banking, and Gravity Dispensing Integration 
         [0043]      FIG. 2A  also illustrates how the functions of water heating and thermal banking may be integrated within turbine solar chimney trombe  170 . The trombe wall may be used to heat water by placing water within the heated area of trombe wall  195 , depicted via a liquid/air heat exchanger  225 . A convective water heating, thermal banking, and gravity dispensing system for water is integrated around heat exchanger  225  as follows. 
         [0044]    A cold water tank  230  contained within a thermally insulated cold chamber  235  contains cold water, and a hot water tank  240  contained within a thermally insulated hot chamber  245  contains water being heated and/or maintained hot (the dividing insulation between cold chamber  235  and hot chamber  245  is omitted in  FIG. 2A  for clarity). Cold tank  230  contains a cold tank outlet  250  near its bottom that enables water to flow into hot tank  240  via hot tank inlet  255 . Further, cooler water near the bottom of hot tank is allowed to flow into heat exchanger  225  via heat exchanger inlet  260 , where it is heated by trombe wall  195 , rises via convective flow, and returns near the top of hot tank  240  via hot water return  265 , which is shown in  FIG. 2A  with a heat exchanger valve  270 . Heat exchanger valve  270  shuts down the convective flow to prevent heat loss whenever trombe wall  195  is not providing heat, such as at night. 
         [0045]    To dispense water, cold tank  230  contains a cold water outlet  275 , and hot tank  240  contains a hot water outlet  280  in the upper portion of hot tank  240  where the water is warmer. A water tap  285  that may be configured for washing, showers, or other purposes mixes the hot and cold water and dispenses potable temperate water  290 . If desired for additional dispensing pressure or because tap  285  is higher than cold tank  230  or hot tank  240 , tap  285  may also contain a simple hand pump. 
         [0046]    As long as the water level in the cold water tank  230  is higher than the water level in hot water tank  240 , then whenever water is dispensed by water tap  285 , gravity will force water to flow from the bottom of cold tank  230  via cold tank outlet  250  to hot tank inlet  255 , where the cold water becomes available to be heated. This gravity fed process also helps ensure that hot tank  240  and its associated heat exchanger  225  remain full and operational. In practice, cold tank  230  would generally be located higher than hot tank  240  to facilitate gravitational water pressure. 
         [0047]    To provide thermal banking for heating and cooling the air within shelter  2 , hot chamber  240  contains a heating door  295 , which when opened to the interior space of shelter  2  allows heat to radiate, conduct, and be convected from the water tank into the air in the interior space, thus heating it. Similarly, cold chamber  245  contains two doors, an interior cooling door  300  that opens to the interior of shelter  2  and an exterior cooling door  305  that opens to the exterior (hidden in  FIG. 2A  by  300 ). To cool the water in cold tank  230 , exterior cooling door  305  is opened during cold weather and at night to allow heat in the water to escape to the exterior environment, while interior cooling door  300  is closed. To cool the interior space, exterior cooling door  305  is closed, and interior cooling door  300  is opened to allow heat from inside shelter  2  to be captured by cold tank  230 . 
         [0048]      FIG. 2A  also illustrates additional trombe wall water heating approaches that will now be described. In trombe walls, transparent window  200  may include a sheet of transparent material such as glass, which does not focus infrared solar radiation. This does not impact trombe wall ventilation functionality, but for heating water it is desirable to obtain a much higher water temperature than is possible by transferring heat from unmagnified solar radiation to heat exchanger  225 . In one embodiment of a trombe wall  195  optimized for heating water, transparent window  200  contains a focusing surface  310  that may be designed to nominally focus incoming light into a linear beam several times taller than it is wide, and to provide some prismatic aiming capability about the horizontal so that solar radiation  130  coming from near vertical orientations can be redirected towards heat exchanger  225 . As the sun goes up and down in the sky, a relatively small linear beam would move up and down along heat exchanger  225 . Such a focusing surface  310  may be achieved conveniently via two-dimensional lens variants such as lenticular lenses and Fresnel lenses, which can ignite paper with a handheld size lens or vaporize a penny in seconds with a  1  meter surface area focusing surface. 
         [0049]    It is noted that in  FIG. 2A , transparent window  200  is shown angled towards the sun  135  to present greater surface area to it, rather than aligned vertically as in some trombe walls. In such a case, heat exchanger  225  could be similarly angled (not shown) or the focusing surface  310  could be segmented or otherwise varied to ensure efficient focusing of solar radiation  130  onto heat exchanger  225 . 
         [0050]    As shown in  FIG. 2B  along a vertical axis of heat exchanger  225 , focusing surface  310  focuses solar radiation  130  onto a focused area  315  that is much smaller than the width of transparent window  200 . This directs more heat per square inch at heat exchanger  225 , and thus enables the water within heat exchanger  225  to be heated hotter than the surrounding air within trombe wall  195  without increasing the net amount of heat admitted by transparent window  200 . 
         [0051]    The position of the sun  135  varies during the course of the day and seasons. In the view of  FIG. 2A , as the sun  135  moves up and down in the sky during the day on the side of shelter  2  that contains trombe wall  195 , solar radiation  130  continues to impinge on heat exchanger  225  since the vertical dimension of focusing surface  310  is greater than that of heat exchanger  225 . Also as shown in  FIG. 2B  from a top view, solar rays  130  continue to focus on heat exchanger  325  for a range of horizontal sun angles with respect to focusing surface  310 , since the horizontal dimension of heat exchanger  325  is greater than the focused area  315 . Specifically, as the sun  135  moves in the horizontal direction shown by arrow  320  over the course of a day or during different seasons, focusing surface  310  ensures that focused area  315  remains directed upon heat exchanger  225 , as shown at off axis focused areas  325 . Focusing surface  310  thus provides an effective solar concentrator for water heating, and a useful integration of same into trombe wall  195 . 
         [0052]    To increase performance of the trombe wall and solar water heating efficiency, external mirror  330  and internal mirror  335  serve to increase the effective surface area of focusing surface  310 , thus delivering more heat to trombe wall  195  and heat exchanger  225  and providing an independent aiming means for concentrating solar radiation  130 . Each of external mirror  330  and internal mirror  335  may be adjusted via pivot or hinge  340 , and may be combined into a single mirror without loss of generality. 
         [0053]    Off-Grid Thermal Appliance and Integration 
         [0054]      FIG. 3A  illustrates a simplified version of a solar concentrator  360  that comprises a focusing surface  310  combined with an open fire  100  which may also be a fueled stove  90 .  FIG. 3A , solar concentrator  360  is shown as a folding multi-faceted reflective mirrored assembly, although rounded optical surfaces may focus more intensely, and any manner of solar concentrator  360  may be used without loss of generality if it suitably concentrates solar energy. As shown in  FIG. 3A , when the solar concentrator  360  is secured to the base of grill rack  365  with a cooking pot  95  above it, a solar concentrator  360  with suitably low optical aberration can focus sufficient solar radiation  130  from the sun  135  to ignite tinder placed in the area of the open fire  100 . 
         [0055]    Once a fire is ignited solar concentrator  360  may be removed. Alternatively, if solar cooking is desired without carbon fuels,  FIG. 3B  shows solar concentrator  360  adjusted vertically upwards versus grill rack  365  and pot  95 , with solar concentrator  360  secured to the top of grill rack  365 . In this configuration, solar cooking can proceed using a pot  95  blackened to absorb heat, contained within an enclosed transparent chamber  370  to retain the heat, such as a high-temperature cooking bag. In addition, open fire  100  or fueled stove  90  below pot  95  can assist the solar process. In one embodiment of such fuel-assisted solar cooking, a more flame-resistant material such as glass would be used for transparent chamber  370 . 
         [0056]    In one embodiment, the top surface  375  of grill rack  365  may convert between a grill and a metal planar surface that seals the area  380  within the bottom of solar concentrator  360  to force smoke from open fire  100  to vent to the outside of solar concentrator  360  and thus protect the reflective surface of solar concentrator  360 . A very small fire  100  or fueled stove  90  such as a gasifier would result in minimal heat loss around solar concentrator  360  and maximum assist to the solar cooking process facilitated by the solar concentrator  360 , with minimal fuel use. 
         [0057]      FIG. 4A  builds on  FIG. 3A and 3B  and integrates water heating functions described in  FIG. 2A  into a complete off-grid thermal appliance  400  that integrates the functions of solar igniter, solar oven, fueled oven, combination solar/fueled oven, solar/fueled water heater, and room heater in a manner that enhances efficiency of the individual functions. The configuration of  FIG. 4A  may be executed as a standalone appliance, or as will be shown, may be integrated within the passive room and cooking ventilator  1  of  FIG. 1  or the more complete turbine solar chimney trombe  195  of  FIG. 2A .  FIG. 4B and 4C  show additional embodiments that achieve the optical properties required for the functionality that will be described for  FIG. 4A . 
         [0058]    In  FIG. 4A , off-grid thermal appliance  400  includes an insulated oven chamber  405  that contains heat and encloses a heat source such as fueled stove  90  or open fire  100 , as well as an optional cooking pot  95 , and a grill rack  365  that may be moved up and down via grill adjuster  410  to adjust the vertical position of fueled stove  90  or open fire  100 . Fire door  415  and oven door  420  provide access to within oven chamber  405  for handling food, fuel, and cleaning, or to allow heat to escape for warming the space around the off-grid thermal appliance  400 . Adjustable air input  425  allows cool air in to support fueled cooking or is closed when solar-only functionality is desired. Flue controller  110  is similarly closed for solar-only operation or to retain heat within the oven when not cooking. 
         [0059]    Solar radiation  130  from the sun  135  is collected and focused by focusing surface  310  adjustable by a pivot or hinge  340 , reflected by internal mirror  335 , and is focused to a small focused area  315  within oven chamber  405 . To enter oven chamber  405 , converging solar radiation  430  passes through thermal window  435  to prevent heat loss from inside oven chamber  405 . A retractable, insulated thermal window cover  440  is also shown, which may be used to retain heat inside oven chamber when no solar radiation  130  is available. When solar energy  130  is available, grill adjuster  410  may be used to locate tinder at the small focused area  315 , and the tinder will rapidly ignite. If grill adjuster  410  is used to locate cooking pot  95  so that small focused area  315  is within or projected upon cooking pot  95 , the food inside cooking pot  95  will be heated. If nothing is placed near the small focused area  315 , the converging solar radiation  430  passes through its focal point and diverges again, impinging on cooking heat exchanger  445 , which is an embodiment of heat exchanger  225  previously described. In the configuration of  FIG. 4A , directing solar energy towards the small focused area  315  in an upwardly manner is beneficial, since heat rises, food may be simultaneously heated from the bottom by solar and fueled heat sources, flames may be ignited while food is above the flame area, and both solar and fueled waste heat rise further to heat exchanger  445 . 
         [0060]    In  FIG. 4A , cooking heat exchanger  445  is a radiator-like air/liquid heat exchanger with high surface emissivity. As a result, collected solar heat may be conducted into and moved away from heat exchanger  445  to limit the heat re-emitted into oven chamber  405 . Control over heat removal is accomplished by connecting heat exchanger  445  to hot tank  240  in a similar manner as  FIG. 2 . First, oven water inlet  450  and oven water outlet  455  are connected to hot tank  240  via loop valve  460 . In the open position, loop valve  460  allows convection to move cool water from heat exchanger inlet  260  on hot tank  240  through loop valve  460  and through oven water inlet  450  into heat exchanger  445 . There the water is heated by solar rays or excess cooking heat from cooking stove  90 , and forced up through oven water outlet  455  back through another path in loop valve  460  where it proceeds through interconnect  465  to flue scavenger  470  which wraps around flue  80  to scavenge additional waste heat from oven chamber  405 , and finally re-enters hot return  265  in hot tank  240  via return line  475 . 
         [0061]    Loop valve  460  may alternatively be adjusted to a closed position via loop valve controller  480 . In the closed position, heat exchanger inlet  260  is connected directly and only to interconnect  465 , while oven water inlet  450  is connected directly and only to oven water outlet  455 . In the closed position, loop valve  460  thus provides for a convective water heating loop using heat captured from flue  80 , while simultaneously forcing heat in heat exchanger  445  to remain within it or escape into oven chamber  405 . This heats oven chamber  405  and anything within it more quickly, such as for preheating before cooking. It also enables oven chamber  405  to keep cooked food warm longer once solar and fueled cooking ceases. 
         [0062]    Since thermal window  435  comprises a small fraction of the spherical space around heat exchanger  445  into which heat can radiate from it, while the inner surface of oven chamber  405  is reflective to reject radiation, most solar radiation  130  impinging on heat exchanger  445  and then emitted, conducted, or convected as heat from heat exchanger  445  will remain within oven chamber  405  where it can be utilized, rather than escaping immediately via flue  80  or thermal window  435 . Closing loop valve  460  thus enables pre-heating oven chamber  405  on hot or cold sunny days before initiating cooking, continuing with solar cooking or fueled cooking or both solar and fueled together, and in general, enables the user to assign thermal priority to cooking over water and room heating when desirable for human comfort and fuel conservation. At any time, extra room heating may be accomplished by opening hot tank door  295  (not shown) as described in  FIG. 2 . 
         [0063]      FIG. 4B  and  FIG. 4C  illustrate additional embodiments for concentrating solar radiation  130  using various means of enabling focusing surface  310  for a solar concentrator  360 . In  FIG. 4B , the focusing surface  310  as well as the functionality of internal mirror  335  of  FIG. 4A  are combined in one reflective concentrator  500 , illustrated as a parabolic surface shape. Reflective concentrator  500  may be adjusted via hinge  340  to aim focused area  315  within oven chamber  405 . Since one problem with mirror surfaces is a delicate reflecting surface that is damaged easily by cleaning or dirt,  FIG. 4C  shows a reflective concentrator  500  comprised of three elements, a focusing surface  310  such as a Fresnel lens, a back mirror  505  consisting of a highly reflective surface, and a backing surface  510  which may be adjusted by a pivot or hinge  340 . Solar radiation  130  impinging on focusing surface  310  is converging as it continues to back mirror  505 , and is converged further upon exiting through focusing surface  310  on its way towards focused area  315  within oven chamber  405 . By sandwiching the mirror  505  between a rugged supporting backing surface  510  and a robust flat refractive focusing surface  310  such as a Fresnel lens, performance and maintainability are ensured. It is noted that in practice, focusing surface  310  may have its optical power elements such as grooves on the side facing back mirror  505  for even easier cleaning of the exterior surfaces. Referring back to  FIG. 2A , it is also clear that external mirror  330  or internal mirror  335  or both may be focusing surfaces in the manner of  FIG. 4B and 4C . 
         [0064]      FIG. 5  provides a table  525  illustrating how the key control adjustments described in  FIG. 4A  may be combined to provide the functions of fuel ignition, fueled cooking, solar cooking, combined solar/fueled cooking, room heating, and water heating. Table  525  summarizes this information in the form of a simple state diagram that defines whether each controllable component within off-grid thermal appliance  400  is open (O) or closed (C) to achieve a given functional result of solar ignition, solar cooking, room heating, etc. In the case of air flow controls such as air input  425  and doors such as oven door  420 , “open” denotes allowing maximum air flow, while “closed” denotes allowing minimum air flow. In the case of Loop Valve  460 , “open” denotes allowing water to flow around the entire water heating sequence described in  FIG. 4A , while “closed” denotes separating the heat exchanger  445  from the remaining components in the water heating sequence. In the case of grill adjuster  410 /focus area  315 , table  525  denotes the target of the converging solar radiation  430  when grill adjuster  410  is correctly positioned. 
         [0065]    Some of the cells in the table include two possible settings, defined as follows. In each case, the first setting is a default, and the alternative setting modifies it. Hot tank door  295  is normally closed except during Room Heating, but may be opened at any time to warm the room during other operations. In the Fueled Cook and Combined Cook columns, the parenthetical settings for oven door  420  and fire door  415  allow heat to escape to the room to heat it during cooking if desired, while loop valve  460  may be closed to retain extra heat within oven chamber  405  instead of giving some up to water. In the room heating column, the first settings for air input  425 , flue controller  110 , and window cover  440  are for solar operation, which is the default since it uses no carbon fuel. For combined solar/fueled operation air input  425  and flue controller  110  are opened, and for fuel-only heating, window cover  440  is additionally closed. It should be appreciated that some elements such as air input  425  and flue controller  110  may be mechanically linked, or if electric power is available from a battery or other source, any or all of the controls in  FIG. 5  and elsewhere herein may be automated. 
         [0066]      FIG. 6  shows an embodiment of off-grid thermal appliance  400  of  FIG. 4A  connected to passive room and cooking ventilator  1  of  FIG. 1A , together installed within turbine solar chimney trombe  170  of  FIG. 2A , to form integrated cooking, heating, and ventilation subsystem  530 . In this embodiment all of the various advantages previously described for each subsystem may be combined within a single system. For example, wind-driven suction from turbine  10  drives cooking efficiency and exhaust ventilation for off-grid thermal appliance  400  regardless of ventilation settings. In addition, because flue  80  rises within trombe chimney  190  and heats the air within it whenever a heat source is contained within oven chamber  405 , room air coming into trombe wall  195  via lower room vent  210  may be heated and returned to shelter  2  via ceiling vent  55  while combustion fumes are sucked out of the structure by turbine  10 , even at night. 
         [0067]    The integrated cooking, heating, and ventilation subsystem  530  of  FIG. 6  provides a shelter or other structure with a complete thermal energy collection, control, retention, banking, and dispensing solution including flame igniter and water pasteurization/heating, as well as a complete ventilation solution for air heating/cooling and exhausting stoves, composters, or other devices while improving their efficiency. The entire system solution is powered by the sun, wind, gravity, and convection instead of electricity, and greatly minimizes the need for carbon-based fuels whose use increases scarcity, economic burden, health impacts, and pollution. By generating biofuel locally from plants or algae fertilized by human waste products as will be later described, a user&#39;s net carbon fuel footprint can be made zero, since all the carbon in the fuel is captured from atmospheric CO2 by the plants or algae and simply returned to the atmosphere when combusted. 
         [0068]    Ventilation-Integrated Electrical Subsystem 
         [0069]      FIG. 7  illustrates additional detail of turbine  10  as used within passive room and cooking thermal ventilator  1  (FIG IA) and turbine solar chimney trombe  170  ( FIG. 2A ), as well as additional features that integrate bidirectional electric motor components to produce electrical power from wind or heat, or use electrical power to drive ventilation. Some previously described detail of passive room and cooking thermal ventilator  1  and turbine solar chimney trombe is omitted for clarity, including the tri-directional air movement detail of  FIG. 2A . 
         [0070]    Additional detail of turbine  10  in  FIG. 7  includes turbine axle  550  about which turbine blades  15  spin and are connected to turbine axle  550  at the top and via brace  555 , as well as upper bearing  75  within insulated bearing housing  560 , and lower bearing  565  which together contain turbine axle  550  and allow it to spin. Insulated bearing housing  560  is insulated to electrically isolate lightning rod  70  from the remainder of shelter  2 , and in use lightning rod  70  would be connected to earth ground via a ground cable (not shown) secured to stationary outer frame  65  and then running down to a conductive ground anchor (similarly not shown). Insulated bearing housing  560  may also seal the bearing against combustion products from outlet port  515 . 
         [0071]      FIG. 7  also shows additional detail for alternate embodiments of a pest screen to prevent insects and other small pests from entering shelter  2  between blades  15  of turbine  10 . Fixed pest screen  570  is a screened mesh that completely fills a roughly planar area that completely encloses cowl  30  just above the top of outlet ports  105  and  515 , and which contains a central opening to allow turbine axle  550  to penetrate it. Alternative embodiments of fixed pest screen  570  include a spinning pest screen  575  secured to brace  555  and the lower insides of blades  15 , and a spinning full screen  575  secured completely about the inside envelope of blades  15 . The latter embodiment requires more mesh material, but completely prevents pests from entering anywhere within the envelope of turbine  10 . It may be appreciated that spinning full screen  575  may form any shape between the curved and horizontal envelopes shown. 
         [0072]      FIG. 7  also shows additional detail of turbine  10  connected to two secondary exhaust sources in the manner of passive room and cooking ventilator  1 . In addition to a cooking exhaust process connecting stove  90  to outlet port  105  via vent hood  85  and flue  80 , a toilet  580  with a toilet door  585  and a composting potty  590  is connected to turbine  10  in a similar manner to flame sources via composter flue  595  and outlet port  515 . This enables wind-driven rotation of turbine  10  to exhaust fumes and scents from composting potty  590  to the exterior, which is a key requirement in human waste composting systems. In addition, any heat sources within shelter  2  that cause turbine  10  to rotate will additionally pull fumes from composting potty  590 . To provide heat for composting, toilet  580  may share a solar collector such as trombe wall  195  with other subsystems, or may use its own solar collector. In addition, pipes containing water heated as earlier described (not shown) may be circulated within composting potty  590  to provide heat. 
         [0073]    In addition to the additional detail described,  FIG. 7  illustrates an electrified turbine ventilator  545  comprising a combination of wind driven ventilation and electric power generation, whereby rotating permanent magnets within wire coils may be used to electrify turbine  10 . In a first embodiment, a generator  600  is connected to turbine axle  550  causing magnets  605  contained within generator  600  to rotate within coils  610  contained within generator  600 . In a further embodiment, coils  610  are attached to cowl  30  in a manner that places them close to blades  15 , and several or all of blades  15  contain magnets  605  rotating past coils  610 . Wind-driven rotation of turbine  10  produces a direct electrical current between positive turbine lead  615  and negative turbine lead  620 . This electrical current may be used to perform electrical work or stored in a battery for later use. DC motors and DC electrical generators are both comprised of spinning magnets and stationary coils, and are equivalent constructs. Therefore, in addition to enabling power generation from wind in a passive turbine ventilation system, magnets  605  and coils  610  also enable use of turbine  10  as a powered ventilation fan driven by electrical power from a battery or other source. 
         [0074]      FIG. 8  illustrates electrified turbine ventilator  545  contained in a complete integrated electrical subsystem  650  that integrates with many of the previously described subsystems as will be described. Electrical subsystem  650  integrates collection of electrical energy from multiple sources, prevents waste, and powers a multiplicity of optional electrical devices that may include electrified turbine ventilator  545 , low-energy LED lights  655 , security/fire alarm  660 , radio  665 , lighter  670 , electronic device charger  675 , gasifier stove  680 , battery charger  685 , UV sanitizing LED  690 , water heating element  695  for hot tank  240  or other uses such as boiling water, composter heater  700 , fan  705  for assisted ventilation of composter  590  or any other purpose, or any other suitably low-power direct current electrical accessory. 
         [0075]    In  FIG. 8 , generator  600  of electrified turbine ventilator  545  is connected to directional charge controller  710 , which may also accept electrical power input from solar panel  715  and/or manual crank  665 . Manual crank  720  contains a generator such as generator  600  from electrified turbine ventilator  545  temporarily removed. Charge controller  710  performs several functions. One function is preventing overcharging of battery  725 , which some charge controllers for solar cells achieve by sensing the level of battery  725  and opening the circuit between the battery and the solar cell to prevent current flow if the battery is fully charged. Charge controllers for wind devices may dump excess wind power into a waste resistor since removal of an electrical load removes a mechanical rotational load on the turbine itself, which can result in over speed conditions. In survival conditions, neither approach to avoiding battery overcharging is optimal, since they waste available energy production that could be utilized. 
         [0076]    The embodiment of charge controller  710  in  FIG. 8  simultaneously avoids battery overcharging and energy waste by utilizing excess energy for a variety of purposes, through shunting excess current from electrified turbine ventilator  545 , solar panel  715 , and manual crank  720  to priority selector  730  whenever the battery is fully charged. Priority selector  730  allows a user to select between various uses of excess electrical power, including UV sanitizing LED  690 , water heating element  695 , composter heater  700 , and fan  705 , although in practice any background accessory might be selectable and one or the other would always be selected, such as by making priority selector  730  a rotary switch. 
         [0077]    For powered rotation of turbine  10 , directional charge controller  710  performs an additional function to electrically disconnect generator  600  from the battery charge sensing of charge controller  710 , and instead connect generator  600  to battery  725  via a user-operated bidirectional controller  735 . Bidirectional controller  735  may be a potentiometer with a rotating knob, wired so that there is a center detent position connecting generator  600  to the battery sensing and charge control circuitry, and so that as bidirectional controller  735  is turned in either direction from center, one polarity or the other is applied from battery  725  to generator  600  positive turbine lead  615  and negative turbine lead  620 . Doing so allows the user to turn turbine  10  in either direction at adjustable speed using power from battery  725 . As should be evident from preceding discussions, electrically rotating turbine  10  in the same direction as the wind nominally turns it will move air in all the ways previously described. Electrically rotating turbine  10  in the opposite direction by changing the polarity of electrical current at positive turbine lead  615  and negative turbine lead  620  will force outside air from the roof peak into the structure. 
         [0078]    While forcibly moving air from the exterior via electrified turbine ventilator  545  in this manner would rarely benefit a complete implementation of turbine solar chimney trombe  170  and integrated electrical system  650 , it can improve comfort under some environmental conditions, such as warm, cloudy, still mornings or nights. In addition, this reversible operation provides important functionality in embodiments where the passive room and cooking ventilator  1  of  FIG. 1  is combined with integrated electrical system  650 , but does not include additional components of turbine solar chimney trombe  170  or off-grid thermal appliance  400 . 
         [0079]    In  FIG. 8 , battery  725  is additionally connected to power distribution panel  740 , which contains various components for controlling electrical power and may physically contain directional charge controller  710  and priority selector  730  for user convenience, although they are shown separate in  FIG. 8  for clarity. Electrical control components may include fuses or breakers  745  to protect electrical components, as well as electrical switches  750  which are connected to various electrical loads previously described, such as lights  655  and security alarm  660 . An inverter (not shown) for powering alternating current devices may also be connected. 
         [0080]    An example benefit of this integration is powering a gasifier heater  765  and gasifier fan  770 . Conventional gasifiers for off-grid use are standalone units that require complexity because they need energy to heat wood thereby releasing volatile compounds to initiate ignition, and a fan to move the volatiles into a combustion area and remove combustion products. The result is far less wood use and dangerous fumes, but the fan and heater each require battery power, and the battery in turn requires a small electrical generator  600  or other means to generate electrical energy from rising heat to recharge the batteries. In  FIG. 1  it can be seen that the ventilating functions are here provided by turbine  10 . In  FIG. 6  it can be seen that the thermal assistance function may be here provided by the sun. In  FIG. 8  it can be seen that thermal and air movement functions are here provided even in the absence of sun or wind, and turbine  10  can perform the function of gasifier fan  770 . By eliminating most of the complexity of gasifier stove  680  in favor of a passive home-scale energy grid, gasifier cost is reduced, gasifiers for use within integrated electrical system  650  can be made locally in developing nations more easily, the gasifier and other system components are less failure-prone, and overall system cost plus maintenance are both reduced. 
         [0081]    Additionally, security/fire alarm  660  is a smoke sensor and/or carbon monoxide sensor to protect occupants from fire that may be further connected to an intrusion sensor  765  on window  120  or entry door  770  to set the alarm off in case of unwanted intrusion. Security/fire alarm  660  may be controlled by remote controller  775  to trigger alarm  660  in case of attack, silence it in case of false alarms, or test its operation. In grid-dependent shelters, dwelling security alarms are large expensive distributed devices, while the present embodiment many be implemented for off-grid shelter applications via slight modification to the circuitry of a very low-cost mass-market smoke alarm. 
         [0082]    Off-Grid Home-Scale Water Subsystem 
         [0083]      FIG. 9  illustrates a complete off-grid water subsystem  800  that provides water functions including collection, transport, storage, purification, heating, dispensing, and recycling. Standardized water containers  805  such as (in the US) 5 gallon water bottles are mass produced for commercial water deliveries, and may be delivered full to a disaster area in large quantities to supply initial water needs, then reused in the present water system. Important aspects of the water subsystem such as heating, cooling, and dispensing have been previously described, and  FIG. 9  omits many previously described details while illustrating water subsystem  800  in an end-to-end fashion. 
         [0084]    In  FIG. 9 , off-grid home-scale water subsystem  800  is divided into clean area  810  and dirty areas  815  and  820 . In clean area  810  all water is potable, while in dirty areas  815  and  820  it is not. Collected water in dirty area  815  is considered unusable until it is treated, and used grey water in dirty area  820  is also considered unusable until treated. The user uses separate water containers  805  for clean area  810 , while water containers  805  may be comingled between dirty areas  815  and  820 . 
         [0085]    Water subsystem  800  begins with collection, which may be accomplished in at least three ways presuming a well or water utility grid is unavailable. First and generally easiest, rainwater may be collected by a rain catchment  825  such as gutters and downspouts, which drain to water containers  805 . A small shelter  2  ( FIG. 1 ) with 170 sq ft under roof can collect 100 gallons from 1″ of rain in this manner, sufficient for a family of four to survive a month. Second, if no rain is available, a nearby water source  830  such as a river may be used to collect dirty water into water containers  805 . Water transporter  835  will be later described to enable human-powered transport of water containers  805  over long distances. Third, water containers  805  may be delivered by an aid provider, and may be used or stored directly as purified water  840 . 
         [0086]    Water collected from rain catchment  825  and local water sources  830  is poured through a pre-filter  845  to remove particulate matter including leaves and insects. Water containers  805  containing pre-filtered water  850  are then poured into water purifier  855 . Water purifier  855  may utilize one or more known techniques to purify and sanitize water, including sand filter  860 , heat pasteurization using solar heater  865  or other heat sources  870  as previously described, distiller  875 , UV LED sanitizer  690 , and/or other means. 
         [0087]    In one embodiment of water purifier  855 , sand filtration  860  would be followed by selection between LED sanitizer  690  and integrated heating using solar heater  865  and other heat sources  870 . Such an embodiment could be achieved using the means described for off-grid thermal appliance  400  to pasteurize or distill water based on the configuration of  FIG. 4A  or  FIG. 6 . In a distiller embodiment, a heat exchanger  445  as shown in  FIG. 4A  would heat water to boiling, and then release boiling water or steam through an interconnect  465 . Such distilled or pasteurized water could either proceed to hot water tank  240 , or steam would condense into a water container  805  containing purified water  840 , or boiling water could be forced into a water container  805  containing purified water  840  via pressure caused by downflowing pre-filtered water  850  instead of pressure from cold tank  830  as described in  FIG. 2B . Off-grid thermal appliance  400  may be modified at extremely low cost and complexity in this manner to add a distiller  875  or pasteurizing treatment that delivers key functionality to water purifier  855 . 
         [0088]    In clean area  810 , water purifier  855  outputs purified water  840  into water containers  805 . A water container  805  containing purified water  840  may be used as cold tank  830  within cold chamber  235  ( FIG. 2A ) by opening water container  805  containing purified water  840  and placing it upside down into gravity dispenser  880 , that feeds water whenever pressure below it is reduced by opening tap  285  to release temperate water  290 . Hot water to mix with the cold water in the tap may be fed from hot tank  240 , heated via any combination of solar radiation  130  captured by solar concentrator  360  to heat exchanger  225 , or open fire  100 , or other fueled heat sources as described in  FIGS. 2A ,  4 A,  6 , or  8 . 
         [0089]    Clean area  810  shows an additional improvement wherein a water container  805  from clean area  815  may be used within a preheater  885  to generate preheated water  890  for gravity feeding into hot tank  240 . In the embodiment of  FIG. 9 , water being heated by preheater  885  is used to drive the gravity feed for hot tank  240  in the manner cold tank  230  provided that function in  FIG. 2A . This enables preheater  885  to be placed on the roof  5  of a shelter  2 , and implemented as a simple solar collector  360  that generates preheated water  890 , which flows via gravity dispenser  880  to hot tank  240  via hot tank inlet  255  to pressurize hot tank  240 . In addition, where heat is used to pasteurize or distill water, heat retained in such purified water  840  may be scavenged by immediately placing a water container with heated purified water  840  into preheater  885 , or by placing the heated water container  805  within shelter  2 . It is noted that while hot tank  240  may be made out of a standard water container  805 , a standard water container  805  is not shown as hot tank  240  in  FIG. 9  since standard water containers tend to have one opening at the top, while hot tank  240  comprises connections at top and bottom for the convective flow and gravity feed as detailed in  FIG. 2A . As may be appreciated, a standard water container  805  may be readily modified to serve as hot tank  240 . Alternatively, a standard water container  805  may be configured with a heat exchanger  225  via its single opening, or a pair of standard containers  805  may be used with a heat exchanger between them. 
         [0090]    As temperate water  290  is dispensed from tap  285 , used, and drained into a drain  895  that may be part of a sink or shower stall, the used gray water  900  is collected into another water container  805  in a dirty area  820 . Gray water  900  may be poured through a pre-filter  845  to remove particulates and then used for purposes such as growing food  910 . If water scarcity is extreme, gray water  900  may be poured directly through pre-filter  845  for re-purification and reuse. To the extent particulates collected by pre-filter  845  and post-filter  905  contain organic matter, such matter may often be desiccated and then used as fuel. 
         [0091]    For black-water generated at composting potty  590  (not shown in  FIG. 9 ), urine is separated from solid waste using a bifurcated seat or by draining from the composting tank. The urine containing nitrogen, phosphorous, and potassium may be used as fertilizer for food gardening, or for algae gardening to process into bio-fuel. The solid waste similarly becomes a soil amendment after aerobic composting through thermophilic decomposition, using heat and ventilation from the previously described subsystems. By using such bio-fuel in combination with solar radiation to power off-grid thermal appliance  400 , a user can achieve minimal carbon and other footprints, by removing carbon from the atmosphere to grow food and algae for fuel, plus recycling human waste to fertilize them. 
         [0092]    In cases where local water sources  830  are used to collect water, it is possible that the collected water must be transported a significant distance. Such water transport is a significant physical challenge for hundreds of millions in the developing world, and often keeps women from income producing work or education. To facilitate transport,  FIG. 10  illustrates detail for enabling a simple but effective embodiment of water transporter  835  that may be produced locally by the poor or disaster victims. 
         [0093]    In  FIG. 10 , standard water container  805  is held securely in cradle  940  by straps  945  such as ropes, or webbing with Velcro ends that may be detached for removal. Cradle  940  may be easily fabricated from PVC plumbing parts or equivalent, including eight straight tubes  950 , four  90  degree elbows  955 , and two three-way corner connections  960 . The two tubes at the ends of cradle  940  form stationary axles  965  that insert through the inner race of wheel bearing  970  and lock to it, while bearing  970  contains wheel  975  connected around its outer race. Wheel  975  is then held onto axle via the inner race of bearing  970  using any simple means such as a pipe cap  980  and retaining screw  985 , cotter pin, or clip. To facilitate towing by a human, draft animal, or bicycle, tow rope  990  containing axle rings  995  apply pulling force to axles  965 , and an additional piece of straight tube  950  may be inserted around rope  990  as a handle. As long as the center of gravity of water container  805  and the water within it remains below an imaginary line connecting axles  965 , cradle  940  will remain stably below water container  805  whenever cradle  940  is pulled by tow rope  990 . 
         [0094]    In one embodiment of water transporter  835 , old bicycle wheels are used as wheel  975 . When both of wheels  975  including their bearings  970  are removed from water transporter  835 , the wheels may be attached to a straight axle and used to form the basis of a cart for transporting goods. Such a cart may be used to transport lightweight foldable building structures, enabling a folding shelter as well as the entire family scale utility grid to be transported using wheels  975 . This can be a critical advantage in disaster relief, as well as refugee situations where permanency is discouraged. 
         [0095]    When water transporter  835  is used within off-grid water subsystem  800 , a complete end-to-end family-scale post-disaster water infrastructure is enabled that duplicates on minimalist scale all of the functions of city-scale water utilities. Analogously, integrating water subsystem  800  with previously described subsystems passive room and cooking ventilator  1 , turbine solar chimney trombe  170 , off-grid thermal appliance  400 , integrated cooking, heating, and ventilation subsystem  530 , and/or integrated electrical subsystem  650  enables complete integration of family-scale thermal, water, power, and waste utility subsystems. 
         [0096]    The various systems and methods described herein enable survival and comfort as well as a developing world version of prosperity, by significantly reducing fuel and water expenses while enabling productive work at night and in bad weather. It enables such potentially transformative lifestyles via sustainable production that requires non-local, rare, or expensive materials only within the solar cell  715 , battery  725 , and generator  600 , while essentially all other components may be made from waste or recycled materials. These systems consume a small fraction of the fossil fuels or other flammable carbon resources that would otherwise be required, and limit total ongoing ecological impact of a family to extremely small carbon, global warming, and other footprints from combustion or any other sources. 
         [0097]    Having described and illustrated the principles of the preferred embodiments, it should be apparent that the embodiments may be modified in arrangement and detail without departing from such principles. Claim is made to all modifications and variation coming within the spirit and scope of the following claims: