Patent Publication Number: US-2015083113-A1

Title: Construction Compromising A Building And An Installation With Solar Heat Storage

Description:
TECHNICAL AREA OF THE INVENTION 
     The current invention relates to a building installation comprising a building comprising a slab or a cellar floor placed in contact with a piece of earth or an air cavity under the building. A fluid hose is placed in the piece of earth under the slab or cellar floor and comprises an earth circuit fluid, which is thermally coupled to a fluid circulation circuit in or by the building such that the earth circuit fluid receives heat from a heated solar collector fluid. The earth circuit fluid circulates in the fluid hose during release of heat energy to the surrounding piece of earth. 
     BACKGROUND FOR THE INVENTION 
     Climate adaptation and the desire to be independent of fossil fuels, together with higher standards to improvements in the indoor climate and a lower energy consumption, will require massive energy renovations of the existing building stock. New construction today comprises typically 0-1% of the existing building stock, where energy renovation is estimated to have a large future potential in the construction business as well as in the reduction of global energy consumption. 
     Due to climate changes and the popular desire to make energy supply independent of fossil fuels, together with a higher standard to improvements in indoor climates and reduction of energy consumption, requires a massive energy renovation of the existing building stock. New construction typically makes up 0-1% of the existing building stock, which is why energy renovation is found to have a large future potential in the construction business. 
     The invention provides a new and profitable way of minimizing heat loss through the slab/cellar floor, often named the sixth facade, in connection with energy renovation or in connection with new construction. The solution of this problem makes up an important prerequisite to reduce heating expenses, the global climate load and energy consumption in buildings which for example use fossil fuels for heating or production of warm water. 
     In order to minimize the heat loss through the slab with known techniques, one has to for example break up the entire floor inside the building, to establish, for example 300 mm insulation and new flooring, in order to maintain the height in the room. This is an expensive and very disruptive solution for the user of the building. In addition, such a known technology often requires a complicated and expensive underpinning of foundations under outer and inner walls with sectional underpinning. Excavating and underpinning are one of the most risky operations on existing buildings, since it often results in subsidence damages and can in the worst case result in collapse. In buildings the lowest floor has a high ceiling height, insulation can be built on top of the existing flooring. This often results in a technical moisture risk and is expensive since door heights, paneling, etc need to be adapted. 
     By using the current invention to raise the temperature in the earth underneath the building by storage of solar heat energy and thereby minimizing the heat loss through the slab or cellar floor, the users of the building can be undisturbed. In addition, the current invention is much more profitable than traditional methods just as well as project risk are very small. 
     GENERAL DESCRIPTION OF THE INVENTION 
     A first aspect of the invention relates to a building installation comprising a building comprising a slab or cellar floor placed in contact with a piece of earth under the building. A solar collector is mounted on or by the building and adapted to heat a through flowing solar collector fluid. A fluid circulation circuit in or by the building is arranged to circulate the solar collector fluid. A fluid hose is placed in the piece of earth under the slab or cellar floor and an edge insulation is placed by the building foundation completely or partly surrounding the piece of earth with the fluid hose. Finally an earth circuit fluid in the fluid hose is thermally coupled to the fluid circulation circuit in the building such that the earth circuit fluid receives heat from the heated solar collector fluid for circulation in the fluid hose during release of heat energy to the surrounding piece of earth. 
     The contact between the slab or cellar floor and the piece of earth under the building can comprise a direct physical contact or the contact can be indirect via a sandwiched layer of air, which can for example be provided via a crawl space. Such a sandwiched layer of air preferably has a height less than 1 meter, for example less than 50 cm. 
     The solar collector can for example be mounted on a building part, such as a roof construction or an outer wall of the building. Alternatively, the solar collector can be placed at a predefined distance from the building and the solar collector fluid can be conducted to and from the solar collector via a partly externally placed fluid circulation circuit. In an external placement of the solar collector, the solar collector is preferably placed at a distance which is less than 300 m from the building in order to reduce heat loss from the fluid circulation circuit. The external placement can for example be used if the solar collector makes up a part of a larger solar collector park or is placed away from the building for other reasons. 
     The thermal coupling between the earth circuit fluid in the fluid hose and the solar collector fluid in the fluid circulation circuit can for example be provided by a heat exchanger. 
     The provided building installation and method for heating of a piece of earth lying under a slab or cellar floor of an existing building is inexpensive and therefore profitable. Furthermore, the finished building installation and method are connected with a low risk when compared with alternative methods for after insulation of slabs or cellar floors. This is attributed due to, amongst others, that the provided building installation can be provided using technologies which each are well proven. The same is true for the below described method for heating of a piece of earth lying under a slab or cellar floor of an existing building accord to a second aspect of the invention. 
     An effective edge insulation of the building can furthermore secure that the solar heat is stored for a longer time under the building so the heat loss through an existing floor construction is reduced as a consequence of the minimized temperature difference between the heater building and the piece of earth under the building. 
     The current invention is also advantageous because storage in the large and free earth body or piece of earth under the building, possibly in combination with traditional heating of water, gives a higher security than normal against boiling in the solar collector, amongst others in periods with low consumption of hot water. Finally the solar collector during low temperature operation is ensured a high performance, and can therefore produce heat also in periods with heavy cloud cover. Use of heat storage under the building is characterized in that heat loss through the slab is minimized significantly in an inexpensive and effective manner which doesn&#39;t disturb the users of the building. Use of storage in earth bodies under buildings ensures a free and large heat storage, which can contain significant energy amounts, for evening out the energy storage from sunny to not so sunny periods. 
     According to a preferred embodiment of the invention, segments of the fluid hose are placed outside the building foundation. This can be advantageous if the fluid hose is lead under the building&#39;s slab or cellar via directional drilling performed in a straight line. This often demands a connection along the building&#39;s two facing facades. This embodiment can be improved further in many installations in that the segments of the fluid hose which are placed outside the building&#39;s foundation are covered, or surrounded, by a thermal insulating material. This reduces the heat loss from the fluid hose and its surrounding earth. 
     According to another preferred embodiment of the invention, the fluid circulation circuit comprises a temperature controlling means or an organ arranged to provide a feed temperature of between 20 and 60 degrees Celsius (C), preferably between 25-40° C., for the earth circuit fluid in the fluid hose. This temperature controlling means or organ can for example comprise a mixing valve. Another embodiment of the current building installation comprises a buffer tank connected to the fluid circulation circuit which is dimensioned to contain between 300 liters and 5000 liters of solar collector fluid. In this way, heat energy produced by the solar collector on sunny days can be saved and be used to heat up the earth circuit fluid in the fluid hose on cooler or not so sunny days and nights. 
     The person skilled in the art will understand that the current building installation can be used to limit the heat loss from a long list of different types of buildings with the need for heating, such as houses, multistory buildings, factories, office buildings, warehouses, etc. 
     A second aspect of the invention relates to a method of heating a piece of earth located under a slab or cellar floor of an existing building. This method comprises the steps:
     laying a fluid hose under the building&#39;s slab or cellar floor with the help of directional drilling,   heating a solar collector fluid in a fluid circulation circuit placed in or by the building with the help of a solar collector mounted on or by the building,   transferring heat energy from the solar collector fluid to an earth circuit fluid in the fluid hose via thermal coupling such that the earth circuit fluid releases heat energy to the surrounding piece of earth. This method can be used to establish solar heat based heating of pieces of earth located under already existing buildings with the previously mentioned advantages.   

     According to a preferred embodiment, the method comprises an addition step of providing en edge insulation by the building&#39;s foundation which completely or partially surrounds the piece of earth with the fluid hose. 
    
    
     
       DESCRIPTION OF THE FIGURE 
         FIG. 1  shows a house placed above a piece of earth with drilled fluid hoses according to a preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     The house  100  comprises a solar collector  1  set up on the roof of the house, for example on a frame. For optimal utilization of the suns energy, the solar collector  1  is preferably placed facing south. The house  100  comprises a facade  15  covered with an ordinary insulating climate shield  8 . A heat carrying solar collector fluid is pumped around in a fluid circulation circuit which comprises internal pipes  2 , 7  which respectively conduct the solar collector fluid to and from the solar collector  1 . This heat carrying solar collector fluid is heated in the solar collector  1  according to well known principles and is conducted back to the fluid circulation circuit through the internal pipe  2 . The heat carrying fluid can for example consist of water in this embodiment of the invention, but could alternatively be water mixed with a fitting percentage of an anti freeze component, such as alcohol, glycol, etc. The fluid circulation circuit will normally also comprise a buffer tank  4  which can store a predetermined volume of heated solar collector fluid for example between 300 liters and 5000 liters. A mixing valve  13  controls the feed temperature on a heat carrying earth circuit fluid such that its temperature is adapted to the actual installation. Finally the fluid circulation circuit comprises a hot water tank  3  and pipe connections  10 , 11 , 12  to provide hot, colt and hot circulation water to the house  100 . The heated solar collector fluid is lead from the solar collector to the buffer tank  4 . A heat exchanger is provided in connection with the buffer tank  4  such that the heat energy from the heated solar collector fluid is transferred to the earth circuit fluid which circulates in a separate earth circuit comprising one or more fluid hoses  5 . In this described embodiment the earth circuit fluid comprises water and this is led through the mixing valve  13  and down under the house&#39;s slab  17  and through the above mentioned fluid hoses  5 . The fluid hoses  5  are drilled down under the house&#39;s slab  17  with the help of directional drilling. In other embodiments of the invention, where a building is constructed as a new construction, the fluid hoses  5  can be placed under the slab or cellar without the use of drilling for example by placing these in fittingly formed grooves in a piece of earth under the building. In these embodiments, the fluid hoses  5  are arranged completely within the building&#39;s foundation. 
     As illustrated in  FIG. 1 , certain hose segments  6  of the fluid hoses  5  extend past the house&#39;s foundation  16  and its abutting edge insulation  9 . Leading the hose segments outside the buildings foundation  16  in the current embodiment occurs since the leading from the directional drilling performed in a straight line typically demands connection between the house&#39;s two opposing facades. These hose segments  6  are preferably thermally insulated in the horizontal plane, in other words parallel with the illustrated earth surface  14  out towards the piece of earth in order to minimize the heat loss from these hose segments  6 . The fluid hoses  5  can for example comprise one or more stiff plastic pipes for example PE and/or one or more steel pipes. The fluid hoses  5  are with their location in the piece of earth under the house&#39;s slab  17  well protected against frost, whereby in many embodiment of the invention, it is not required to add anti-freeze to the water which circulates in the fluid hoses  5 . The mixing valve  13  ensures as previously mentioned a fitting feed temperature for the heated water which circulates under the house through the fluid hoses  5 . This feed temperature can advantageously be between 25-40° C. such that both a heating of the piece of earth around the fluid hoses  5  is ensured and a cooling of the solar collector  1  is ensured. The return temperature for the heated fluid in the fluid hoses  5  can be between 20-35 C for the above mentioned temperature range of the feed temperature.