Insulating air sheath for buildings and the like

Low grade heat is supplied to heat air which is used to provide an insulating sheath for a building or the like. The low grade heat is obtained from the ground below the hard frost line from either air or water, or from solar collectors, biomass or any other suitable source of such heat, and is used to heat air which is then circulated in a space within the walls of the building, thereby maintaining the internal temperature within the walls at approximately 45.degree.-65.degree. F. The air insulating sheath so provided reduces the driving force which takes heat out of the building in winter and which permits heat entry in summer. The energy required to bring the internal building temperature to a comfortable degree in winter or summer is thereby drastically reduced, as is the cost associated therewith.

BACKGROUND OF THE INVENTION 
This invention relates to a building structure wherein heated air is 
supplied to spaces located in the walls, below the floor and above the 
ceiling of the building to provide a sheath of heated air surrounding the 
internal, useable space within the structure. The air supplied to these 
spaces is heated using low grade heat obtained from the ground, from 
either air or water obtained from below the hard frost line, from solar 
collectors, from biomass or from any other available source of such heat. 
By definition, the term "low grade heat" as used herein denotes heat 
obtainable from various sources but at levels below the temperature needed 
for human comfort, i.e. below approximately 65.degree. F. The temperature 
below the hard frost line in northern regions of the United States remains 
substantially constant year round, at a low of approximately 45.degree. F. 
in northernmost states (except Alaska) to 50.degree.-55.degree. F. in the 
middle states. In southern regions which do not freeze, the ground 
temperature several feet below ground level remains constant year round at 
approximately 65.degree. F. The heat that is available from either air or 
water obtained from below ground at depths which do not vary in 
temperature year round is ideal as the source of low grade heat to be used 
in accordance with the principles of this invention. 
U.S. Pat. No. 4,089,142, discloses a building structure including a 
concrete slab which forms the building structure foundation which supports 
the building enclosure mounted thereon and is interposed between the 
building enclosure and the ground. Means are provided for thermally 
insulating the periphery of the slab from the ground, downwardly from the 
surface of the ground to at least the extent of the ground frost line and 
the placement of a series of edge abutting parallel rows of end-to-end 
abutting hollow cinder or concrete blocks, in axial alignment underlying 
the concrete slab and axially aligned in heat transfer relationship 
therewith and with the ground below the frost line. The hollow blocks form 
a series of parallel transverse air circulation paths and means are 
provided for communicating these air flow paths within said blocks to the 
interior of said building enclosure such that thermal radiation entering 
the building structure interior and impinging upon the building interior 
causes heat to be circulated by air flow through said parallel air flow 
paths within the cinder blocks and within the interior of said building 
blocks acting as a heat sink. 
The aforesaid patent discloses heating of the concrete slab by providing 
glass windows on the vertical walls of the building structure on the sides 
facing the sun to permit direct impingement of the sun on the upper 
surface of the concrete slab and building structure interior to thermally 
heat air flowing within the building structure by convection. 
U.S. Pat. No. 3,527,921 discloses a building structure provided with a 
peripheral foundation insulated to approximately the depth of minimal 
seasonal temperature variations. The floor of the building is a concrete 
slab and sand is provided below the slab with electric heating mats 
located in the sand aproximately one foot below the slab to permit storing 
heat energy in the sand and in the ground beneath so that electric power 
can be used to heat the building for substantial periods of time either to 
take advantage of off-peak power or to minimize the effects of electrical 
power failures. 
U.S. Pat. No. 3,965,694 discloses a system having the capability of being 
used as both a heating and cooling system. Therein, at least one heat pump 
is provided to pump heat from a heat source to the air conditioning system 
to prevent freezing of the system. The heat pump also removes heat from 
the system, when it is used as a cooling system, and diffuses it into the 
earth. The earth is also utilized as a source of heat to be supplied to 
the system. 
None of the known prior art references provides or suggests the building 
structure of this invention, namely a building structure in which the 
useable living space is substantially surrounded by an insulating sheath 
of air, said air maintained at a temperature in the approximate range of 
45.degree.-65.degree. F., said air being heated to this temperature range 
by a suitable source of low grade heat. 
SUMMARY OF THE INVENTION 
A building structure is provided comprising a foundation supporting a 
building having floor, sidewalls, ceiling and a roof and means for 
circulating air maintained in the temperature range of approximately 
45.degree.-65.degree. F. below and adjacent the floor, above and adjacent 
the ceiling, and within spaces in the walls, thereby providing an 
insulating sheath of air substantially surrounding the useable space 
within the building. 
Also provided is the method of insulating a building structure, the 
building structure having a foundation supporting a building having floor, 
sidewalls, ceiling and a roof, the method comprising circulating air 
maintained in the temperature range of 45.degree.-65.degree. F. below and 
adjacent the floor, above and adjacent the ceiling, and within spaces in 
the walls, thereby providing an insulating sheath of air substantially 
surrounding the building. The air is preferably heated to the temperature 
range by circulating it through the ground below the hard frost line at 
the location of the building structure. The air may be heated to the 
temperature range by heat exchange with water obtained from below the hard 
frost line at the location of the building structure, or by using solar 
collection devices, biomass degradation and the like.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS WITH 
REFERENCE TO THE DRAWINGS 
Low grade heat is supplied to heat air which is used to provide an 
insulating sheath for a building or the like. The low grade heat is 
obtained from the ground below the hard frost line from either air or 
water, or from solar collectors, biomass or any other suitable source of 
such heat, and is used to heat air which is then circulated in a space 
within the walls of the building, thereby maintaining the internal 
temperature within the walls at approximately 45.degree.-65.degree. F. The 
air insulating sheath so provided reduces the driving force which takes 
the heat out of the building in winter and which permits heat entry in 
summer. The energy required to bring the internal building temperature to 
a comfortable degree in winter or summer is thereby drastically reduced, 
as is the cost associated therewith. 
When older homes were built, batt insulation, designed to be installed 
between framing members, was non-existent. Builders then depended on the 
dead air space within wall cavities to act as an insulation or they 
specifically framed a design allowing natural convection within a wall to 
achieve air circulation, presumably to control moisture buildup, wood 
decay, and particularly for ventilation in the warm months. Air entry 
locations in the foundation of such homes could be blocked off in the cold 
months, thereby changing the free flow of ventilation air to a dead air 
gap for winter insulation. 
In the present invention, the foundation (above ground level) of the older 
building structure should be as air tight as possible as should the 
external walls and roof. An air circulator, which may be a fan, is used to 
force low-grade warm air into the crawl space or basement of the building, 
creating a low pressurization of the area. 
The warm air will cover the bottom of the floor and, because of the low 
pressurization, air will flow in an upward direction through the cavities 
within the walls and then into the attic space. The air may be collected 
via a duct and recirculated or discharged to the atmosphere. 
Warm air is continuously being replaced from the air distribution system at 
a rate equal to the amount of air dispersed into the attic, plus the 
fraction of additional air necessary to achieve the low pressurization. 
As the warm forced air makes its ascent upward within the wall cavities, a 
series of changes occur. While the forced air is rising within a wall 
cavity, eddy currents occur and air films can double, producing 4 films 
instead of 2 as is the case with dead air, thereby increasing its 
insulating capability. 
A detailed description of the invention is best provided by reference to 
the accompanying drawings of which FIG. 1 schematically illustrates the 
various features. Therein, building structure 2 is shown being supplied 
air from air ducts 16 which are supplied air from heat exchanger 12. The 
cavities in the walls of building structure 2 are omitted in FIG. 1 for 
convenience, but will be described in detail hereinbelow. The air supplied 
to building structure 2 is preferably obtained by circulating air through 
the underground air tubes 17 located well below the frost line at the 
given location. This air will have a temperature in the range of 
approximately 45.degree. F. to approximately 65.degree. F., depending on 
the latitude of the building. This air can be circulated using the air 
circulator 10, which may be a fan, directly to the building structure 
through supply line 16, or it may be routed through the heat exchanger 12, 
as shown. This air provides an insulating sheath about the building at a 
temperature of approximately 45.degree. F. to 65.degree. F., depending 
upon location. The details of providing the insulating air sheath about 
the building structure are described below in connection with the 
description of FIGS. 2 through 6. 
Other sources of low grade heat supply may be employed to heat the air 
needed to supply the insulating sheath. One method would be to use water 
obtained from one well below the frost line, pipe it through a water line 
18 shown in FIG. 1 to a heat exchange coil 14 which heats the air supplied 
to the structure, and discharge the water after use to a second well as 
shown. If this method is used, it is believed that the two wells should be 
located at least 50 feet apart to insure that the used water will return 
to the ground without adversely affecting the temperature or 
characteristics of water in the supply well. 
Alternatively, the air supply to the building structure could be heated by 
means of solar passive collectors located outside the building structure. 
The greenhouse shown in FIG. 1 is an example of a passive solar collector 
or by various biomass materials such as manure or compost placed in a pit 
into which is inserted an air heating exchange coil 22, also shown in FIG. 
1. 
Used air from the attic of building structure may be collected and 
recirculated to the heat exchanger 12 by means of return line 8 to aid in 
the overall efficiency of the system if necessary or desirable. 
FIG. 2 shows the foundation, wall structure, in part broken away, and roof 
of a building structure using the air insulating sheath of this invention 
for retrofitting of existing buildings which were built after World War II 
using Western platform type construction methods. Therein, heated (or 
cool) air is supplied from air supply line 16 to the open area below the 
flooring of the building structure and to the air distributor 6, which is 
preferably PVC piping in this type of construction. From the distributor 
6, air passes into ducts 4 extending through sole plate 40 and into the 
spaces between the studs 66 in the wall of the building, passing upwardly 
as indicated by the arrows between the exterior sheathing 42 and inside 
wall 48. If there is insulation 46 in the wall cavity, the air passes 
between the insulation and the exterior sheathing and inside wall. Air 
openings 64 are provided in the top plate 68 to permit the air to pass 
from the wall spaces into the attic opening 62, from whence it can be 
discharged or sent back to the air supply heat exchanger 12. 
Also shown in FIG. 2 are the building foundation 28, floor joists 24, 
subflooring 26, roof rafters 52, ceiling joists 56 and ceiling 58 of 
building structure 2. 
FIG. 3 shows the building structure in cross-section, wherein air enters 
the space below the flooring 26 and pressurizes the air within the 
foundation. As indicated by the arrow, air enters supply line 16 which 
feeds air distributor 6, and passes through air ducts 4 which, preferably, 
are 1-inch diameter flexible plastic pipe extending through openings in 
sole plate 40. The air discharges from ducts 4 into the space between 
exterior sheathing 42 and interior wall 48, passing upwardly as shown by 
the arrows. The air then passes through the openings 64 in the top plate 
68 and passes into the attic space 62. 
As thus described, air supplied at 45.degree. F. to 65.degree. F. surrounds 
the interior living space of the building structure and provides an 
insulating sheath or envelope around the building. 
For completeness, additional components of building structure 2 shown in 
FIG. 3 include footings 30, foundation blocks 28, anchor bolt 32, termite 
shield 34, sill 36, header 38, siding 44, wall insulation (if any) 46, 
soffit 50, roof rafter 52, roofing 54, ceiling joist 56, ceiling 58, 
ceiling insulation 60 and attic space 62. 
FIGS. 4-6 show an alternative embodiment for providing the air insulating 
sheath around a building according to this invention to be used 
principally on new construction. FIG. 4 shows a front elevational view, in 
part doubly broken away, of a construction wherein a space or gap is 
provided adjacent the exterior sheathing of the walls of the structure to 
provide a passageway for the insulating air. Air enters distributor 6 from 
duct 16 and passes sidwardly and upwardly as indicated by the arrows into 
the space or air channel 72 between the internal sheathing 42 and the 
exterior sheathing 70. This air passes upwardly between furring strips 76 
and passes into the attic through ducts 74 as shown, from whence it may be 
recirculated to circulator 10 (not shown). 
The side cross-sectional view of the building structure 2 shown in FIG. 5 
may provide a better understanding of the construction of this alternative 
embodiment. Air entering distributor 6 from supply line 16 passes into air 
channel 72 between interior sheathing 42 and exterior sheathing 70, and 
passes upwardly as shown by the arrows exiting through ducts 74 into attic 
space 62. 
Structural details of the building structure shown in FIGS. 4 and 5 are 
identical to those shown in FIGS. 2 and 3 for convenience of illustration. 
FIG. 6 shows a top view, partly in cross-section, of the wall shown in FIG. 
4 taken along the line 6--6 thereof. This figure shows the relative 
positioning of the interior wall 48, wall studs 66, interior sheathing 42, 
furring strips 76 and exterior sheathing 70, all to provide for air 
channel 72 through which the insulating air passes. 
While the invention has been disclosed herein in connection with certain 
embodiments and detailed descriptions, it will be clear to one skilled in 
the art that modifications or variations of such details can be made 
without deviating from the gist of this invention, and such modifications 
or variations are considered to be within the scope of the claims 
hereinbelow.