U.S. patent application number 12/114774 was filed with the patent office on 2009-11-05 for energy efficient building.
This patent application is currently assigned to SKIDMORE OWINGS & MERRILL LLP. Invention is credited to William F. Baker, JR., Christopher B. Cooper, Roger Eugene Frechette, III, NIcholas Holt.
Application Number | 20090275279 12/114774 |
Document ID | / |
Family ID | 41257411 |
Filed Date | 2009-11-05 |
United States Patent
Application |
20090275279 |
Kind Code |
A1 |
Holt; NIcholas ; et
al. |
November 5, 2009 |
ENERGY EFFICIENT BUILDING
Abstract
A solar engine, which is vertically aligned along an interior
portion of a building, is heated by solar radiation. The solar
engine includes a warm air chamber at an upper portion of the solar
engine and a hollow core positioned below the warm air chamber.
Habitable spaces are positioned around the outside of the core
toward an exterior of the building. Solar radiation on the warm air
chamber creates a high temperature zone in the warm air chamber
that induces a stack effect in which air rises through the core due
to the lower temperatures in the core, and results in a negative
pressure in the core. Air enters at a lower portion of the building
and is pulled through the core by the solar engine. If the windows
on the outside of the habitable spaces are opened, the negative
pressure in the core causes passive cross ventilation from the
outside of the building through the habitable spaces and into the
core, where the air rises to the warm air chamber and then out of
the building. This allows the habitable spaces to be naturally
cooled and ventilated with no energy costs. Solar radiation may be
directed into the warm air chamber and core using a reflector at
the top of the building. One or more wind turbines and generators
positioned around the top of the core convert the moving air from
the core into electrical energy to power the building.
Inventors: |
Holt; NIcholas; (NEW YORK,
NY) ; Cooper; Christopher B.; (Brooklyn, NY) ;
Frechette, III; Roger Eugene; (Lake Forest, IL) ;
Baker, JR.; William F.; (Evanston, IL) |
Correspondence
Address: |
SONNENSCHEIN NATH & ROSENTHAL LLP
P.O. BOX 061080, WACKER DRIVE STATION, WILLIS TOWER
CHICAGO
IL
60606-1080
US
|
Assignee: |
SKIDMORE OWINGS & MERRILL
LLP
New York
NY
|
Family ID: |
41257411 |
Appl. No.: |
12/114774 |
Filed: |
May 4, 2008 |
Current U.S.
Class: |
454/237 |
Current CPC
Class: |
Y02A 30/00 20180101;
Y02A 30/272 20180101; Y02B 10/30 20130101; F24F 5/0075 20130101;
Y02B 10/70 20130101; F24S 20/66 20180501; Y02B 30/90 20130101; F24F
2005/0064 20130101; F03G 6/045 20130101; Y02E 10/46 20130101; F05B
2240/911 20130101; Y02B 10/20 20130101 |
Class at
Publication: |
454/237 |
International
Class: |
F24F 7/00 20060101
F24F007/00 |
Claims
1. A building ventilation system comprising: a warm air chamber
located in an upper portion of a building, the warm air chamber
having a warm air chamber inlet at a bottom portion of the warm air
chamber and a warm air chamber outlet at a top portion of the warm
air chamber, at least a portion of the top of the warm air chamber
comprising a transparent material, air in the warm air chamber
being heated by solar radiation radiating on the air via the
transparent material; and a hollow core extending vertically down
from the warm air chamber inlet along an interior portion of the
building, at least a portion of a side wall of the core being
defined by an interior wall of a habitable space, the core having a
first core opening coupled to an outside air duct that extends to
an outer portion of the building and having a second core opening
coupled to the habitable space via the interior wall of the
habitable space, the air in the core being a lower temperature than
the air in the warm air chamber and therefore the air in the core
rising toward and through the warm air chamber inlet creating a
negative pressure in the core relative to a pressure outside the
building and effecting a suction of outside air from outside the
building through the outside air duct and into the core, the air
from the core that rises into the warm air chamber mixing with the
air in the warm air chamber and at least a portion of the mixed air
exiting the warm air chamber through the warm air chamber
outlet.
2. A building ventilation system as claimed in claim 1, wherein the
negative pressure in the core relative to the pressure outside the
building effects a suction of outside air from outside the building
through the habitable chamber and into the core via the second core
opening.
3. A building ventilation system as claimed in claim 1, wherein a
portion of the air in the core enters the habitable chamber via the
second core opening to provide one of ventilation and heated air to
the habitable chamber.
4. A building ventilation system as claimed in claim 1, further
comprising: a reflector located at the top of the building, the
reflector reflecting solar radiation into the warm air chamber, the
solar radiation reflected into the warm air chamber by the
reflector increasing the temperature of the air in the warm air
chamber.
5. A building ventilation system as claimed in claim 4, wherein the
reflector reflects solar radiation into the core, the solar
radiation reflected into the core by the reflector increasing the
temperature of the air in the core.
6. A building ventilation system as claimed in claim 4, wherein the
warm air chamber comprises a warm air chamber reflector that
reflects solar radiation onto the reflector.
7. A building ventilation system as claimed in claim 1, further
comprising: at least one wind turbine located at the warm air
chamber inlet, the wind turbine having an axle that is horizontally
aligned along the warm air chamber inlet and having at least one
blade that rotates with the axle when air from the core contacts
the blade on its way into the warm air chamber; and a generator
that is mechanically coupled to the axle, the generator converting
mechanical energy from the rotating axle into electrical energy
that powers the building.
8. A building ventilation system as claimed in claim 1, wherein at
least a portion of the side wall of the core comprises a reflective
surface that reflects solar radiation down into the core.
9. A method for ventilating a building, the method comprising the
steps of: heating air in a warm air chamber, which is located in an
upper portion of a building, using solar radiation that radiates
through a transparent top of the warm air chamber, the warm air
chamber having a warm air chamber inlet at a bottom portion of the
warm air chamber and a warm air chamber outlet at a top portion of
the warm air chamber, a hollow core extending vertically down from
the warm air chamber inlet along an interior portion of the
building, at least a portion of a side wall of the core being
defined by an interior wall of a habitable space, the core having a
first core opening and a second core opening that is coupled to the
habitable space via the interior wall of the habitable space; and
providing an outside air duct having a first end that extends to an
outer portion of the building and a second end that is coupled to
the first core opening, the air in the core being a lower
temperature than the air in the warm air chamber and therefore the
air in the core rising toward and through the warm air chamber
inlet creating a negative pressure in the core relative to a
pressure outside the building and effecting a suction of outside
air from outside the building through the outside air duct and into
the core.
10. The method of claim 9, wherein the negative pressure in the
core relative to the pressure outside the building effects a
suction of outside air from outside the building through the
habitable chamber and into the core via the second core
opening.
11. The method of claim 9, wherein a portion of the air in the core
enters the habitable chamber via the second core opening to provide
one of ventilation and heated air to the habitable chamber.
12. The method of claim 9, wherein a reflector located at the top
of the building reflects solar radiation into the warm air chamber,
the solar radiation reflected into the warm air chamber by the
reflector increasing the temperature of the air in the warm air
chamber.
13. The method of claim 12, wherein the reflector reflects solar
radiation into the core, the solar radiation reflected into the
core by the reflector increasing the temperature of the air in the
core.
14. The method of claim 12, wherein the warm air chamber comprises
a warm air chamber reflector that reflects solar radiation onto the
reflector.
15. The method of claim 9, further comprising the step of:
generating electricity by: providing at least one wind turbine
located at the warm air chamber inlet, the wind turbine having an
axle that is horizontally aligned along the warm air chamber inlet
and having at least one blade that rotates with the axle when air
from the core contacts the blade on its way into the warm air
chamber; and providing a generator that is mechanically coupled to
the axle, the generator converting mechanical energy from the
rotating axle into electrical energy that powers the building.
16. The method of claim 9, wherein at least a portion of the side
wall of the core comprises a reflective surface that reflects solar
radiation down into the core.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to building energy
systems, and more particularly to controlling ventilation and
temperature and generating power in buildings using the stack
effect.
BACKGROUND OF THE INVENTION
[0002] Conventional building designs rely on powered
building-mechanical systems to bring ventilation into habitable
spaces from the outside of the building. These conventional designs
typically include powered louvers positioned on the outer surfaces
of the building that open to allow air to enter the habitable
spaces for ventilation, heating, and cooling. Typically, powered
fans draw the outside air through the louvers and into the
habitable spaces, and then expel the air from the habitable spaces
to the outside of the building. This conventional approach requires
large energy consumption to drive the louvers and power the fans. A
need exists for improved energy efficiency in buildings.
SUMMARY OF THE INVENTION
[0003] Methods and systems consistent with the present invention
improve building energy efficiency. A solar engine, which is
vertically aligned along an interior portion of a building, is
heated by solar radiation. The solar engine includes a warm air
chamber at an upper portion of the solar engine and a hollow core
or void positioned below the warm air chamber. Habitable spaces are
positioned around the outside of the core toward an exterior of the
building. Solar radiation on the warm air chamber creates a high
temperature zone in the warm air chamber. This creates a stack
effect in which air rises through the core due to the lower
temperatures in the core, and results in a negative pressure in the
core. Air enters at a lower portion of the building and is pulled
through the core by the solar engine. If the windows on the outside
of the habitable spaces are opened, the negative pressure in the
core causes passive cross ventilation from the outside of the
building through the habitable spaces and into the core, where the
air rises to the warm air chamber and then out of the building.
This allows the habitable spaces to be naturally cooled and
ventilated with no energy costs.
[0004] The habitable spaces may also be ventilated by drawing air
out from the core and into the habitable spaces. In this case,
mechanical units in the habitable spaces draw air, which is moving
upward through the core, into the habitable spaces. The air from
the core ventilates the habitable spaces and is expelled to the
exterior of the building. Habitable spaces in a lower portion of
the building may generate high internal loads and may require
cooling in the interior zones. As air passes through the core along
the interior surfaces of the habitable spaces it is preheated by
energy transfer with the surrounding conditioned space. The
preconditioning of the air by drawing it through the core as
opposed to the exterior of the building saves considerable heating
energy. Further, air from the core provides more consistent
ventilation compared to air brought in through louvers located
outside the building, which are susceptible to changing wind
conditions and often cannot pull in air since the suction forces of
the wind may outweigh the external static pressure of the louver
fan.
[0005] The stack effect may be enhanced by providing one or more
solar reflectors in the warm air chamber. Solar radiation reflects
from the solar reflector down into the warm air chamber and core.
The solar radiation may be directed farther down into the core
through the use of additional reflector or reflective surfaces
within the core. The introduction of solar energy into the core
further heats the air in the core, resulting in a higher air
velocity through the solar engine and enhancing the stack effect.
The introduction of light into the core may also beneficially
illuminate the interior portions of the habitable spaces located
around the core. This allows for reduced energy consumption for
illuminating the habitable spaces.
[0006] Further, one or more wind turbines positioned in the solar
engine may be used to convert the wind energy of the air moving
upward through the solar engine into electricity to power the
building. Thus, methods and systems consistent with the present
invention reduce the amount of energy required to ventilate a
building and also generate electricity that may be used to power
the building.
[0007] In accordance with systems consistent with the present
invention, a building ventilation system is provided. The building
ventilation comprises:
[0008] a warm air chamber located in an upper portion of a
building, the warm air chamber having a warm air chamber inlet at a
bottom portion of the warm air chamber and a warm air chamber
outlet at a top portion of the warm air chamber, at least a portion
of the top of the warm air chamber comprising a transparent
material, air in the warm air chamber being heated by solar
radiation radiating on the air via the transparent material;
and
[0009] a hollow core extending vertically down from the warm air
chamber inlet along an interior portion of the building, at least a
portion of a side wall of the core being defined by an interior
wall of a habitable space, the core having a first core opening
coupled to an outside air duct that extends to an outer portion of
the building and having a second core opening coupled to the
habitable space via the interior wall of the habitable space, the
air in the core being a lower temperature than the air in the warm
air chamber and therefore the air in the core rising toward and
through the warm air chamber inlet creating a negative pressure in
the core relative to a pressure outside the building and effecting
a suction of outside air from outside the building through the
outside air duct and into the core, the air from the core that
rises into the warm air chamber mixing with the air in the warm air
chamber and at least a portion of the mixed air exiting the warm
air chamber through the warm air chamber outlet.
[0010] In accordance with methods consistent with the present
invention, a method for ventilating a building is provided. The
method comprises the steps of:
[0011] heating air in a warm air chamber, which is located in an
upper portion of a building, using solar radiation that radiates
through a transparent top of the warm air chamber, the warm air
chamber having a warm air chamber inlet at a bottom portion of the
warm air chamber and a warm air chamber outlet at a top portion of
the warm air chamber, a hollow core extending vertically down from
the warm air chamber inlet along an interior portion of the
building, at least a portion of a side wall of the core being
defined by an interior wall of a habitable space, the core having a
first core opening and a second core opening that is coupled to the
habitable space via the interior wall of the habitable space;
and
[0012] providing an outside air duct having a first end that
extends to an outer portion of the building and a second end that
is coupled to the first core opening, the air in the core being a
lower temperature than the air in the warm air chamber and
therefore the air in the core rising toward and through the warm
air chamber inlet creating a negative pressure in the core relative
to a pressure outside the building and effecting a suction of
outside air from outside the building through the outside air duct
and into the core.
[0013] Other systems, methods, features, and advantages of the
invention will become apparent to one with skill in the art upon
examination of the following figures and detailed description. It
is intended that all such additional systems, methods, features,
and advantages be included within this description, be within the
scope of the invention, and be protected by the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate an
implementation of the invention and, together with the description,
serve to explain the advantages and principles of the invention. In
the drawings,
[0015] FIG. 1 is a cross-sectional view of a building consistent
with the present invention;
[0016] FIG. 2 is a top cross-sectional view of the core;
[0017] FIG. 3 is a functional cross-sectional view of the building
showing air flow through the solar engine using the stack
effect;
[0018] FIG. 4 is a cross-sectional side view of a conventional
habitable space;
[0019] FIG. 5 is a cross-sectional side view of a habitable space
consistent with the present invention;
[0020] FIG. 6 is a cross-sectional view of the building with a
reflector;
[0021] FIG. 7 is a cross-sectional view of the building with an
alternative reflector;
[0022] FIG. 8 is a cross-sectional view of the building with wind
turbines at the top of the core; and
[0023] FIG. 9 is a cross-sectional top view of the core with wind
turbines around the top of the core.
DETAILED DESCRIPTION
[0024] Reference will now be made in detail to an implementation
consistent with the present invention as illustrated in the
accompanying drawings. Wherever possible, the same reference
numbers will be used throughout the drawings and the following
description to refer to the same or like parts.
[0025] Methods and systems consistent with the present invention
improve building energy efficiency. FIG. 1 is a vertical
cross-sectional view of an illustrative building 100 consistent
with the present invention. The illustrative building comprises a
plurality of floors 1-n of habitable spaces 102 in a lower portion
of the building and a crown 104 at an upper portion of the
building. The habitable spaces 102 are positioned around an
exterior portion of the building. The interior walls 106 of the
habitable spaces 102 form the outer boundary of a core 108 or open
space at an interior portion of the building. In the illustrative
example, the core is an atrium that extends the height of the
habitable spaces. Although the core is shown in the illustrative
example as extending along the entire height of the habitable
spaces, the core may alternatively stop short of the lower
floors.
[0026] Referring to FIG. 2, the illustrative building 100 has a
circular cross section. However, the building is not limited to
this configuration. The building may alternatively have another
cross-sectional shape, such as square, rectangular, and the like,
and may have different cross-sectional shapes at various points
along the height of the building. Further, although the
illustrative core 108 has a circular cross section and is located
at the center of the illustrative building, the core may have a
cross-section of any shape or position within the building.
[0027] Conventional building designs rely on powered
building-mechanical systems to bring ventilation into habitable
spaces from the outside of the building. These conventional designs
typically include powered louvers positioned on the outer surfaces
of the building that open to allow air to enter the habitable
spaces for ventilation, heating, and cooling. Typically, powered
fans draw the outside air through the louvers and into the
habitable spaces, and then expel the air from the habitable spaces
to the outside of the building. This conventional approach requires
large energy consumption to drive the louvers and power the fans.
Methods and systems consistent with the present invention reduce
energy consumption by providing a solar engine within the building
that effects natural ventilation through the habitable spaces.
[0028] Referring to FIG. 3, the connected spaces of the crown 104
and the core 108 form a solar engine 302. The illustrative solar
engine is depicted in solid lines. In the illustrative example, the
crown has a width that is greater than the width of the core. Thus,
air enters the crown from the core through a via at the base of the
crown. At least a portion of a roof 304 of the crown comprises
transparent material, such as glass, plastic, and the like. Solar
radiation 306 heats the roof of the crown and enters the crown
through the transparent material, which heats the air within the
crown, forming a high temperature zone relative to the core. Thus,
the crown is referred to herein as a warm air chamber 308.
[0029] The air in the warm air chamber 308 is warmer than the air
in the core. Further, the air in an upper portion of the core is
warmer than air in a lower portion of the core due to solar
radiation illuminating the air in the upper portion of the core.
This causes the air to rise toward the top of the core and into the
warm air chamber, creating a negative pressure in the core. This
negative pressure in the core results in a stack effect in which
air 310 from outside the building is suctioned through ventilation
shafts and may be suctioned through windows, through the habitable
spaces, into the core. As long as the air in the core is warmer
than the outside air, the stack effect is maintained.
[0030] The outside air enters the building through outer
ventilation openings 312 and may also enter the building through
open windows 314 in the habitable spaces 102. The negative pressure
in the core draws the outside air through the outer ventilation
openings 312 and then through inner ventilation openings 316 into
the core. The negative pressure may also draw outside air through
one or more windows 314 and then through inner ventilation openings
316 into the core. The inner ventilation openings may be, for
example, interior window openings, vias, ventilation shaft
openings, voids in walls, doorways, and the like. One having skill
in the art will appreciate that the windows can be any suitable
opening, such as but not limited to exterior window openings, vias,
ventilation shaft openings, voids in an exterior wall, doorways,
and the like. In the illustrative embodiment, the windows are
closable, however, they may alternatively be permanently open. Air
enters at a lower portion of the building and is pulled up through
the core by the negative pressure in the core. Warm air is expelled
from the crown via one or more exhaust openings 318 in the crown.
The exhaust openings may be located in an exterior side wall of the
crown, in the roof of the crown, or both.
[0031] In the illustrative example, the outer ventilation openings
312, inner ventilation openings 316, windows 314, and exhaust
openings 318 may be any size suitable for effecting air flow from
the outside of the building into the core. The outer ventilation
openings 312, inner ventilation openings 316, windows 314, and
exhaust openings 318 may have a height and width greater than 0 m.
In an experiment, when the outer ventilation openings 312 are 6.0 m
high and the exhaust openings are 3.0 m wide, the average wind
speed at the top of the core is 7.0 m/s in the transitional season
and 7.5 m/s in the winter season. During the transitional season,
the ambient air was 17.degree. C., the building external surface
was 20.degree. C., the core surface was 27.degree. C., the crown
internal surface was 45.degree. C., and the building rooftop was
40.degree. C. It was found that the air inside the core averaged
between 18.degree. C. and 20.degree. C., which was 1 to 3.degree.
C. warmer than the outside air temperature. The air temperature in
the building crown was an even higher temperature, from 20 to
23.degree. C. or higher than the ambient air temperature. During
the winter season, the ambient air was 1.degree. C., the building
external surface was 5.degree. C., the core surface was 14.degree.
C., the crown internal surface was 25.degree. C., and the building
rooftop was 20.degree. C. As air moved up the core, it was found
that the air temperature in the core increased by more than
2.degree. C. when it reached the top of the core. After the air
enters the warm air chamber, the temperature was further increased
by another 1 to 2.degree. C. During the winter season, outside air
was suctioned into the outer ventilation openings 312 at a speed of
around 3.5 m/s. As the air was warmed up by the core wall surface
it flowed upward toward the top of the core and entered the warm
air chamber with a peak velocity of 9.0 m/s.
[0032] Through experimentation and modeling, the inventors have
discovered that the air temperature in the crown can be increased
when certain materials are used in the external walls of the crown.
For example, in an experiment, when the crown walls were normal
double panel glazing, the outer panel had a reflectance of 0.08 and
an absorptance of 0.16, and the inner panel had a reflectance of
0.08 and an absorptance of 0.16. When absorptive inner panel
glazing was used, the outer panel had a reflectance of 0.08 and an
absorptance of 0.16, and the inner panel had a reflectance of 0.08
and an absorptance of 0.41. When the absorptive inner panel glazing
had a low-e coating (such as a low-e value of 0.20), the outer
panel had a reflectance of 0.08 and an absorptance of 0.16, and the
inner panel had a reflectance of 0.08 and an absorptance of
0.41.
[0033] In the experiment, it was discovered that the normal double
panel glazing had a surface temperature of around 36.degree. C.
during peak sunlight hours, the absorptive inner panel glazing had
a surface temperature of around 43.degree. C. during peak sunlight
hours, and the absorptive inner panel glazing with a low-e coating
had a surface temperature of around 44.degree. C. Thus, absorptive
internal panel glazing at the crown with a low-e coating provided
increased temperatures in the crown.
[0034] Further, the temperature within the crown may be further
increased by providing internal surfaces in the crown that have a
dark color, such as black. In an experiment, it was discovered that
when normal double panel glazing was used on the crown and when an
internal vertical black cylinder was located at a central portion
of the crown, the outer panel had a reflectance of 0.08 and an
absorptance of 0.16 and a surface emissivity of 0.90; the inner
panel had a reflectance of 0.08 and an absorptance of 0.16 and a
surface emissivity of 0.90; and the inner cylinder surface had a
reflectance of 0.10 and an absorptance of 0.90 and a surface
emissivity of 0.90. In this experiment, the normal double panel
glazing had a surface temperature of around 36.degree. C. during
peak sunlight hours and the internal black cylinder had a surface
temperature of around 42.degree. C.
[0035] When absorptive internal panel glazing was used with an
internal black cylinder in the core, the outer panel had a
reflectance of 0.08 and an absorptance of 0.16 and a surface
emissivity of 0.90; the inner panel had a reflectance of 0.08 and
an absorptance of 0.41 and a surface emissivity of 0.90; and the
inner cylinder surface had a reflectance of 0.10 and an absorptance
of 0.90 and a surface emissivity of 0.90. In this experiment, the
absorptive internal panel glazing had a surface temperature of
around 40.degree. C. during peak sunlight hours and the internal
black cylinder had a surface temperature of around 42.degree.
C.
[0036] Thus, absorptive internal panel glazing, particularly with a
low-e coating, and one or more internal black surfaces, such as
internal cylinders, in the crown provide greater air temperatures
within the warm air chamber, which enhances the stack effect and
air movement through the core.
[0037] In the illustrative example, at least a portion of the
interior walls 106 of the habitable spaces comprise a reflective
surface on their side that faces the core. Thus, solar radiation
that enters the core is reflected off the reflective surface and
downward toward a lower portion of the core. This enhances the
stack effect by heating the air in the lower portion of the core.
The reflective surface may comprise any suitable material that
reflects solar radiation, such as but not limited to at least one
of glass, plastic, metal, a painted surface, and the like.
[0038] FIG. 4 is a cross-sectional view of a conventional habitable
space 402. In accordance with conventional ventilation practices,
ventilation and comfort control is provided to the conventional
habitable space 402 through the use of a circulation fan 404, a
mechanical ventilation system 406, or floor heating system 412. The
mechanical ventilation system 406 includes air ducts that couple to
a powered heating, ventilation, and air conditioning unit (not
pictured). A person in the conventional habitable space 402 turns
on the circulation fan 404 or the mechanical ventilation system 406
using a control actuator 410, such as a wall switch or thermostat
operator. When the circulation fan 404 or mechanical ventilation
system 406 turns on, the room air is circulated. The mechanical
ventilation system 406 may also provide heated or conditioned air
to the room. The heating system 412 in the floor 414 may also be
turned on to heat the room. Thus, the conventional habitable space
402 requires energy to be consumed to operate the circulation fan
404, mechanical ventilation system 406, and floor heating system
412 in order to ventilate, heat, and cool the room. Outside air may
enter the conventional habitable space 402 through a window 408.
However, unlike methods and systems consistent with the present
invention, air is not introduced into or extracted from the
conventional habitable space 402 using a solar engine.
[0039] In accordance with methods and systems consistent with the
present invention, the stack effect induced in the core
beneficially provides natural ventilation through the habitable
spaces. This allows the habitable space to be naturally ventilated,
cooled, and heated with reduced or no energy costs. FIG. 5 is a
cross-sectional view of an illustrative habitable space 102
consistent with the present invention. The habitable space 102
includes a window 314 located at an exterior side of the building
and an inner ventilation opening 316 that forms a via into the
core. When the window 314 on the outside of the habitable space is
opened, the negative pressure in the core causes passive cross
ventilation of air 310 from the outside of the building through the
habitable space and into the core, where the air rises to the warm
air chamber and then out of the building. This allows the habitable
space to be naturally cooled and ventilated with no energy
costs.
[0040] The ventilation and comfort controls in the habitable space
102 may be supplemented, for example, by a circulation fan 502,
mechanical ventilation system 504, and floor heating system 506
located under a floor 508. Alternative or additional ventilation
and comfort control systems may be used. For example, a person in
the habitable space 102 may use a control operator 510 to turn on
at least one of the circulation fan 502 or the mechanical
ventilation system 504 to further cool the air in the room.
Alternatively, the person may use the control operator 510 to turn
on at least one of the floor heating system 506 or mechanical
ventilation system 504 to heat the room. In the illustrative
example, the control actuator operator is, for example, a wall
switch, thermostat, or the like, that is mechanically or
electrically coupled to a control system that can operate at least
one of the circulation fan 502, mechanical ventilation system 504,
and the floor heating system 506.
[0041] The control operator 510 may also actuate an exhaust fan
512, as well as vents 514 and 516 in the window 314 and inner
ventilation opening 316, respectively. In an illustrative example,
the control operator 510 may turn off the circulation fan 502,
mechanical ventilation system 504, and floor heating system 506;
turn on exhaust fan 512; and open vents 514 and 516. This allows
natural ventilation to be drawn through the room by the solar
engine, with the exhaust fan 512 assisting with drawing air into
the core 108. In this case, only the exhaust fan 512 is consuming
energy, while the room is being cross ventilated and heated cooled
by outside air. Alternatively, the exhaust fan 512 may be turned
off, allowing the room to be cooled and ventilated using only the
suction force of the solar engine and no energy consumption.
[0042] In an embodiment, a pressure sensor 518 may monitor room
pressure or take a differential pressure between the room and the
core. If the room pressure drops to a level below a predetermined
threshold or below the pressure in the core, then the pressure
sensor may signal the mechanical ventilation system 504 to turn on
to force air into the room. This creates a positive pressure
relative to the core and assists with the stack effect.
Alternatively, the mechanical ventilation system 504 may vary its
speed up or down to maintain a particular pressure in the room that
is greater than the pressure in the core.
[0043] The habitable space 102 may also be ventilated by drawing
air out from the core, through the inner ventilation opening 316,
and into the habitable space. This may be done for example during
the winter season, when the exterior building facade may be closed.
In this case, at least one of the exhaust fan 512 or mechanical
ventilation unit 504 may draw air, which is moving upward through
the core, into the habitable space. The air from the core
ventilates the habitable space and is expelled to the exterior of
the building or to the mechanical ventilation system.
[0044] Habitable space in a lower portion of the building may
generate high internal loads and may require cooling in the
interior zones. As air passes through the core along the interior
surfaces of the habitable spaces it is preheated by energy transfer
with the surrounding conditioned space. The preconditioning of the
air by drawing it through the core as opposed to the exterior of
the building saves considerable heating energy. Further, air from
the core provides more consistent ventilation compared to air
brought in through louvers located outside the building, which are
susceptible to changing wind conditions and often cannot pull in
air since the suction forces of the wind may outweigh the external
static pressure of the louver fan.
[0045] Referring to FIG. 6, the stack effect may be enhanced by
providing one or more solar reflectors 602 at the crown of the
building. Solar radiation reflects off surfaces of the crown onto
the solar reflector, which directs the solar radiation into the
core. Thus, solar radiation that may reflect off the crown in a
direction that would not normally allow the solar radiation to
enter the core is directed into the core by reflecting off the
solar reflector. Thus, the solar reflector in combination with the
reflective surfaces of the crown form a heliostatic system that
directs solar radiation into the core.
[0046] The solar reflector 602 has a reflective surface 604
comprising one or more reflective materials, such as one or more
mirrors, glass, metal, and the like. In the illustrative example
shown in FIG. 6, the reflective surface 604 has a generally
parabolic shape and comprises a plurality of mirror sections that
fit together to form the reflective surface. The reflective surface
may have alternative shapes or orientations, such as the
orientation shown in FIG. 7, and the like. The solar reflector's
reflective surface may be chosen to provide a particular reflective
angle. For example, a solar reflector that has a reflective surface
with greater angle may direct solar radiation farther down into the
core. This is shown in the illustrative example of FIG. 7, in which
the solar reflector 702 has a reflective surface 704 that directs
solar radiation farther down into the core than the illustrative
solar reflector of FIG. 6.
[0047] The surfaces of the crown may be treated with one or more
reflective materials, such as one or more mirrors, glass, metal,
and the like. Further one or more surfaces of the crown may be
adjustable, either manually or automatically using a control
system, to adjust the angle of the surface of the crown to allow
more light to reflect onto the solar reflector.
[0048] Solar radiation reflects from the solar reflector down into
the warm air chamber and core. The solar radiation may be directed
farther down into the core through the use of one or more
additional reflectors or reflective surfaces within the core. For
example, one or more walls of the habitable chambers 102 that face
the core may have windows or mirrored surfaces that reflect light
down into the core. In another illustrative example, at least a
portion of the walls of the core may be painted a reflective color,
such as white, silver, or gold, to reflect light down into the
core. The introduction of solar energy into the core further heats
the air in the core, resulting in a higher air velocity through the
solar engine, thereby enhancing the stack effect.
[0049] The introduction of light into the core also beneficially
illuminates the interior portions of the habitable spaces located
around the core. For example, one or more of the habitable spaces
may have windows or open vias adjacent the core that let light into
the habitable spaces. This allows for reduced energy consumption
for illuminating the habitable spaces.
[0050] As air rises toward the top of the core, it mixes with
warmer air and increases velocity. As shown in FIG. 8, wind
turbines 802 positioned around the top exit of the core rotate
within this moving air, driving generators that convert the
mechanical turning energy into electricity. In the illustrative
example, the wind turbines are manufactured by Windside of Finland.
However, alternative wind turbines may be used.
[0051] In the illustrative example, the wind turbines are
horizontally disposed and coupled at a first end to a side wall at
the top edge of the core and coupled at an opposite end to a
ceiling 804 positioned at the top of the core. The ceiling 804 is
at least partially transparent or has one or more vias therethrough
to allow solar radiation to pass through the ceiling into the core.
In the illustrative example, the ceiling comprises supported glass
plates that allow sunlight to pass into the core.
[0052] Each wind turbine comprises blades that are rotatable about
its horizontal axis. When warm air passes over the wind turbine's
blades, the wind turbine rotates about its horizontal axis. The
wind turbine has an axle that is mechanically coupled to a
generator 806. As the wind turbine rotates, its axle rotates and,
in turn, causes the generator to convert the axle's mechanical
energy into electricity.
[0053] FIG. 9 shows a top view looking down onto a plurality of
illustrative wind turbines 802 that are positioned around the top
of the core 108. As depicted, each wind turbine is coupled at a
first end to a generator 806 mounted near a side wall at the top
edge of the core and coupled at an opposite end to the ceiling 804.
The illustrative ceiling 804 is substantially solid. Therefore, as
air rises up through the core, it is forced to pass through the
space between the core side wall 106 and the ceiling 804.
Accordingly, at least some of the air moves across one or more of
the wind turbines, causing the wind turbines to rotate and generate
electricity at the generators. The generated electricity may be
used as a power source for the building. Thus, methods and systems
consistent with the present invention reduce the amount of energy
required to ventilate a building and also generate electricity that
may be used to power the building.
[0054] The foregoing description of an implementation of the
invention has been presented for purposes of illustration and
description. It is not exhaustive and does not limit the invention
to the precise form disclosed. Modifications and variations are
possible in light of the above teachings or may be acquired from
practicing the invention. For example, the described implementation
includes software but the present implementation may be implemented
as a combination of hardware and software or hardware alone. The
invention may be implemented with both object-oriented and
non-object-oriented programming systems. The scope of the invention
is defined by the claims and their equivalents.
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