U.S. patent application number 13/318410 was filed with the patent office on 2012-03-01 for ventilator system for recirculation of air and regulating indoor air temperature.
Invention is credited to Mark Clawsey.
Application Number | 20120052786 13/318410 |
Document ID | / |
Family ID | 43031619 |
Filed Date | 2012-03-01 |
United States Patent
Application |
20120052786 |
Kind Code |
A1 |
Clawsey; Mark |
March 1, 2012 |
VENTILATOR SYSTEM FOR RECIRCULATION OF AIR AND REGULATING INDOOR
AIR TEMPERATURE
Abstract
An air circulator for amplifying and manipulating high volumes
of low velocity air in order to circulate and regulate indoor air
temperature within a commercial or an industrial environment. The
air circulator includes a housing and a support member. The housing
has an airflow passageway with a bottom end defining an air intake
and a top end defining an air outlet. The air circulator further
includes a fan positioned within the airflow passageway of the
housing substantially adjacent to the top end of the housing. The
support member supports the housing so as to dispose the air intake
above the ground. The fan and the air outlet are configured to
discharge air having a significant vertical component and a
significant lateral component.
Inventors: |
Clawsey; Mark; (Cambridge,
CA) |
Family ID: |
43031619 |
Appl. No.: |
13/318410 |
Filed: |
May 3, 2010 |
PCT Filed: |
May 3, 2010 |
PCT NO: |
PCT/CA2010/000661 |
371 Date: |
November 1, 2011 |
Current U.S.
Class: |
454/229 ;
454/230 |
Current CPC
Class: |
F24F 8/108 20210101;
F24F 2221/125 20130101; F24F 7/065 20130101; Y02A 50/20 20180101;
F24F 2110/10 20180101; F24F 11/30 20180101 |
Class at
Publication: |
454/229 ;
454/230 |
International
Class: |
F24F 7/007 20060101
F24F007/007 |
Foreign Application Data
Date |
Code |
Application Number |
May 1, 2009 |
US |
61174597 |
Claims
1. An apparatus for circulating air comprising: a) a housing having
an airflow passageway with a bottom end defining an air intake and
a top end defining an air outlet; b) a support member for
supporting the housing and for disposing the air intake above a
support surface; c) a fan positioned within the airflow passageway
of the housing substantially adjacent to the top end of the
housing; and d) a drive coupled to the fan for operating the fan so
as to blow air from the air intake to the air outlet;
2. The apparatus of claim 1, wherein the fan and the air outlet are
configured such that the air exiting the air outlet has a flow
direction with a significant vertical component and a significant
lateral component.
3. The apparatus of claim 2, wherein the vertical component is
between about 40% to 80% of the total airflow, and the lateral
component is between about 60% to 20% of the total flow.
4. The apparatus of claim 2, wherein the vertical component is
about 60% of the total airflow, and the lateral component is about
40% of the total airflow.
5. The apparatus of claim 1, wherein: a first height is defined
between the fan and the top end of the housing; a second height is
defined between the bottom end of the housing and the top end of
the housing; and the first height is less than half of the second
height.
6. The apparatus of claim 1, wherein: a first height is defined
between the fan and the top end of the housing; a second height is
defined between the bottom end of the housing and the top end of
the housing; and the first height is less than one third of the
second height.
7. The apparatus of claim 1, wherein: a first height is defined
between the fan and the top end of the housing; a second height is
defined between the bottom end of the housing and the top end of
the housing; and the first height is about one tenth of the second
height.
8. The apparatus of claim 1, wherein the fan is positioned between
about 0 inches and about 10 inches below the top end of the
housing.
9. The apparatus of claim 1, further comprising at least one air
filter for filtering air passing through the airflow passageway of
the housing, the air filter positioned at least 20 inches below the
fan.
10. The apparatus of claim 1, further comprising at least one air
filter for filtering air passing through the airflow passageway of
the housing, and wherein a second height is defined between the
bottom end of the housing and the top end of the housing, and
wherein a third height is defined between the at least one filter
and the fan such that the third height is more than about half of
the second height.
11. The apparatus of claim 1, further comprising at least one air
filter for filtering air passing through the airflow passageway of
the housing, and wherein a second height is defined between the
bottom end of the housing and the top end of the housing, and
wherein a third height is defined between the at least one filter
and the fan such that the third height is more than about two
thirds of the second height.
12. The apparatus of claim 1, further comprising at least one air
filter having a rectangular shape for filtering air passing through
the airflow passageway of the housing.
13. The apparatus of claim 1, further comprising at least one air
filter defining a filtration surface area for filtering air passing
through the airflow passageway of the housing, and wherein the
airflow passageway of the housing has a cross-sectional area less
than the filtration surface area.
14. An apparatus for circulating air comprising: a) a housing
having an airflow passageway with a bottom end defining an air
intake and a top end defining an air outlet; b) a support member
for supporting the housing and for disposing the air intake above a
support surface; c) a fan positioned within the airflow passageway
of the housing; and d) a drive coupled to the fan for operating the
fan so as to blow air from the air intake to the air outlet e)
wherein the fan and the air outlet are configured such that the air
exiting the air outlet has a flow direction with a significant
vertical component and a significant lateral component.
15. A system for circulating air comprising: a) an air circulator
comprising: i) a housing having airflow passageway with a bottom
end defining an air intake and a top end defining an air outlet;
ii) a support member for supporting the housing and for disposing
the air intake above a support surface; iii) a fan positioned
within the airflow passageway of the housing; and iv) a drive
coupled to the fan for operating the fan so as to blow air from the
air intake to the air outlet; b) a first temperature sensor for
measuring air temperature in a lower portion of a building; c) a
second temperature sensor for measuring air temperature in an upper
portion of the building; d) a controller for determining a
temperature differential based on measurements from the first and
second temperature sensors, wherein the controller operates the fan
based on the temperature differential.
16. The system of claim 15, wherein the controller adjusts a fan
speed for the fan based on the temperature differential.
17. The system of claim 16, wherein the controller outputs an AC
electrical signal having a frequency for operating the fan, and
wherein the controller adjusts the frequency to control the fan
speed.
18. The system of claim 17, wherein the AC electrical signal output
by the controller has a substantially constant voltage.
19. The system of claim 15, wherein the fan is positioned
substantially adjacent to the top end of the housing.
20. The system of claim 15, wherein the fan and the air outlet are
configured such that the air exiting the air outlet has a flow
direction with a significant vertical component and a significant
lateral component.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 61/174,597 filed on May 1, 2009 and
entitled "SYSTEM FOR REGULATING INDOOR AIR TEMPERATURE", the entire
contents of which are hereby incorporated by reference herein for
all purposes.
TECHNICAL FIELD
[0002] The embodiments herein relate in general to apparatus and
systems for air distribution and circulation, and in particular, to
ductless apparatus and systems for circulating high volumes of low
velocity air to regulate indoor air temperature.
INTRODUCTION
[0003] Heating, ventilation and air conditioning (HVAC) systems
generally contribute to the comfort and satisfaction of workers,
customers and tenants within indoor spaces by controlling and
regulating air temperature. Properly tuned, HVAC systems can help
improve employee productivity and contribute to good air quality.
However, HVAC systems are often very inefficient and account for
some of the highest energy costs in industrial and commercial
environments.
[0004] It is now quite common for commercial buildings, especially
newer buildings, to have large open spaces with high ceilings.
Often such buildings are "open concept" facilities with minimal or
no vertical walls. New challenges are presented in addressing air
movement in such large open spaced facilities. In particular,
conventional HVAC systems are generally poor at circulating air
throughout these large open spaces. Due to this poor air
circulation, discrete layers of warm and cool air tend to separate,
with warm air rising towards the ceiling, while cooler air settles
near the floor. Depending on operating conditions, the temperature
differential between the floor and the ceiling can be quite high,
in some case as much as 20 degrees Fahrenheit (or more).
[0005] Some known devices have been developed that attempt to
improve air circulation. For example, U.S. Pat. No. 5,078,574
(Olsen) describes floor to ceiling room temperature gradients being
minimized by a portable floor mounted upstanding tubular unit
having air intake ports adjacent the bottom, an open top with air
directing louvers, and an electric motor driven fan having blades
spanning the interior of the tube above the ports and substantially
below the open top. According to Olsen, the unit can be positioned
on the floor of a room in an out of the way location and will
circulate air throughout the room without causing a draft to
minimize temperature variations between the floor and the ceiling
of the room. The unit receives air adjacent the floor and projects
it in a substantially confined upstanding column to the ceiling
where it dissipates throughout the room area to flow back to the
intake ports of the unit.
[0006] Another known approach, U.S. Pat. No. 4,347,782 (Hoecke)
discloses a device which recirculates air to raise air temperature
near the floor (in winter), and to provide a direct flow of air
blown generally horizontally slightly above persons standing on the
floor (in summer). A fan assembly is housed in a unitary duct-like
housing, which is open near its base to take in air. The duct-like
housing is capped with an outlet hood, which adjustably telescopes
on the housing so that air flow from openings in the outlet hood
can be adjusted for winter or summer operation.
[0007] Another approach is discussed in U.S. Pat. No. 4,103,146
(Rampe). Rampe discloses an apparatus for ductlessly circulating
large volumes of air in industrial facilities and the like. The
apparatus includes an upstanding structure, which defines a
vertically extending chamber. Openings are provided in lower and
upper portions of the structure and communicate the chamber with
lower and upper strata of ambient air. A blower assembly is housed
within the structure intermediate the lower and upper openings.
According to Rampe, in operation the apparatus is positioned
substantially centrally in a room and the blower assembly is
energized to move air upwardly through the chamber. The lower and
upper openings are arranged such that air from the lower strata is
drawn substantially radially toward the lower openings, and such
that air discharging from the upper openings into the upper strata
moves substantially radially outwardly toward walls of the room.
According to Rampe, the effect of this type of operation is to
establish a primary substantially toroidal air flow circulation
beside the apparatus, and to induce the establishment of a
secondary substantially toroidal air flow circulation above the
apparatus. These primary and secondary circulation torri promote a
thorough intermixing of air from all parts of the room and promote
temperature uniformity throughout the room.
[0008] In spite of these known devices, the inventor has identified
a need for new or improved apparatus and systems for regulating
indoor air temperature.
SUMMARY
[0009] According to one aspect there is provided a ductless air
distribution system for amplifying and/or manipulating high volumes
of low velocity air in order to circulate and regulate indoor air
temperature.
[0010] In accordance with another aspect there is provided a
portable or permanent ductless air distribution system for
amplifying and/or manipulating high volumes of low velocity air in
order to circulate and regulate indoor air temperature within a
commercial or industrial environment using one or more natural air
streams. The system includes a support member and a housing having
a top end and a bottom end. The system further includes a fan
assembly mounted above the bottom end and below the top end of the
housing. An air intake may be positioned across the bottom end of
the housing. An air outlet may be positioned across the top end of
the housing and may incorporate a self-regulating control system.
The support member supports the housing above the ground so that
the air intake may be positioned directly in the natural air stream
generated by the air distribution system.
[0011] Conveniently, the system may be used in both the winter and
summer. In some cases the system may change the air within an
industrial environment two to four times every hour. Furthermore,
the system may be sized and configured to operate such that the
temperature differential between the ceiling and the ground may be
within one to two degrees Fahrenheit during use.
[0012] Some embodiments as described herein relate to systems and
methods for controlling environmental parameters within an indoor
environment using methods of forced mechanical convection to
induce, amplify and/or manipulate the effects of natural convection
phenomena, including at least one of the air de-lamination
phenomena and the Coanda effect, to provide generally complete air
distribution, circulation, de-stratification, and mixing of air
within an indoor environment.
[0013] In some embodiments, some advantages provided by the systems
and apparatus as described herein may include equalization of the
temperature throughout an industrial or commercial environment
(e.g. between the ceiling and ground level), elimination of hot and
cold spots (e.g. for improving comfort), elimination of drafts from
ceiling fans, improved air quality, reduction in energy
consumption, and self-regulation.
[0014] According to another aspect, there is an apparatus for
circulating air. The apparatus includes a housing having an airflow
passageway with a bottom end defining an air intake and a top end
defining an air outlet, and a support member for supporting the
housing and for disposing the air intake above a support surface.
The apparatus also includes a fan positioned within the airflow
passageway of the housing substantially adjacent to the top end of
the housing, and a drive coupled to the fan for operating the fan
so as to blow air from the air intake to the air outlet.
[0015] The fan and the air outlet may be configured such that the
air exiting the air outlet has a flow direction with a significant
vertical component and a significant lateral component. In some
embodiments, the vertical component may be between about 40% to 80%
of the total airflow, and the lateral component may be between
about 60% to 20% of the total flow. In some embodiments, the
vertical component may be about 60% of the total airflow, and the
lateral component may be about 40% of the total airflow.
[0016] A first height may be defined between the fan and the top
end of the housing, and a second height may be defined between the
bottom end of the housing and the top end of the housing. In some
embodiments, the first height may be less than half of the second
height. Furthermore, in some embodiments, the first height may be
less than one third of the second height. Further still, in some
embodiments, the first height may be about one tenth of the second
height.
[0017] The fan may be positioned between about 0 inches and about
10 inches below the top end of the housing.
[0018] The apparatus may include at least one air filter for
filtering air passing through the airflow passageway of the
housing. The air filter may be positioned at least 20 inches below
the fan.
[0019] A second height may be defined between the bottom end of the
housing and the top end of the housing, and a third height may be
defined between the at least one filter and the fan. In some
embodiments, the third height may be more than about half of the
second height. Furthermore, in some embodiments, the third height
may be more than about two thirds of the second height.
[0020] The at least one air filter may have a rectangular
shape.
[0021] The at least one air filter may define a filtration surface
area. Furthermore, the airflow passageway of the housing may have a
cross-sectional area less than the filtration surface area.
[0022] According to another aspect, there is an apparatus for
circulating air. The apparatus includes a housing having an airflow
passageway with a bottom end defining an air intake and a top end
defining an air outlet, and a support member for supporting the
housing and for disposing the air intake above a support surface.
The apparatus also includes a fan positioned within the airflow
passageway of the housing, and a drive coupled to the fan for
operating the fan so as to blow air from the air intake to the air
outlet. The fan and the air outlet are configured such that the air
exiting the air outlet has a flow direction with a significant
vertical component and a significant lateral component.
[0023] The fan may be positioned substantially adjacent to the top
end of the housing.
[0024] According to another aspect, there is a system for
circulating air. The system comprises an air circulator including a
housing having airflow passageway with a bottom end defining an air
intake and a top end defining an air outlet, and a support member
for supporting the housing and for disposing the air intake above a
support surface. The air circulator also includes a fan positioned
within the airflow passageway of the housing, and a drive coupled
to the fan for operating the fan so as to blow air from the air
intake to the air outlet. The system also comprises a first
temperature sensor for measuring air temperature in a lower portion
of a building, and a second temperature sensor for measuring air
temperature in an upper portion of the building. Furthermore, the
system comprises a controller for determining a temperature
differential based on measurements from the first and second
temperature sensors. The controller operates the fan based on the
temperature differential.
[0025] The controller may adjust a fan speed for the fan based on
the temperature differential. Furthermore, the controller may
output an AC electrical signal having a frequency for operating the
fan, and wherein the controller adjusts the frequency to control
the fan speed. The AC electrical signal output by the controller
may have a substantially constant voltage.
[0026] The fan may be positioned substantially adjacent to the top
end of the housing.
[0027] Other aspects and features will become apparent, to those
ordinarily skilled in the art, upon review of the following
description of some exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The drawings included herewith are for illustrating various
examples of articles, apparatus, systems and methods of the present
specification and are not intended to limit the scope of what is
taught in any way. In the drawings:
[0029] FIG. 1 is a perspective view of an air circulator according
to one embodiment;
[0030] FIG. 2 is a cross-sectional view of the air circulator of
FIG. 1 taken along line 2-2;
[0031] FIG. 3 is a schematic diagram of an airflow pattern
generated by the air circulator of FIG. 1 within an indoor
environment;
[0032] FIG. 4 is a schematic diagram of an airflow pattern
generated by a prior art air circulator within the same indoor
environment as in FIG. 3;
[0033] FIG. 5 is a schematic diagram of a system for circulating
air within a building according to another embodiment;
[0034] FIG. 6 is a perspective view of an air circulator according
to yet another embodiment; and
[0035] FIG. 7 is a cross sectional view of the air circulator of
FIG. 6 taken along line 7-7.
DETAILED DESCRIPTION
[0036] A number of factors and phenomena have been recognized
herein as being worthy of consideration when designing apparatus
and systems for circulating air.
[0037] One factor is de-lamination. De-lamination is a phenomenon
whereby warm airflows and cool airflows tend to repel one another.
For example, an upper layer of warm air will tend to float on top
of a lower layer of cool air, generally without mixing between the
layers. The upper and lower layers may be referred to as
"stratified layers" having stratified layer "heights".
De-lamination is a result of different air temperatures, densities
and turbulence intensity between cool and warm airflows, and
generally results in energy waste and/or reduced efficiencies
within an HVAC system.
[0038] It has been discovered that with higher velocity airflow,
the temperature dependant de-lamination phenomenon begins to
disappear, such that the heights of stratified layers tend to
decrease.
[0039] For instance, in one example with stratified layers, if the
airflow velocity is 1.2 m/s and the temperature differential
between the hot and cold layers is 30.degree. F., the stratified
layer height (e.g. the height of each layer) might be about 1.4
meters. However, if the airflow velocity is increased to about 1.6
m/s in the same environment, the stratified layer height may reduce
to about 0.7 meters. Furthermore, as the airflow velocity increases
beyond about 2.0 m/s, the stratified layer height will tend to
decrease further, and may in fact approach zero.
[0040] Similarly, as the temperature differential between the hot
and cold layers decreases, the stratified layer height also tends
to decrease. For example, if an airflow velocity of 1.2 m/s and a
temperature differential of about 30.degree. F. might correspond to
a stratified layer height of about 1.4 meters, while if the
temperature differential between the hot and cold layers was
10.degree. F., the stratified layer height might approach zero.
[0041] When the stratified layer height is larger, this tends to
promote repelling of hot and cold layers (e.g. mixing of the layers
of hot and cold air is inhibited). Conversely, when the stratified
layer height is smaller, this tends to promote mixing between the
hot and cold layers. Accordingly, it has been discovered that
controlling airflow velocity can influence whether hot and cold
layers of air tend to repel each other, or whether the layers of
air tend to mix with each other.
[0042] Another phenomenon that affects airflow is the Coanda
effect. The Coanda effect is the tendency of a moving fluid jet to
stay attached to an adjacent or nearby surface.
[0043] For example, air-conditioning systems may exploit the Coanda
effect to increase the distance traveled by cool air using a
ceiling-mounted diffuser. In particular, a ceiling-mounted diffuser
may take advantage of the Coanda effect by discharging air near the
ceiling. The discharged air will tend to "stick" to the ceiling
while traveling away from the diffuser. Accordingly, the cool air
may travel further along the ceiling before tending to drop down
towards the ground (in comparison to mounting the diffuser in free
air without the neighboring ceiling, where the cooled air will tend
to fall more quickly).
[0044] In some embodiments, apparatus and systems for circulating
air as described herein may attempt to use at least one of the
de-lamination phenomenon and the Coanda effect.
[0045] Referring now to FIGS. 1 and 2, illustrated therein is a
ductless air distribution apparatus or "air circulator" 20 made in
accordance with one embodiment. The air circulator 20 generally
includes a housing 22 and a support member 30 for supporting the
housing 22 above a ground surface (e.g. the floor of a
building).
[0046] The housing 22 generally has a bottom end 24, a top end 26,
and an airflow passageway 28 located therebetween (as shown in FIG.
2). The bottom end 24 defines an air intake, while the top end 26
defines an air outlet.
[0047] The air circulator 20 also includes a fan 32 and a drive 34.
The fan 32 is mounted in the airflow passageway 28 of the housing
22 between the bottom end 24 and the top end 26, and generally
adjacent the top end 26. The drive 34 is coupled to the fan 32 for
rotating the fan 32 so as to blow air through the airflow
passageway 28 from the air intake (at the bottom end 24) to the air
outlet (at the top end 26).
[0048] In some embodiments, the drive 34 may be an electric motor
having an output shaft 36 coupled to a central hub of the fan 32.
In other embodiments, the drive 34 may have different
configurations, for example, the drive 34 may be coupled to the fan
32 using pulleys (for example as shown in FIG. 7).
[0049] Generally, the fan 32 and drive 34 enable the air circulator
20 to amplify and manipulate high volumes of low velocity air in
order to circulate and regulate indoor air temperature, for example
within a commercial or industrial environment. In particular, the
fan 32 and the air outlet are generally configured to discharge an
airflow from the air outlet having both a significant vertical
component and a significant lateral component. In other words, the
air circulator 20 blows air both vertically upwards and laterally
outwards relative to the top end 26 of the housing 22. This
configuration tends to promote air circulation and mixing of the
warm and cool layers of air, as will be described below.
[0050] In some embodiments, the housing 22 may include a plurality
of side panels 38 (e.g. four panels as shown in the illustrated
embodiment), which may be metal, plastic or another suitable
material. In some embodiments, the panels 38 may be sized and
shaped so that the housing 22 has a box-like shape. In particular,
the housing 22 may be shaped as a vertically oriented square tube,
with the airflow passageway 28 extending generally vertically
through the center of the tube.
[0051] The support member 30 generally supports the housing 22
above the support surface (e.g. a floor within a commercial or
industrial building) so that the air intake is positioned at least
partially within in the natural air stream generated by the air
circulator 20 (as shown in FIG. 3).
[0052] The support member 30 may include a plurality of leg members
40 sized and shaped to allow air to flow into the air intake. In
the illustrated embodiment, there are four leg members 40
interconnected by cross-members 42. Generally, the leg members 40
and cross-members 42 are sized and shaped so as to not inhibit
airflow into the air intake.
[0053] In some embodiments, one or more of the leg members 40 may
be supported by caster wheels 44, which may allow the air
circulator 20 to be moved by rolling the air circulator 20 along
the ground surface (e.g. to different locations within an
industrial building).
[0054] In other embodiments, the support member 30 may be fixed to
the ground surface. For example, the support member 30 may include
leg members 40 that are bolted to the ground surface.
[0055] In the illustrated embodiment, the air intake encompasses
the entire bottom end 24 of the housing 22, and the air outlet
encompasses the entire top end 26 of the housing 22. However, in
other embodiments the air intake and air outlet may encompass less
than the entire bottom end 24 and top end 26, respectively, of the
housing 22.
[0056] In some embodiments, the housing 22 may include a lower
protective grill 50 and an upper protective grill 52. The grills
50, 52 generally have one or more openings that are sized and
shaped to allow airflow to pass therethrough, but which prevent
undesired objects, such as hands or fingers, from entering the
airflow passageway 28. The grills 50, 52 may be designed to
minimally impede the airflow through the air intake and the air
outlet. In some examples, one or both of the grills 50, 52 may be
removably coupled to the housing 22.
[0057] In some embodiments, the removable upper grill 52 is located
as close as possible to the fan 32.
[0058] As mentioned above, the fan 32 and the air outlet are
generally configured such that air exiting the air outlet has a
flow direction with both a significant vertical component and a
significant lateral component. In some embodiments, this may be
achieved by positioning the fan 32 substantially adjacent to the
air outlet (i.e. adjacent the top end 26 of the housing 22).
[0059] For example, the fan 32 may be separated from the top end 26
by a distance corresponding to a first height H1 as shown in FIG.
2. In some embodiments, the first height H1 may be between about 0
inches and about 10 inches. In some embodiments the first height H1
might be between 2 inches and 8 inches. In some embodiments, the
first height H1 may be about 4 inches.
[0060] In some embodiments, the distance between the bottom end 24
and the top end 26 may define a second height H2. Furthermore, the
first height H1 may be defined relative to the second height H2.
For example, the first height H1 may be less than half of the
second height H2. In some embodiments, the first height H1 may be
less than one third of the second height H2. In some embodiments,
the first height H1 may be about one tenth of the second height
H2.
[0061] In some embodiments, the top end 26 of the housing 22 may
include a guide 54, such as a shroud or a panel with a cylindrical
cut-out. The guide 54 may at least partially encase the fan 32 and
direct airflow from the fan 32 out of top end 26 through the air
outlet (and may assist in imparting one or both of the significant
vertical component and significant lateral component to the
airflow).
[0062] For example, the guide 54 may deflect air traveling upwards
through the airflow passageway 28 to inhibit the discharged air
from traveling substantially laterally at a certain height above
the ground surface (e.g. at a height corresponding to the occupant
head height), and to project a substantial column of air vertically
towards the ceiling. This configuration may provide comfort to
occupants standing near the air circulator 20 (e.g. by deflecting
air leaving the air circulator 20 so that it does not directly
strike the occupants). This configuration may also promote air
circulation using the de-lamination phenomenon and the Coanda
effect.
[0063] In some embodiments, the guide 54 may be generally circular
and may be sized slightly larger than the diameter of the fan 32.
In some embodiments, the guide 54 may be up to about 2 inches
larger than the diameter of the fan.
[0064] Referring now specifically to FIGS. 3 and 4, the air
circulator 20 described herein tends to promote better air
circulation over a wider area in comparison to prior art air
circulators.
[0065] FIG. 3 illustrates a simulated airflow induced by the air
circulator 20 described herein, which discharges an airflow having
both a significant vertical component and a significant horizontal
component. By comparison, FIG. 4 illustrates a simulated airflow
induced by a prior art air circulator having a significant vertical
component but no significant horizontal component.
[0066] In some embodiments, the air circulator 20 may provide a
vertical component that is between about 40% to 80% of the total
airflow, and a lateral component that is between about 60% to 20%
of the total airflow. In some embodiments, the vertical component
may be about 60% of the total airflow and the lateral component may
be about 40% of the total airflow.
[0067] Providing an airflow having both a significant vertical
component and a significant horizontal component may tend to
promote air circulation over a wider area, which tends to promote
de-stratification of the surrounding air and a reduction in
temperature differentials within an indoor environment.
[0068] By configuring the air circulator 20 to discharge an airflow
having both a significant vertical component and a significant
horizontal component, the air circulator 20 can take advantage of
at least one of the de-lamination phenomenon and the Coanda
effect.
[0069] Regarding de-lamination, the lateral component of the
discharged airflow tends to have a lower temperature in comparison
to adjacent air because the air circulator 20 takes cooler air near
the floor and blows it into warmer air that is located higher up
above the floor. Provided that the discharge airflow has a
sufficiently low velocity to avoid de-stratification for a given
temperature differential between the cool air and warm air, the
cool air and the warm air tend to repel each other such that one
floats on the other with limited heat and mass transfer
therebetween. Since the cool and warm air repel each other, the
cool airflow tends to travel further laterally outward before
mixing with the warm air (thus extending the effective mixing range
of the air circulator 20).
[0070] Using the repelling nature of warm and cool air to encourage
mixing is counterintuitive because many prior art HVAC systems want
to promote mixing as quickly as possible so as to de-stratify air
within an indoor environment. However, promoting mixing (e.g.
through turbulent flow) tends to reduce the distance that the
discharged cool air can travel because it mixes with nearby
stationary warm air and loses its lateral momentum. This tends to
result in a de-stratified area localized around the air circulator,
but other areas further from the air circulator remain stratified
and tend to have significant temperature differentials between the
ceiling and the floor.
[0071] In contrast, the present air circulator 20 takes advantage
of the repelling effect between warm and cool airflows and enables
discharged air to travel further laterally outwards from the air
circulator 20 and cover a substantially broader lateral area.
[0072] Regarding the Coanda effect, the vertical component of the
airflow is generally configured to impinge the ceiling such that
the airflow spreads out laterally along the ceiling. Due to the
Coanda effect, this component of the discharged airflow tends to
stay attached to, or at least adjacent to, the ceiling and thus
tends to spread out laterally further from the vertical component
of the airflow before falling down and mixing with the warmer air
below.
[0073] The outward spreading along the ceiling is further enhanced
by the de-lamination phenomenon, since the discharged airflow that
moves along the ceiling is cooler than the warmer air it replaced.
Accordingly, the cooler discharged air tends to repel the warmer
air in the same way as described previously so as to increase the
lateral distance traveled along the ceiling by the cooler air.
[0074] The combined effect of the significant vertical component
and the significant horizontal component means the discharged
airflow tends to spread out over greater lateral distances in
comparison to prior art systems. Accordingly, the air circulator 20
tends to promote de-stratification over a wider interior space in
comparison to known prior art air circulators.
[0075] Another benefit of the present air circulator 20 is that the
air discharged generally does not require ducting. Ducting tends to
be costly to ship and install and also introduces frictional losses
due to interactions between the airflow and the interior surfaces
of the ducting (and which tend to increase the power requirements
for circulating air).
[0076] The air circulator 20 also utilizes the Coanda effect at the
air intake of the housing 22. For example, air discharged from the
air circulator 20 eventually pushes warmer air downward toward a
lower portion of the indoor environment (e.g. towards the floor).
The air circulator 20 then draws this air in through the air inlet
at the bottom end 24, which tends to induce an air current that
travels across the floor. This air current along the floor tends to
stay attached to the floor (according to the Coanda effect).
[0077] Generally, the air circulator 20 works to gently pull cool
air across the floor. In some embodiments, the air circulator 20
may pull air from over two hundred feet away. Discharged air is
propelled upward and outward across the upper level (e.g. ceiling).
At the same time, drawing cool air from the floor into the air
circulator 20 creates a low-pressure layer, which pulls the warmer
air near the ceiling back down to the ground.
[0078] Accordingly, the air circulator 20 tends to create a natural
rolling airflow pattern, which mixes the cool air with the warm air
and reduces the temperature gradient within the building.
[0079] Furthermore, placing the air circulator 20 within this
natural rolling air stream and exposing the air stream to at least
a portion of the air intake at the bottom end 24 of the air
circulator 20 tends to increase the efficiency of the air
circulator 20, which enables the air circulator 20 to de-stratify
the air and reduce temperature gradients faster. As a result, the
air circulator 20 tends to quickly de-stratify the air and equalize
the temperature differential within a few degrees Fahrenheit.
[0080] Generally, the air circulator 20 can equalize temperatures
within a building during both the summer and winter. By way of
example, during the winter the warm air from the building heating
system tends to collect at the top of a building (e.g. in an
atrium). The air circulator 20 can bring this warm air down to
floor level or occupant level.
[0081] During the summer, the cool air or conditioned air may have
difficulty reaching the top portion of an atrium because it tends
to settle at the bottom of the building near the floor. The air
circulator 20 can distribute the cool air that is collected near
the floor back up to the top. Accordingly, the air circulator 20
may be used to maintain overall improved comfort levels in
operation during both summer and winter seasons.
[0082] In some embodiments, the air circulator 20 can increase the
overall efficiency of existing HVAC systems by 20% or more. The air
circulator 20 may also reduce the short cycling on/off of the
existing HVAC rooftop units and unit heaters (e.g. by stabilizing
the on and off cycles). Accordingly, the air circulator 20 may
reduce electrical power consumption and may allow a building to
downsize HVAC rooftop blower motors, which may result in energy
savings. In some embodiments, the air circulator 20 may be used to
replace ceiling fans.
[0083] The present air circulator 20 may also have the ability to
capture and distribute latent heat produced by manufacturing
equipment, which can further enhance efficiencies. For example, the
natural rolling airflow that passes along the floor tends to pick
up heat generated by manufacturing equipment. This heat capture
ability can reduce operator fatigue by sweeping the heat from their
work areas and generally equalizing temperatures throughout an
indoor work environment.
[0084] The air circulator 20 may also reduce heat losses through
the ceiling and walls of a building. For example, heat losses occur
when warm air within the building transfers heat to the cooler air
outside the building through the walls and ceiling. These heat
losses tend to increase as the temperature differential between the
inside air and the outside air increases.
[0085] When there is no air circulation, warmer air tends to rise
and collect in a stratified layer near the ceiling. This layer of
warm air tends to increase both the temperature differential and
the heat losses through the ceiling. In contrast, the air
circulator described herein circulates air within the building and
inhibits the formation of a stratified layer of warm air by mixing
it with cooler air closer to the floor. Accordingly, the air
circulator may reduce the air temperature near the ceiling, which
may reduce both the temperature differential and heat losses.
[0086] In some embodiments, the height of the air intake above the
ground can be important because it sets the height at which
incoming air is drawn into the fluid passageway 28. For example,
when the height of the air intake is lowered, incoming air is drawn
from a lower height, which generally corresponds to cooler air.
Drawing in cooler air tends to provide more efficient air
circulation and de-stratification because it tends to utilize the
maximum (or at least a significant) temperature differential
between the air near the ground and the air near the ceiling.
However, the air intake should be set above the ground some minimum
height, otherwise static pressure increases and tends to reduces
the efficiency of the air circulator 20.
[0087] As shown in FIG. 2, the height of the air intake above the
ground corresponds to a clearance height C. For example, in some
embodiments the clearance height C of the air intake may be between
one foot and four feet above the ground. In some embodiments, the
clearance height C of the air intake above the ground may be about
two feet.
[0088] Setting the air intake height to about two feet may be
useful when using the air circulator 20 near a loading dock door
area. For example, air above the two-foot level tends to remain at
the existing temperature set point for the HVAC system (e.g. 70
degrees Fahrenheit or some other set point).
[0089] Furthermore, the air circulator 20 tends to force the air
from outside the loading dock door to remain below the two-foot
level. Accordingly, in the winter, loading dockworkers will tend
not to feel the cold air from outside the loading dock because it
is kept at a low height. Once the dock door is closed, the air
circulator 20 can reduce the heat recovery time for that area. For
example, in some cases, the temperature of the area may be brought
back up to the desired temperature within minutes by circulating
air in the loading dock area with air throughout the rest of the
building.
[0090] In some embodiments, the air circulator 20 may include an
outlet adjustment mechanism for adjusting the size of the air
outlet. For example, the outlet adjustment mechanism may increase
or decrease the radius of the circular guide 54. Adjusting the size
of the air outlet enables the air circulator 20 to alter the
vertical and/or lateral components of the airflow, for example, to
manipulate the de-lamination phenomenon and/or the Coanda effect
depending on the particular configuration of the building, or the
air temperatures within the building.
[0091] The outlet adjustment mechanism may adjust the size of the
air outlet between a first size and a second size, with the second
size being smaller than the first size. Generally, the larger first
size allows the fan to blow more air laterally outward relative to
the housing 22 in comparison to the second size. Accordingly, the
larger first size may utilize the de-lamination phenomenon to a
greater extent. The smaller second size may allow the fan to blow
more air upward relative to the housing in comparison to the first
size. Accordingly, the smaller second size may utilize the Coanda
effect to a greater extent.
[0092] Adjusting the size of the air outlet may be beneficial when
dealing with varying ceiling heights. If the ceiling height is low
in relation to the discharge of the air circulator 20, the radius
of the guide 54 could be increased to allow for more lateral
airflow.
[0093] Furthermore, the adjustment mechanism may include louvers
(not shown) for directing air discharged from the air outlet. For
example, if an obstacle was preventing the air circulator 20 from
functioning as desired, the louvers could be positioned to direct
airflow around the obstacle. An example of this would be when the
air circulator 20 is located within proximity to an interior
partition or wall and the louvers could direct airflow around the
wall.
[0094] In some embodiments, the louvers could also be used to
adjust the vertical and lateral components of the airflow.
[0095] An alternative to increasing and decreasing the radius of
the circle would be to provide a plurality of different removable
upper grills 52, each of which may act as different type of
diffuser. For example, each upper grill 52 could provide a
different diffusion pattern for the discharged air, which may be
used to alter or manipulate the de-lamination phenomenon and/or
Coanda effect.
[0096] By changing diffusers or making the air outlet adjustable,
for example, either automatically or manually, it may be possible
to adjust or change the discharge airflow for summer and winter
operation. For example, the air circulator 20 may include a
different diffusion pattern for summer and winter applications
(e.g. the summer diffuser could take advantage of the Coanda Effect
in an effort to distribute the cooler air-conditioned air over a
larger area by keeping the cooler air attached or adjacent to the
ceiling plane).
[0097] If the ceiling height of the space being serviced by the air
circulator 20 is too high to justify utilization of the Coanda
Effect (e.g. the airflow may diffuse before impinging the ceiling),
a different summer diffuser design could be designed with a
different diffusion pattern to take advantage of the de-lamination
phenomenon (e.g. the float and repelling effects) by discharging
the air in a more substantially lateral direction. In this example,
the air circulator 20 might also reduce the actual volume of air
being serviced by effectively decreasing the size of the building
such that warm air near the ceiling remains un-serviced during the
summer months. This may be desirable because servicing the warmer
air near the ceiling might actually increase the load on the air
conditioning unit.
[0098] In some embodiments, the air circulator 20 uses a 36-inch
diameter fan 32. However, generally any size fan 32 will work
depending on the size of the area being serviced. For example, in a
large area a large fan (or multiple fans) can be used, while in a
small area the fan size can be reduced. Generally, the housing 22
for the fan 32 may be a few inches larger than the diameter of the
fan 32.
[0099] By way of example, in some embodiments the air circulator 20
may be effective in a space that is about 10,000 square feet or
more. In particular, an air circulator 20 with a 36-inch fan 32 may
work effectively within a 10,000 square foot building having a
twenty foot high ceiling such that air changes occur two to four
times per hour.
[0100] While the air circulator 20 may work well in a 10,000 square
foot building, the air circulator 20 may be effective in a variety
of different building sizes (e.g. larger than 10,000 square feet,
smaller than 10,000 square feet, and so on). In some embodiments,
multiple air circulators 20 can be used in larger spaces.
[0101] In some embodiments, a plurality of smaller air circulators
can be used to replace one large air circulator, or visa versa. The
number and size of air circulators utilized may depend upon desired
aesthetics, fan noise levels, floor space, and the size of fan that
can be used within a pre-determined amount of space.
[0102] It may be possible to estimate the relationship of the size
of building to the size of the required air circulator using a
sizing calculation. The sizing calculation is based on the total
volume of air within a space divided by the flow rate (e.g. cubic
feet per hour) that the air circulator can move. The calculation
determines the time it takes the air circulator to theoretically
service all of the air within the space. A similar sizing
calculation utilizes the flow rate divided by the volume of air
within the space so as to determine the theoretical number of air
changes per hour within the building.
[0103] The amount of air circulation may change between summer and
winter operation. By way of example, it might be desirable in the
summer to increase the amount of air changes per hour in an effort
to increase the velocity of the air at occupant height so as to
create a greater cooling effect. In the winter, it might be
desirable to lower the number of air changes per hour and
corresponding air velocity in an effort to reduce the chilling
effect and increase occupant comfort. Accordingly, the sizing
calculation may take into account the air changes per hour desired
for both summer and winter operation.
[0104] In some embodiments, the air circulator 20 may include a
self-regulator or controller 70 for controlling the air circulator
20. For example, referring to FIG. 2, the controller 70 may be
operatively coupled to the drive 34 for controlling the speed of
the fan 32. In particular, the controller 70 may provide electrical
power to the drive 34 through a cable 72 and may adjust the amount
of power supplied to control the speed of the fan 32. Furthermore,
the controller 70 may receive electrical power from a source such
as a 120V wall socket through a plug 74 on the outside of the
housing 22 as shown in FIG. 1. In other embodiments, the controller
70 may control other aspects of the air circulator 20, such as the
air outlet adjustment mechanism.
[0105] As shown in the illustrated embodiment, the controller 70
may include a touch screen 76 for adjusting parameters. For
example, the touch screen 76 may enable a user to select the
desired temperature for the indoor environment.
[0106] The touch screen 76 may allow the user to select other
parameters such as the fan speed or the horizontal or vertical
components of the discharge airflow. The user may select these
setting using one of several presets. In generally, these
parameters can help the user regulate the temperature throughout
the indoor environment.
[0107] Referring now to FIG. 5, illustrated therein is an air
circulation system 100 made in accordance with another embodiment.
The system 100 is generally used to circulate air within an indoor
environment such as a building 102, which may be a commercial
building or an industrial building.
[0108] The system 100 includes an air circulator 120, which may be
similar to the air circulator 20 described previously, and similar
elements are given similar reference numerals incremented by one
hundred. For example, the air circulator 120 includes a housing
122, a support 130, a fan 132 and a drive 134.
[0109] The system 100 also includes two temperatures sensors 160,
162 and a controller 170 in communication with the temperature
sensors 160, 162. The first temperature sensor 160 is for measuring
a first air temperature T1 in a lower portion of the building 102,
and the second temperature sensor 162 is for measuring a second air
temperature T2 in an upper portion of the building 102.
[0110] The controller 170 controls the air circulator 120 based on
the first and second temperatures T1 and T2. The controller 170 may
be similar to the controller 70 described previously. For example,
in some embodiments, the controller 170 may be part of the air
circulator 120. In other embodiments, the controller 170 may be
located separately from the air circulator 120. For example, the
controller 170 may control multiple air circulators and the
controller 170 may be in remote communication with each of the air
circulators.
[0111] Operation of the system 100 commences by detecting a first
air temperature T1 from the first temperature sensor 160 near the
ground level of the building 102 and detecting a second air
temperature T2 from the second temperature sensor 162 near the
ceiling of the building 102. The controller 164 then calculates a
temperature differential based on the first and second temperatures
T1 and T2, and then operates the air circulator 120 based on the
calculated temperature differential. For example, if the
temperature differential is above a threshold value, which
indicates the air within the building is stratified, the controller
170 might turn on the air circulator 120 by sending a signal to the
drive 134. The controller 170 may continue monitoring the
temperature differential so that once the temperature differential
is below a threshold value, the controller turns off the air
circulator 120.
[0112] The controller 170 may operate other aspects of the air
circulator 120 based on the temperature differential. For example,
the controller 170 may adjust the speed of the fan 132 based on the
temperature differential. For example, if the temperature
differential is high, the controller 164 may operate the drive 134
at a higher speed. If the temperature differential is low, the
controller 164 may operate the drive 134 at a lower speed. In some
embodiments, the controller 64 may operate the drive 134 at one of
several preset speeds. In other embodiments, the controller 164 may
operate the drive 134 using an analogue type signal that allows a
continuous range of speeds, as will be described below.
[0113] The controller 164 may also adjust the operating speed of
the drive 134 based on other events. For example, if there is a
change in the indoor environment such as a door opening, the
controller 164 may increase the speed of the drive 134, for
example, up to full speed. When the door closes, the controller 164
may decrease the speed back down to the previous speed.
[0114] The controller 170 may also control the outlet adjustment
mechanism or other aspects of the air circulator 120 so as to
adjust the vertical and lateral components of the airflow
discharged from the air circulator 120.
[0115] In some embodiments, the system 100 may control the speed of
the fan 132 by adjusting the frequency of a signal sent to the
drive 134. For example, the controller 170 may receive a 120VAC
two-phase signal and convert it to a three-phase AC signal that is
output to the drive 134. The controller 164 may use the three-phase
AC signal to control the speed of the drive 134 by adjusting the
frequency of the three-phase AC signal. This method of control may
have advantages over the prior art.
[0116] Prior art systems tend to control the speed of the drive by
adjusting the voltage using a rheostat, which has numerous
drawbacks. For example, the rheostat in these systems often
produces a noticeable motor hum, in part, due to the size of the
drive (e.g. motor) required to produce the optimal amount of
air-changes-per-hour. In contrast, utilizing the system 100
described above to adjust fan speed based on frequency tends to
reduce motor hum and noise and allows the user to tune the system
100 (e.g. by adjusting fan speed) for a specific application or
building environment.
[0117] In some embodiments, the self-regulating control system 100
may continue operating even after an industrial or a commercial
facility is de-stratified, for example, such that the fan 132
operates at a reduced speed. Operating the fan 132 at reduced speed
can help maintain de-stratification within the building, for
example, to within a temperature differential of about 1.degree. F.
to 2.degree. F. for some buildings. Once the air current is induced
in a building, it is easy to maintain using discharged air with
less velocity.
[0118] The system 100 may adjust the fan speed for other purposes.
For example, the system 100 can to be tuned to meet the desired
effects for occupants. An example would be to vary the fan speed
between summer and winter to produce a wind chill effect induced by
higher speed air currents. By speeding the current up in the summer
it allows for an occupant to perceive the temperature as being
cooler than it actually is, for example, by as much as three or
more degrees Fahrenheit. In the winter, the current speed can be
reduced to reduce the wind chill effect so as to increase the
perceived temperature felt by occupants. The system 100 may also
turn the air circulator 120 off during the night when the space is
un-occupied.
[0119] Another reason for adjusting the fan speed is to create
"vertical air curtains" at loading bay doors. For example, during
the winter, it may be desirable to increase the speed of the fan,
which may keep colder air outside the building below the air intake
of the air circulator 120, and may prevent loading dock workers
from feeling the cold air. Accordingly, when the loading bay door
is opened, the system 100 automatically increases the fan speed.
When the loading bay door is closed, the system 100 automatically
slows the fan 132 down.
[0120] Similarly, during summer operation, it may be desirable to
increase the velocity of the air current within the building when a
loading bay door is opened, which may establish an "air curtain"
and may also provide a wind chill effect.
[0121] Referring now to FIGS. 6 and 7, illustrated therein is an
air circulator 220 made in accordance with an embodiment of the
present invention. The air circulator 220 is similar in many
respects to the air circulator 20 described previously and similar
elements are given similar reference numerals incremented by two
hundred.
[0122] The air circulator 220 includes a housing 222, a support
230, a fan 232, and a drive 234. The housing 222 has a bottom end
224 defining an air intake and a top end 226 defining an air
outlet.
[0123] One difference is that the fan 232 is positioned further
away from the top end 226 in comparison to the air circulator 20
described previously. In particularly, the height H1 between the
top end 226 and the fan 232 is approximately 8 inches.
[0124] The housing 222 also includes a guide 254 encasing the fan
232. One difference is that the guide 254 has a slopped profile
that narrows as it gets closer to the air outlet. This may help
direct the airflow out of the air circulator 220, for example, so
that the discharged air has a significant vertical component and a
significant lateral component.
[0125] Another difference is that the drive 234 is coupled to fan
232 through a series of pulleys and a belt. In particular, one
pulley 280 is coupled to the drive 234, which is in turn coupled to
a second pulley 282 through a belt 284. The second pulley 282 is
also coupled to a shaft 236, which is coupled to the hub of the fan
232.
[0126] The air circulator 220 also includes a controller 270,
however, the controller 270 is located behind a plate 271 that is
removably attached to the housing 222 for concealing the control
panel 270. The controller 270 receives power from a power source
through a power cord 274, which extends outward from the rear of
the housing 222.
[0127] The air circulator 220 also includes one or more filters 280
that remove particulates from the air. The filters 280 may be MERV
8 filters, HEPA filters or another suitable air filter. As shown in
the illustrated embodiment, the filters 280 are positioned on the
support 230 between leg members 240 and cross-members 242 along the
vertical sides of the support 230 and along the bottom side of the
support 230 (shown in FIG. 7).
[0128] The filters 280 may be rectangular filters. Furthermore, the
filters 280 may be of a standard rectangular size used in
filtration industry.
[0129] The filters 280 may have a cumulative filtration surface
area that is larger then the cross-sectional area of the airflow
passageway 228. For example, in the illustrated embodiment, the
filters 280 on the vertical sides of the support 230 increase the
surface area tend to increase the filtration surface area in
comparison to using one filter along the air intake 224 at the
bottom of the housing 222. In particular, the filtration surface
area is approximately three times larger than the cross-section of
the airflow passageway 28. Increasing the filtration surface area
tends to reduce the velocity of the air flowing through the filters
280, which may improve the effectiveness of the filters 280.
[0130] In some embodiments, the filters 280 may be located in
different positions. For example, one filter may be positioned at
the bottom end of the housing 222.
[0131] As shown, the fan 232 is generally spaced apart from the
filters 280. Positioning the fan 232 closer to the top end 226 of
the housing 222 tends to improve filtration. In particular, when
the fan 232 is positioned closer to the bottom end 224, the speed
of the air coming through the filters 280 tends to increase, which
reduces the effectiveness of the filters 280. By placing the fan
232 further away from the bottom end 224, the speed of the air
coming through the filters 280 decreases, which may improve the
effectiveness of the filters 280.
[0132] Assuming the width of the cross-members 242 is minimal, the
distance between the fan 232 and the filters 280 generally
corresponds to a third height H3 between the fan 232 and the bottom
end 224 of the housing 222. Generally, the third height H3 is at
least about 20-inches. In the illustrated embodiment, the third
height H3 is about 24-inches.
[0133] In other embodiments, the height of the fan 232 above the
filters 280 may be defined in relative terms. In particular, the
third height H3 may be defined relative to the second height H2
between the bottom end 224 and the top end 226 of the housing 222.
For example, the third height H3 may be more than about half of the
second height H2, or the third height H3 may be more than about two
thirds of the second height H2. In the illustrated embodiment,
third height H3 is about nine tenths of the second height H2.
[0134] By way of example, the inventor has determined that the air
circulator 220 as described above and having a 36 inch fan 232, and
using a 0.5 horsepower drive 234 provides an air speed between
about 200 to 500 feet-pet-minute at about 10,000
cubic-feet-per-minute. The filtration provided by the air
circulator 220 is comparable to other prior art systems, but the
air circulator 220 uses about one third of the energy compared to
the other prior art systems.
[0135] The air filters 280 can help reduce odours. For example, the
air filters may incorporate charcoal cartridges that reduce or
eliminate odours and chemical particulates from cleaning/sanitizing
agents, or from other manufacturing processes. The air filters 280
may also reduce airborne allergens.
[0136] In some embodiments, the air circulator 220 may be adapted
to provide fresh-air or "make-up air" capabilities, for example, by
providing a length of ducting between the air intake and a source
of fresh air (e.g. outside air).
[0137] The air circulator 220 may also be fitted with a heating
source so as to heat air being circulated within an indoor
environment. For example, the heating source may include a solar
heating coil or a hydronic heating coil, or a heat source fueled by
natural gas, oil, or electricity. The air circulator 220 may also
be fitted with a cooling device such as an air conditioner.
[0138] While the above description provides examples of one or more
apparatus, methods, or systems, it will be appreciated that other
apparatus, methods, or systems may be within the scope of the
present description as interpreted by one of skill in the art.
[0139] Other variations and modifications of the invention are
possible. All such modifications or variations are believed to be
within the sphere and scope of the invention as defined by the
claims appended hereto.
* * * * *