Abstrict A method and system for climate control uses a desiccant in an
automobile. The desiccant removes humidity or moisture from air
passing through the ventilation system. The desiccant is recharged
or dried by application of a vacuum. The lower pressure generated
by the vacuum reduces the temperature at which water evaporates
or boils off of the desiccant material.
Claims What is claimed is:
1. A system for climate control using desiccant in an automobile,
the system comprising: a desiccant exposed to air within an automobile;
and a vacuum source operative to generate a low pressure area adjacent
at least a portion of the desiccant.
2. The system of claim 1 further comprising an air duct operatively
connected with an automobile passenger compartment wherein the desiccant
is exposed to air within the air duct.
3. The system of claim 1 wherein the vacuum source comprises a
vacuum pump associated with an engine of the automobile.
4. The system of claim 1 wherein the vacuum source comprises suction
responsive to flowing liquid.
5. The system of claim 4 wherein the flowing liquid comprises engine
coolant.
6. The system of claim 1 wherein the desiccant comprises a cartridge
of silica gel.
7. The system of claim 1 further comprising an activated carbon
filter adjacent the desiccant.
8. The system of claim 1 wherein the desiccant comprises a segmented
desiccant cartridge.
9. The system of claim 8 wherein a first segment of the segmented
desiccant cartridge is exposed to an airstream and a second segment
of the segmented desiccant cartridge is exposed to the vacuum source.
10. The system of claim 9 further comprising an actuator operable
to reverse the exposure of the first and second segments.
11. A method for climate control with a desiccant in an automobile,
the method comprising: (a) exposing a desiccant to air within an
automobile; and (b) generating a low pressure area adjacent at least
a portion of the desiccant.
12. The method of claim 11 wherein (a) comprises exposing the desiccant
within an air duct.
13. The method of claim 11 wherein (b) comprises generating the
low pressure area with a vacuum pump.
14. The method of claim 11 wherein (b) comprises generating the
low pressure area with fluid flow.
15. The method of claim 14 wherein (b) comprises generating the
low pressure area with engine coolant.
16. The method of claim 11 wherein (a) comprises exposing silica
gel.
17. The method of claim 11 further comprising: (c) removing humidity
from the air in response to (a).
18. The method of claim 11 further comprising: (c) filtering the
air with an activated carbon filter.
19. The method of claim 11 wherein the desiccant comprises a segmented
desiccant cartridge and (a) comprises exposing a first segment of
the segmented desiccant cartridge; further comprising (c) exposing
a second segment of the segmented desiccant cartridge to the low
pressure area.
20. The method of claim 11 further comprising: (c) switchably positioning
a first portion of the desiccant to be exposed pursuant to (a) and
a second portion to be exposed to the low pressure area.
21. A system for climate control using desiccant in an automobile,
the system comprising: an air duct; a vacuum chamber; a desiccant
positionable within the air duct and the vacuum chamber; an actuator
operatively connected with the desiccant, the position of the desiccant
relative to the air duct and the vacuum chamber responsive to the
actuator; and a controller connected with the actuator.
Description BACKGROUND
[0001] This invention relates to dehumidification in an enclosed
area. In particular, a method and system for climate control using
a desiccant in an automobile is provided.
[0002] Humidity in automobiles condenses on windows, impairing
a vehicle operator's vision. For lower temperatures with high humidity,
the typical ventilation system in an automobile may be incapable
of effectively, efficiently or quickly removing the condensation.
For example, air is recirculated from within a passenger compartment.
Recirculating the air delays or prevents removal of the condensation
from the window.
[0003] Desiccant systems have been developed for use in busses.
Desiccants absorb a limited amount of moisture. Once the limited
amount of moisture has been absorbed, the desiccant is dried or
recharged by application of heat. The desiccant is exposed to exhaust
gases from the engine. However, it is undesirable to route exhaust
gases adjacent to the air duct or ventilation system of the bus.
The proximity and connection between the exhaust gases and the air
ducts for ventilation may allow leakage of exhaust into the passenger
compartment. Furthermore, the exhaust gases can foul or otherwise
deteriorate the desiccant material.
BRIEF SUMMARY
[0004] The present invention is defined by the following claims,
and nothing in this section should be taken as a limitation on those
claims. By way of introduction, the preferred embodiment described
below includes a method and system for climate control using a desiccant
in an automobile.
[0005] A desiccant removes humidity or moisture from air passing
through the ventilation system. The desiccant is recharged or dried
by application of a vacuum. The lower pressure generated by the
vacuum reduces the temperature at which water evaporates or boils
off of the desiccant material.
[0006] In one aspect, a method and system for climate control of
a desiccant in an automobile are provided. A desiccant is exposed
to air within an automobile. A vacuum source is operative to generate
a low pressure area adjacent to at least a portion of the desiccant.
[0007] In another aspect, a system for climate control using a
desiccant in an automobile is provided. The system includes an air
duct and a vacuum chamber. A desiccant is positionable within the
air duct and the vacuum chamber. An actuator operatively connects
with the desiccant. The position of the desiccant relative to the
air duct in the vacuum chamber is responsive to the actuator. A
controller connects with the actuator.
[0008] Further aspects and advantages of the invention are discussed
below in conjunction with the preferred embodiments.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0009] FIG. 1 is a diagram of one embodiment of a system for climate
control using desiccant.
[0010] FIG. 2 is a diagram of another embodiment of a system for
climate control using a desiccant.
[0011] FIG. 3 is a flow chart diagram representing one embodiment
of the operation of the system of FIG. 2.
[0012] FIG. 4 is a perspective view of a system for climate control
using a desiccant of yet another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] The embodiments discussed below use a vacuum or low pressure
to recharge a desiccant. The humidity or moisture absorbed by the
desiccant is removed by evaporation due to the low pressure. The
desiccant is repetitively used to remove humidity or moisture from
the air in the passenger compartment of an automobile. When air
is recirculated within the passenger compartment through the ventilation
system in high humidity and lower temperature environments, the
desiccant removes humidity. The drier air within the passenger compartment
does not allow formation of condensation on windows. The system
also allows use of recirculating air for faster warming up of the
vehicle during particularly low temperature environments. The system
may decrease the load on an air conditioning system in a higher
temperature environments.
[0014] FIG. 1 shows one embodiment of a system for climate control
using a desiccant. A desiccant 10 is provided in or adjacent to
an air duct 12 and a vacuum chamber 14. The air duct 12 comprises
a metallic, plastic or other tube or chamber of air. The air duct
12 is shaped as a tube, cylinder, rectangular or square shaped tube
or any other geometric body for the transport of air. The air duct
12 may be of any of various sizes. The air duct 12 connects with
a passenger compartment of an automobile in one embodiment. For
example, the air duct 12 comprises a return air duct of an air handling
case in an automobile. As yet another example, the air duct 12 comprises
an air intake inlet or vent of the return air duct behind or below
a dashboard of an automobile. In alternative embodiments, the air
duct 12 connects with other chambers, compartments or bodies of
air where reduced humidity is desired.
[0015] The desiccant 10 comprises a silica-based desiccant cartridge.
In alternative embodiments, the desiccant comprises a zeolite, clay
base or salt base desiccant. One to two pounds or other amounts
of silica desiccant material are placed within a plastic or metallic
cartridge allowing exposure of the desiccant 10 to air. The desiccant
10 is shaped in any of various shapes, such as a rectangular or
circular volume. The desiccant 10 is sized such that it fits within
or adjacent to the air duct 12 impeding none, a portion or the
entire air duct 12.
[0016] Additional material may be provided with the desiccant 10.
For example, activated carbon is incorporated within the desiccant
material 10 or adjacent to the desiccant 10. Activated carbon reduces
odors within the air traveling through or near the desiccant 10.
Alternatively or additionally, a biocide, such as antifungal or
antimold material, is included with or adjacent to the desiccant
material 10. Other air purifying or conditioning materials may be
used.
[0017] The vacuum chamber 14 comprises a vacuum source. The vacuum
chamber 14 comprises a volume of various shapes and sizes, such
as a generally rectangular volume sized to include at least a portion
of the desiccant 10. The vacuum chamber 14 may be larger than the
volume needed to house the desiccant material 10. The vacuum chamber
14 is formed from plastic, metal or other material able to withstand
a lower pressure without collapse.
[0018] The vacuum chamber 14 has a low pressure. One or more of
various mechanisms may be used for generating the low pressure.
For example, the engine vacuum generated by an engine of an automobile
is used to create the low pressure within the vacuum chamber 14.
As another example, the Bernoulli affect is used to generate a vacuum
within the vacuum chamber 14. The flow of fluid within the automobile
is used to generate a suction, resulting in a vacuum. In one embodiment,
a hose connects the vacuum chamber 14 to an engine coolant hose.
The flow of engine coolant creates a suction within the vacuum chamber
14.
[0019] Water within the desiccant 10 in or adjacent to the vacuum
chamber 14 is boiled or evaporated from the desiccant 10. The recharged
desiccant 10 is exposed to air in the passenger compartment, allowing
the recirculation of air within an automobile without excessive
fogging on windows and reducing the load on an air conditioning
system by removing latent heat from the air. The passive desiccant
10 reduces the power consumption of a climate control system within
an interior of an automobile in high humidity environments.
[0020] As shown, the desiccant 10 is within both the vacuum chamber
14 and the air duct 12. In one embodiment, the desiccant 10 is moveable
between or within each location. The desiccant 10 may be positioned
adjacent to one or both the air duct 12 and the vacuum chamber 12.
The desiccant 10 may be fixedly molted in alternative embodiments.
[0021] FIG. 2 shows one embodiment of a system for climate control
using a desiccant in an automobile. The system includes a desiccant
cartridge 20 first and second vacuum chambers 22 24 an air duct
26 a vacuum tube 28 a vacuum source 30 an actuator 32 a controller
34 a temperature sensor 36 and a humidity sensor 38.
[0022] In response to control signals from the controller 34 the
actuator 32 acts to move portions of the desiccant cartridge 20
into the air duct 26 and other portions into one of the vacuum chambers
22 24. Continuous or substantially continuous removal of humidity
from air within the air duct 26 is provided. The air duct 26 desiccant
cartridge 20 and the vacuum chambers 22 24 comprise the same or
similar materials, shapes, and sizes discussed above with respect
to FIG. 1.
[0023] The desiccant cartridge 20 is segmented. A wall or barrier
40 separates the desiccant cartridge 20 into at least two portions.
The barrier 40 of one embodiment separates the desiccant cartridge
20 in half. The barrier 40 is positioned such that a seal or partial
seal is provided to separate a portion of a desiccant cartridge
20 within a vacuum chamber 22 24 from the portion of the desiccant
cartridge 20 within the air duct 26. In the dual vacuum chamber
embodiment shown in FIG. 2 the ends of the desiccant cartridge
20 are also shaped so as to provide a seal or partial seal between
the vacuum chambers 22 24 and the air duct 26. The desiccant cartridge
20 comprises a metal, plastic or other material in a web (i.e.,
screen) or partial web-partial enclosure for exposing desiccant
to air.
[0024] The desiccant cartridge 20 is mounted within slots or apertures
within the vacuum chambers 22 and 24. In one embodiment, rails or
other guiding mechanisms are additionally provided to guide the
desiccant cartridge 20 as it is positioned within the vacuum chambers
22 24 and the air duct 26. Rollers may also be provided for positioning
the desiccant cartridge 20.
[0025] Two vacuum chambers 22 24 are provided so that while one
portion of the desiccant cartridge 20 is within the air duct 26
the other portion is exposed to the low pressure within one of the
vacuum chambers 22 24. When the desiccant cartridge 20 is repositioned,
the recharged portion of the desiccant cartridge 20 is exposed within
the air duct 26 and the portion of the desiccant cartridge 20 storing
more water is positioned in the associated vacuum chamber 22 24.
For example, a left or first half of a desiccant cartridge 20 is
positionable within a first vacuum chamber 22 and the air duct 26.
A right or second half of the desiccant cartridge 20 is positionable
within the air duct 26 and a second vacuum chamber 24. The portion
of the desiccant cartridge 20 exposed within the air duct 26 is
switched from one portion to the other of the desiccant cartridge
20. In alternative embodiments, a wheel structure is used for the
desiccant cartridge 20 and a single vacuum chamber 22 24 are provided.
The desiccant cartridge 20 is recharged by rotating the portion
of the desiccant cartridge 20 exposed within the air duct 26 into
the vacuum chamber 22. In other alternative embodiments, different
structures and different numbers of associated vacuum chambers may
be provided.
[0026] The vacuum source 30 is connected through the vacuum hose
28 to the vacuum chambers 22 and 24. The same or different sources
of vacuum 30 may be used for each of the vacuum chambers 22 24.
In one embodiment, the vacuum source 30 comprises a fluid pump,
such as provided in a coolant system. A portion of the vacuum hose
28 comprises a hose for carrying engine coolant. An additional hose
is connected to the coolant hose for generating a suction with the
Bernoulli effect for the vacuum chambers 22 and 24. For example,
a T connection is used. In an alternative embodiment, the vacuum
source 30 comprises an engine vacuum or an auxiliary belt or electric
powered vacuum pump. For example, an auxiliary electrically powered
vacuum pump is provided in the engine compartment of the automobile.
The vacuum hose 28 communicates a suction or low pressure to the
vacuum chambers 22 24. In alternative embodiments, the vacuum source
30 connects directly to or is within the vacuum chambers 22 24.
[0027] The vacuum hose 28 comprises a rubber, plastic, fiber, metal,
combinations thereof or other material for transmitting liquid or
gas, such as air, to generate suction.
[0028] Where the Bernoulli effect is used, a degasser or other
device for removing air sucked into the flowing fluid to create
the low pressure is preferably provided. For example, coolant systems
within automobiles typically have a degasser.
[0029] The actuator 32 comprises an electric motor with a push
rod assembly. The actuator 32 is electrically activated to move
the rod and connected desiccant cartridge 20. Alternatively, an
actuator with an associated gear, pulley or belt system is used
for repositioning or switching the desiccant cartridge 20. The actuator
32 is positioned within or adjacent to a vacuum chamber 24 the
air duct 26 or another location. The actuator 32 is positioned such
that the desiccant cartridge 20 switchably recharges and exposes
recharged desiccant within the air duct 26. The actuator 32 may
alternatively directly connect with the cartridge 20. In alternative
embodiments, hydraulic, vacuum operated, or non-electric actuator
devices are used for positioning the desiccant cartridge 20.
[0030] A controller 34 controls operation of the actuator 32. The
controller 34 comprises an application specific integrated circuit,
a digital signal processor, an analog circuit, a general processor,
combinations thereof or other device for receiving inputs and outputting
control signals to the actuator 32. In one embodiment, the controller
34 comprises a multifunction processor used for other control within
the automobile.
[0031] The controller 34 receives inputs from one or move devices.
In one embodiment, the controller 34 receives inputs from the temperature
sensor 36 the humidity sensor 38 and a recirculation control button
42. Different, additional, or fewer inputs may be provided. The
temperature sensor 36 the humidity sensor 38 and the recirculation
control button 42 comprise any one or more of various sensors or
buttons used in automobiles for climate control or other purposes
for the operation of the automobile. For example, the temperature
and humidity sensors 32 38 used for automatic climate control are
also used as input to the controller 34 for operation of the actuator
32. The recirculation button 42 comprises a button, slide or other
input device for the operator of the automobile to select recirculation
of air within the ventilation system.
[0032] The controller 34 responds to the input from one or more
devices, such as the temperature sensor 36 the humidity sensor
38 and the recirculation control button 42. In response to the
inputs, the controller 34 causes the actuator 32 to reposition the
desiccant cartridge 20. In one embodiment where the climate control
system is set to recirculate air within the passenger compartment,
the controller monitors the temperature and humidity from the temperature
sensor 36 and humidity sensor 38. Where a threshold level of humidity
and a threshold lower temperature is detected, the controller 34
causes the actuator to position a recharged portion of the desiccant
cartridge 20 within or adjacent to the air duct 26. The controller
34 then periodically repositions the desiccant cartridge 20 or,
after a predetermined time, monitors the environment as discussed
above until another reposition is triggered.
[0033] Repositioning of the desiccant cartridge 20 after a time
or periodically continues until the climate control system is removed
from a recirculation mode, the temperature exceeds a threshold,
the humidity 38 becomes sufficiently low, an air conditioning compressor
turns on, another event occurs or combinations thereof. Depending
on the desiccant, an amount of wator vapor that is about 20-50%
of the dry weight of the desiccant may be absorbed. For example,
two to three hours are used to absorb water vapor after one reposition
of the desiccant cartridge 20. It is estimated that one hour is
needed for recharging, but this time may differ as a function of
various factors including the amount of vacuum.
[0034] In other embodiments, the controller 34 also controls the
vacuum source 30. For example, the controller 34 turns the vacuum
source 30 on or off in conjunction with actuation of the actuator
32 and continued periodic actuation. In yet other alternative embodiments,
the controller 34 operates valves or switches to control the supply
of low pressure to the vacuum chambers 22 and 24.
[0035] FIG. 3 shows a flow chart of one embodiment representing
the operation of the climate control system of FIG. 2. The flow
chart represents one embodiment for exposing a desiccant to air
within the passenger compartment and a generating a low pressure
to remove liquid from the desiccant. In act 50 selection of a recirculation
setting is detected. In act 52 a temperature within the passenger
is detected. In act 54 the humidity within the passenger compartment
is detected. In alternative embodiments, any one or more of act
50 52 or 54 may be skipped. In response to activation of the recirculation
setting, a range of temperatures and range of humidities, a vacuum
is applied to the desiccant material. In act 56 application of
the low pressure by activating a pump, generating a Bernoulli effect,
or positioning a portion of a desiccant material within a vacuum
chamber removes liquid from the desiccant material. To further remove
humidity from air within the passenger compartment, the desiccant
material is shifted to expose recharged desiccant within the air
in communication with the passenger compartment in act 58. For example,
silica desiccant material is exposed to air within an air duct while
another portion of a desiccant material is exposed to a low pressure
vacuum. Other filtering may be provided in act 58 such as providing
for carbon activated filtering. Periodically as a function of time,
detected environmental conditions, or other inputs, the desiccant
material is shifted in act 58 so that recharged desiccant is exposed
to air associated with the passenger compartment and other portions
of the desiccant material are exposed to a low pressure for recharging
the desiccant.
[0036] FIG. 4 is a perspective view of another embodiment of the
climate control system 60. The climate control system includes a
desiccant system 62 and an air handling unit 64. The air handling
unit 64 is adapted for mounting behind a dash board of an automobile.
The air handling unit 64 provides heated, cooled and/or filtered
air to the passenger compartment.
[0037] The air handling unit includes an inlet duct or vent 66.
The inlet vent 66 is adapted for drawing air from the passenger
compartment in to the air handling unit 64.
[0038] The desiccant system 62 connects to the inlet vent 66. In
one embodiment, the desiccant system 62 covers the inlet vent 66.
The desiccant system 62 comprises a housing 68 and two nipples 70.
The housing 68 comprises metal, plastic, other materials or combinations
thereof. The housing 68 contains two vacuum chambers and an air
flow or air duct section as described above with reference to FIG.
2. The air flow section allows air to pass from the passenger compartment,
through the housing 68 and into the inlet vent 66.
[0039] In the embodiment shown, each vacuum chamber is associated
with one of the nipples 70. The vacuum from the vacuum source is
provided through the nipples 70. The desiccant is about 2/3 the
length of the housing 68. The desiccant slides between 1) exposing
a first half in the air flow section and placing a second half in
one of the vacuum chambers and 2) exposing the second half in the
air flow section and placing the first half in the other vacuum
chamber.
[0040] While the invention has been described above by reference
to various embodiments, it will be understood that many changes
and modifications can be made without departing from the scope of
the invention. For example, any of various sources of vacuum and
desiccant materials may be used, whether now known or later developed.
Additionally, different relative sizes and shapes of various components
of the climate control system may be used.
[0041] It is therefore intended that the foregoing detailed descriptions
be understood as an illustration of the presently preferred embodiments
of the invention, and not as a definition of the invention. It is
only the following claims, including all equivalents, that are intended
to define the scope of this invention. |