Water cooler abstract
This invention uses an air to air heat exchanger to cool the air
passing through an evaporative water cooler. This enables the evaporative
water cooler to cool water to a temperature very near to the dewpoint
temperature. The water so cooled may be used to remove heat from
other media. One use of the cooled water is to remove heat from
a habitation. This invention provides in hot arid climates a method
of cooling air inside a habitation to a temperature providing comfort
to the occupants at a much lower cost and at a much lower usage
of electrical energy than previous methods.
Water cooler claims
1. A method of cooling air inside of a habitable enclosed space
drawing a first stream of air from the ambient surrounding the
said enclosed space;
wherein the first stream of air is passed, in heat exchange relationship,
through the a chamber of an air to air heat exchanger, the said
first stream of air is then caused to pass to an evaporative cooler
to be in contact with a quantity of water, thereby cooling by evaporation
the water and the air; then the first stream of air is passed, in
heat exchange relationship, through a second chamber of the air
to air heat exchanger in a direction countercurrent to the air flow
direction in the first chamber of the air to air heat exchanger,
thereby cooling the first stream of air in the first chamber of
the air to air heat exchanger before it touches the said water,
and heating the first stream of air in the second chamber of the
air to air heat exchanger before it is returned into the ambient
surrounding the said enclosed space; the first stream of air is
then expelled into the ambient surrounding the said habitable enclosed
the cooled water is then collected and pumped to a collection tank
from which a first portion of said water is circulated through a
first chamber of an air to water heat exchanger which is inside
of the said habitable enclosed space, and a second portion of said
water is pumped back to said evaporative cooler;
a second stream of air is dram from the body of air, which is inside
of the said habitable enclosed space; wherein the second stream
of air is passed, in heat exchange relationship, through the second
chamber of the air to water heat exchanger, thereby cooling the
second stream of air; and the second stream of air is expelled into
the body of air, which is inside of the said habitable enclosed
space, thereby mixing with and cooling that body of air.
Water cooler description
The cooling of liquid water by causing air to contact some of the
water and mixing some water molecules into the air, is the process
of evaporative cooling. Water which changes state from a liquid
to a gas in order to join with the gasses comprising the air, removes
some heat from the water remaining in the liquid state. The heat
mentioned is the latent heat of vaporization. Each gram of water
vaporized requires the removal of 540 calories.
Factors involved in the effectiveness of evaporative cooling include
1. The temperature of the liquid water. Water tends to evaporate
less easily at lower temperatures.
2. The temperature of the air.
3. The ratio of gaseous water molecules to other molecules in the
4. The movement of air molecules relative to the liquid surface.
A common evaporative cooler used to reduce the temperature of an
inhabited area, utilizes the air stream exiting from contact with
the liquid water. The mentioned contact usually occurs as the air
moves through small spaces in a layer of loosely joined wettable
material such as wood shavings, shredded paper or some other wettable
material. The air so used is cooled by conduction with the surface
of the unvaporized liquid water. It has been found through examination
that the temperature of the liquid water being recycled through
the wettable material in a common evaporative cooler, operating
normally, may be several degrees cooler than the temperature of
the air stream. The air remains at a higher temperature than the
water because conductive heat transfer to the liquid water from
the air stream cannot be completed during the limited contact which
occurs in this process.
The air stream from an evaporative cooler used for cooling a habitation
is usually introduced through one or more openings in the habitation
and allowed to exit through one or more other openings. The improvement
in comfort level for the inhabitants depends upon the immediate
effectiveness of the evaporative cooler as determined by factors
which include those listed above. It has been observed that the
use of evaporative cooling, as described, for inhabitants of hot
arid climates is sometimes acceptable to those inhabitants but is
often considered inadequate. These inadequacies are often endured
because the common alternative method of habitation cooling, while
usually providing a more comfortable environment, is more expensive
to manufacture and to operate. Air conditioning, the cooling method
referred to, is a Carnot cycle refrigerator using a phase changing
substance such as Freon.
Air conditioning used for habitation cooling usually recirculates
the air inside the habitation. Heat is removed by passing some of
that air through a heat exchanger called an evaporator which includes
the vaporization phase change apparatus of the Carnot cycle refrigerator.
Heat acquired by the vaporizing substance is transferred to outside
air being passed through another heat exchanger called a condenser,
which includes the liquefaction phase change apparatus of the Carnot
cycle refrigerator. Electrical energy is usually used to perform
the work required to move the phase changing substance from the
evaporator to the condenser. The amount of energy required to remove
a quantity of heat from a habitation is much greater using a Carnot
cycle refrigerator than the amount of energy required to move the
same quantity of heat using an evaporative water cooler.
The invention disclosed by this specification provides, in hot
arid climates, habitation cooling as comfortable as air conditioning
while using much less electrical energy. This invention uses evaporative
cooling to establish a reservoir of cooled water which may be used
to remove heat from other media including air inside a habitation.
The cooled water may be circulated through an air to water heat
exchanger through which a portion of the habitation air is passed.
The innovation which sets this invention apart from previous products
is the use of an air to air heat exchanger between the air stream
entering the moist wettable material of the evaporative cooler and
the air stream exiting the moist wettable material. The use of the
mentioned heat exchanger effectively removes heat from the air used
for evaporation so that less heat is transferred from the air stream
to the liquid water in the moist wettable material. This allows
the water to cool to a temperature which is limited only by the
dewpoint of the air entering the evaporative cooler. In hot arid
environments, the dewpoint may occasionally rise above the maximum
temperature at which this invention will cool water satisfactorily.
An adequate insulated reservoir of water, cooled during time periods
of effectiveness, will provide a means to remove heat from air in
a habitation during short periods of ineffectiveness.
DESCRIPTION OF DRAWINGS
FIG. 1 illustrates the basic idea of this invention which is the
combination of an air to air heat exchanger with an evaporative
FIG. 2 is another illustration of the idea of this invention with
the addition an application.
FIG. 3 is an unscaled illustration of one type of air to air heat
exchanger suitable for inclusion as part of this invention.
FIG. 4 demonstrates the assembly of the heat exchanger mentioned
FIG. 5 is an unscaled illustration of the invention as it may be
used to cool a habitation.
A basic explanation of this invention may be facilitated by reference
to FIG. 1. An air permeable, wettable material such as excelsior
or shredded paper, shown as reference number 5 is wet with water
delivered by a pump, shown as reference number 6 from a water reservoir,
shown as reference number 8. Air is moved through the wettable material
by a blower, shown as reference number 4. The items so far mentioned
comprise a common evaporative cooler. In the production of this
invention a commercially available evaporative cooler may be used
to provide those items so far mentioned. The air which is moved
through the wettable material is drawn from the outside environment
through an air to air heat exchanger, shown as reference number
1 through a passageway, shown as reference number 2. After moving
through the wettable material, the air travels through another passageway,
shown as reference number 3 through the air to air heat exchanger,
then returns to mix with the outside air. The mentioned air enters
the air to air heat exchanger at the temperature of the outside
environment. As the air travels through the heat exchanger, heat
is removed from the incoming air and added to the outgoing air.
As the incoming air leaves the heat exchanger, its temperature has
been reduced to nearly the same temperature as the outgoing air
as it leaves the wettable material. As the air passes through the
wettable material, some of the water vaporizes and in doing so,
removes heat from the water which remains liquid. The air is cooled
by transferring heat to the liquid water in the wettable material.
The air entering the wettable material has been cooled during passage
through the air to air heat exchanger and is at a temperature only
slightly greater than the temperature of the liquid water. Only
a small amount of heat is available for transfer to the liquid water.
Under the mentioned circumstances, if the air entering the wettable
material is above the dewpoint temperature, vaporization will occur
and the temperature of the water will decrease. The water may be
cooled to very nearly the dewpoint temperature.
FIG. 2 depicts the same items as previously mentioned using the
same reference numbers and adds a depiction of the use of water
cooled through operation of this invention to remove heat from a
habitation. Water from the reservoir shown as reference number 8
is passed through an air to water heat exchanger, shown as reference
number 11 which is inside the habitation. Air from inside the habitation
is passed by a blower, shown as reference number 10 through the
air to water heat exchanger, which cools the air by conduction.
Operation of pumps and blowers which pertain to this invention may
be controlled using well established methods and materials such
as temperature sensors, thermostats and relays to maintain an air
temperature inside a habitation which may be acceptable to the occupants
of the habitation.
Effective performance by this invention requires a suitable air
to air heat exchanger between the air stream entering and the air
stream exiting the invention. A heat exchanger of any design, construction
method or materials may be included in realization of this invention.
The following description is presented as an example only and places
no restrictions on the scope of this invention.
The construction of one suitable heat exchanger may be seen by
referring to the unscaled illustrations identified as FIG. 3 and
FIG. 4. All dimensions mentioned in this description are those used
in the initial application of this invention and may vary. All materials
mentioned in this description are those used in the initial application
of this invention. Any suitable materials may be used in the construction
and application of this invention. The item shown as reference number
13 represents one subassembly of the heat exchanger. The subassembly
consists of a sheet of aluminum, 3 strips of compressed wood fiber
board and a suitable adhesive. In this example, the aluminum sheet
is 8 feet long, 20 inches wide and 0.03 inches thick. Strips of
compressed wood fiber board are attached with adhesive along 2 edges
of the aluminum sheet as shown. Each fiber board strip is 85 inches
long, 0.75 inches wide and 0.25 inches thick. During assembly, the
first fiber board strip is attached with one end in alignment with
one end of the aluminum sheet and with one edge aligned with an
edge of the aluminum sheet as shown. Another similar fiber board
strip is attached with one end in alignment with the same end of
the aluminum sheet as the first fiberboard strip but at the opposite
edge of the aluminum sheet. A third fiberboard strip which is 20
inches long, 0.75 inches wide and 0.25 inches thick is attached
as shown with one edge in alignment with other end of the aluminum
The item shown as reference number 14 represents a subassembly
similar to that represented by reference number 13 but rotated 180
degrees. The heat exchanger is assembled by stacking previously
described subassemblies as shown by FIG. 4. Note that the position
of the short fiberboard strip of each succeeding subassembly is
at the end of the heat exchanger opposite that of the short fiberboard
strip of the subassembly to which it is attached. Eighty subassemblies
are stacked as described to form the heat exchanger. A sheet of
fiberboard 8 feet long, 20 inches wide and 0.25 inches thick is
attached to the top subassembly. Air forced into either end of the
heat exchanger will exit through the sides of the heat exchanger
near the other end. The completed heat exchanger is represented
by FIG. 3 reference number 1. For clarity, only 8 subassemblies
FIG. 5 is a general representation of essential elements of this
invention configured for operation. Connections for electrical energy,
control items and water supply are included using good common practice
and have been omitted from FIG. 5 for clarity. Construction of this
invention includes a box, shown as reference number 2 which forms
a passageway for air between the air to air heat exchanger and the
wettable material, formed of any suitable material such as metal,
wood or plastic, with dimensions allowing enclosure of a commercially
available evaporative cooler, shown as reference numbers 3 4 and
5 with adequate space between the inside surface of the box and
the evaporative cooler for air flow around the evaporative cooler.
The dimensions of one such box which was incorporated into an operational
example of this invention are, length 48 inches, width 48 inches
and height 40 inches. Six pieces of plywood are used. The bottom
and top (Not shown) each measure 48 inches by 48 inches by 0.75
inches. the 4 sides each measure 48 inches by 40 inches by 0.75
inches. Common adhesive and fasteners are used in assembly. The
top is easily detachable for access inside the box. An evaporative
cooler is installed inside the box as shown. A suitable hole is
cut in one side of the box to allow insertion of one end of the
previously mentioned air to air heat exchanger with the end connected
with the air outlet duct, shown as reference number 3 of the evaporative
cooler. A water reservoir shown as reference number 8 is connected
to the evaporative cooler using common plumbing materials and techniques.
Pumps, shown as reference numbers 6 and 12 may be used to introduce
to and remove water from the evaporative cooler. Note that the evaporative
cooler and the mentioned box are shown without top covers which
will be required for operation.
FIG. 5 reference numbers 10 and 11 depict a blower and an air to
water heat exchanger respectively which are installed inside a habitation.
During normal operation water from the reservoir, shown as reference
number 8 is circulated through the air to water heat exchanger
using common plumbing materials and techniques by a pump, shown
as reference number 9. Air inside the habitation is moved through
the air to water heat exchanger by the blower, effectively reducing
the temperature of the air inside the habitation.