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BACKGROUND OF THE INVENTION
This invention relates to a room ventilator and, more particularly, to a
regenerative room ventilator of the type wherein polluted air is removed
from and fresh air is supplied to the room, and wherein heat is
transferred between the polluted, or room, air and the fresh air.
In an effort to conserve energy, buildings, and particularly dwellings, are
constructed in a manner which minimizes leakage between air within the
structure and exterior air. Sources of leakage, such as joints, windows,
doors and other openings, typically are sealed effectively to prevent any
leakage of warm interior air during the cold winter season or cool,
air-conditioned interior air during the summer season. While such sealing
techniques have improved energy conservation, the resultant reduction of
air infiltration has aggravated indoor pollution.
Polluted, or stale, room air generally is not replaced with fresh air in
sealed houses unless a door or window is opened or other effective
ventilating equipment is provided. In its simplest form, a room ventilator
may be constructed merely as a register or duct in an outside wall or roof
of a house to permit polluted room air to pass therethrough to the
exterior and to allow fresh air to enter the house. Such a simple
ventilator is, however, a source of energy loss by allowing warm air to
escape during the winter and by allowing cool air to escape during the
summer.
More complicated air exchangers have been proposed wherein exhaust and
inlet conduits are disposed in heat exchange relationship to permit the
heat from exhausted room air to be transferred to incoming fresh air. Such
exchangers reduce energy loss by replacing polluted room air with fresh
air. However, one difficulty encountered with such exchangers is the
installation thereof. Generally, these devices are installed by suspending
them beneath the floor or elevating them above a ceiling in a house. If
the house is a completed structure, such installation is time-consuming
and expensive because substantial renovations in the building itself may
be needed. Also, the respective flows of polluted and fresh air in such
exchangers typically are in the horizontal direction, thus requiring
relatively large horizontal structures to effect proper heat exchange
between these air flows. Moreover, because the polluted and fresh air flow
in horizontal channels, the polluted air inlet and fresh air outlet to a
room are constrained to be closely spaced to each other. This results in
feedback or "cross-talk" by which the fresh air is fed back into the
polluted air discharge channel. Consequently, the efficiency of such
exchangers in removing pollution and in warming the incoming fresh air is
reduced. One type of exchanger is adapted to be installed in a
partially-opened window of the house. While this installation is
relatively simple, it suffers from the disadvantages of obscuring a
substantial portion of the window area, it is aesthetically displeasing,
it exhibits the aforementioned cross-talk, and it is relatively noisy in
operation.
Although vertically oriented heat exchangers have been known, such as
described in U.S. Pat. Nos. 1,871,322, 1,960,325, 2,091,119, 2,360,094 and
2,488,333, as examples, such heat exchange apparatus generally is not used
as a room ventilator by which polluted, stale room air is replaced by
fresh air.
OBJECTS OF THE INVENTION
Therefore, it is an object of the present invention to provide an improved,
relatively simple, easily installed room ventilator.
Another object of this invention is to provide a simple, efficient room
ventilator which functions to remove polluted air from the vicinity of the
ceiling of a room and to supply fresh air to that room in the vicinity of
its floor.
A further object of this invention is to provide a room ventilator wherein
vertically disposed exhaust air and fresh air conduits are adjacent one
another for counterflow heat exchange, whereby incoming fresh air is
heated efficiently from outgoing polluted air.
An additional object of this invention is to provide a room ventilator of
the aforementioned type wherein inlet and exhaust blowers are located at
the exterior of the building structure so as to minimize noise from within
while exhausting polluted air to the exterior of the building and drawing
fresh air in from the outside.
Yet another object of this invention is to provide a room ventilator of the
aforementioned type wherein the exhaust air and fresh air conduits are
formed of respective sets of interdigitated channels which are surrounded
by yet another conduit, whereby each fresh air channel is substantially
surrounded by polluted air flow, thereby improving the heat exchange
efficiency of the ventilator.
Various other objects, advantages and features of the present invention
will become readily apparent from the ensuing detailed description, and
the novel features will be particularly pointed out in the appended
claims.
SUMMARY OF THE INVENTION
In accordance with this invention, room air ventilator apparatus for use in
a house is provided with a first vertically disposed conduit through which
polluted room air flows to the exterior of the house, the first conduit
including a first set of vertically disposed channels, a second conduit
through which fresh air flows to the room, the second conduit including a
set of vertically disposed channels interdigitated with the aforementioned
first set, and a jacket surrounding and spaced from the interdigitated
channels so as to form a third vertically disposed conduit in the space
between the jacket and the channels. Polluted air flows through the first
set of channels in counterflow relationship with the fresh air which flows
through the second set of channels. The third conduit is in fluid
communication with the first conduit; and a removal register is coupled to
the third conduit in the vicinity of the ceiling of the room so as to
permit polluted air to pass through the removal register to the third
conduit and then into the first conduit to be exhausted from the house. An
exhaust blower is in fluid communication with the first conduit to
discharge the polluted room air. An inlet blower is in fluid communication
with the second conduit to supply fresh air thereto; and a supply register
is coupled to the second conduit in the vicinity of the floor of the room
to supply to the room fresh air which flows through the second conduit.
In accordance with one embodiment of the present invention, the exhaust and
inlet blowers are driven by a common drive motor. In accordance with
another embodiment, these blowers are driven by respective motors which
may be singly and individually turned off. The latter embodiment provides
further energy conservation when, for example, the temperature of the room
air is relatively high, whereupon the exhaust blower remains idle and the
ventilator serves to draw in fresh air which will be heated only minimally
in the heat exchanger included in the ventilator.
In one advantageous aspect of the invention, the exhaust and inlet blowers
are located at the exterior of the house. This serves to minimize noise
perceived from the interior.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description, given by way of example, will best be
understood in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of a typical room in which the present
invention finds ready application;
FIG. 2 is a perspective view, partially broken away, of a portion of the
ventilator apparatus in accordance with this invention;
FIG. 3 is a sectional front view of the ventilator apparatus;
FIG. 4 is a sectional view taken along lines 4--4 in FIG. 3;
FIG. 5 is a sectional view taken along lines 5--5 of FIG. 3; and
FIG. 6 is a perspective view of the exhaust and inlet blowers which are
used with the ventilator apparatus of the present invention.
DETAILED DESCRIPTION OF A CERTAIN PREFERRED EMBODIMENT
The present invention finds ready application as a room ventilator for the
kitchen of a typical dwelling. Polluted air caused by several
contaminants, such as CO, NO, NO.sub.2, SO.sub.2, ozone and radon,
commonly found in kitchens is replaced by fresh air. The present invention
also may be used as a ventilator for other rooms in the house, such as the
bathroom, furnace room, and the like.
Referring now to the drawings, wherein like reference numerals are used
throughout, FIG. 1 is a perspective view of a kitchen in which room
ventilator 10 of the present invention is installed. As best shown in
FIGS. 1-4, this room ventilator is constructed to provide longitudinal
channels through which polluted air flows from the kitchen to the exterior
of the house and interdigitated longitudinal channels through which fresh
air flows from the exterior of the house to the kitchen. It will be
appreciated that the respective air flows are linear, that is, they flow
in a substantially straight line, as opposed to being rotary. It will also
be understood that the polluted air and the fresh air exhibit a
counterflow relationship, that is, they flow in opposite longitudinal
directions. This facilitates heat exchange therebetween.
As best shown in FIG. 1, a removal register 38 is located in the vicinity
of the ceiling of the kitchen to permit polluted air to pass therethrough
into room ventilator 10, this polluted air first flowing downward within
the ventilator from removal register 38 and then upward through an exhaust
air conduit to be discharged from the house. FIG. 1 also illustrates a
supply register 60 located in the vicinity of the floor of the kitchen.
This supply register permits fresh air which is brought into ventilator 10
from outside the house to pass into the kitchen. Since removal and supply
registers 38 and 60 are separated by the length of ventilator 10, which
may be on the order of about 6 to 7 feet, there is little possibility of
any feedback or cross-talk between the polluted air which is removed from
the room and the fresh air which is supplied to it. That is, the fresh air
does not mix readily with the polluted air to be discharged quickly from
the room by way of removal register 38.
It will be appreciated that, since the removal register is located in the
vicinity of the ceiling, warm polluted air containing the aforementioned
contaminants is readily removed from the kitchen. That is, the removal
register is disposed at the very location at which pollutants are more
concentrated.
Turning now to FIGS. 2-5, it is seen that room ventilator 10 is comprised
of a vertically disposed exhaust air conduit 12 formed of a first set of
vertically disposed channels 16, and a vertically disposed fresh air
conduit 14 formed of a second set of vertically disposed channels 18.
Channels 16 and 18 are interdigitated such that, as best shown in FIG. 5,
these channels alternate with one another. The exhaust air channels are
isolated from the fresh air channels, and each set of channels is formed
of longitudinal ducts. Thus, when viewed from left-to-right in FIG. 5, a
fresh air channel, or duct 18a is adjacent an exhaust air channel, or duct
16a, which is next followed by a fresh air channel 18b and then an exhaust
air channel 16b and then a fresh air channel 18c and then an exhaust air
channel 16c, and so on. Fresh air channels 18a, 18b, 18c . . . are
interdigitated with exhaust air channels 16a, 16b, 16c . . . . Preferably,
both the exhaust and fresh air channels are constructed of heat conductive
material to facilitate the transfer of heat from, for example, the room
air which flows through the exhaust air channels to the fresh air which
flows through the fresh air channels. As an example, the interdigitated
channels which constitute the exhaust and fresh air conduits may be formed
of aluminum or other readily available heat-conductive material.
From FIGS. 3 and 5, it will be appreciated that polluted room air flows in
the upward direction through channels 16a, 16b, 16c, . . . , and that
fresh air flows in the downward direction through channels 18a, 18b, 18c,
. . . . Thus, the room air and the fresh air flow in respective, isolated
conduits in a counterflow relationship. This counterflow arrangement
improves the heat exchange efficiency between the respective air flows.
Thus, during the winter season when the room air is warmer than the
outside air, the fresh air which flows through fresh air conduit 14 is
heated by the room air which flows through exhaust air conduit 12.
Conversely, during the summer months when air-conditioning apparatus is
used to cool the room air relative to the outside air, the fresh air which
flows through fresh air conduit 14 is cooled by the room air which flows
through exhaust air conduit 12.
A jacket 20 surrounds the exhaust and fresh air conduits, as shown in FIGS.
2-5, this jacket being spaced from the interdigitated channels so as to
form a surrounding conduit 22. Removal register 38 is positioned in the
wall of jacket 20 so as to permit room air in the vicinity of the ceiling
to pass therethrough into surrounding conduit 22.
The bottom portion 24 of exhaust air conduit 12 is in fluid communication
with conduit 22. More particularly, and as shown in FIG. 3, channels 16a,
16b, 16c, . . . of exhaust air conduit 12 open, at the bottom of the
exhaust air conduit, to surrounding conduit 22 so as to permit air to pass
from conduit 22 to these channels, whereupon this air then flows upward
through exhaust air conduit 12 to the top portion 26 thereof. It will be
recognized that the bottom portion of fresh air conduit 14 is closed with
respect to surrounding conduit 22 and, thus, there is no mixing of the air
in conduit 22 with the air in conduit 14.
The top portion 26 of exhaust air conduit 12 is coupled to a hood 28 which,
in turn, is connected by an exhaust duct 30 to an exhaust blower 34. As
shown in FIG. 2, only channels 16 of exhaust air conduit 12 open into hood
28. Channels 18 of fresh air conduit 14 are effectively sealed, or
isolated, from the hood, as also shown in FIG. 3.
Thus, room air is seen to enter removal register 38 to flow downward
through conduit 22 and then to enter channels 16 of exhaust air conduit 12
at the bottom portion 24 thereof, whereupon the room air then flows upward
through the exhaust air conduit into hood 28 to be discharged via exhaust
duct 30 and exhaust blower 34. As shown in FIG. 4, exhaust duct 30 passes
through an opening 32 in an exterior wall W of the house. The exhaust duct
then is coupled to exhaust blower 34 which, when driven, discharges the
polluted room air through an exhaust vent 36 exteriorly of the room.
As shown in FIGS. 2-4, a top portion 40 of fresh air conduit 14 opens to a
fresh air chamber 42 which is formed by an interior housing 44. This
interior housing is illustrated in FIG. 2 as being box-shaped and
encompasses opening 32 in exterior wall W. Thus, fresh air chamber 42 is
in fluid communication with opening 32 and also with top portion 40 of
fresh air conduit 14. Air which passes from the exterior of the house
through opening 32 into chamber 42 then enters channels 18 of fresh air
conduit 14 to flow downwardly through these channels. This air is seen to
flow in a counter-direction to the flow of room air through channels 16 of
exhaust air conduit 12.
From FIGS. 2-4, it will be seen that an enclosure 56 surrounds the bottom
portion 54 of fresh air conduit 14. This enclosure 56 serves to isolate,
or seal, the channels, or longitudinal ducts, which constitute the fresh
air conduit from surrounding conduit 22. Moreover, enclosure 56 is
provided with a lower wall 58 which may be perforated to provide
communication only between channels 16a, 16b, 16c, . . . and surrounding
conduit 22. There is no communication, however, between conduit 22 and
channels 18a, 18b, 18c, . . . of the fresh air conduit. Thus, room air may
pass through the perforations of lower wall 58 from conduit 22 into the
channels, or longitudinal ducts, which constitute exhaust air conduit 12,
but this room air is not permitted to pass through enclosure 56 into the
channels, or longitudinal ducts, which constitute the fresh air conduit.
The front wall of enclosure 56, as viewed in FIG. 2, opens to supply
register 60 so as to permit fresh air to pass from the channels that
constitute fresh air conduit 14 through enclosure 56 and supply register
60 into the kitchen. Advantageously, supply register 60 is located in the
vicinity of the floor of the kitchen.
It can be seen from FIG. 4 that opening 32 in exterior wall W communicates
between chamber 42 formed within interior housing 44 and a chamber 48
which is formed within an exterior housing 46. This exterior housing 46 is
illustrated, in perspective, in FIG. 6. From FIGS. 4 and 6, it is
appreciated that exhaust duct 30 and exhaust blower 34 are disposed within
exterior housing 46. Also, an inlet blower 50 is positioned within housing
46, this blower being coupled to an inlet vent 52 which opens to the
exterior of this housing. Blower 50 also is provided with a port 51 which
discharges fresh air that has been received from vent 52 into chamber 48.
The fresh air then passes from chamber 48 through opening 32 into top
portion 40 of the longitudinal ducts which constitute fresh air conduit
14. Thereafter, this fresh air flows in the downward direction through the
fresh air ducts to exit at bottom portion 54 thereof into enclosure 56 and
then through supply register 60 to the kitchen.
In one embodiment of the present invention a single drive motor 62 is
coupled to both exhaust blower 34 and inlet blower 50. For example, a
common drive shaft may be coupled to both blowers such that both may be
driven by the single, common motor 62. In an alternative embodiment,
exhaust blower 34 and inlet blower 50 are driven by respective exhaust and
inlet motors. In this alternative embodiment, one of these motors may be
deenergized, preferably to turn off inlet blower 50. For example, if the
room air is too hot, particularly in the vicinity of the ceiling, but the
outside air is relatively cool, as in the late afternoon or early evening
hours of the summer, inlet blower 50 may be deactivated while exhaust
blower 34 operates to discharge the room air. With inlet blower 50
deactivated, counterflow movement of the room and fresh air is reduced
and, therefore, fresh air is not drawn in and heated by ventilator 10.
Rather, the discharged room air is replaced by fresh air which enters the
kitchen by infiltration, i.e. the inherent leakage by which fresh air
enters the house. If desired, a flapper valve, such as valve 66 (shown in
broken lines in FIGS. 4 and 6) hinged to port 51, may be provided at the
output of blower 50 to block fresh air from entering chamber 48 unless
this blower actually is operating. As another example, if the outside air
is relatively warm but the inside air is too cold, as in the mid- or
late-morning hours of the winter, inlet blower 50 may be deactivated while
exhaust blower 34 remains operating. This avoids the cooling off of the
warm fresh air by the cold room air in ventilator 10. Here too, the
discharged room air is replaced by infiltration. This selective operation
and deactivation of the blower motors may be achieved by manual switches
or, preferably, by temperature sensors and suitable control circuits, such
as electronic difference amplifiers.
In operation, let it be assumed that both exhaust blower 34 and inlet
blower 50 are operated. Polluted room air passes through removal register
38 in the vicinity of the ceiling of the kitchen. If desired, as shown in
FIG. 3, a pair of removal registers 38a and 38b may be provided on
opposite walls of jacket 20.
The polluted room air flows in the downward direction in conduit 22 and
then passes into channels 16a, 16b, 16c, . . . of exhaust air conduit 12
to flow upward through the longitudinal ducts which constitute these
channels. This polluted room air then exits from channels 16a, 16b, 16c, .
. . into hood 28 and then is discharged via exhaust duct 30 and exhaust
blower 34 through exhaust vent 36 to the exterior of the house.
Concurrently with this flow of polluted room air, the operation of inlet
blower 50 serves to suck in fresh air from the outside through inlet vent
52, this fresh air being expelled by port 51 into chamber 48. This chamber
acts as an inlet duct to couple the fresh air through opening 32 into the
longitudinal ducts 18 which constitute fresh air conduit 14. The fresh air
then flows in the downward direction through the channels of the fresh air
conduit, exiting via the front wall of enclosure 56 through supply
register 60 to the vicinity of the floor of the kitchen. Hence, the fresh
air and the polluted room air flow in counterdirections to each other
through the interdigitated sets of channels 16 and 18.
As viewed in FIG. 5, it is seen that a channel 18a, 18b, 18c, . . . through
which the fresh air flows is substantially surrounded by the flow of
polluted room air. That is, channel 18a is adjacent channel 16a, the
latter having polluted air flowing therethrough; and channel 18a also is
surrounded on its three remaining sides by conduit 22 through which
polluted room air also flows. Similarly, channel 18b is adjacent channels
16a and 16b through which polluted room air flows, and the remaining two
sides of channel 18b are adjacent conduit 22. Since each channel through
which fresh air flows is substantially surrounded by room air flow, the
efficiency of the heat transfer between these channels is improved. Of
course, the air flow through channels 16 is in the counterdirection to the
air flow through channels 18; although the direction in which the air
flows through conduit 22 is the same as the direction in which the fresh
air flows. Although counterflow is not present between conduit 22 and the
channels of fresh air conduit 14, some heat exchange is carried out
nevertheless.
While the present invention has been particularly shown and described with
reference to a preferred embodiment thereof, it will be readily
appreciated by those of ordinary skill in the art that various changes and
modifications in form and details may be made without departing from the
spirit and scope of the invention. For example, in a simple embodiment,
exhaust air conduit 12 may be formed merely as a substantially cylindrical
inner conduit and fresh air conduit 14 may be provided as an annular
conduit surrounding the exhaust air conduit. Also, the relationship
between exhaust duct 30 and chamber 48 may be interchanged. That is, a
duct, or hose, may be used to couple port 51 of inlet blower 50 to fresh
air conduit 14 while a simple housing, such as exterior housing 46,
containing a chamber such as chamber 48 may be used to provide fluid
communication between exhaust air conduit 12 and exhaust blower 34.
Although not shown, filters may be provided, if desired, in the fresh air
channel to remove undesired particulate matter from the fresh air which is
drawn into the ventilator and supplied to the kitchen.
It is intended that the appended claims be interpreted as including the
foregoing as well as various other modifications.
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