Exhaust and fresh air ventilation system for a room air conditioner

A room air conditioner is provided with a ventilation system for exhausting room air to the outdoors through the air conditioner or alternatively for admitting fresh air from outdoors in through the air conditioner. The actuator is a rotary knob which has a pair of cables attached to it such that rotary motion of the knob in the first direction will cause one of the cables to pull on one of the doors to open it, while rotary motion of the knob in the other direction will cause the other of the cables to pull on the other door to open it. The doors are spring biased to return to the closed position and the knob has a detent device to hold it in a selected open or closed position.

BACKGROUND OF THE INVENTION 
The present invention relates to construction of a room air conditioner and 
more particularly to the provision of an exhaust and fresh air ventilation 
system in such an air conditioner. 
In room air conditioners it is oftentimes desirable to draw fresh air from 
outdoors into the room through the air conditioner by utilizing the fans 
of the air conditioner and at other times it is desirable to exhaust room 
air out to the outdoors again using the fans of the air conditioner. 
However, in past constructions the arrangements for providing either the 
exhaust function or the fresh air function have resulted in relatively 
complex controls and air conduit arrangements. It would therefore be an 
improvement in the art if there were provided a simplified control 
mechanism and a simplified air conduit path which would minimize the space 
requirements in the air conditioner to provide these functions. 
SUMMARY OF THE INVENTION 
The present invention provides a room air conditioner including a 
ventilation system to exhaust room air and to provide fresh air from the 
outdoors. This system utilizes a simple manual control mechanism in which 
a single rotary actuator is utilized to provide either the exhaust air 
function or fresh air function. Further, very simplified air conduit 
arrangements are provided which do not require any additional useable 
space within the air conditioner for providing these functions. 
Such an air conditioner has an external housing within which all of the 
components for the air conditioner are located. The air conditioner 
includes a compressor, a condenser and an evaporator in the standard 
arrangement, all of these components being located within the housing. A 
divider wall separates an interior of the housing into two spaces, a first 
space containing the condenser and communicating with an area outside of 
the room, and a second space containing the evaporator and communicating 
with the room to an inlet opening and a discharge opening. 
A means for moving air, which may be a blower wheel, creates a low pressure 
zone in an area adjacent to the evaporator causing air to flow from the 
room through the inlet opening and into the evaporator where it is cooled. 
The air moving means also creates a high pressure zone on an opposite side 
of the air moving means in an area adjacent to the discharge opening. This 
causes air to flow back into the room through the discharge opening. 
The ventilation system comprises a first openable door means in the divider 
wall which is in communication with the high pressure zone. Opening of 
this door permits air to be exhausted from the second space containing the 
evaporator into the first space containing the condenser and from there 
out to the outdoors. 
A second openable door means is provided in the divider wall in 
communication with the low pressure zone. When this door is open, air is 
drawn from the first space which contains the condenser into the second 
space which contains the evaporator. Thus, fresh air is drawn from the 
outdoors through the divider wall by means of this second openable door. 
A single mechanical actuator provides the control mechanism for operating 
both the first openable door means and second openable door means. This 
mechanical actuator includes a knob which is positioned at the front of 
the air conditioner for easy access by a user. The knob is connected to an 
axle extending into the air conditioner housing and which ends in a wheel 
which has a pair of cables attached to it, one cable going to each of the 
doors. When the knob is rotated in a first direction, one of the cables is 
pulled by the cam wheel to cause a selected one of the doors to open while 
the other cable is slackened. When the knob is turned in the opposite 
direction the opposite cable is pulled by the cam wheel to open the second 
door. Both doors are spring loaded so as to remain closed unless the knobs 
are rotated. The knob includes a detent to hold the selected door open 
once the knob is rotated into the open door position for the respective 
door. The center point of rotational travel for the knob will result in 
both doors being spring biased closed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In FIG. 1 there is illustrated an overall perspective view of a room air 
conditioner embodying the principles of the present invention, generally 
at 10. Such a room air conditioner 10 is placed in an opening of a wall of 
a room to provide cooling of the air within the room. The walls of the 
room provide an enclosure for isolating the room from the area outside of 
the room. Oftentimes these air conditioners fit through prefabricated 
openings in the room walls or through windows. 
The air conditioner 10 has a housing or enclosure 11 including a front 
panel 12 which faces into the room to be cooled. The front panel 12 has a 
number of openings 14 which comprise air inlet openings to permit air from 
the room to be drawn into the enclosure 11 of the air conditioner 10. The 
front panel 12 also has a plurality of openings 16 to permit air to be 
discharged back into the room from the air conditioner 10. A control panel 
18 is provided which contains various control actuators 19 for the air 
conditioner 10. The air conditioner enclosure 11 also includes a number of 
openings 20 in sidewalls 21 of the enclosure to permit air from outside of 
the room to be drawn into the enclosure as is necessary during the 
operation of the air conditioner 10. 
FIG. 2 illustrates the internal components of the air conditioner 10. It is 
seen that the air conditioner 10 has a compressor 22 for compressing a 
refrigerant which flows through a conduit 24 and through a condenser 26 
where heat from the refrigerant is released. The refrigerant is then 
caused to flow through an evaporator 28 where heat is absorbed into the 
refrigerant. The refrigerant then returns to the compressor 22 for 
repeating the cycle. A single motor 30 is provided to drive a first air 
moving device in the form of a fan 32 to cause air to flow through the 
condenser 26 to exhaust heat from the condenser through rear air outlets 
34 to the area outside of the room. The air driven by this fan 32 is drawn 
into the enclosure 11 through the openings 20 in the side walls 21 of the 
enclosure 11. 
The motor 30 also drives a second air moving means 38 which may be in the 
form of a blower wheel. The blower wheel 38 creates a low pressure zone in 
an area 40 adjacent to the evaporator 28, but on the blower wheel side of 
the evaporator. This causes air from the room to flow through the openings 
14 in the front grill 12 and through the evaporator 28, thereby releasing 
heat from the air to the refrigerant flowing through the evaporator, and 
then into the blower wheel 38. The air is then discharged from the blower 
wheel 38 into a zone 42 (FIGS. 3, 4 and 7) at a higher pressure from where 
the air flows out through the openings 16 in the front panel 12 to return 
to the room. 
In order to prevent the air which is being cooled by flowing through the 
evaporator 28 from mixing with the outdoor air, a divider wall 50 is 
provided which separates the interior of the air conditioner enclosure 11 
into two spaces. A first space 52 is the area which includes the condenser 
26, the compressor 22 and motor 30 and is referred to as the hot side of 
the air conditioner 10. A second space 54 includes the evaporator 28 and 
the blower wheel 38 and is referred to as the cool side of the air 
conditioner 10. Thus, during normal cooling operation by the air 
conditioner 10, the air from within the room is circulated through the 
evaporator 28 and blower wheel 38 and returned to the room, the whole time 
remaining in the second space 54 within the air conditioner 10. In the 
meantime, outdoor air is drawn into the first space 52 of the housing to 
flow over the compressor 22, the motor 30, through the fan 32 and 
condenser 26 to return outdoors carrying the waste heat with it. The two 
air flows thus remain isolated from one another by the divider wall 50. 
However, it is desirable to provide the ability to exhaust room air from 
the room through the air conditioner 10 by utilizing the air moving 
devices 38, 32 within the air conditioner during certain occasions and, 
during other occasions, to draw fresh outdoor air into the room, again 
using the fans of the air conditioner. In order to accomplish these 
alternate uses of the air conditioner 10, a pair of openings 62, 64 are 
provided in the divider wall. The first opening 62 is normally closed by a 
first door 66 which is pivotally secured to the divider wall 50. The door 
is engaged by a spring 68 to be normally biased into a closed position 
relative to the opening 62. The opening 62 is positioned in communication 
with the high pressure zone 42, created by the blower wheel 38, such that 
when the door 66 is opened, air from within the high pressure zone will be 
caused to flow out through the opening 62 past the door 66 into the first 
area 52 of the air conditioner housing 11. 
The second opening 64 is normally closed by a door 70 (FIGS. 6 and 7) which 
is secured to the divider wall 50 and is pivotally openable. The second 
door 70 also is engaged by a spring 72 to normally hold the door 70 in a 
closed position relative to the second opening 64. The second opening 64 
is positioned to communicate with the low pressure zone 40 created by the 
blower wheel 38. To provide this communication an air conduit 74 is formed 
in a blower wheel scroll 76 as best seen in FIGS. 4, 5 and 7. The scroll 
76 has a generally spiral wall 80 which surrounds a portion of the blower 
wheel 38. The wall 80 gets progressively further away from the blower 
wheel 38 in a direction of rotation of the blower wheel leading toward the 
high pressure zone 42. A lower left portion 81 of the scroll 76, as seen 
in FIG. 4, has a passage 82 formed therein which, in turn, has an opening 
84 formed through a sidewall 86 thereof communicating with the opening 64 
in the divider wall. Therefore, the air conduit 74 is formed by the 
passage 82 in the scroll 76, in an unused portion of the scroll, thus not 
requiring use of any useable space within the air conditioner housing 11. 
A forward end of the passage 82 is engaged by an evaporator shroud 88 (FIG. 
3) and an opening 90 is formed in the evaporator shroud which is in 
alignment with the passage 82 of the scroll 76. This allows air to flow 
through opening 64, opening 84, into air passage 82 and then through the 
opening 90 in the evaporator shroud 88 to exit into a rear area of the 
evaporator 28 itself. The air then flows upwardly along the evaporator 
shroud 88 and through a large opening 92 in the evaporator shroud leading 
into the low pressure zone 40 created by the blower wheel 38. Thus, 
outdoor air is drawn in through the opened door 70 by the blower wheel 38 
to be moved to the high pressure zone 42 and discharged into the room 
through the discharge openings 16 in the front panel 12 of the air 
conditioner housing 11. 
A single actuator 94 (FIGS. 6 and 8) is provided for opening both of the 
doors 66, 70. The actuator consists of a knob 96 accessible from the front 
of the air conditioner at the control panel 18. The knob 96 is connected 
to rotate an axle 98 which extends through the control area 99 for the air 
conditioner and which is carried in a pair of bearings 100, 102 and 
extends into the first space 52 on the backside of the divider wall 50. At 
an end of the axle 98 there is carried a wheel 104 which also rotates with 
the axle 98 and knob 96. A pair of cables 106, 108 extend from the wheel 
104 at a periphery thereof. Rotation of the knob 96 will cause rotation of 
the wheel 104 and will cause one or the other of the cables 106, 108 be 
pulled by the wheel 104, thus pulling an opposite end of one of the cables 
106, 108 toward the cam wheel 104. The cable not pulled will be slackened 
by rotation of the wheel. The opposite ends of the cables are attached to 
the doors 66, 70 respectively. Thus, rotation of the knob 96 in a first 
direction of rotation will cause the first door 66 to be pivoted open 
against the bias of spring 68. Rotation of the knob 96 in the opposite 
direction will cause the opening of door 70 against the bias of spring 72 
as shown in FIGS. 6 and 7. 
A detent mechanism 110 is provided on the actuator 94 such that when the 
knob 96 is rotated to a fresh air position, the door 70 remains opened 
against the bias of spring 72 until the detent holding force is overcome 
by manual rotation of the knob 96 back to the central position allowing 
the door 70 to be closed under the bias of spring 72. Similarly, when the 
knob 96 is rotated to the exhaust air position, the door 66 is held open 
against the spring bias 68 until manual force on the knob 96 overcomes the 
holding force of the detent 110 to permit the door 66 to be closed by the 
spring 68. 
In a preferred arrangement the detent mechanism comprises a stationary 
cylindrical bearing member 102 captured on said divider wall 50 through 
which the axle 98 or an extension 112 thereof extends. An end face of the 
cylindrical member has three indents 114 spaced apart by 60.degree.. The 
wheel 104 has three protrusions 116 also spaced apart by 60.degree. which 
are complementarily shaped to the indents 114. A wave washer 118 holds the 
wheel 104 against the cylindrical member 112 so that the wheel can be 
moved to any one of the three positions of: the first door open, the 
second door open or both doors closed. 
As is apparent from the foregoing specification, the invention is 
susceptible of being embodied with various alterations and modifications 
which may differ particularly from those that have been described in the 
preceding specification and description. It should be understood that we 
wish to embody within the scope of the patent warranted hereon all such 
modifications as reasonably and properly come within the scope of our 
contribution to the art.