AIR CONDITIONER WITH REFRIGERANT SENSOR

TECHNICAL FIELD

[0001]The disclosed systems and methods relate generally to a heating and cooling device (e.g., an air conditioner) that contains a refrigerant sensor to detect refrigerant leaks. The refrigerant sensor is physically located outside of the casing of the heating and cooling device and is connected to the interior of the heating and cooling device through air channels that pass through the casing.

BACKGROUND

[0002]A heating and cooling device (e.g., an air conditioner) will generally include a heat exchanger, which may include coils through which a refrigerant flows, e.g., an A-coil. One common type of refrigerant used by such heating and cooling devices is an A2L refrigerant. The designation A2L indicates that the refrigerant is non-toxic (A), is flammable (2), and has a low burning velocity (L). Other refrigerants may also be used, with varying parameters.

[0003]In the heating and cooling device, the refrigerant is cooled in a cooling operation and heated in a heating operation, and air is passed over the coils. This causes the air to exchange heat with the refrigerant passing through the coils and be either heated or cooled depending upon the type or operation being performed.

[0004]During heating and cooling operations, a coil-based heat exchanger can leak refrigerant into the air surrounding the heat exchanger. This often happens where pipes are brazed, though other types of leaks are also possible.

[0005]Leaks in a heat exchanger coil are undesirable for several possible reasons. First, if the refrigerant used in heating and cooling devices is toxic, leaked refrigerant may cause a health hazard to people in the building containing the heating and cooling device. Leaked refrigerant from the heating and cooling device can be blown into the area being heated or cooled and may be breathed by those inside that the building containing the heating and cooling device. Second, if the refrigerant is flammable, leaked refrigerant can increase the fire risk in the building containing the heating and cooling device. Third, since the proper operation of a coil-based heat exchanger requires sufficient refrigerant pass through the coils, a leakage of refrigerant can cause the heating and cooling device to function less efficiently. Fourth, leaked refrigerant must be replaced, meaning that a refrigerant leak will result in additional costs for operating the heating and cooling device.

[0006]As a result, many heating and cooling devices contain one or more refrigerant sensors to detect refrigerant leaks so that they can be identified and corrected quickly, and so avoid or minimize the problems identified above.

[0007]However, space inside a heating and cooling device may be limited, restricting the available places at which a refrigerant sensor could be places inside the heating and cooling device.

[0008]It therefore may be desirable to locate the refrigerant sensor outside of the casing of the heating and cooling device and facilitate the movement of air from inside the heating and cooling device to the outside refrigerant sensor.

SUMMARY OF THE INVENTION

[0009]In some aspects, the techniques described herein relate to an air conditioner, including: a heat exchanger; a casing surrounding the heat exchanger, the casing including a first hole and a second hole; a refrigerant sensor provided outside of the casing and configured to detect a presence of refrigerant in air passing through the refrigerant sensor; a first air passage that is arranged between an inside of the casing and the refrigerant sensor via the first hole; and a second air passage that is arranged between the inside of the casing and the refrigerant sensor via the second hole.

[0010]In some aspects, the techniques described herein relate to an air conditioner, wherein the first hole includes a first notch outside of a first circumference of the first hole, the first notch being configured to accommodate the first air passage, and the second hole includes a second notch outside of a second circumference of the second hole, the second notch being configured to accommodate the second air passage.

[0011]In some aspects, the techniques described herein relate to an air conditioner, wherein the first and second air passages include first and second pipes, respectively.

[0012]In some aspects, the techniques described herein relate to an air conditioner, wherein the first and second pipes are rigid.

[0013]In some aspects, the techniques described herein relate to an air conditioner, wherein the first and second pipes are flexible.

[0014]In some aspects, the techniques described herein relate to an air conditioner, wherein the first and second air passages include first and second air hoses, respectively.

[0015]In some aspects, the techniques described herein relate to an air conditioner, wherein the first air passage includes a third air passage that is arranged between the inside of the casing and the outside of the casing via the first hole, and a fourth air passage that is arranged between the third air passage and the refrigerant sensor, and the second air passage includes a fifth air passage that is arranged between the inside of the casing and the outside of the casing via the second hole, and a sixth air passage that is arranged between the fifth air passage and the refrigerant sensor.

[0016]In some aspects, the techniques described herein relate to an air conditioner, wherein a fourth length of the fourth air passage and a sixth length of the sixth air passage are both twelve inches or lower.

[0017]In some aspects, the techniques described herein relate to an air conditioner, wherein the third and fourth air passages include third and fourth pipes, respectively, and the fifth and sixth air passages include fifth and sixth pipes, respectively.

[0018]In some aspects, the techniques described herein relate to an air conditioner, wherein the third air passage includes a third pipe, the fourth air passage includes a fourth hose, the fifth air passage includes a fifth pipe, and the sixth air passage includes a sixth hose.

[0019]In some aspects, the techniques described herein relate to an air conditioner, wherein the first hole is both horizontally displaced and vertically displaced from the second hole.

[0020]In some aspects, the techniques described herein relate to an air conditioner, further including: a first refrigerant passage that is arranged between the heat exchanger and the outside of the casing via the first hole; and a second refrigerant passage that is arranged between the heat exchanger and the outside of the casing via the second hole.

[0021]In some aspects, the techniques described herein relate to an air conditioner, wherein the first refrigerant passage includes a first refrigerant pipe with a first pipe width smaller than a first hole width of the first hole, the first air path includes a first air pipe with a second pipe width smaller than the first pipe width, and a sum of the first pipe width and the second pipe width is no larger than the first hole width.

[0022]In some aspects, the techniques described herein relate to an air conditioner, wherein the second refrigerant passage includes a second refrigerant pipe with a third pipe width smaller than a second hole width of the second hole, the second air path includes a second air pipe with a fourth pipe width smaller than the third pipe width, and a sum of the third pipe width and the fourth pipe width is no larger than the second hole width.

[0023]In some aspects, the techniques described herein relate to an air conditioner, wherein the refrigerant sensor is configured to determine whether an amount of refrigerant in the inside air rises above a threshold level.

[0024]In some aspects, the techniques described herein relate to an air conditioner, wherein the refrigerant sensor is attached to the outside of the casing.

[0025]In some aspects, the techniques described herein relate to an air conditioner, further including an air pump configured to pump air through the first air path from the inside of the casing to the refrigerant sensor.

[0026]In some aspects, the techniques described herein relate to an air conditioner, further including an air pump configured to pump through the second air path from the refrigerant sensor to the inside of the casing.

[0027]In some aspects, the techniques described herein relate to an air conditioner, further including: a first refrigerant passage; and a second refrigerant passage; wherein the casing further includes a third hole and a fourth hole, the first refrigerant passage is arranged between the heat exchanger and the outside of the casing via the third hole, and the second refrigerant passage is arranged between the heat exchanger and the outside of the casing via the fourth hole.

[0028]In some aspects, the techniques described herein relate to an air conditioner, including: a heat exchanger; a casing surrounding the heat exchanger, the casing including a first hole and a second hole; a refrigerant sensor provided outside of the casing and configured to detect the presence of refrigerant in air passing through the refrigerant sensor; a first air passage that is arranged between an inside of the casing and the refrigerant sensor via the first hole; a second air passage that is arranged between the inside of the casing and the refrigerant sensor via the first hole; a first refrigerant passage that is arranged between the heat exchanger and the outside of the casing via the first hole; and a second refrigerant passage that is arranged between the heat exchanger and the outside of the casing via the second hole, wherein the first air passage includes a first bend inside the casing such that a first inside opening of the first air passage and a second inside opening of the second air passage are at different heights.

[0029]In some aspects, the techniques described herein relate to an air conditioner, wherein the second air passage includes a second bend inside the casing.

[0030]In some aspects, the techniques described herein relate to an air conditioner, wherein the first air passage includes a third air passage that is arranged between the inside of the casing and the outside of the casing via the first hole, and a fourth air passage that is arranged between the third air passage and the refrigerant sensor, and the second air passage includes a fifth air passage that is arranged between the inside of the casing and the outside of the casing via the second hole, and a sixth air passage that is arranged between the fifth air passage and the refrigerant sensor.

[0031]In some aspects, the techniques described herein relate to an air conditioner, wherein a fourth length of the fourth air passage and a sixth length of the sixth air passage are both twelve inches or lower.

[0032]In some aspects, the techniques described herein relate to an air conditioner, further including an air pump configured to pump through the first air path from the inside of the casing to the refrigerant sensor.

[0033]In some aspects, the techniques described herein relate to an air conditioner, further including an air pump configured to pump through the second air path from the refrigerant sensor to the inside of the casing.

[0034]In some aspects, the techniques described herein relate to a method of detecting refrigerant in conditioned air from an air conditioner, the method including: drawing inside air from inside a casing of the air conditioner proximate to a heat exchanger into a first air passage; passing the inside air through the first air passage from the inside of the casing to a refrigerant sensor attached to an outside of the casing through a first hole in the casing; detecting a threshold level of refrigerant in the inside air at the refrigerant sensor; passing the inside air from the refrigerant sensor to the inside of the casing via the second passage through a second hole in the casing.

[0035]In some aspects, the techniques described herein relate to a method, wherein the passing of the inside air through the first air passage further includes: passing the inside air through a third air passage from the inside of the casing to the outside of the casing through the first hole; and passing the inside air from the third air passage to the refrigerant sensor via a fourth air passage located outside of the casing.

[0036]In some aspects, the techniques described herein relate to a method, wherein the passing of the inside air through the second air passage further includes: passing the inside air from the refrigerant sensor to a fifth air passage via a sixth air passage located outside of the casing; and passing the inside air from the sixth air passage to the inside of the casing through the second hole.

[0037]In some aspects, the techniques described herein relate to a method, wherein the passing of the inside air through the first air passage further includes pumping the inside air through the first air passage from the inside of the casing to the refrigerant sensor.

[0038]In some aspects, the techniques described herein relate to a method, wherein the passing of the inside air through the second air passage further includes pumping the inside air from the refrigerant sensor to the inside of the casing.

[0039]In some aspects, the techniques described herein relate to a method, wherein the second hole is the same as the first hole.

[0040]In some aspects, the techniques described herein relate to a method, wherein the second hole is different from the first hole.

BRIEF DESCRIPTION OF THE DRAWINGS

[0041]The accompanying figures, where like reference numerals refer to identical or functionally similar elements and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate an exemplary embodiment and to explain various principles and advantages in accordance with the present disclosure.

[0042]FIG. 1 is a side view of air conditioner with an external refrigerant sensor according to an exemplary device;

[0043]FIG. 2 is a perspective view of the air conditioner of FIG. 1 with a wall of the air-conditioner casing removed according to an exemplary device;

[0044]FIG. 3 is a cross-sectional view of the wall of the air-conditioner casing of the air conditioner of FIG. 1 according to an exemplary device;

[0045]FIG. 4 is a side view of the air conditioner of FIG. 1 illustrating air passages connected to a sensor case according to an exemplary device;

[0046]FIG. 5A is a perspective view of the refrigerant sensor and the air passages with the back of the sensor case off according to an exemplary device;

[0047]FIG. 5B is a perspective view of the refrigerant sensor and the air passages with the back of the sensor case on according to an exemplary device;

[0048]FIG. 5C is a perspective view of the refrigerant sensor and the air passages with the back of the sensor case on according to an alternate exemplary device;

[0049]FIG. 5D is a perspective view of the refrigerant sensor and the air passages with the back of the sensor case on and an air pump attached to one air passage according to an alternate exemplary device;

[0050]FIG. 6 is a close-up view of the wall of the air conditioner casing of FIG. 1 according to an exemplary device;

[0051]FIG. 7 is an overhead view of refrigerant sensor of FIG. 1 according to an exemplary device;

[0052]FIG. 8 is a side view of refrigerant sensor of FIG. 1 according to an exemplary device;

[0053]FIG. 9 is a perspective view of refrigerant sensor of FIG. 1 according to an exemplary device;

[0054]FIG. 10 is a close-up view of wall of an air-conditioner casing of an air conditioner according to an alternate exemplary device;

[0055]FIG. 11 is a close-up view of wall of an air-conditioner casing of an air conditioner according to an alternate exemplary device;

[0056]FIG. 12 is a side view of air conditioner with an external refrigerant sensor according to an alternate exemplary device;

[0057]FIG. 13 is a cross-sectional view of the wall of the air-conditioner casing of the air conditioner of FIG. 12 according to the alternate exemplary device;

[0058]FIG. 14 is a close-up view of wall of the air-conditioner casing of the air conditioner of FIG. 12 according to the alternate exemplary device;

[0059]FIG. 15 is a cross-sectional view of the wall of an air-conditioner casing according to an alternate exemplary device;

[0060]FIG. 16 is a cross-sectional view of the wall of an air-conditioner casing according to an alternate exemplary device;

[0061]FIG. 17 is a cross-sectional view of the wall of an air-conditioner casing according to an alternate exemplary device;

[0062]FIG. 18 is a flow chart of an exemplary method of detecting refrigerant in conditioned air from an air conditioner.

DETAILED DESCRIPTION

[0063]The instant disclosure is provided to further explain in an enabling fashion the best modes of performing one or more embodiments of the present invention. The disclosure is further offered to enhance an understanding and appreciation for the inventive principles and advantages thereof, rather than to limit in any manner the invention. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.

[0064]It is further understood that the use of relational terms such as first and second, and the like, if any, are used solely to distinguish one from another entity, item, or action without necessarily requiring or implying any actual such relationship or order between such entities, items or actions. It is noted that some embodiments may include a plurality of processes or steps, which can be performed in any order, unless expressly and necessarily limited to a particular order; i.e., processes or steps that are not so limited may be performed in any order.

Air Conditioner With External Refrigerant Sensor

[0065]FIG. 1 is a side view of air conditioner 100 with external refrigerant sensor 170 according to an exemplary device.

[0066]As shown in FIG. 1, the air conditioner 100 includes an air-conditioner casing 110 that surrounds most of the elements that make up the air conditioner 100. The air conditioner 100 includes a first hole 120 in the air-conditioner casing 110, a second hole 125 in the air-conditioner casing 110, a first refrigerant passage 130, a second refrigerant passage 135, a first gap 140, a second gap 145, a first air passage 150, a second air passage 155, a sensor case 160 (not shown in FIG. 1), and an external refrigerant sensor 170. The external refrigerant sensor 170 includes a first sensor input 180, a second sensor input 185, a communication connection 190, and one or more refrigerant fasteners 195.

[0067]The first hole 120 and the second hole 125 are formed in the side of the air-conditioner casing 110. In the exemplary device of FIG. 1, the first hole 120 and the second hole 125 are displaced from each other in both a horizontal and a vertical direction. In the exemplary device of FIG. 1, the first hole 120 and the second hole 125 are both circular in shape. However, this is by way of example only. Alternate exemplary devices could use different shapes for the first and second holes 120, 125. Furthermore, the sizes and shapes of the first and second hole 120, 125 need not be the same.

[0068]The first refrigerant passage 130 is arranged to pass through the first hole 120, while the second refrigerant passage 135 is arranged to pass through the second hole 125. These refrigerant passages 130, 135 allow refrigerant to pass between an inside and an outside of the air-conditioner casing 110, e.g. to/from a heat exchange coil inside the air-conditioner casing 110. In the device disclosed in FIG. 1, the first and second refrigerant passages 130, 135 may be metal or plastic pipes.

[0069]The first refrigerant passage 130 is smaller than the first hole 120, allowing for a first gap 140 to be formed between the circumference of the first hole 120 and the first refrigerant passage 130. Similarly, the second refrigerant passage 135 is smaller than the second hole 125, allowing for a second gap 145 to be formed between the circumference of the second hole 125 and the second refrigerant passage 135. Although not shown, these gaps 140, 145 can be filled with a cushioning or insulating material to protect the first and second refrigerant passages 130, 135 from touching or interfering with the circumference of the first and second holes 120, 125, respectively. This cushioning or insulating material may be foam, rubber, or any other suitable cushioning or insulating material.

[0070]A first air passage 150 is formed in the first gap 140, while a second air passage 155 is formed in the second gap 145. This allows the first and second air passages 150, 155 to pass through the air-conditioner casing 110 without the requirement of making additional holes for them. In such a device, however, the first and second air passages 150, 155 must be no larger in width than a width of the largest part of the first and second gaps 140, 145, respectively. This width is typically sufficient to allow for sufficient air to flow in the first and second air passages 150, 155 between the inside of the air-conditioner casing 110 and the external refrigerant sensor 170 for the external refrigerant sensor 170 to sample sufficient inside air to detect the presence of refrigerant in the inside air. In the device disclosed in FIG. 1, the first and second air passages 150, 155 may wholly or partly include metal or plastic pipes. These pipes may be flexible pipes or rigid pipes.

[0071]The sensor case 160 is attached to the wall of the air-conditioner casing 110 and serves to protect the external refrigerant sensor 170. In various designs, the sensor case 160 can have a panel that may be opened to reveal the external refrigerant sensor 170 inside, or may be detachable from the air-conditioner casing 110 to expose the external refrigerant sensor 170.

[0072]Although not shown in FIG. 1, the sensor case 160 is configured to connect to the first and second air passages 150, 155 to allow air to pass between the inside of the air-conditioner casing 110 and the inside of the sensor case 160.

[0073]The external refrigerant sensor 170 is a circuit configured to detect the presence of refrigerant in air proximate to the refrigerant sensor 170. It can be configured to identify a quantifiable level of refrigerant in the nearby air, or it can be configured to identify when the level of refrigerant in the nearby air rises above the threshold refrigerant level in various embodiments. In some designs the refrigerant sensor 170 will be configured to detect a minimum threshold of refrigerant that will activate safety features and a response such as sounding an alarm, shutting off the air conditioner 100, or turning on a fan to circulate and dilute leaked refrigerant in the air in or proximate to the air conditioner 100. In a design in which the refrigerant is an A2L refrigerant, the refrigerant sensor 170 is an A2L refrigerant sensor.

[0074]The first and second sensor inputs 180, 185 operate to receive the inside air from the inside of the air-conditioner casing 110 provided via the first and second air passages 150, 155. The refrigerant sensor 170 is configured to perform the refrigerant detection operation on the air received at the first and second sensor inputs 180, 185 using refrigerant detection circuitry (not shown).

[0075]The communication connection 190 provides for communication between the refrigerant sensor 170 and a controller (not shown) for the air conditioner 100 to allow the external refrigerant sensor 170 to communicate the refrigerant level to the controller. In the design of FIG. 1, the communication connection 190 is a socket connected to the refrigerant detection circuitry and configured to accept a communication line that will extend to the controller. In alternate embodiments, the communication connection 190 could be a wireless antenna, or a combination of a socket and wireless antenna.

[0076]The refrigerant fasteners 195 are provided to secure the refrigerant sensor 170 to the wall of the air-conditioner casing 110. These refrigerant fasteners 195 can be screws, bolts, clamps, glue pads, or the like.

[0077]Although in the design of FIG. 1, the sensor case 160 and the refrigerant sensor 170 are attached to a wall of the air-conditioner casing 110, this is by way of example only. In alternate designs, the sensor case 160 and the refrigerant sensor 170 can be located at a point proximate to the air-conditioner casing 110 but not attached to it.

[0078]If there are requirements that the refrigerant sensor 170 detect the leak within a particular time period, it may be desirable to limit the length of a connection between the sensor case 160 and the air-conditioner casing 110. In some designs, this distance can be limited to be no greater than twelve inches. However, alternate embodiments can modify this distance as required by system parameters to make it either greater or smaller.

[0079]FIG. 2 is a perspective view of the air conditioner 100 of FIG. 1 with a wall of the air-conditioner casing 110 removed according to an exemplary device. As shown in FIG. 2, a heat exchanger 210 is formed inside of the air-conditioner casing 110. A drip pan 220 is formed beneath the heat exchanger 210.

[0080]The first refrigerant passage 130 and the second refrigerant passage 135 are connected to the heat exchanger 210 in such a way as to allow a refrigerant to pass through the coils in the heat exchanger 210 via the first and second refrigerant passages 130, 135. In this way, refrigerant can be moved into, out of, or through the coils in the heat exchanger 210 using the first and second refrigerant passages 130, 135.

[0081]FIG. 3 is a cross-sectional view 300 of the wall of the air-conditioner casing 110 of the air conditioner 100 of FIG. 1 along line I-I′ according to an exemplary device. As shown in FIG. 3, the wall of the air-conditioner casing 110 includes the first hole 120 and the second hole 125. The first refrigerant passage 130 and the first air passage 150 both pass through the first hole 120, and the second refrigerant passage 135 and the second air passage 155 both pass through the second hole 125.

[0082]The first air passage 150 includes a third air passage 310 and a fourth air passage 315 connected to each other. The third air passage 310 is formed inside of the air-conditioner casing 110 and extends a small length outside of the air-conditioner casing 110. The third air passage 310 extends inside of the air-conditioner casing 110 to an area inside the air-conditioner casing 110 proximate to where a refrigerant leak is considered most likely, e.g., close to where refrigerant coils in the heat exchanger 210 are brazed. The fourth air passage 315 is connected to the third air passage 310 and extends from the third air passage 310 to the sensor case 160 surrounding the external refrigerant sensor 170. In some exemplary devices the fourth air passage 315 will be permanently affixed to the third air passage 310. In other exemplary devices, the fourth air passage 315 may be detachably affixed to the third air passage 310.

[0083]The first refrigerant passage 130 and the first air passage 150 have a widths such that they will both fit within the first hole 120. In other words, a sum of a width of the first refrigerant passage 130 and the width of the first air passage 150 will be no larger than a largest width of the first hole 120, e.g., the diameter of the first hole 120 when the first hole 120 is a circle.

[0084]Although in the exemplary device shown in FIG. 3, the third air passage 310 is shown as extending a short length outside of the air-conditioner casing 110, this is by way of example only. In alternate implementations, the fourth air passage 315 may extend a short length inside of the air-conditioner casing 110 and the third air passage 310 may be connected to the fourth air passage 315 inside the air-conditioner casing 110. Likewise, in some exemplary implementations, the third air passage 310 and the fourth air passage 315 may be connected exactly at the wall of the air-conditioner casing 110. In other alternate implementations, the first air passage 150 may be a single element extending from a location of a potential leak inside the air-conditioner casing 110 to the sensor case 160.

[0085]The second air passage 155 includes a fifth air passage 320 and a sixth air passage 325 connected to each other. The fifth air passage 320 is formed inside of the air-conditioner casing 110 and extends a small length outside of the air-conditioner casing 110. The fifth air passage 320 extends inside of the air-conditioner casing 110 to an area inside the air-conditioner casing 110 different from where the inside end of the third air passage 310 is located, and at a location with a different pressure than the inside end of the third passage 310 so that the difference in pressure will cause air to flow from the inside of the air-conditioner casing 110 to the sensor case 160 and back again via the first and second air passages 150, 155. The sixth air passage 325 is connected to the fifth air passage 320 and extends from the fifth air passage 320 to the sensor case 160 surrounding the external refrigerant sensor 170. In some exemplary devices the sixth air passage 325 will be permanently affixed to the fifth air passage 320. In other exemplary devices, the sixth air passage 325 may be detachably affixed to the fifth air passage 320.

[0086]The second refrigerant passage 135 and the second air passage 155 have widths such that they will both fit within the second hole 125. In other words, a sum of a width of the second refrigerant passage 135 and the width of the second air passage 155 will be no larger than a largest width of the second hole 125, e.g., the diameter of the second hole 125 when the second hole 125 is a circle.

[0087]Although in the exemplary device shown in FIG. 3, the fifth air passage 320 is shown as extending a short length outside of the air-conditioner casing 110, this is by way of example only. In alternate implementations, the sixth air passage 325 may extend a short length inside of the air-conditioner casing 110 and the fifth air passage 320 may be connected to the sixth air passage 325 inside the air-conditioner casing 110. Likewise, in some exemplary implementations, the fifth air passage 320 and the sixth the air passage 325 can be connected exactly at the wall of the air-conditioner casing 110. In other alternate implementations, the second air passage 155 may be a single element extending from a location of a potential leak inside the air-conditioner casing 110 to the sensor case 160.

[0088]FIG. 4 is a side view of the air conditioner 100 of FIG. 1 illustrating air passages 315, 325 connected to a sensor case 160 according to an exemplary device. As shown in FIG. 4, the fourth air passage 315 extends from the third air passage 310 (not shown in FIG. 4), which extends out of the first gap 140 between the first refrigerant passage 130 and a circumference of the first hole 120, to the sensor case 160. Similarly, the sixth air passage 325 extends from the fifth air passage 315 (not shown in FIG. 4), which extends out of the second gap 145 between the second refrigerant passage 135 and a circumference of the second hole 125, to the sensor case 160.

[0089]By having the fourth and sixth air passages 315, 325 connected to the sensor case 160, the disclosed air conditioner 100 can allow air to flow from inside the air-conditioner casing 110 to the external refrigerant sensor 170 (not shown in FIG. 4) inside the sensor case 160 and back again. This allows the external refrigerant sensor 170 to receive a constant flow of air from inside the air-conditioner casing 110 to allow it to detect any refrigerant contained in such air.

[0090]In various exemplary implementations, the fourth and sixth air passages 315, 325 may be metal pipes, plastic pipes, flexible hoses, or any suitable structure for carrying air.

[0091]In some exemplary implementations, a length of both the fourth and the sixth air passages 315, 325 may be kept to a length of twelve inches or lower. This is done to allow the external refrigerant sensor 170 to detect a threshold level of refrigerant in the air inside the air-conditioner casing 110 within a set period of time. Alternate implementations may increase or decrease this minimum length depending upon the threshold level of refrigerant detected, the accuracy and efficiency of the external refrigerant sensor 170, and the length of time allowed for detection of leaked refrigerant.

[0092]FIG. 5A is a perspective view of the refrigerant sensor 170 and the air passages 315, 325 with the back of the sensor case 160 off according to an exemplary device. As shown in FIG. 5A, the fourth and sixth air passages 315, 325 are connected to the sensor case 160 such that the fourth and sixth air passages 315, 325 extend into the sensor case 160 to provide air from the air-conditioner casing 110 to the external refrigerant sensor 170 inside the sensor case 160.

[0093]Although the exemplary device in FIG. 5A shows the fourth and sixth air passages 315, 325 extending into the sensor case 160, this is by way of example only. Alternate embodiments could affix the fourth and sixth air passages 315, 325 to the sensor case 160 such that they do not extend inside the sensor case 160.

[0094]FIG. 5B is a perspective view of the refrigerant sensor and the air passages 315, 325 with the back of the sensor case 160 on according to an exemplary device. As shown by FIG. 5B, the fourth and sixth air passages 315, 325 are attached to the sensor case 160 such that air from inside the air-conditioner casing 110 passes to the inside of the sensor case 160 without any leakage into outside air. In this way, air from inside the air-conditioner casing 110 can be provided to the external refrigerant sensor (not shown in FIG. 5B) without contamination from outside air.

[0095]In operation, air moving from inside the air-conditioner casing 110 to inside the sensor case 160 passes through one of the fourth and sixth air passages 315, 325, and air moving from inside the sensor case 160 back to the inside of the air-conditioner casing 110 passes through the other of the fourth and sixth air passages 315, 325.

[0096]The communication connection 190 extends outside of the sensor case 160 to allow a communication cable to connect to the communication connection 190. In alternate implementations in which a wireless communication connection is used, i.e., in which the wireless communication connection is a wireless antenna, the wireless communication connection may either extend outside of the sensor case 160 or be contained entirely within the sensor case 160.

[0097]FIG. 5C is a perspective view of the refrigerant sensor 170 and the air passages 315, 325 with the back of the sensor case 560 on according to an alternate exemplary device. As shown in FIG. 5C, the sensor case 560 is arranged to be smaller, such that it covers only a portion of the refrigerant sensor 170 that includes the first and second sensor inputs (not shown in FIG. 5C). The refrigerant fasteners 195 are arranged to be outside of the sensor case 560.

[0098]In this way the sensor case 560 can be attached to the refrigerant sensor 170 in such a way that the refrigerant sensor 170 can be attached and removed from the air-conditioner casing 110 without removing the sensor case 560 from refrigerant sensor 170.

[0099]FIG. 5D is a perspective view of the refrigerant sensor and the air passages 315, 325 with the back of the sensor case 160 on and an air pump 570 attached to one air passage 315 according to an alternate exemplary device.

[0100]FIG. 5D is similar to FIG. 5B, except that an air pump 570 is attached to the fourth air passage 315. In some exemplary implementations, the fourth and sixth air passages 315, 325 are arranged to be at different heights such that a difference in air pressure will cause air to flow through the fourth and sixth air passages 315, 325 from the inside of the air-conditioner casing 110 to the inside of the sensor case 160, and vice versa. However, in situations in which a guaranteed airflow is desirable, an air pump 570 can be provided in one of the fourth and sixth air passages 315, 325 to pump the air.

[0101]Although FIG. 5D shows the fourth and sixth air passages 315, 325 being attached to the air-conditioner casing 110/third and fifth air passages 310, 320 at different heights, the presence of the air pump 570 means that in some exemplary implementations, the fourth and sixth air passages 315, 325 may be attached to the air-conditioner casing 110/third and fifth air passages 310, 320 at the same height.

[0102]Although FIG. 5D shows the air pump 570 being attached to the fourth air passage 315, alternate exemplary implementations may attach the air pump 570 to the sixth air passage 325. In other words, the air pump 570 can be attached to either the air passage 315, 325 through which air passes from the inside of the air-conditioner casing 110 to the inside of the sensor case 160, or to the air passage 315, 325 through which air passes from the inside of the sensor case 160 to the inside of the air-conditioner casing 110. In other alternate exemplary implementations the air pump 570 could be attached to one of the third and fifth air passages 310, 320 inside of the air-conditioner casing 110.

[0103]FIG. 6 is a close-up view 600 of the wall of the air-conditioner casing 110 of FIG. 1 according to an exemplary device. According to FIG. 6, first and second holes 120, 125 are formed in the wall of the air-conditioner casing 110. A first refrigerant passage 130 passes through the first hole 120, while a second refrigerant passage 135 passes through the second hole 125. A first gap 140 is formed between the first refrigerant passage 130 and a circumference of the first hole 120, while a second gap 145 is formed between the second refrigerant passage 135 and a circumference of the second hole 125. A first air passage 150 passes through the first gap 140, while a second air passage 155 passes through the second gap 145. The first air passage 150 includes a fourth air passage 315, while the second air passage 155 includes a sixth air passage 325. The fourth and sixth air passages 315, 325 are connected to a sensor case 160.

[0104]The air-conditioner casing 110, the first and second holes 120, 125, the first and second refrigerant passages 130, 135, the first and second gaps 140, 145, the first and second air passages 150, 155, and the sensor case 160 all operate as described above with respect to FIG. 1. Their description will not be repeated for simplicity of disclosure.

[0105]In the device of FIG. 6, the portions of the first and second air passages 150, 155 that pass through first and second gaps 140, 145 are located at positions that are horizontally and vertically displaced from each other. This allows a pressure difference between their openings inside the air-conditioner casing 110 to cause air from inside the air-conditioner casing 110 to flow through the first and second air passages 150, 155 through the sensor case 160.

[0106]As shown in FIG. 6, the portions of the first and second air passages 150, 155 that pass through the first and second gaps 140, 145 are displaced horizontally from each other by a distance A and are displaced vertically from each other by a distance B. In exemplary devices in which the first and second air passages 150, 155 are both straight passages, it may be desirable to keep the distance B at 3 inches or greater to maintain a desired pressure difference between openings of the first and second air passages 150, 155 inside the air-conditioner casing 110. However, this is by way of example only. Alternate exemplary devices may set the distance B lower than 3 inches, depending upon system parameters.

[0107]Although the exemplary device of FIG. 6 shows the first and second holes 120, 125 being horizontally and vertically displaced from each other, other exemplary devices could have them only vertically displaced from each other or only horizontally displaced from each other. In such case, the position which the first and second air passages 150, 155 that pass through the first and second gaps 140, 145 may still be arranged such that they are both vertically and horizontally displaced from each other. For example, if the first and second holes 120, 125 were only horizontally displaced, the first air passage 150 could pass through the first gap 140 towards the top of the first gap 140 and the second air passage 155 could pass through the second gap 145 toward the bottom of the second gap 145.

Refrigerant Sensor

[0108]FIGS. 7-9 show various views of the refrigerant sensor 170 of FIG. 1. FIG. 7 is an overhead view of refrigerant sensor of FIG. 1 according to an exemplary device. As shown in FIG. 7, the refrigerant sensor 170 includes a first sensor input 180, a second sensor input 185, the communication connection 190, a bottom surface 710, a first side wall 730, a second side wall 735, a third side wall 740, a fourth side wall 745, and a fastener opening 750.

[0109]The first sensor input 180, the second sensor input 185, and the communication connection 190 all operate as described above with respect to FIG. 1. For ease of disclosure, their description will not be repeated.

[0110]The bottom surface 710 forms a base for the refrigerant sensor 170 and is the surface of the refrigerant sensor 170 that is attached to the wall of the air-conditioner casing 110.

[0111]The first side wall 730 and the second side wall 735 extend the length of the bottom surface 710 in one direction on opposite sides of the bottom surface. The third side wall 740 and the fourth side wall 745 extend between the first and second side wall 730, 735 to form an enclosed area that holds refrigerant detection circuitry (not shown) configured to detect refrigerant in the air adjacent to the external refrigerant sensor 170. The bottom surface 710 and a top surface 720 (not shown) serve to enclose the space containing the refrigerant detection circuitry.

[0112]The first and second sensor inputs 180, 185 extend from the refrigerant detection circuitry through the top surface 720 such that they are exposed to an outside of the refrigerant sensor 170, allowing them to detect refrigerant proximate to the refrigerant sensor 170.

[0113]The communication connection 190 extends from the second side wall 735 and the top surface 720 and connects to the refrigerant detection circuitry.

[0114]The fastener openings 750 are holes in the bottom surface 710 arranged to allow the refrigerant fasteners 195 to affix the external refrigerant sensor 170 to the wall of the air-conditioner casing 110. For example, if the refrigerant fasteners 195 are screws or bolts, the fastener openings 750 are holes that the screws or bolts pass through. In exemplary implementations in which the external refrigerant sensor 170 is attached using elements that need not pass through the bottom surface 710, the fastener openings 750 may be omitted.

[0115]FIG. 8 is a side view of refrigerant sensor 170 of FIG. 1 according to an exemplary device. As shown in FIG. 8, the first and second side walls 730, 735 have a trapezoidal shape with the wider of the two parallel sides attached to the bottom surface 710.

[0116]The first and second sensor inputs 180, 185 extend above the top surface 720 and above the side walls 730, 735, 740, 745 to allow for efficient detection of refrigerant in the air proximate to the external refrigerant sensor 170. However, this is by way of example only. Alternate exemplary implementations could have the top surface 720 formed below a top of the side walls 730, 735, 740, 745, creating a hollow defined by the top surface 720 and the side walls 730, 735, 740, 745, with the first and second sensor inputs 180, 185 formed in the hollow.

[0117]FIG. 9 is a perspective view of refrigerant sensor 170 of FIG. 1 according to an exemplary device. As shown in FIG. 9, the top surface 720 is slightly recessed from the top of the side walls 730, 735, 740, 745, although the first and second sensor inputs 180, 185 still extend above the top of the side walls 730, 735, 740, 745.

Alternate Devices

[0118]FIG. 10 is a close-up view of wall of an air-conditioner casing 1010 of an air conditioner 1000 according to alternate exemplary device. The air conditioner 1000 is similar to the air conditioner 100 of FIG. 1 except for the configuration of the openings in the air-conditioner casing 1010.

[0119]The air-conditioner casing 1010 includes first and second holes 1020, 1025, first and second refrigerant passages 1030, 1035, first and second gaps 1040, 1045, first and second air passages 1050, 1055, and first and second notches 1060, 1065 in the first and second holes 1020, 1025, respectively.

[0120]The first hole 1020 and the second hole 1025 are formed in the side of the air-conditioner casing 1010. In the exemplary device of FIG. 10, the first hole 1020 and the second hole 1025 are displaced from each other in both a horizontal and a vertical direction.

[0121]The first refrigerant passage 1030 is arranged to pass through the first hole 1020, while the second refrigerant passage 1035 is arranged to pass through the second hole 1025. These refrigerant passages 1030, 1035 allow refrigerant to pass between an inside and an outside of the air-conditioner casing 1010, e.g. to/from a heat exchange coil inside the air-conditioner casing 1110. In the device disclosed in FIG. 10, the first and second refrigerant passages 1030, 1035 may be metal or plastic pipes.

[0122]The first refrigerant passage 1030 is smaller than the first hole 1020, allowing for a first gap 1040 to be formed between the circumference of the first hole 1020 and the first refrigerant passage 1030. Similarly, the second refrigerant passage 1035 is smaller than the second hole 1025, allowing for a second gap 1045 to be formed between the circumference of the second hole 1025 and the second refrigerant passage 1035. Although not shown, these gaps 1040, 1045 can be filled with a cushioning or insulating material to protect the first and second refrigerant passages 1030, 1035 from touching or interfering with the circumference of the first and second holes 1020, 1025, respectively.

[0123]The first notch 1060 is formed along the circumference of the first hole 1120, providing an extension of the first gap 1040 to accommodate the first air passage 1050. Similarly, the second notch 1065 is formed along the circumference of the second hole 1025, providing extension of the second gap 1045 to accommodate the second air passage 1055. In this way, the first and second air passages 1050, 1055 need not displace any of the cushioning or insulating material formed in the first and second gaps 1040, 1045.

[0124]A first air passage 1050 is formed in the first notch 1060, while a second air passage 1055 is formed in the second notch 1065. This allows the first and second air passages 1050, 1055 to pass through the air-conditioner casing 110 without the requirement of making additional holes for them. In such a device, the first and second notches 1060, 1065 are sized such that the first and second air passages 1050, 1055 can pass through them. In some exemplary implementations the first and second notches 1060, 1065 can be made wider than the first and second air passages 1050, 1055 to allow insulating cushioning or insulating material to be placed between the first and second air passages 1050, 1055 and a circumference of the first and second notches 1060, 1065, respectively. In the device disclosed in FIG. 1, the first and second air passages 150, 155 may wholly or partly include metal or plastic pipes.

[0125]As shown in FIG. 10, the portions of the first and second air passages 1050, 1055 that pass through the first and second notches 1060, 1065 are displaced horizontally from each other by a distance A and are displaced vertically from each other by a distance B. In exemplary devices in which the first and second air passages 1050, 1055 are both straight passages, it may be desirable to keep the distance B at 3 inches or greater to maintain a desired pressure difference between openings of the first and second air passages 1050, 1055 inside the air-conditioner casing 110. However, this is by way of example only. Alternate exemplary devices may set the distance B lower than 3 inches, depending upon system parameters.

[0126]Although the exemplary device of FIG. 10 shows the first and second holes 1020, 1025 being horizontally and vertically displaced from each other, other exemplary devices could have them only vertically displaced from each other or only horizontally displaced from each other. In such case, the position which the first and second air passages 1050, 1055 that pass through the first and second notches 1060, 1065 may still be arranged such that they are both vertically and horizontally displaced from each other. For example, if the first and second holes 1020, 1025 were only horizontally displaced, the first notch 1060 could be arranged towards the top of the first gap 1040 and the second notch 1065 could be arranged toward the bottom of the second gap 1045, allowing for the first and second air passages 1050, 1055 to be both horizontally and vertically displaced from each other.

[0127]FIG. 11 is a close-up view of wall of an air-conditioner casing 1110 of an air conditioner 1100 according to second exemplary device. The air conditioner 1100 is similar to the air conditioner 100 of FIG. 1 except for the configuration of the openings in the air-conditioner casing 1110.

[0128]The air-conditioner casing 1110 includes first and second holes 1120, 1125, first and second refrigerant passages 1130, 1135, first and second gaps 1140, 1145, first and second air passages 1150, 1155, and third and fourth holes 1160, 1165.

[0129]The first hole 1120, the second hole 1125, the third hole 1160, and the fourth hole 1165 are all formed in the side of the air-conditioner casing 1110. In the exemplary device of FIG. 10, the first hole 1120 and the second hole 1125 are displaced from each other in both a horizontal and a vertical direction, and the third hole 1160 and the fourth hole 1165 are displaced from each other in both a horizontal and a vertical direction.

[0130]The first refrigerant passage 1130 is arranged to pass through the first hole 1120, while the second refrigerant passage 1135 is arranged to pass through the second hole 1125. These refrigerant passages 1130, 1135 allow refrigerant to pass between an inside and an outside of the air-conditioner casing 1110, e.g. to/from a heat exchange coil inside the air-conditioner casing 1110. In the device disclosed in FIG. 11, the first and second refrigerant passages 1130, 1135 are metal or plastic pipes.

[0131]The first refrigerant passage 1130 is smaller than the first hole 1120, allowing for a first gap 1140 to be formed between the circumference of the first hole 1020 and the first refrigerant passage 1130. Similarly, the second refrigerant passage 1135 is smaller than the second hole 1125, allowing for a second gap 1145 to be formed between the circumference of the second hole 1125 and the second refrigerant passage 1135. Although not shown, these gaps 1140, 1145 can be filled with a cushioning or insulating material to protect the first and second refrigerant passages 1130, 1135 from touching or interfering with the circumference of the first and second holes 1120, 1125, respectively.

[0132]The third hole 1160 is formed separate from the first and second holes 1120, 1125. Similarly, the fourth hole 1165 is formed separate from the first and second holes 1120, 1125.

[0133]The first air passage 1150 is arranged to pass through the third hole 1160, while the second air passage 1155 is arranged to pass through the fourth hole 1165. These air passages 1150, 1155 allow air to pass between an inside and an outside of the air-conditioner casing 1110, e.g. between a position proximate to a heat exchange coil inside the air-conditioner casing 1110 and an external refrigerant sensor 170 located outside the air-conditioner casing 1110. In the device disclosed in FIG. 11, the first and second air passages 1150, 1155 may wholly or partly include metal or plastic pipes.

[0134]As shown in FIG. 11, the portions of the first and second air passages 1150, 1155 that pass through the third and fourth holes 1160, 1165 are displaced horizontally from each other by a distance A and are displaced vertically from each other by a distance B. In exemplary devices in which the first and second air passages 1150, 1155 are both straight passages, it may be desirable to keep the distance B at 3 inches or greater to maintain a desired pressure difference between openings of the first and second air passages 1150, 1155 inside the air-conditioner casing 110. However, this is by way of example only. Alternate exemplary devices may set the distance B lower than 3 inches, depending upon system parameters.

[0135]FIG. 12 is a side view of air conditioner 1200 with an external refrigerant sensor 170 according to an alternate exemplary device.

[0136]As shown in FIG. 12, the air conditioner 1200 includes an air-conditioner casing 110 that surrounds most of the elements that make up the air conditioner 100. The air conditioner 100 includes a first hole 120 in the air-conditioner casing 110, a second hole 125 in the air-conditioner casing 110, a first refrigerant passage 130, a second refrigerant passage 135, a first gap 140, a second gap 145, a first air passage 1250, a second air passage 1255, a sensor case 160, and an external refrigerant sensor 170. The external refrigerant sensor 170 includes a first sensor input 180, a second sensor input 185, a communication connection 190, and one or more refrigerant fasteners 195.

[0137]The air conditioner 1200 of FIG. 12 is similar to the air conditioner 100 save for the position of first and second air passages 1250, 1255. Elements with the same number as in FIG. 1 perform the same function and their description will not be repeated.

[0138]In the device of FIG. 12, the first and second air passages 1250, 1255 both pass through the first gap 140 between the first refrigerant passage 130 and a circumference of the first hole 120. However, the first and second air passages 1250, 1255 are positioned in the first gap 140 such that they are displaced from each other both horizontally and vertically.

[0139]FIG. 13 is a cross-sectional view 1300 of the wall of the air-conditioner casing 110 of the air conditioner 1200 of FIG. 12 along line XIII-XIII′ according to the alternate exemplary device. along line I-I′ according to an exemplary device. As shown in FIG. 13, the wall of the air-conditioner casing 110 includes the first hole 120 and the second hole 125. The first refrigerant passage 130, the first air passage 1250, and the second air passage 1255 all pass through the first hole 120, and the second refrigerant passage 135 passes through the second hole 125.

[0140]The first air passage 1250 includes a third air passage 1310 and a fourth air passage 1315 connected to each other. The third air passage 1310 is formed inside of the air-conditioner casing 110 and extends a small length outside of the air-conditioner casing 110. The third air passage 1310 extends inside of the air-conditioner casing 110 to an area inside the air-conditioner casing 110 proximate to where a refrigerant leak is considered most likely, e.g., close to where refrigerant coils in the heat exchanger 210 are brazed. The fourth air passage 1315 is connected to the third air passage 1310 and extends from the third air passage 1310 to the sensor case 160 surrounding the external refrigerant sensor 170. In some exemplary devices the fourth air passage 1315 will be permanently affixed to the third air passage 1310. In other exemplary devices, the fourth air passage 1315 may be detachably affixed to the third air passage 1310.

[0141]Although in the exemplary device shown in FIG. 13, the third air passage 1310 is shown as extending a short length outside of the air-conditioner casing 110, this is by way of example only. In alternate implementations, the fourth air passage 1315 may extend a short length inside of the air-conditioner casing 110 and the third air passage 1310 may be connected to the fourth air passage 1315 inside the air-conditioner casing 110. Likewise, the third air passage 1310 and the fourth air passage 1315 may be connected just at the wall of the air-conditioner casing 110. In other alternate implementations, the first air passage 1250 may be a single element extending from a location of a potential leak inside the air-conditioner casing 110 to the sensor case 160.

[0142]The second air passage 1255 includes a fifth air passage 1320 and a sixth air passage 1325 connected to each other. The fifth air passage 1320 is formed inside of the air-conditioner casing 110 and extends a small length outside of the air-conditioner casing 110. The fifth air passage 1320 extends inside of the air-conditioner casing to an area inside the air-conditioner casing 110 different from where the inside end of the third air passage 1310 is located, and at a location with a different pressure than the inside end of the third passage 1310 so that the difference in pressure will cause air to flow from the inside of the air-conditioner casing 110 to the sensor case 160 and back again via the first and second air passages 1250, 1255.

[0143]The sixth air passage 1325 is connected to the fifth air passage 1320 and extends from the fifth air passage 1320 to the sensor case 160 surrounding the external refrigerant sensor 170. In some exemplary devices the sixth air passage 1325 will be permanently affixed to the fifth air passage 1320. In other exemplary devices, the sixth air passage 1325 may be detachably affixed to the fifth air passage 1320.

[0144]In the exemplary device of FIG. 13, the fifth air passage 1320 includes a bend on the inside of the air-conditioner casing 110 such that an opening of the third air passage 1310 and an opening of the fifth air passage 1320 are further separated in either a horizontal direction, a vertical direction, or both. This can allow for a greater pressure difference between the air at these ends of the air passages 1310, 1320, which can improve the flow of air through the first and second air passages 1250, 1255. Although this bend is shown specifically in the exemplary devices of FIGS. 12 and 13, it is equally applicable to other exemplary devices.

[0145]The first refrigerant passage 130, the first air passage 1250, and the second air passage 1255 have widths such that they will all fit within the first hole 120. This means that a largest width of the first hole 120, e.g., the diameter of the first hole 120 when the first hole 120 is a circle, must be at least somewhere between a sum of a width of the first refrigerant passage 130 and the larger of the width of the first air passage 1250 and the width of the second air passage 1255 and the sum of the widths of the first refrigerant passage 130, the first air passage 1250, and the second air passage 1255. The particular minimum width of largest width of the first hole 120 depends upon the orientation of the first refrigerant passage 130 the first air passage 1250, and the second air passage 1255 inside the hole. If these three passages 130, 1250, 1255 are arranged in a line, the minimum width must be larger than if the first and second air passages 1250, 1255 are arranged in other positions.

[0146]Although in the exemplary device shown in FIG. 13, the fifth air passage 1320 is shown as extending a short length outside of the air-conditioner casing 110, this is by way of example only. In alternate implementations, the sixth air passage 1325 may extend a short length inside of the air-conditioner casing 110 and the fifth air passage 1320 may be connected to the sixth air passage 1325 inside the air-conditioner casing 110. Likewise, the fifth air passage 1320 and the sixth air passage 1325 may be connected just at the wall of the air-conditioner casing 110. In other alternate implementations, the second air passage 1255 may be a single element extending from a location of a potential leak inside the air-conditioner casing 110 to the sensor case 160.

[0147]FIG. 14 is a close-up view 1400 of the wall of the air-conditioner casing 110 of the air conditioner 1200 of FIG. 12 according to the alternate exemplary device. According to FIG. 14, first and second holes 120, 125 are formed in the wall of the air-conditioner casing 110. A first refrigerant passage 130 passes through the first hole 120, while a second refrigerant passage 135 passes through the second hole 125. A first gap 140 is formed between the first refrigerant passage 130 and a circumference of the first hole 120, while a second gap 145 is formed between the second refrigerant passage 135 and a circumference of the second hole 125. First and second air passages 1250, 1255 pass through the first gap 140. The first air passage 150 includes a fourth air passage 315, while the second air passage 155 includes a sixth air passage 325. The fourth and sixth air passages 315, 325 are connected to a sensor case 1460.

[0148]The air-conditioner casing 110, the first and second holes 120, 125, the first and second refrigerant passages 130, 135, the first and second gaps 140, 145, the first and second air passages 1250, 1255, and the sensor case 1460 all operate as described above with respect to FIGS. 1 and 12. Their description will not be repeated for simplicity of disclosure.

[0149]In the device of FIG. 14, the portions of the first and second air passages 150, 155 that pass through first gap 140 are located at positions that are horizontally and vertically displaced from each other. This allows a pressure difference to cause air from inside the air-conditioner casing 110 to flow through the first and second air passages 1250, 1255 through the sensor case 160.

[0150]As shown in FIG. 14, the portions of the first and second air passages 1250, 1255 that pass through the first gap 140 are displaced horizontally from each other by a distance A and are displaced vertically from each other by a distance B. In exemplary devices in which the first and second air passages 1250, 1255 are both straight passages, it may be desirable to keep the distance B at 3 inches or greater to maintain a desired pressure difference between openings of the first and second air passages 1250, 1255 inside the air-conditioner casing 110. However, this is by way of example only. Alternate exemplary devices may set the distance B lower than 3 inches, depending upon system parameters.

[0151]FIGS. 15-17 are cross-sectional views of the wall of an air-conditioner casing 110 according to alternate exemplary devices. These cross-sectional views of the wall of the air-conditioner casing 110 show how various first and second air passages may contain bends in them inside the air-conditioner casing 110. Specifically, one or both of the various disclosed first and second air passages may contain bends to ensure that inside openings of the first and second air passages are different heights or otherwise experience a pressure difference, allowing for a more efficient airflow through respective first and second air passages.

[0152]FIG. 15 is a cross-sectional view 1500 of the wall of an air-conditioner casing 110 in which first and second air passages 150, 1555 pass through separate holes 120, 125 in the air-conditioner casing 110, the first air passage 150 is straight, and the second air passage 1555 is bent.

[0153]The exemplary device of FIG. 15 is similar to the exemplary device of FIG. 3, and elements with the same label operate as described above with respect to FIG. 3.

[0154]In the exemplary device of FIG. 15, the second air passage 1555 includes a fifth air passage 1520 and a sixth air passage 1525 connected to each other. The fifth air passage 1520 is formed inside of the air-conditioner casing 110 and extends a small length outside of the air-conditioner casing 110. The fifth air passage 1520 extends inside of the air-conditioner casing 110 to an area inside the air-conditioner casing 110 different from where the inside end of the third air passage 310 is located, and at a location with a different pressure than the inside end of the third passage 310 so that the difference in pressure will cause air to flow from the inside of the air-conditioner casing 110 to the sensor case 160 and back again via the first and second air passages 150, 1555.

[0155]The sixth air passage 1525 is connected to the fifth air passage 1520 and extends from the fifth air passage 1520 to the sensor case 160 surrounding the external refrigerant sensor 170. In some exemplary devices the sixth air passage 1525 will be permanently affixed to the fifth air passage 1520. In other exemplary devices, the sixth air passage 1525 may be detachably affixed to the fifth air passage 1520.

[0156]In the exemplary device of FIG. 15, the fifth air passage 1520 includes a bend on the inside of the air-conditioner casing 110 such that an opening of the third air passage 310 and an opening of the fifth air passage 1520 are further separated in either a horizontal direction, a vertical direction, or both. This can allow for a greater pressure difference between the air at these ends of the air passages 310, 1520, which can improve the flow of air through the first and second air passages 150, 1555.

[0157]FIG. 16 is a cross-sectional view 1600 of the wall of an air-conditioner casing 110 in which first and second air passages 1650, 1555 pass through separate holes 120, 125 in the air-conditioner casing 110, and the first and second air passages 1650, 1555 are both bent.

[0158]The exemplary device of FIG. 16 is similar to the exemplary device of FIGS. 3 and 15, and elements with the same label operate as described above with respect to FIGS. 3 and 15.

[0159]In the exemplary device of FIG. 16, the first air passage 1650 includes a third air passage 1610 and a fourth air passage 1615 connected to each other, and the second air passage 1555 includes a fifth air passage 1520 and a sixth air passage 1525 connected to each other.

[0160]The third air passage 1610 is formed inside of the air-conditioner casing 110 and extends a small length outside of the air-conditioner casing 110.

[0161]The fourth air passage 1615 is connected to the third air passage 1610 and extends from the third air passage 1610 to the sensor case 160 surrounding the external refrigerant sensor 170. In some exemplary devices the fourth air passage 1615 will be permanently affixed to the third air passage 1610. In other exemplary devices, the fourth air passage 1615 may be detachably affixed to the third air passage 1610.

[0162]The fifth air passage 1520 extends inside of the air-conditioner casing 110 to an area inside the air-conditioner casing 110 different from where the inside end of the third air passage 1610 is located, and at a location with a different pressure than the inside end of the third passage 1610 so that the difference in pressure will cause air to flow from the inside of the air-conditioner casing 110 to the sensor case 160 and back again via the first and second air passages 1650, 1555.

[0163]The sixth air passage 1525 is connected to the fifth air passage 1520 and extends from the fifth air passage 1520 to the sensor case 160 surrounding the external refrigerant sensor 170. In some exemplary devices the sixth air passage 1525 will be permanently affixed to the fifth air passage 1520. In other exemplary devices, the sixth air passage 1525 may be detachably affixed to the fifth air passage 1520.

[0164]In the exemplary device of FIG. 16, the third and fifth air passages 1610, 1520 each include a bend on the inside of the air-conditioner casing 110 such that an opening of the third air passage 1610 and an opening of the fifth air passage 1520 are further separated in either a horizontal direction, a vertical direction, or both. This can allow for a greater pressure difference between the air at these ends of the air passages 1610, 1520, which can improve the flow of air through the first and second air passages 1650, 1555.

[0165]FIG. 17 is a cross-sectional view 1700 of the wall of an air-conditioner casing 110 in which first and second air passages 1750, 1355 pass through a single hole 120 in the air-conditioner casing 110, and the first and second air passages 1750, 1355 are both bent.

[0166]The exemplary device of FIG. 17 is similar to the exemplary device of FIG. 13, and elements with the same label operate as described above with respect to FIG. 13.

[0167]The third air passage 1710 is formed inside of the air-conditioner casing 110 and extends a small length outside of the air-conditioner casing 110.

[0168]The fourth air passage 1715 is connected to the third air passage 1710 and extends from the third air passage 1710 to the sensor case 160 surrounding the external refrigerant sensor 170. In some exemplary devices the fourth air passage 1715 will be permanently affixed to the third air passage 1710. In other exemplary devices, the fourth air passage 1715 may be detachably affixed to the third air passage 1710.

[0169]The fifth air passage 1320 extends inside of the air-conditioner casing 110 to an area inside the air-conditioner casing 110 different from where the inside end of the third air passage 1710 is located, and at a location with a different pressure than the inside end of the third passage 1710 so that the difference in pressure will cause air to flow from the inside of the air-conditioner casing 110 to the sensor case 160 and back again via the first and second air passages 1750, 1355.

[0170]The sixth air passage 1325 is connected to the fifth air passage 1320 and extends from the fifth air passage 1320 to the sensor case 160 surrounding the external refrigerant sensor 170. In some exemplary devices the sixth air passage 1325 will be permanently affixed to the fifth air passage 1320. In other exemplary devices, the sixth air passage 1325 may be detachably affixed to the fifth air passage 1320.

[0171]In the exemplary device of FIG. 17, the third and fifth air passages 1710, 1320 each include a bend on the inside of the air-conditioner casing 110 such that an opening of the third air passage 1710 and an opening of the fifth air passage 1320 are further separated in either a horizontal direction, a vertical direction, or both. This can allow for a greater pressure difference between the air at these ends of the air passages 1710, 1320, which can improve the flow of air through the first and second air passages 1750, 1355.

Method of Operation

[0172]FIG. 18 is a flowchart 1800 of an exemplary method of detecting refrigerant in conditioned air from an air conditioner.

[0173]As shown in operation 1810, inside air is drawn from inside an air-conditioner casing of an air conditioner proximate to a heat exchanger into a first air passage.

[0174]As shown in operation 1820, the inside air passes through the first air passage from the inside of the air-conditioner casing to a refrigerant sensor attached to an outside of the air-conditioner casing through a first hole in the casing.

[0175]As shown in operation 1830, a level of refrigerant in the inside air is detected at the refrigerant sensor and a determination is made as to whether the level of refrigerant detected in the inside air rises above a set threshold amount.

[0176]As shown in operation 1840, if operation 1830 determines that the level of refrigerant in the inside air is not above the set threshold level, it is determined that no refrigerant leak exists, and a controller is notified, as necessary.

[0177]As shown in operation 1850, if operation 1830 determines that the level of refrigerant in the inside air is above the set threshold level, it is determined that a refrigerant leak exists, and a controller is notified, as necessary. In such case, corrective measures may be taken, e.g., sounding an alarm, displaying alert, stopping operation of the air conditioner, etc.

[0178]As shown in operation 1860, the inside air then passes from the refrigerant sensor back to the inside of the air-conditioner casing via the second passage through a second hole in the air-conditioner casing.

[0179]Although in the exemplary devices shown in FIGS. 15-17, the various fifth air passages are shown as extending a short length outside of the air-conditioner casing 110, this is by way of example only. In alternate implementations, respective sixth air passages may extend a short length inside of the air-conditioner casing 110 and respective fifth air passages may be connected to corresponding sixth air passages inside the air-conditioner casing 110. Likewise, in some exemplary implementations, respective fifth and sixth air passages can be connected exactly at the wall of the air-conditioner casing 110. In other alternate implementations, one or more of respective first and second air passages may be a single element extending from a location inside the air-conditioner casing 110 to the sensor case 160.

Conclusion

[0180]This disclosure is intended to explain how to fashion and use various embodiments in accordance with the invention rather than to limit the true, intended, and fair scope and spirit thereof. The foregoing description is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The embodiment(s) was chosen and described to provide the best illustration of the principles of the invention and its practical application, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims, as may be amended during the pendency of this application for patent, and all equivalents thereof, when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled. The various circuits described above can be implemented in discrete circuits or integrated circuits, as desired by implementation.