Patent Description:
A ceiling-embedded air conditioner (indoor unit) installed behind the ceiling of an air-conditioned room is connected to an outdoor unit that is installed outdoor through a refrigerant line, to forms a refrigerant circuit. The ceiling-embedded air conditioner includes a box-shaped main unit that is installed behind the ceiling, and a decorative panel that covers the bottom surface of the main unit, and that is exposed from the ceiling surface.

<FIG> illustrates a conventional ceiling-embedded air conditioner. <NUM> denotes to a main unit, and <NUM> denotes to a decorative panel having an intake port <NUM>, and an outlet port <NUM> provided with wind deflectors <NUM>. The main unit <NUM> is surrounded by a housing <NUM> the top side and the lateral sides of which are made of steel plates. Provided inside the main unit <NUM> are a sirocco fan <NUM> that sucks the air from the intake port <NUM> provided to the decorative panel <NUM>, a fan casing <NUM> in which the sirocco fan <NUM> is housed, a heat exchanger <NUM> that has a V shape rotated by <NUM> degrees, and against which the wind coming out of the sirocco fan <NUM> and guided by the fan casing <NUM> blows, a drain pan <NUM> that collects dew drops formed on the heat exchanger <NUM>, and an outlet guide <NUM> that changes the direction of the airflow passed through the heat exchanger <NUM>, from a horizontal direction to a downward direction, and that guides the air to the outlet port <NUM> of the decorative panel <NUM>.

<FIG> illustrates another conventional ceiling-embedded air conditioner. <NUM> denotes to a main unit, and <NUM> denotes to a decorative panel having an intake port <NUM> and an output port <NUM> that is provided with wind deflectors <NUM>. The main unit <NUM> is surrounded by a housing <NUM> the top side and the lateral sides of which are made of steel plates. Provided inside the main unit <NUM> are a heat exchanger <NUM> folded by an angle of <NUM> degrees or so, and diagonally positioned near the intake port <NUM> of the decorative panel <NUM>, a sirocco fan <NUM> that sucks the air from the intake port <NUM> via the heat exchanger <NUM>, a drain pan <NUM> that collects the dew drops formed on the heat exchanger <NUM>, and an outlet guide <NUM> that changes the direction of the airflow coming of the sirocco fan <NUM> from a horizontal direction to a downward direction, and that guides the air to an output port <NUM> of the decorative panel <NUM>.

The conventional ceiling-embedded air conditioners explained with reference to <FIG> and <FIG> have a structure in which an outlet ventilation path 16a extending along the outlet guide <NUM> to the outlet port <NUM> or an outlet ventilation path 35a extending along the outlet guide <NUM> to the output port <NUM> opens straight downwards, and the direction of the wind is changed to the frontward direction (toward the right in <FIG>, <FIG>) using the use of the wind deflectors <NUM> provided to the outlet port <NUM> or the wind deflectors <NUM> provided to the output port <NUM>. Therefore, as the wind deflectors <NUM>, <NUM> change the direction of the wind, the direction is changed sharply, and the flow velocity of the wind drops quickly, and such sudden changes make it difficult to extend the reachable distance of the wind in the frontward direction.

Such a ceiling-embedded air conditioner according to the prior art is, for example, shown in <CIT>.

It is the object of the present invention to provide a ceiling-embedded air conditioner capable of alleviating a drop in the flow velocity of the outgoing air flow, and extending the reachable distance of the outgoing air flow in the frontward direction.

The object of the present invention is achieved by a ceiling-embedded air conditioner having the features of claim <NUM>.

According to the present invention, because the bottom opening of the outlet guide tube faces a direction below the front plate of the main unit, because the outlet ventilation path connecting the top opening to the bottom opening is curved, and because the bottom end of the bottom opening protrudes more downwards than the decorative panel does, the wind coming out of the fan unit is gently guided downwards toward the front, by the outlet ventilation path having a curved outlet guide tube, without changing the direction of the wind in up-and-down directions using up-and-down wind deflectors. Therefore, it is possible to alleviate a drop in the flow velocity of the outgoing air, and to extend its reachable distance in the frontward direction.

<FIG> is a schematic illustrating an installation of a ceiling-embedded air conditioner according to an embodiment of the present invention.

A ceiling-embedded air conditioner <NUM> according to an embodiment of the present invention will now be explained. This ceiling-embedded air conditioner <NUM> is mounted on a ceiling T1 of the air-conditioned room R, as illustrated in <FIG>, and is connected to an outdoor unit, not illustrated, installed outdoor through a refrigerant line, to form a refrigerant circuit. The ceiling-embedded air conditioner <NUM> includes a box-shaped main unit <NUM> that is installed in a garret T2, and a decorative panel <NUM> that is mounted on the bottom surface of the main unit <NUM>, in a manner exposed to the air-conditioned room R. The main unit <NUM> has an electrical equipment box <NUM> having a control board mounted on a side surface, as illustrated in <FIG>.

Outlet guide tubes <NUM>, <NUM>, <NUM>, <NUM> are provided as outlet ports, from the left to the right, on the front side of the decorative panel <NUM>. The outgoing direction of the wind in the up-and-down directions can be adjusted by adjusting the wind passing through the leftmost outlet guide tube <NUM> using the outlet guide tube <NUM> and an up-and-down wind deflector <NUM> rotating with a leftmost rotating plate <NUM>; adjusting the wind passing through the center outlet guide tubes <NUM>, <NUM> using a shared up-and-down wind deflector <NUM>; and adjusting the wind passing through the rightmost outlet guide tube <NUM> using the outlet guide tube <NUM> and an up-and-down wind deflector <NUM> rotating with a rightmost rotating plate <NUM>. The rotating plate <NUM> is provided rotatably toward the left by <NUM> degrees from the position illustrated in <FIG>, and the rotating plate <NUM> is provided rotatably toward the right by <NUM> degrees from the position illustrated in <FIG>.

Behind the line along which the outlet guide tubes <NUM>, <NUM>, <NUM>, <NUM> are aligned on a bottom surface <NUM> of the decorative panel <NUM> (the surface facing the air-conditioned room R illustrated in <FIG>), an intake port <NUM> having an elongated shape in a left-to-right direction is provided, and the intake port <NUM> is covered by a grill <NUM>. A protruding portion <NUM> protruding downwards, in the manner to be described later, is provided between the grill <NUM> and the up-and-down wind deflectors <NUM>, <NUM>, and <NUM>, within a section between the grill <NUM> and a front part <NUM> of the bottom surface <NUM> of the decorative panel <NUM>, and protrudes more downwards than the front part <NUM> does.

<FIG> illustrates a view of the main unit <NUM> with the decorative panel <NUM> removed, in a direction looking up from below, and <FIG> illustrates an exploded view of the main unit <NUM> in the direction looking up from below. The main unit <NUM> includes, in addition to the electrical equipment box <NUM>, a housing <NUM> made of a steel plate, a heat exchanger <NUM>, a fan unit <NUM>, a drain pan <NUM>, and a drain pump <NUM> having an intake port <NUM> and a discharge port <NUM>.

The housing <NUM> has a box-like shape having a top plate <NUM> that has a rectangular shape, and a front plate <NUM>, a rear plate <NUM>, a left plate <NUM>, and a right plate <NUM> that extend from the respective four sides of the top plate <NUM>. The electrical equipment box <NUM> illustrated in <FIG> is mounted on the right plate <NUM>, and a drainpipe <NUM> is attached to the same right plate <NUM>. Two attachment clamps <NUM> are mounted on each of the left plate <NUM> and the right plate <NUM>, on the side facing the top plate <NUM>. The main unit <NUM> is installed in the garret T2, by having the attachment clamps <NUM> suspended from suspension bolts, not illustrated, that are fixed in the garret T2.

The heat exchanger <NUM> is housed in the housing <NUM>, and includes a first heat exchanger <NUM> disposed near the front plate <NUM> of the housing <NUM>, and a second heat exchanger <NUM> disposed near the rear plate <NUM>. The first heat exchanger <NUM> is inclined in such a manner that the upper side thereof is positioned near the front plate <NUM> of the housing <NUM>, and the second heat exchanger <NUM> is inclined in such a manner that the upper side thereof is positioned near the rear plate <NUM> of the housing <NUM>. These heat exchangers <NUM>, <NUM> have their top ends attached to the top plate <NUM> of the housing <NUM>. A motor shaft support plate <NUM> supporting a motor rotational shaft <NUM>, which will be described later, is attached to ends of the heat exchangers <NUM>, <NUM>, the ends being those on the side facing the left plate <NUM>, and a motor shaft support plate <NUM> supporting a motor rotational shaft <NUM>, which will be described later, is attached to ends of the heat exchangers <NUM>, <NUM>, the ends being those on the side facing the right plate <NUM>.

The fan unit <NUM> includes a double-shaft fan motor <NUM> having a motor mount <NUM>, two impellers <NUM>, <NUM> that are fixed to one motor rotational shaft <NUM> of the fan motor <NUM>, two impellers <NUM>, <NUM> that are fixed to the other motor rotational shaft <NUM> of the fan motor <NUM>, and fan casings <NUM> to <NUM> that cover the respective impellers <NUM> to <NUM>. Each of the fan casings <NUM> to <NUM> includes a top mount 731a to 734a to be attached to the top plate <NUM> of the housing <NUM>, an intake opening 731b to 734b provided on one side surface, and an outlet tube 731c to 734c provided in a manner protruding downwards. Each pair of the impeller <NUM> and the fan casing <NUM>, the impeller <NUM> and the fan casing <NUM>, the impeller <NUM> and the fan casing <NUM>, and the impeller <NUM> and the fan casing <NUM> forms a sirocco fan.

The drain pan <NUM> is made from an insulator material <NUM> made of polystyrene foam. This insulator material <NUM> has four outlet port openings <NUM> to <NUM> passing through a top surface 810a to a bottom surface 810b thereof, provided in a manner arranged along a line. The drain pan <NUM> has a substantially rectangular shape having a rear end 810c and a front end 810d thereof as its long sides, as illustrated in <FIG>.

The top surface 810a of the insulator material <NUM> is provided with a groove <NUM> that receives the dew drops formed on the second heat exchanger <NUM> and is formed between an outer wall <NUM> on the side of the rear end 810c and an inner wall <NUM> on the rear side. A groove <NUM> configured to receive the dew drops formed on the first heat exchanger <NUM> is formed between an outer wall <NUM> on the side of the front end 810d, and an inner wall <NUM> on the front side. A groove <NUM> is also provided between an outer wall <NUM> on the side of a right end 810e, and an inner wall <NUM> on the right side. A groove <NUM> serving as a drain pan configured to receive the dew drops attached to the outside of the fan casings <NUM> to <NUM> is also provided between the inner wall <NUM> and side walls 821a to 824a of the outlet port openings <NUM> to <NUM>. A groove <NUM> serving as a drain pan configured to receive the dew drops attached to the outside of the fan casings <NUM> to <NUM> is also provided between the inner wall <NUM> and side walls 821a to 824a of the outlet port openings <NUM> to <NUM>. A drain tank <NUM> is provided at the rear right on the top surface 810a of the insulator material <NUM>. The groove <NUM> and the groove <NUM> are continuous to the drain tank <NUM>, and the groove <NUM> is continuous to the groove <NUM>. In other words, the drain water collected into the grooves <NUM>, <NUM>, <NUM> are further collected into the drain tank <NUM>. The grooves <NUM>, <NUM> do not communicate with the grooves <NUM>, <NUM>.

On the side of the bottom surface 810b of the insulator material <NUM>, a reinforcement metal piece <NUM> having the shape illustrated in <FIG> is mounted, by embedding. The reinforcement metal piece <NUM> has a long piece <NUM> corresponding to the rear end 810c of the drain pan <NUM>, a long piece <NUM> corresponding to the front end 810d, a short piece <NUM> connecting the left ends of the long piece <NUM> and the long piece <NUM> in <FIG>, a short piece <NUM> connecting the right ends of the long piece <NUM> and the long piece <NUM> in <FIG>, and attachment pieces <NUM>, <NUM>. The entire shape of the reinforcement metal piece <NUM> is a rectangular shape surrounding the outside of the outlet port openings <NUM> to <NUM> provided to the drain pan <NUM>, with the rectangular shape delineated by the long pieces <NUM>, <NUM> and the short pieces <NUM>, <NUM>. To embed the reinforcement metal piece <NUM> in the insulator material <NUM>, the reinforcement metal piece <NUM> is positioned inside a mold for forming the insulator material <NUM> in advance, and polystyrene foam is then caused to foam so that the reinforcement metal piece <NUM> is embedded therein. In this manner, the reinforcement metal piece <NUM> is integrated with the insulator material <NUM> in such a manner that the long piece <NUM>, <NUM> are embedded in the insulator material <NUM>, with the short pieces <NUM>, <NUM> and the attachment pieces <NUM>, <NUM> exposed.

The outlet guide tube <NUM> of the decorative panel <NUM> is provided communicatively with the outlet port opening <NUM> of the drain pan <NUM>, and the outlet guide tube <NUM> is provided communicatively with the outlet port opening <NUM> of the drain pan <NUM>. The outlet guide tube <NUM> is provided communicatively with the outlet port opening <NUM> of the drain pan <NUM>, and the outlet guide tube <NUM> is provided communicatively with the outlet port opening <NUM> of the drain pan <NUM>. The up-and-down wind deflector <NUM> in the leftmost outlet guide tube <NUM> and the up-and-down wind deflector <NUM> in the rightmost outlet guide tube <NUM> are rotationally adjustable by an angle of <NUM> degrees, as mentioned earlier.

The outlet guide tube <NUM> will now be explained as an example. As illustrated in <FIG>, the outlet guide tube <NUM> has a top opening <NUM> that communicates with the outlet tube 732c of the fan casing <NUM>, on the outlet port opening <NUM> of the drain pan <NUM>, a bottom opening <NUM> that is positioned facing diagonally downwards toward the front, and an outlet ventilation path <NUM> that extends from the top opening <NUM> to the bottom opening <NUM>, and that is smoothly curved. The up-and-down wind deflector <NUM> shared with the outlet guide tube <NUM> is mounted on the bottom opening <NUM> serving as an outlet port opening. A right-and-left wind deflector <NUM> for the outlet guide tube <NUM> is also mounted on the outlet ventilation path <NUM> on the upper rear portion. A bottom end 323a of the bottom opening <NUM> protrudes more downwards than the front part <NUM> of the bottom surface <NUM> of the decorative panel <NUM> does. The same type of the right-and-left wind deflector, not illustrated, as the right-and-left wind deflector <NUM> is also mounted on an outlet ventilation path, not illustrated, in the outlet guide tube <NUM>. Right-and-left wind deflectors, not illustrated, are also mounted on the leftmost outlet guide tube <NUM> and the rightmost outlet guide tube <NUM>, respectively. The up-and-down wind deflectors <NUM>, <NUM> are also provided rotatably by the rotations of the rotating plate <NUM>, <NUM>. However, because these parts are irrelevant to the present invention, detailed explanations thereof will be omitted.

Assembling of the ceiling-embedded air conditioner <NUM> will now be explained by referring to <FIG> as appropriate. To begin with, the housing <NUM> of the main unit <NUM> is placed on an assembly table with the top plate <NUM> facing upwards, and the assembled heat exchangers <NUM>, <NUM> are then fixed onto the inner side of the top plate <NUM>.

After positioning the assembled fan unit <NUM> between the heat exchangers <NUM>, <NUM>, the motor mount <NUM> of the fan motor <NUM> is fixed to the top plate <NUM> with screws. The one motor rotational shaft <NUM> is then supported on the motor shaft support plate <NUM>, and the other motor rotational shaft <NUM> is then supported on the motor shaft support plate <NUM>. The top mounts 731a to 734a of the respective fan casings <NUM> to <NUM> are then screwed onto the top plate <NUM>.

At this time, as illustrated in <FIG>, the fan unit <NUM> is placed nearer to the first heat exchanger <NUM> on the front side than to the second heat exchanger <NUM> on the rear side so that L1<L2 is established, denoting the distance between the center C1 of the motor rotational shafts <NUM>, <NUM> of the fan unit <NUM> and a center C2 of the first heat exchanger <NUM> on the front side in the up-and-down direction as L1, and denoting the distance between C1 and a center C3 of the second heat exchanger <NUM> on the rear side in the up-and-down direction as L2.

The drain pump <NUM> is then attached to the inner side of the right plate <NUM> of the housing <NUM>, and the discharge port <NUM> is joined to the drainpipe <NUM> illustrated in <FIG>. After aligning the second heat exchanger <NUM> with the groove <NUM> provided on the top surface 810a of the drain pan <NUM>, and aligning the first heat exchanger <NUM> with the groove <NUM>, the drain pan <NUM> is pushed up from below so that the drain pan <NUM> fits inside of the housing <NUM>, and the short piece <NUM> of the reinforcement metal piece <NUM> is fixed to the left plate <NUM> of the housing <NUM> with screws, and the attachment pieces <NUM>, <NUM> are screwed onto the right plate <NUM>. With the drain pan <NUM> mounted in the manner described, the rear end 810c faces a space S1, which will be described later, and the front end 810d faces a space S2, which will also be described later.

As a result of the steps described above, the outlet tubes 731c to 734c of the respective four fan casings <NUM> to <NUM> in the fan unit <NUM> get inside of the side walls 821a to 824a of the four outlet port openings <NUM> to <NUM>, respectively, on the top surface 810a of the drain pan <NUM>, and the outlet tubes 731c to 734c of the respective fan casings <NUM> to <NUM> come to communicate with the outlet port openings <NUM> to <NUM>, respectively, on the drain pan <NUM>. Furthermore, the intake port <NUM> of the drain pump <NUM> is positioned inside the drain tank <NUM> on the drain pan <NUM>.

Because the assembled main unit <NUM> is packed separately from the decorative panel <NUM>, when the ceiling-embedded air conditioner <NUM> is installed, the package is unpacked, and the main unit <NUM> is installed in the garret T2 by hanging the main unit <NUM> from a plurality of suspension bolts embedded in the garret T2. The decorative panel <NUM> is then attached from the side of the air-conditioned room R, as illustrated in <FIG>. The top opening <NUM> of the outlet guide tube <NUM> provided on the decorative panel <NUM> is then inserted into the outlet port opening <NUM> from the bottom surface 810b of the drain pan <NUM>, as illustrated in <FIG>, so that the outlet guide tube <NUM> becomes communicative with the outlet tube 732c of the fan casing <NUM>. The remaining outlet guide tubes <NUM>, <NUM>, <NUM> are also inserted into the respective outlet port openings <NUM>, <NUM>, <NUM> of the drain pan <NUM>, so that the remaining outlet guide tubes <NUM>, <NUM>, <NUM> become communicative with the outlet tubes 731c, 733c, 734c of the fan casings <NUM>, <NUM>, <NUM>, respectively. The decorative panel <NUM> is then fixed to the housing <NUM> of the main unit <NUM> with screws, and a refrigerant line, a power line, a signal line, and the like, not illustrated, are connected thereto.

In the ceiling-embedded air conditioner <NUM> assembled in the manner described above, as illustrated in <FIG>, the space S1 between the second heat exchanger <NUM> on the rear side and the rear plate <NUM> becomes communicative with the space S2 between the first heat exchanger <NUM> on the front side and the front plate <NUM> of the housing <NUM> through a space S3 between the bottom surface 810b of the drain pan <NUM> and the decorative panel <NUM>. This space S3 not only serves as a space where the outlet guide tubes <NUM>, <NUM>, <NUM>, <NUM> are positioned, but also serves as a space where the outlet guide tubes are connected to each other.

Based on the above, in the ceiling-embedded air conditioner <NUM> according to the embodiment, the outlet guide tube <NUM> has the bottom opening <NUM> with a bottom end 232a thereof protruding more downwards than the front part <NUM> of the bottom surface <NUM> of the decorative panel <NUM> does, and the bottom opening <NUM> has an opening plane facing diagonally downwards toward the front. Furthermore, the outlet ventilation path <NUM> is smoothly curved toward the direction below the front plate <NUM>. Therefore, the outlet guide tube <NUM> is less likely cause volume loss in the air that the rotating impeller <NUM> blows, and it becomes possible to extend the reachable distance of the outgoing air flow in a frontward direction with respect to the ceiling-embedded air conditioner <NUM>. The same is applicable to the outlet guide tubes <NUM>, <NUM>, <NUM>.

The air collected from the intake port <NUM> of the decorative panel <NUM> reaches the second heat exchanger <NUM> through the space S1 provided between the second heat exchanger <NUM> on the rear side and the rear plate <NUM>. The air collected from the intake port <NUM> of the decorative panel <NUM> reaches the first heat exchanger <NUM> on the front side via the space S3 and the space S2, the space S3 being formed between the bottom surface 810b of the drain pan <NUM> and the decorative panel <NUM> and between the outlet guide tubes <NUM>, <NUM>, <NUM>, <NUM>, the space S2 being formed between the front-side first heat exchanger <NUM> and the front plate <NUM>. Therefore, a sufficient amount of air can be sent to the first heat exchanger <NUM>, which is at a greater distance than the second heat exchanger <NUM> with respect to the intake port <NUM>, and therefore, the same level of heat exchange be achieved by the first heat exchanger <NUM> as that achieved by the second heat exchanger <NUM>, and hence, it becomes possible to improve the heat exchange efficiency of the ceiling-embedded heat exchangers. At this time, because the first heat exchanger <NUM> is inclined in such a manner that the upper side thereof is positioned near the front plate <NUM> of the housing <NUM>, and the second heat exchanger <NUM> is inclined in such a manner that the upper side thereof is positioned near the rear plate <NUM> of the housing <NUM>, and also because the air is collected into the spaces S1, S2 from below, the angle at which the direction of the incoming air is changed is increased from a right angle to a more gradual obtuse angle, so that the ventilation resistance is reduced, and the heat-exchange efficiency between the air and the refrigerant in the first and second heat exchangers <NUM>, <NUM> is improved, compared with a configuration without the inclinations. Furthermore, by providing the inclinations to the first and the second heat exchangers <NUM>, <NUM>, the width of the heat exchangers in the up-and-down direction can be increased, compared with a configuration in which the heat exchangers are provided at a right angle. In this manner, it becomes possible to provide heat exchangers with a larger heat-exchanging surface areas, and the heat-exchange efficiency is also improved from this point of view.

Furthermore, as illustrated in <FIG>, denoting the distance between the center C1 of the motor rotational shafts <NUM>, <NUM> in the fan unit <NUM> and the center C2 of the first heat exchanger <NUM> in the up-and-down direction as L1, and denoting the distance between C1 and the center C3 of the second heat exchanger <NUM> in the up-and-down direction as L2, these distances are set so that L1<L2 is established. At this time, the outlet tubes 731c to 734c of the respective fan casings <NUM> to <NUM> are configured to face straight downwards, that is, to face the drain pan <NUM>. Therefore, the outlet tubes 731c to 734c do not hit the first heat exchanger <NUM> or the second heat exchanger <NUM>. Based on the above, it is possible to achieve an arrangement in which the fan unit <NUM> is positioned nearer to the first heat exchanger <NUM> than to the second heat exchanger <NUM>, and as a result, the volume of the air sucked into the first heat exchanger <NUM> positioned nearer to the fan unit <NUM> is increased. As a result, because the volume of the air sucked into the first heat exchanger <NUM> is set larger than that sucked into the second heat exchanger <NUM>, compared with a configuration in which L1=L2, it becomes possible even for the first heat exchanger <NUM>, which has a longer airflow path than that of the second heat exchanger <NUM>, to achieve the same level of heat-exchange efficiency as that achieved by the second heat exchanger <NUM>, and therefore, the balance is improved. In other words, by setting L1<L2, the volume of the air sucked into the first heat exchanger <NUM> is increased, and the balance of the heat-exchange efficiency between the first heat exchanger <NUM> and the second heat exchanger <NUM> is improved. Furthermore, if L2 is set in the same manner as that conventionally practiced, because the first heat exchanger <NUM> is positioned nearer to the rear plate <NUM> of the housing <NUM>, it is possible to position the front plate <NUM> of the housing <NUM> nearer to the rear plate <NUM>, and the size of the housing <NUM> in the front-and-back direction can be reduced. Furthermore, when a part of the fan casings <NUM> to <NUM> of the fan unit <NUM> on the side of the first heat exchanger <NUM> is brought into abutment against the first heat exchanger <NUM>, the part of the fan casings <NUM> to <NUM> facing the first heat exchanger <NUM> may be provided with a flat profile, by cutting along the line D1 illustrated in <FIG>.

Furthermore, the fan casings <NUM> to <NUM> in the fan unit <NUM> are positioned in such a manner that the side walls of the outlet tubes 731c to 734c get inside of the side walls 821a to 824a of the outlet port openings <NUM> to <NUM>, respectively, provided to the drain pan <NUM>. The drain pan <NUM> has the groove <NUM> on the side of the side walls 821a to 824a with respect to the groove <NUM> for the second heat exchanger <NUM>, and the groove <NUM> on the side of the side walls 821a to 824a with respect to the groove <NUM> for the first heat exchanger <NUM>. Therefore, when dew drops become attached outside of the fan casings <NUM> to <NUM>, the dew drops fall into and are received by the grooves <NUM>, <NUM> on the drain pan <NUM>. In this manner, it is possible to prevent the dew drops from falling into the room by following the outlet guide tubes <NUM>, <NUM>, <NUM>, <NUM> of the decorative panel <NUM>. Because only a slight amount of dew falls from the fan casings <NUM> to <NUM>, the grooves <NUM>, <NUM> do not communicate with the grooves <NUM>, <NUM>, but may also be provided communicatively.

Claim 1:
A ceiling-embedded air conditioner comprising:
a main unit (<NUM>); and
a decorative panel (<NUM>) that has an intake port (<NUM>) and an outlet guide tube (<NUM>) and is mounted on a bottom surface of the main unit, wherein
the main unit includes:
a box-shaped housing (<NUM>) that has a top plate, a front plate (<NUM>), a rear plate, a left plate, and a right plate;
a heat exchanger (<NUM>, <NUM>) that is disposed inside the housing (<NUM>);
a fan unit (<NUM>) that is disposed inside the housing (<NUM>) and includes a sirocco fan configured to collect air from the intake port (<NUM>) and discharge the air from an outlet tube (732c); and
a drain pan (<NUM>) that collects dew drops formed on the heat exchanger (<NUM>, <NUM>) and has an outlet port opening (<NUM>) through which the air discharged from the outlet tube (732c) of the sirocco fan passes toward the outlet guide tube (<NUM>) of the decorative panel (<NUM>),
the outlet guide tube (<NUM>) of the decorative panel (<NUM>) has: a top opening (<NUM>) that communicates with the outlet tube (732c) of the sirocco fan through the outlet port opening (<NUM>) of the drain pan (<NUM>); a bottom opening (<NUM>) that faces a direction below the front plate (<NUM>) of the main unit (<NUM>); and an outlet ventilation path (<NUM>) that connects the top opening (<NUM>) to the bottom opening (<NUM>) and is curved, and
a bottom end (323a) of the bottom opening (<NUM>) protrudes more downwards than a front part (<NUM>) of a bottom surface (<NUM>) of the decorative panel (<NUM>) does.