GB2561989A

GB2561989A - Heat exchanger ventilation device

Info

Publication number: GB2561989A
Application number: GB1808485.5A
Authority: GB
Inventors: Takada Masaru; Momose Ippei; Tsuda Keishi; Hayashi Akira; Hasuike Kazuki
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2016-02-19
Filing date: 2016-02-19
Publication date: 2018-10-31
Anticipated expiration: 2036-02-19
Also published as: WO2017141443A1; GB2561989B; GB201808485D0; JP6444545B2; JPWO2017141443A1

Abstract

A heat exchanger ventilation device comprises: a case (1) comprising an air supply channel and an air exhaust channel; an air supply blower (11) that is disposed in the air supply channel and that generates an air supply flow to the air supply channel; an air exhaust blower (12) that is disposed in the air exhaust channel and generates an air exhaust flow to the air exhaust channel; a heat exchanger (2) that performs heat exchange between the air supply flow and the air exhaust flow by way of intersecting the air supply channel and the air exhaust channel; and a drain pan (20) that accepts the condensation from the heat exchanger (2). The drain pan (20) comprises a supply-side drain pan that is disposed on the discharge-side of the air supply flow in the heat exchanger (2), an exhaust-side drain pan that is disposed on the discharge-side of the air exhaust flow in the heat exchanger (2), and a water channel that connects the supply-side drain pan and the exhaust-side drain pan. The exhaust-side drain pan comprises a drain outlet (21) that drains condensation to the outside of the case (1).

Description

(54) Title of the Invention: Heat exchanger ventilation device Abstract Title: Heat exchanger ventilation device (57) A heat exchanger ventilation device comprises: a case (1) comprising an air supply channel and an air exhaust channel; an air supply blower (11) that is disposed in the air supply channel and that generates an air supply flow to the air supply channel; an air exhaust blower (12) that is disposed in the air exhaust channel and generates an air exhaust flow to the air exhaust channel; a heat exchanger (2) that performs heat exchange between the air supply flow and the air exhaust flow by way of intersecting the air supply channel and the air exhaust channel; and a drain pan (20) that accepts the condensation from the heat exchanger (2). The drain pan (20) comprises a supply-side drain pan that is disposed on the discharge-side of the air supply flow in the heat exchanger (2), an exhaust-side drain pan that is disposed on the discharge-side of the air exhaust flow in the heat exchanger (2), and a water channel that connects the supply-side drain pan and the exhaust-side drain pan.

The exhaust-side drain pan comprises a drain outlet (21) that drains condensation to the outside of the case (1).

1/3

FIG.1

33a

2/3

FIG.2

3/3

FIG.3

24 24

DESCRIPTION

HEAT EXCHANGE VENTILATOR

Field [0001] The present invention relates to a heat exchange ventilator that performs heat exchange between an air supply flow and an air exhaust flow via a heat exchanger while performing simultaneous air supply and exhaust ventilation .

Background [0002] The heat exchange ventilator includes: an air supply path, for supplying air, in which supply air from outdoor receives thermal energy of exhaust air from indoor and the temperature and humidity of the supply air becomes closer to those of the exhaust air; and an air exhaust path, for exhausting air, in which the thermal energy of the exhaust air is imparted to the supply air. The air paths intersect with each other in the heat exchanger and exchange the thermal energy. It is necessary to insert and remove the heat exchanger from a main body at the time of manufacturing or maintenance after installation, and the heat exchanger is held by heat exchanger frames and guide rails so as to be slidable mainly along a direction perpendicular to the air path. There are a sensible heat exchanger for exchanging only sensible heat and a total heat exchanger for exchanging the sensible heat and latent heat.

[0003] The heat exchange ventilator including the heat exchanger is configured to have a gap between the heat exchanger frame and the guide rail so that the heat exchanger is easily slidable. However, a contact portion between the heat exchanger frame and the guide rail is a boundary between the air supply path and the air exhaust path so that the gap may become a factor to deteriorate airtightness .

[0004] Therefore, improvement to reduce air leakage between the air supply path and the air exhaust path has been made. As a result, a heat exchange ventilator which can increase an effective-ventilation-efficiency equal to or higher than 95% has been developed, where the effectiveventilation-efficiency indicates a ratio of fresh air that comes from outside to a total air supplied into the room. [0005] As the air leakage from the gap between the air supply path and the air exhaust path is reduced, transition of odor from the air exhaust flow to the air supply flow through the total heat exchanger has become a new problem. The total heat exchanger can simultaneously exchange the heat and the humidity between the air supply flow and the air exhaust flow and largely contributes to reduction in an air conditioning load. However, when the humidity is exchanged, odor components dissolve into moisture, and the dissolved odor components move to the other so that the odor transitions together with the humidity.

[0006] As one of countermeasures against this new problem, there is a method of using a sensible heat exchanger for heat exchange ventilation at a place where the odor is disturbing. However, if the sensible heat exchanger is used, in a case where temperatures of inside and outside the room are largely different, such as in the summer or the winter, dew condensation is likely to be caused as warm air is cooled by cold air in a heat exchanger portion. Therefore, in a heat exchange ventilator disclosed in Patent Literature 1, a drain pan for receiving dew condensation and a drain discharge port for discharging the dew condensation to the outside are provided.

Citation List

Patent Literature [0007] Patent Literature 1: Japanese Patent No. 3204258

Summary

Technical Problem [0008] Due to a change of an air condition inside and outside the room, the dew condensation occurs on the air supply flow side and also on the air exhaust flow side, therefore it is necessary to provide drain pans on both sides inherently. However, especially, if the drain pan is provided also on the air supply side, the odor in a drain pipe is suctioned from the drain discharge port of the drain pan at the time of operating or stopping a product. When the odor is leaked to supply air of the product, the odor is different from that in a target room, and accordingly, a person staying in the target room especially feels uncomfortable about the odor.

[0009] On the other hand, if the drain discharge port is not provided, the dew condensation occurs as long as the heat exchange ventilation is performed and the temperatures of the supply air and the exhaust air are different from each other. Therefore, in a case where the drain pan is filled with water, there is no countermeasure but to stop the ventilation. With this countermeasure, since the ventilation is stopped, a very uncomfortable environment is made .

[0010] The present invention has been made in view of the above problems. An object of the present invention is to obtain a heat exchange ventilator capable of receiving dew condensation water on both an air supply flow side and an air exhaust flow side and preventing odor in a drain pipe from being mixed to supply air.

Solution to Problem [0011] To solve the above problems and achieve the object, the present invention includes: a casing which includes an air supply path and an air exhaust path; an air supply blower which is provided in the air supply path and generates an air supply flow in the air supply path; an air exhaust blower which is provided in the air exhaust path and generates an air exhaust flow in the air exhaust path; a heat exchanger which makes the air supply path and the air exhaust path intersect with each other and performs heat exchange between the air supply flow and the air exhaust flow; and a drain pan which receives dew condensation water from the heat exchanger. In the present invention, the drain pan includes: an air supply side drain pan provided on the outlet side of the air supply flow in the heat exchanger; an air exhaust side drain pan provided on the outlet side of the air exhaust flow in the heat exchanger; and a water passage which connects the air supply side drain pan and the air exhaust side drain pan.

In the present invention, the air exhaust side drain pan includes a drain discharge port for discharging the dew condensation water to outside of the casing.

Advantageous Effects of Invention [0012] A heat exchange ventilator according to the present invention can receive dew condensation water on both an air supply flow side and an air exhaust flow side and prevent odor in a drain pipe from being mixed to supply air .

Brief Description of Drawings [0013] FIG. 1 is a schematic configuration diagram of a heat exchange ventilator according to a first embodiment of the present invention.

FIG. 2 is a top view of a drain pan of the heat exchange ventilator according to the first embodiment.

FIG. 3 is a cross-sectional diagram illustrating another configuration of the drain pan of the heat exchange ventilator according to the first embodiment.

FIG. 4 is a schematic top view illustrating another configuration of the drain pan of the heat exchange ventilator according to the first embodiment.

Description of Embodiments [0014] Hereinafter, a heat exchange ventilator according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments.

[0015] First Embodiment.

FIG. 1 is a schematic configuration diagram of a heat exchange ventilator according to a first embodiment of the present invention. A heat exchange ventilator 10 is disposed in a ceiling plenum and ventilates a room by supplying and exhausting air through ducts connected thereto. A casing 1 which forms an outer shape and is a hexahedral box includes an exterior side surface la and an interior side surface lb being opposite to the exterior side surface la. An exterior suction port 31 for suctioning outside air is provided on the exterior side surface la, and an interior air outlet 33 for supplying the outside air suctioned from the exterior suction port 31 into the room is provided on the interior side surface lb.

An interior suction port 32 for suctioning air in the room is provided on the interior side surface lb; and an exterior exhaustion port 34 for exhausting the air in the room, suctioned from the interior suction port 32, to the outside is provided on the exterior side surface la.

[0016] In the casing 1, an air supply path for communicating between the exterior suction port 31 and the interior air outlet 33 and an air exhaust path for communicating between the interior suction port 32 and the exterior exhaustion port 34 are formed. The air exhaust path and the air supply path are independent from each other. Furthermore, a heat exchanger 2 is disposed to be positioned in the middle of the air supply path and in the middle of the air exhaust path and performs total heat exchange between an air supply flow passing through the air supply path and an air exhaust flow passing through the air exhaust path. An air supply blower 11 and an air exhaust blower 12 are respectively disposed in the air supply path and the air exhaust path, and respectively generate the air supply flow and the air exhaust flow. In FIG. 1, dashed arrows A indicate the air supply flow, and solid arrows B indicate the air exhaust flow.

[0017] The heat exchanger 2 has a quadrangular prism and rectangular parallelepiped shape and is disposed at the substantially center of the casing 1 in a front view. In a front view, the heat exchanger 2 is disposed so that two diagonals between four corners of the square are extended along a vertical direction and a horizontal direction. In other words, the four corners of the heat exchanger 2 are positioned on an upper side, a lower side, a left side, and a right side. The heat exchanger 2 includes a heat exchanger air supply path 2a through which the air supply flow passes and a heat exchanger air exhaust path 2b through which the air exhaust flow passes. The two paths are independent from each other and intersect with each other in a front view. That is, the heat exchanger 2 makes the air supply path and the air exhaust path intersect with each other and exchange heat between the air supply flow and the air exhaust flow.

[0018] In a front view, the heat exchanger 2 is incorporated so that the four corners of the heat exchanger 2 have contact with a top board 3, a bottom plate 4, and partition walls 7 and 8 partitioning the air supply path and the air exhaust path, where the top board 3 and the bottom plate 4 form the casing 1. With this structure, an interior of the casing 1 is divided into an outside air chamber 31a, a return air chamber 32a, an air supply chamber 33a, and an air exhaust chamber 34a. The outside air chamber 31a is disposed on the upstream side of the heat exchanger 2 in the air supply path; the return air chamber 32a is disposed on the upstream side of the heat exchanger 2 in the air exhaust path; the air supply chamber 33a is disposed on the downstream side of the heat exchanger 2 in the air supply path; and the air exhaust chamber 34a is disposed on the downstream side of the heat exchanger 2 in the air exhaust path.

[0019] Next, a support structure of the heat exchanger 2 will be described. Since the heat exchanger 2 is formed by using a relatively soft material such as paper and a resin sheet, to hold the heat exchanger 2 in the casing 1 while maintaining the shape thereof, heat exchanger frames 2f are integrally provided on the outer side of the four corners of the heat exchanger 2 by a method such as bonding, where the heat exchanger frames 2f are formed of a material such as a plastic having rigidity.

[0020] The heat exchanger frame 2f has a projected shape extending outward of each of the four corners of the heat exchanger 2. Guide rails 5a, 5b, 5c, and 5d to which the heat exchanger frames 2f are fitted are provided in portions facing the four projections of the heat exchanger frames 2f on the top board 3, a drain pan 20, and the partition walls 7 and 8. Each of the guide rails 5a, 5b,

5c, and 5d includes a groove having a width wider than the width of the projection of the heat exchanger frame 2f. [0021] Since it is necessary to take out the heat exchanger 2 at the time of maintenance, a gap is provided between each of the guide rails 5a, 5b, 5c, and 5d and each of the heat exchanger frames 2f. Therefore, it is desirable to devise a method for preventing air leakage such as sticking an elastic seal material (not illustrated) to the heat exchanger frame 2f.

[0022] The air supply blower 11 for generating the air supply flow is disposed in the air supply path. The air exhaust blower 12 for generating the air exhaust flow is disposed in the air exhaust path. Even when the air supply blower 11 and the air exhaust blower 12 are disposed on the upstream side or the downstream side of the heat exchanger 2, the air flow can be generated. However, to minimize unevenness of air supply to the heat exchanger 2, the air supply blower 11 and the air exhaust blower 12 are both disposed on the downstream side of the heat exchanger 2 in general. In the first embodiment, the air supply blower 11 is disposed in the air supply chamber 33a, and the air exhaust blower 12 is disposed in the air exhaust chamber 34a.

[0023] The reference characters + and surrounded by corner-rounded rectangles in FIG. 1 indicate static pressures in the air supply path or the air exhaust path. The reference character + indicates that a positive pressure is generated, and the reference character indicates that a negative pressure is generated. In the outside air chamber 31a, in both spaces closer to the exterior suction port 31 and closer to the heat exchanger 2, the negative pressure is generated. In the return air, chamber 32a, in both spaces closer to the interior suction port 32 and closer to the heat exchanger 2, the negative pressure is generated. In the air supply chamber 33a, the positive pressure is generated in an area closer to the interior air outlet 33, and the negative pressure is generated in an area closer to the heat exchanger 2. In the air exhaust chamber 34a, the positive pressure is generated in an area closer to the exterior exhaustion port 34, and the negative pressure is generated in an area closer to the heat exchanger 2. That is, in spaces closer to the heat exchanger 2 of the outside air chamber 31a, the return air chamber 32a, the air supply chamber 33a, and the air exhaust chamber 34a, the negative pressure is generated. In this way, by disposing both the air supply blower 11 and the air exhaust blower 12 on the downstream side of the heat exchanger 2, a difference between the static pressures in the air supply path and the air exhaust path around the heat exchanger 2 can be reduced, and an effect of reducing the air leakage can be obtained.

[0024] The air supply path is provided in the casing 1 so as to connect the exterior suction port 31 and the interior air outlet 33 to the heat exchanger 2. The air exhaust path is provided in the casing 1 so as to connect the interior suction port 32 and the exterior exhaustion port 34 to the heat exchanger 2. In the first embodiment, including the arrangement of the air supply blower 11 and the air exhaust blower 12, the air supply path, the air exhaust path, the air supply blower 11, and the air exhaust blower 12 are disposed so that the air supply flow and the air exhaust flow are blown downward from upper side in a direction of gravity relative to the heat exchanger 2 as illustrated in FIG. 1. That is, in the first embodiment, the air supply flow and the air exhaust flow pass through the heat exchanger 2 obliquely downward. With this structure, in a case where a sensible heat exchanger is used as the heat exchanger 2 to prevent odor transition, dew condensation water generated in the heat exchanger air supply path 2a and the heat exchanger air exhaust path 2b is guided by the air supply flow or the air exhaust flow and is naturally dropped from the inside of the heat exchanger 2 into the drain pan 20 provided below the heat exchanger 2.

[0025] Contrary to the heat exchange ventilator according to the first embodiment in FIG. 1, a structure in which the air supply flow and the air exhaust flow pass through the heat exchanger upward from the lower side in the direction of gravity is used, the direction of the air supply flow and the air exhaust flow is reverse to the direction of the flow of the dew condensation water. Therefore, the dew condensation water may stay in the heat exchanger. When the dew condensation water stays in the heat exchanger, the dew condensation water clogs the air path and locally increases a pressure loss of the heat exchanger, and the air supply flow and the air exhaust flow flowing through the heat exchanger become uneven. When the air supply flow and the air exhaust flow flowing through the heat exchanger are uneven, an amount of heat recovery is reduced due to deterioration in a heat exchange efficiency.

[0026] In a case where one of the air supply blower and the air exhaust blower is disposed on the upstream side of the heat exchanger and the other one is disposed on the downstream side, in a pressure distribution around the heat exchanger, the one disposed on the upstream side of the heat exchanger has a positive pressure, and the one disposed on the downstream side has a negative pressure.

The strong positive pressure and negative pressure are adjacent to each other around the heat exchanger.

Therefore, even when the sizes of the gaps are the same, in a case where one of the air supply blower and the air exhaust blower is disposed on the upstream side of the heat exchanger and the other one is disposed on the downstream side, the amount of the air leakage is increased than that in a case where both blowers are disposed on the downstream side of the heat exchanger. In a case where the air supply blower is disposed on the upstream side of the heat exchanger, the air supply flow leaks to the air exhaust flow. Therefore, although a problem due to the odor is not caused, an amount of air supply is reduced. Therefore, in a case where the air supply blower is disposed on the upstream side of the heat exchanger, power consumption to supply the same amount of the air supply is more than that in a case where both the air supply blower and the air exhaust blower are disposed on the downstream side of the heat exchanger, accordingly the arrangement described above is undesirable.

[0027] Next, the drain pan 20 to receive the dew condensation water from the heat exchanger 2 will be described. FIG. 2 is a top view of a drain pan of the heat exchange ventilator according to the first embodiment. The drain pan 20 receives the dew condensation water from the heat exchanger 2. The drain pan 20 includes an air supply side drain pan 20a provided on the outlet side of the air supply flow in the heat exchanger 2 and an air exhaust side drain pan 20b provided on the outlet side of the air exhaust flow in the heat exchanger 2. As illustrated in FIG. 1, both portions where the air supply side drain pan 20a and the air exhaust side drain pan 20b are disposed are portions where the negative pressure is generated. A rib 20c is provided between the air supply side drain pan 20a and the air exhaust side drain pan 20b. The guide rail 5c is integrally formed on the rib 20c. The guide rail 5c may be created separately from the drain pan 20 and be fixed to the rib 20c. A water passage 22 is provided in the rib 20c, and the air supply side drain pan 20a and the air exhaust side drain pan 20b are connected to each other with the water passage 22. A drain discharge port 21 used to drain the dew condensation water is provided in the air exhaust side drain pan 20b. The drain discharge port 21 is connected to a drain pipe 60.

[0028] Furthermore, a bottom surface of the air supply side drain pan 20a is inclined downward toward the water passage 22, and the water passage 22 is inclined downward toward the air exhaust side drain pan 20b. Furthermore, a bottom surface of the air exhaust side drain pan 20b is inclined downward toward the drain discharge port 21. Therefore, the bottom surface of the whole drain pan 20 is inclined downward toward the drain discharge port 21.

[0029] Since the dew condensation water from the heat exchanger 2 is generated as a high temperature air is cooled, the dew condensation water is generated from the air supply flow in the summer and from the air exhaust flow in the winter. Therefore, in principle, it is necessary to apply a drain pan with a size capable of receiving the whole lower surface of the outlets of the heat exchanger on the air supply side and the air exhaust side. In some products, the drain pan is provided only on the air supply side or the air exhaust side due to cost or restriction of the structure. However, especially, in a case where the heat exchanger is a sensible heat exchanger, the dew condensation in the summer cannot be ignored. Therefore, it is necessary to provide the drain pans on both the air supply side and the air exhaust side. Since the dew condensation water is not temporary generated but is continuously generated if an air condition is met, in a case where an air volume that is treated by the heat exchange ventilator is large, it is necessary to discharge the dew condensation water on the air supply side and the dew condensation water on the air exhaust side from the drain pan.

[0030] Furthermore, in a case where both the air supply blower and the air exhaust blower are disposed on the downstream side of the heat exchanger, a space connected to the drain discharge port has a negative pressure as illustrated in FIG. 1. Therefore, when the drain discharge port is provided in the drain pan on the air supply side, air in the drain pipe 60 is suctioned together with odor and supplied to the air supply flow.

[0031] In the first embodiment, the drain discharge port 21 is provided only in the air exhaust side drain pan 20b, and the drain discharge port 21 is not provided in the air supply side drain pan 20a. However, if the drain discharge port 21 is not provided in the air supply side drain pan 20a, in a case where the dew condensation water is dropped on the air supply side, the dew condensation water cannot be discharged.

[0032] Therefore, in the first embodiment, as illustrated in FIG. 2, the water passage 22 which connects the air supply side drain pan 20a and the air exhaust side drain pan 20b is provided and the dew condensation water in the air supply side flows into the air exhaust side. In the configuration illustrated in FIG. 2, the air supply side drain pan 20a and the air exhaust side drain pan 20b are integrated. That is, the drain pan 20 is an integrated molded body of the air supply side drain pan 20a and the air exhaust side drain pan 20b. However, in the drain pan 20, the air supply side drain pan 20a and the air exhaust side drain pan 20b may be separately provided, and the water passage 22 may be additionally provided. Note that if the air supply side drain pan 20a and the air exhaust side drain pan 20b are integrated, joints which may cause leakage of water can be reduced. Therefore, it is preferable to integrate the air supply side drain pan 20a and the air exhaust side drain pan 20b.

[0033] Since the air exhaust path and the air supply path are connected via the water passage 22 of the drain pan 20, an amount of pressure loss of a duct connected to the outside of the product and for flowing air is changed, and, for example, the negative pressure of the air supply path becomes higher than the negative pressure of the air exhaust path by increasing the air volume of the air supply path, air is leaked by a difference between the static pressures. As a countermeasure against this, it is effective to change settings of the air supply blower 11 and the air exhaust blower 12 and to set the rotation speed of the air exhaust blower 12 to be higher than the rotation speed of the air supply blower 11 at the time of operating the product. That is, both the air supply blower 11 and the air exhaust blower 12 are provided on the downstream side of the heat exchanger 2, and the air volume of the air exhaust flow is made higher than the air volume of the air supply flow. If the rotation speed of the air exhaust blower 12 is higher than the rotation speed of the air supply blower 11, the negative pressure of the air exhaust path becomes higher than the negative pressure of the air supply path. Therefore, the leakage of air through the water passage 22 occurs from the air supply path toward the air exhaust path, and the leakage of the odor of the air exhaust flow to the air supply flow can be prevented.

[0034] In addition, it is possible to make a structure through which air is not flowed and water is flowed by contriving the shape of the water passage 22. FIG. 3 is a cross-sectional diagram illustrating another configuration of the drain pan of the heat exchange ventilator according to the first embodiment. The water passage 22 has a hole shape at a trap portion 23. Since the bottom surface of the drain pan 20 is inclined downward toward the drain discharge port 21, if the trap portion 23 where the water is accumulated is provided in the water passage 22, an edge 23b of the trap portion 23 on the water discharging side on the right side in FIG. 3 is lower than an edge 23a on the water supplying side of the trap portion 23 on the left side in FIG. 3. Therefore, after the trap portion 23 is filled with water, the water overflows from the edge 23b on the water discharging side and flows toward the drain discharge port 21. At that time, by providing a wall 24 above the trap portion 23, air is not circulated if water is accumulated in the trap portion 23. Therefore, in this structure, although air cannot pass through the trap portion 23, water can pass through the trap portion 23. [0035] In addition, a structure can be used in which the trap portion 23 is not provided and only the wall 24 is provided. FIG. 4 is a schematic top view illustrating another configuration of the drain pan of the heat exchange ventilator according to the first embodiment. As illustrated in FIG. 4, there is a method of reducing an air flow rate by providing a single or a plurality of walls 24 in the water passage 22 to increase the pressure loss without completely blocking air. In a case where the plurality of walls 24 is provided, the air path can have a labyrinth structure, and an effect of reducing the air flow rate is high. Therefore, this structure can be also applied. However, with this method, since the leakage of the air cannot be completely prevented, it is desirable to use this method together with the method of setting the rotation speed of the air exhaust blower to be higher than the rotation speed of the air supply blower at the time of operating the product.

[0036] A case where the sensible heat exchanger is used as the heat exchanger 2 has been described. However, since even in a case where a total heat exchanger is applied to the heat exchanger 2, the dew condensation water is generated with less frequency. Therefore, in a case of the total heat exchanger, the similar structure is effective for preventing the odor from being returned from the drain discharge port 21.

[0037] With this structure, even when the air supply side drain pan 20a and the air exhaust side drain pan 20b are provided on both of the air supply side and the air exhaust side as assuming that the dew condensation occurs on both sides, the transition of the odor from the air exhaust flow to the air supply flow can be prevented while maintaining an even air supply to the heat exchanger 2 by contriving the arrangement of the air paths and the air blowers and contriving the shape of the drain pan 20 and the position of the drain discharge port 21. Furthermore, in a case where the drain pan 20 is provided to deal with the dew condensation water generated when the sensible heat exchanger is used in consideration of the odor and a layout is employed in which the air supply blower 11 and the air exhaust blower 12 are disposed on the downstream side of the heat exchanger 2, a problem can be solved that the odor in the drain pipe 60 is suctioned from the drain discharge port 21. Therefore, air with an air quality close to outside air with less odor transition can be supplied to the target space, and comfort of a user can be improved. [0038] Even at a place where the heat exchange ventilator previously cannot be used due to concern over the transition of the odor, the heat exchange ventilator can be provided by using the present invention, and heat exchange between supply air and exhaust air at the time of ventilation can be performed. Therefore, even in a space where heat of the exhaust air has been discarded previously, by exchanging the heat and transferring the heat to the supply air, an air conditioning load in the room can be reduced, and energy used for the air conditioning can be reduced.

[0039] Furthermore, with a simple structure formed by integrating the air supply side drain pan 20a with the air exhaust side drain pan 20b, the product can be easily manufactured and assembled, and cost can be reduced. In addition, since the drain discharge port 21 is provided only on the air exhaust side, a drain pipe can be easily connected at the time of installing the product.

[0040] The structures indicated in the above embodiment indicate exemplary contents of the present invention and can be combined with another known technique. Furthermore, the structures indicated in the embodiment can be partially omitted and changed without departing from the scope of the present invention.

Reference Signs List [0041] 1 casing; la exterior side surface; lb interior side surface; 2 heat exchanger; 2a heat exchanger air supply path; 2b heat exchanger air exhaust path; 2f heat exchanger frame; 3 top board; 4 bottom plate; 5a, 5b, 5c, 5d guide rail; 7, 8 partition wall; 10 heat exchange ventilator; 11 air supply blower; 12 air exhaust blower; 20 drain pan; 20a air supply side drain pan; 20b air exhaust side drain pan; 20c rib; 21 drain discharge port; 22 water passage; 23 trap portion; 23a edge on water supplying side; 23b edge on water discharging side; 24 wall; 31 exterior suction port; 31a outside air chamber; 32 interior suction port; 32a return air chamber; 33 interior air outlet; 33a air supply chamber; 34 exterior exhaustion port; 34a air exhaust chamber; 60 drain pipe.

Claims

1. A heat exchange ventilator comprising:

a casing including an air supply path and an air exhaust path;

an air supply blower provided in the air supply path and to generate an air supply flow in the air supply path;

an air exhaust blower provided in the air exhaust path and to generate an air exhaust flow in the air exhaust path;

a heat exchanger to make the air supply path and the air exhaust path intersect with each other and perform heat exchange between the air supply flow and the air exhaust flow; and a drain pan to receive dew condensation water from the heat exchanger, wherein the drain pan includes an air supply side drain pan provided on an outlet side of the air supply flow in the heat exchanger, an air exhaust side drain pan provided on an outlet side of the air exhaust flow in the heat exchanger, and a water passage connecting the air supply side drain pan and the air exhaust side drain pan, and the air exhaust side drain pan includes a drain discharge port to discharge the dew condensation water to outside of the casing.

2. The heat exchange ventilator according to claim 1, wherein the air supply flow and the air exhaust flow pass through the heat exchanger obliquely downward.

3. The heat exchange ventilator according to claim 1, wherein the air supply blower and the air exhaust blower are both disposed on a downstream side of the heat exchanger, and an air volume of the air exhaust flow is higher than an air volume of the air supply flow.

5

4. The heat exchange ventilator according to claim 1, wherein the water passage has a structure through which air is not circulated and water is circulated.

10

5. The heat exchange ventilator according to any one of claims 1 to 4, wherein the drain pan is an integrally molded body of the air supply side drain pan and the air exhaust side drain pan.