Description

VENTILATION SYSTEM FOR ENERGY RECOVERY

Technical Field

[1] The present invention relates to a ventilation system for energy recovery, and more particularly to a ventilation system for energy recovery that has a greatly reduced weight and a thinner outer cover, can solve problems caused by vibration or noise from a fan motor, and can be easily assembled without creating a gap between components to thereby reduce time and effort of assembly while ensuring convenient management. Background Art

[2] A well-known existing general ventilation system has employed a single blower

(fan motor) to expel indoor air from a room to the outside.

[3] However, if only indoor air is expelled to the outside by the single fan motor, not only are cool and warm air discharged together from the room to the outside without any separation, but outdoor air also flows into the room without undergoing heat exchange, unnecessarily incurring cost related to cooling or warming the room.

[4] Furthermore, when cool or warm air abruptly flows into the room, indoor air rapidly varies in temperature, which causes discomfort to persons present in the room.

[5] Particularly, if only indoor air is expelled with a window or door of the room closed, fresh air cannot flow into the room so that an oxygen deficit can arise and room humidity cannot be controlled. Accordingly, it is difficult for the conventional ventilation system to maintain a comfortable indoor environment.

[6] To solve such problems, a ventilation system for energy recovery has been proposed to perform heat exchange between outdoor air and indoor air before supplying the outdoor air into the room.

[7] Fig. 1 is a schematic view of a conventional ventilation system for energy recovery.

[8] Referring to Fig. 1, the conventional ventilation system includes a main body 110 made of a metallic material, a plurality of outer covers 160a~160d made of steel and coupled to an outer surface of the main body 110, a steel bracket 170 joined and coupled to the outer covers 160a~160d, and a plurality of fan motors 150a and 150b supported by the steel bracket 170 inside the main body 110 and causing air to flow inside the main body 110. The outer covers 160a~160d and the steel bracket 170 are fastened in place via a plurality of screws 180 or rivets.

[9] In this configuration, when the plural fan motors 150a, 150b are operated, for example, indoor air flows out while moving in a direction indicated by arrows A and A' and outdoor air flows in while moving in a direction indicated by arrows B and B' (see Fig. 1), thereby ventilating the room.

Disclosure of Invention

Technical Problem

[10] However, the conventional ventilation system for energy recovery is generally heavy since most of interior or exterior structure thereof is manufactured of relatively heavy materials, such as metallic materials, mold materials, etc.

[11] Further, although the steel outer covers 160a~160d form an outer appearance of the ventilation system, there is no substantial contact between the outer covers 160a ~160d and inner walls, and thus, each of the outer covers 160a~160d is inevitably formed to have a thick thickness (t) in order to maintain strength.

[12] Further, since the metallic outer covers 160a~160d and the steel bracket 170 coupled to the outer covers 160a~160d are assembled one by means of a plurality of screws, rivets, and the like, not only is assembly efficiency deteriorated, but time and effort of assembly are also increased while causing inconvenient management in the later.

[13] Particularly, since assembly of the components using the screws 180 and the like has its own limitation, a gap is inevitably created between the respective components and causes air leakage therethrough. To prevent such leakage, joined portions between the components must be separately filled with silicone (not shown) or padding, thereby increasing work efforts.

[14] Also, in the conventional ventilation system for energy recovery, the fan motors

150a and 150b are directly secured to the steel bracket 170 and the steel bracket 170 is also secured to the outer covers 160a~160d, so that vibration or noise from the fan motors 150a and 150b are directly transferred to the steel bracket 170 or the outer covers 160a~160d when the fan motors 150a and 150b are operated for ventilation. In this case, collision or friction is likely to occur between the metallic components, thereby causing vibration or noise higher than the initial vibration or noise of the fan motors 150a and 150b.

[15] The present invention is conceived in view of the above problems, and an object of the present invention is to provide a ventilation system for energy recovery that has a greatly reduced weight, is configured to easily constitute a structure for air flow, permits easy assembly of components without creating a gap between the components to thereby reduce time and effort of assembly, includes outer covers capable of being easily disassembled or assembled to allow convenient maintenance of the system while maintaining a pleasing outward appearance, and can solve problems caused by vibration or noise emanating from a fan motor. Technical Solution

[16] In accordance with an aspect of the present invention, the above and other objects

of the present invention can be accomplished by the provision of a ventilation system for energy recovery including: upper and lower molded bodies made of a non-metallic material, detachably coupled to each other, and formed with a plurality of air through- holes and an air flow guide allowing intake and exhaust flow of air, a fan motor accommodating part and a mounting guide, the air through-holes being formed at opposite sides of the upper and lower molded bodies when assembled; a heat exchanger mounted inside the mounting guide formed in the upper and lower molded bodies and performing heat exchange of air flowing through the upper and lower molded bodies; a fan motor supporter formed integrally with at least one of the upper and lower molded bodies by insert molding and extending into the fan motor accommodating part; a plurality of fan motors accommodated in the fan motor accommodating part of the upper molded body, coupled to the fan motor supporter and driving air to flow into and out of the plurality of air through-holes; a plurality of outer covers closely coupled to lateral sides of the upper and lower molded bodies coupled to each other; a plurality of corner holding parts coupled to a corner between the plurality of outer covers to hold a pair of the outer covers; and a cover and a base plate detachably coupled to an upper side of the upper molded body and a lower side of the lower molded body, respectively.

[17] The plurality of air through-holes formed in the upper and lower bodies may include first and second air through-holes defining an air exhaust channel to allow indoor air to flow outside and third and fourth air through-holes defining an air intake channel to allow outdoor air to flow into a room, and the heat exchanger is disposed in a region where the air exhaust channel and the air intake channel intersect.

[18] The heat exchanger may be made of multilayered paper sheets and may include a plurality of air flow holes stacked on top of each other while crossing each other to allow air to flow in directions corresponding to the air exhaust channel and the air intake channel.

[19] The plurality of outer covers may include first and second outer covers coupled to the lateral sides of the upper and lower molded bodies having the first to fourth air through-holes, and third and fourth outer covers coupled to the lateral sides of the upper and lower molded bodies not having the air through-holes. Here, the first and second outer covers are formed with first to fourth air guide ducts corresponding to the first to fourth air through-holes, and sealing members are provided between the first and second outer covers and the corresponding lateral sides of the upper and lower molded bodies.

[20] The upper and lower molded bodies may be made of polypropylene (PP). With a mold for the upper molded body filled with polypropylene (PP), the fan motor supporter is inserted into the mold, followed by gas injection into the mold and ignition

inside the mold using an igniter, so that the upper molded body can be foamed to allow the fan motor supporter to be formed integrally with the upper molded body.

[21] The fan motor supporter may include a first bracket partially exposed to an outside of the upper molded body while partially covering an outer surface of the upper molded body, and a second bracket joined to the first bracket and disposed between the upper and lower molded bodies while being located in the fan motor accommodating part.

[22] A plurality of the corner holding parts may include a joint slidably fitted to each of bent parts extending from any one pair of outer covers adjacent to each other on the corner, a plurality of caps coupled to upper and lower ends of the joint to bring the bent part and the joint into close contact with each other, and a securing member fastening the cap to the joint.

[23] The joint may include a rounded exterior portion, a plurality of ribs, each protruding from an inner wall of the exterior portion and having one end contacting one surface of the bent part, an interior portion provided inside the exterior portion separated by a space from the exterior portion, a contact supporter connected to the exterior and interior portions and having one end bent in a direction crossing the plurality of ribs to be contact- supported by one end of the bent part, and a securing portion protruding from inside the interior portion and receiving the securing member.

[24] The bent part may have an approximately L-shape, and each of the caps may include a first insertion portion inserted into the L-shaped bent part, a second insertion portion inserted into the space, and a superficial portion constituting surfaces of the first and second insertion portions and having a through-hole formed at a location corresponding to the securing portion.

[25] One side of the first insertion part contacting the bent part may be formed with a tapered portion to press the bent part toward the joint when the cap is coupled to the joint.

[26] The ventilation system may further include: a locking part provided to the cover and the upper molded body to elastically lock and unlock the cover with respect to the upper molded body, wherein the locking part includes a plurality of locking pieces coupled to the upper side of the upper molded body and each having a locking hole formed on one surface thereof; and a plurality of lockers coupled to an inner surface of the cover corresponding to the plurality of locking pieces and locked into the locking holes of the corresponding locking pieces, and wherein among the plurality of lockers, a first locker located at one side of the cover is additionally provided with an elastic member to elastically bias the first locker in a direction of locking a second locker located at the other side of the cover into the locking hole of the corresponding locking piece such that the second locker can be locked into the locking hole of the cor-

responding locking piece.

Advantageous Effects

[27] In the ventilation system for energy recovery according to an exemplary embodiment of the present invention, a fan motor supporter for supporting fan motors is integrally formed with an upper molded body made of a non-metallic material such as Styrofoam (polypropylene, PP) by insert molding, and metallic outer covers are closely assembled to outer surfaces of the upper and lower molded bodies. Accordingly, air through-holes capable of guiding stable intake and exhaust flow of air are formed without using a motor casing, a greatly reduced weight can be obtained, and the outer covers can be kept relatively thin as compared to the conventional system.

[28] Further, components can be firmly and closely assembled to one another without creating a gap therebetween, thereby preventing air leakage through the gap. In particular, the ventilation system of the invention has enhanced assembly efficiency, thereby ensuring convenient assembly of the components while reducing time and effort of assembly.

[29] Further, upper and lower moulding bodies of the system can absorb vibration or noise emanating from the fan motors, thereby solving problems caused by vibration or noise from the fan motors.

Brief Description of the Drawings

[30] Fig. 1 is a schematic view of a conventional ventilation system for energy recovery.

[31] Fig. 2 is a front perspective view of a ventilation system for energy recovery according to an exemplary embodiment of the present invention.

[32] Fig. 3 is a bottom perspective view of the ventilation system of Fig. 2.

[33] Fig. 4 is an exploded perspective view of the ventilation system of Fig. 2.

[34] Figs. 5 and 6 are perspective views of the ventilation system of Fig. 4 viewed from different angles.

[35] Fig. 7 is a perspective view illustrating arrangement of a fan motor supporter and an upper molded body.

[36] Fig. 8 is a perspective view the fan motor supporter integrally inserted into the upper molded body of Fig. 7.

[37] Fig. 9 is a picture of a heat exchanger to be mounted on a mounting guide shown in

Figs. 7 and 8.

[38] Fig. 10 is an enlarged view of Area 'C shown in Fig. 4.

[39] Figs. 11 and 12 are front and rear perspective views of a corner holding part, respectively.

[40] Fig. 13 is a cross-sectional view of the corner holding part coupled between a pair

of outer covers.

[41] Fig. 14 is a side view of a cover and the upper molded body for explaining a configuration of a locking part.

[42] *Description of reference numbers of main parts in the drawings*

[43] 10 : upper molded body 12 : mounting guide

[44] 13a~13d : air through-hole 14a,14b : fan motor accommodationg part

[45] 20 : lower molded body 30 : heat exchanger

[46] 40 : fan motor supporter 50a, 50b : fan motor

[47] 60a~60d : outer cover 62a~62d : air guide duct

[48] 66 : control box 70 : corner holding part

[49] 71 : joint 75 : cap

[50] 78 : securing member 80 : cover

[51] 85 : base plate 86 : foot member

[52] 90 : locking part 91, 92 : locking pieces

[53] 93, 94 : lockers 95 : elastic member

Best Mode for Carrying Out the Invention

[54] Exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[55] Fig. 2 is a front perspective view of a ventilation system for energy recovery according to an exemplary embodiment of the present invention; Fig. 3 is a bottom perspective view of the ventilation system of Fig. 2; Fig. 4 is an exploded perspective view of the ventilation system of Fig. 2; Figs. 5 and 6 are exploded perspective views of the ventilation system of Fig. 4 viewed from different angles; Fig. 7 is a perspective view illustrating arrangement of a fan motor supporter and an upper molded body; Fig. 8 is a perspective view the fan motor supporter integrally inserted into the upper molded body of Fig. 7; Fig. 9 is a picture of a heat exchanger to be mounted on a mounting guide shown in Figs. 7 and 8; Fig. 10 is an enlarged view of Area 'C'θshown in Fig. 4; Figs. 11 and 12 are front and rear perspective views of a corner holding part, respectively; Fig. 13 is a cross-sectional view of the corner holding part coupled between a pair of outer covers; and Fig. 14 is a side view of a cover and the upper molded body for explaining a configuration of a locking part.

[56] Referring to Figs. 2 to 7, a ventilation system for energy recovery according to an exemplary embodiment of the present invention includes an upper molded body 10, a lower molded body 20, a heat exchanger 30, a fan motor supporter 40, fan motors 50a and 50b, outer covers 60a~60d, a corner holding part 70, a cover 80, and a base plate 85.

[57] Hereinafter will be described these and other components of the ventilation system

in more detail.

[58] The upper and lower molded bodies 10 and 20 constitute a main body of the ventilation system according to this embodiment. Although these bodies are conventionally made of a metallic material, the upper and lower molded bodies 10 and 20 are made of a plastic material, such as Styrofoam, polypropylene (PP), and the like, in this embodiment. Particularly, when the upper molded body 10 is made of polypropylene (PP), the fan motor supporter 40 made of a metallic material is also formed therewith, as described below.

[59] As such, the upper and lower molded bodies 10 and 20 are made of polypropylene

(PP) or the like, and, the outer covers 60a~60d (see Figs. 4 to 6) are closely coupled to the upper and lower molded bodies 10 and 20, as described below, so that the upper and lower molded bodies 10 and 20 can absorb a majority of vibration and noise emanating from the fan motors 50a and 50b, thereby solving problems caused by vibration or noise from the fan motors 50a and 50b.

[60] Both the upper and lower molded bodies 10 and 20 are manufactured to have an approximately rectangular block shape and are coupled to each other to constitute a single body. To couple the upper and lower molded bodies 10 and 20, the upper molded body 10 is formed at a lower side with a plurality of grooves 10a (see Fig. 6), and the lower molded body 20 is formed at an upper side with a plurality of protrusions 20a (see Figs. 4 and 5) corresponding to the grooves 10a. The protrusions 20a are respectively fitted to the grooves 10a, thereby coupling the upper and lower molded bodies 10 and 20 to each other.

[61] Coupling between the grooves 10a and the protrusions 20a alone may not be sufficient to prevent involuntarily separation of the upper and lower molded bodies 10 and 20 from. However, according to the present embodiment, the upper and lower molded bodies 10 and 20 are combinationally supported by the four outer covers 60a~60d, the cover 80, the base plate 85, and the corner holding part 70, preventing involuntary separation of the upper and lower molded bodies 10 and 20.

[62] Further, a bored rectangular mounting guide 12 (see Figs. 7 and 8) is formed in the upper molded body 10. The mounting guide 12 is used for mounting the heat exchanger 30 and has a diamond shape inclined at an angle of 45 degrees when viewed from a front side. The mounting guide 12 may be formed when forming the upper molded body 10 or may be bored through the upper molded body 10 after forming the upper molded body 10.

[63] The upper molded body 10 is formed with two fan motor accommodating parts 14a and 14b (see Figs. 7 and 8) bilaterally symmetrical with respect to the mounting guide 12. Then, the two fan motors 50a and 50b are respectively accommodated in the fan motor accommodating parts 14a and 14b via the fan motor supporter 40 to generate air

flow.

[64] The fan motor accommodating parts 14a and 14b are disposed in channels connecting first to fourth air through-holes 13a~13d (see Figs. 4, 5 and 7), respectively. The first to fourth air through-holes 13a~13d are formed at opposite lateral sides of the upper and lower molded bodies 10 and 20 to allow air intake and exhaust. The first to fourth air through-holes 13a~13d may also be formed integrally with the upper and lower molded bodies 10 and 20 when molding the upper and lower molded bodies 10 and 20.

[65] The first and second air through-holes 13a and 13b constitute an air exhaust channel

(not shown) to exhaust indoor air to the outside, i.e., to cause air to flow in a direction indicated by arrows A and A' shown in Fig. 2. On the other hand, the third and fourth air through-holes 13c and 13d constitute an air intake channel (not shown) to introduce outdoor air into the room, i.e., to cause air to flow in a direction indicated by arrows B and B' shown in Fig. 2.

[66] With regard to such air flows, the two fan motor accommodating parts 14a and 14b are formed in the air exhaust and intake channels, and provided with the fan motors 50a and 50b, thereby allowing air to stably flow along the air exhaust and intake channels, respectively.

[67] As schematically indicated by arrows of Fig. 2, the air exhaust channel and the air intake channel intersect. At this intersecting region, the mounting guide 12 is formed and the heat exchanger 30 is mounted to the mounting guide 12. Thus, the heat exchanger 30 performs heat exchange between outdoor air and indoor air in the region where the outdoor air and the indoor air intersect.

[68] Referring to Fig. 9, the heat exchanger 30 is manufactured of multilayered paper sheets. The heat exchanger 30 made of paper is formed with a plurality of air flow holes 31a and 31b intersecting each other to allow air to flow in directions corresponding to the air exhaust channel and the air intake channel, respectively.

[69] The plurality of air flow holes 31a and 3 Ib of the heat exchanger 30 are alternately stacked on top of one another, and, air flowing into the room and air flowing to the outside flow through different layers while exchanging heat and humidity. As such, when introduced into the room, outdoor air is first subjected to heat exchange with indoor air through the heat exchanger, which is advantageous in maintaining the temperature and humidity of the room.

[70] The fan motor supporter 40 for supporting the fan motors 50a and 50b is formed integrally with the upper molded body 10, as will be described with reference to Figs. 7 and 8.

[71] As described above, the upper molded body 10 is made of, for example, polypropylene (PP) to suppress vibration or noise, whereas the fan motor supporter 40

is made of a metallic material to firmly support the fan motors 50a and 50b. Hence, in order to incorporate the fan motor supporter 40 to the upper molded body 10, this embodiment employs an inserting molding process and a foaming process.

[72] Specifically, with a mold (not shown) for the upper molded body 10 filled with polypropylene (PP), the metallic fan motor supporter 40 is inserted into the mold, followed by gas injection into the mold and ignition inside the mold using an igniter, so that the fan motor supporter 40 can be formed integrally with the upper molded body 10 during foaming of the upper molded body 10. Here, the igniter is used to perform ignition by applying a high voltage pulse between electrodes in a metal halide lamp.

[73] With this method, the fan motor supporter 40 can be formed integrally with the upper molded body 10 as shown in Fig. 8.

[74] The fan motor supporter 40 includes a first bracket 40a partially exposed outside the upper molded body 10 while partially covering an outer surface of the upper molded body 10, and a second bracket 40b connected to the first bracket 40a and disposed between the upper and lower molded bodies 10 and 20 corresponding to the two fan motor accommodating parts 14a and 14b.

[75] The first bracket 40a has an approximately square-cornered C shape and is disposed on front and opposite lateral sides of the upper molded body 10. The second bracket 40b has doughnut-shaped holes corresponding to the fan motor accommodating parts 14a and 14b. Thus, the fan motors 50a and 50b are fastened to the second bracket 40b while being accommodated in the fan motor accommodating parts 14a and 14b.

[76] Accordingly, even when vibration or noise emanating from the fan motors 50a and

50b is transferred to the metallic second bracket 40b, vibration or noise transferred to the second bracket 40b is mostly absorbed by the upper and lower molded bodies 10 and 20, thereby solving problems caused by the vibration and noise problems of the fan motors 50a and 50b. In addition, the bracket 40b may be configured to mount cover mounting components.

[77] Since both the upper and lower molded bodies 10 and 20 are manufactured to have a rectangular block shape, four lateral sides (not shown) are provided when the upper and lower molded bodies 10 and 20 are coupled to each other. These four lateral sides are coupled to the plurality of outer covers 60a~60d, respectively.

[78] The outer covers 60a~60d (see Figs. 4 to 6) include the first and second outer covers 60a and 60b coupled to the lateral sides of the upper and lower molded bodies 10 and 20 having the first to fourth air through-holes 13a~13d formed therein, and the third and fourth outer covers 60c and 6Od coupled to the lateral sides of the upper and lower molded bodies 10 and 20 not having the air through holes.

[79] The first and second outer covers 60a and 60b are formed with first to fourth air

guide ducts 62a~62d corresponding to the first to fourth air through-holes 13a~13d. Further, sealing members (not shown) are provided between the first and second outer covers 60a and 60b and the lateral sides of the upper and lower molded bodies 10 and 20. There may be provided four sealing members that form a substantially rectangular loop.

[80] The first to fourth air guide ducts 62a~62d are made of a plastic material, whereas the first to fourth outer covers 60a~60d are made of a metallic material.

[81] Conventionally, the outer covers 160a~160d (see Fig. 1) are inevitably quite thick so as to maintain strength. However, according to this embodiment, since the first to fourth outer covers 60a~60d are closely attached to the lateral sides of the upper and lower molded bodies 10 and 20, respectively, there is no need for the first to fourth outer covers 60a~60d to be thick. Accordingly, the first to fourth outer covers 60a~60d are made of a relatively thin metallic material as compared to the conventional system.

[82] For reference, a control box 66 is further mounted to the third outer cover 60c.

Further, mounting hooks 67 are provided at a lower area of the third and fourth outer covers 60c and 6Od to mount the ventilation system in place. The mounting hooks 67 have an elongated hole shape, which is open at one side thereof.

[83] After the first to fourth outer covers 60a~60d are brought into close contact with the lateral sides of the upper and lower molded bodies 10 and 20, the corner holding parts 70 are used to secure the first and fourth outer covers 60a~60d to the lateral sides of the upper and lower molded bodies 10 and 20.

[84] Since the corner holding parts 70 are provided between the four outer covers

60a~60d, the four corner holding parts 70 are also needed for coupling pairs of outer covers 60a and 60b; 60b and 60c; 60c and 6Od; and 6Od and 60a.

[85] Alternatively, the four outer covers 60a~60d may be provided as a single bent outer cover, and the single bent outer cover may be held by a single corner holding part 70.

[86] For convenience, reference numeral 70 denoting the corner holding parts will not be subdivided, and there will be a description with respect to a process for holding the first and fourth outer covers 60a and 6Od using a single corner holding part 70 with reference to Figs. 10 through 13. The other outer covers can also be coupled in the same manner as the first and fourth outer covers 60a and 6Od.

[87] Referring to Figs. 10 to 13, the corner holding part 70 includes a joint 71 slidably fitted to each of bent parts 68 extending from the first and fourth outer covers 60a and 6Od adjacent to each other, plural (two) caps 75 coupled to upper and lower ends of the joint 71 to bring the bent part 68 and the joint 71 into close contact with each other, and a securing member 78 to fasten the caps 75 to the joint 71.

[88] As shown in the figure, the bent part 68 has an approximately L-shape. In other words, the bent part 68 comprises a transverse portion 68a and a vertical portion 68b

vertically bent from the transverse portion 68a to form the L-shape.

[89] The joint 71 slidably fitted to the bent part 68 includes a rounded exterior portion

7 Ia, a plurality of ribs 7 Ib, each of which protrudes from an inner wall of the exterior portion 71a and has one end contacting the transverse portion 68a of the bent part 68, an interior portion 71c provided inside the exterior portion 71a and separated by a space 7 If from the exterior portion 71a, a contact supporter 7 Id connected to the exterior portion 71a and the interior portion 71c, and having one end bent in a direction crossing the plurality of ribs 71b to be contact-supported by the vertical portion 68b of the bent part 68, and a securing portion 7 Ie protruding from inside the interior portion 71c and receiving the securing member 78 such as a bolt. Here, the joint 71 may be formed of plastics by injection-molding.

[90] Each of the caps 75 coupled to the upper and lower ends of the joint 71 includes a first insertion portion 75a inserted between the transverse portion 68a and the vertical portion 68b of the bent part 68, a second insertion portion 75b inserted into the space 7 If, and a superficial portion 75c constituting surfaces of the first and second insertion portions 75a and 75b and having a through-hole 75d formed at a location corresponding to the securing portion 7 Ie.

[91] One side of the first insertion part 75a substantially contacting the vertical portion

68b of the bent part 68 is formed with a tapered portion 75e to press the vertical portion 68b of the bent part 68 toward the joint 71 when the cap 75 is coupled to the joint 71. With respect to the superficial portion 75c, the one side of the first insertion part 75a is formed with the tapered portion 75e, a cross-section of which gradually decreases toward the end of the first injection part 75a. The tapered portion 75e serves to more firmly fasten the first and fourth outer covers 60a and 6Od described below.

[92] Thus, in the state that the joint 71 is inserted into the bent part 68 extending from the adjacent first and fourth outer covers 60a and 6Od, the caps 75 are disposed on the upper and lower ends of the joint 71 and are then pressed toward the joint 71.

[93] Then, the first insertion part 75a of the cap 75 is inserted between the transverse portion 68a and the vertical portion 68b of the bent part 68, and the second insertion part 75b is inserted into the space 7 If. At this time, since the tapered portion 75e of the first insertion part 75a presses the vertical portion 68b of the bent part 68 toward the securing portion 7 Ie of the joint 71, one pair of first and fourth outer covers 60a and 6Od can be secured while being tightened with respect to one corner holding part 70. With this configuration, the plurality of outer covers 60a~60d can be easily and firmly secured without separate screw fastening. Finally, the securing members 78 such as bolts are coupled to the caps 75, thereby fastening the caps 75 to the joint 71.

[94] In the meantime, the cover 80 and the base plate 85 are detachably coupled to the upper side and the lower side of the upper and lower molded bodies 10 and 20, re-

spectively, thereby forming, along with the outer covers 60a~60d, an outer appearance of the ventilation system of the invention. [95] Unlike the outer covers 60a~60d, the cover 80 and base plate 85 may be made of a plastic material. Further, a plurality of foot members 86 is provided on the rear of the base plate 85. [96] The base plate 85 may be coupled to the lower molded body 20 through the outer covers 60a~60d by screws and the like. This is because there is no need for frequent opening of the base plate 85. [97] According to one embodiment of the present invention, at least the cover 80 can be easily detached from the upper molded body 10. [98] For this purpose, the cover 80 and the upper molded body 10 are provided with a locking part 90 to elastically lock and unlock the cover 80 with respect to the upper molded body 10. [99] The locking part 90 will now be described with reference to Figs. 5, 6 and 14. Here, a part Pl is locked to and unlocked from a part P2 and a part Ql is locked to and unlocked from a part Q2. [100] As shown in Fig. 5, the locking part 90 includes four locking pieces 91, 92, P2 and

Q2 coupled to the upper side of the upper molded body 10 and each formed with a locking hole 91a, 92a on one surface thereof; and four lockers 93 and 94 coupled to an inner surface of the cover 80 corresponding to the two locking pieces 91 and 92 and locked into the locking holes 91a and 92a of the locking pieces 91 and 92. The four lockers 93 and 94 are screwed to corresponding positions, and reference numerals denoting screws are omitted. [101] Among the four lockers 93 and 94, a first locker 93 (refer to Pl) located at one side of the cover 80 is additionally provided with an elastic member 95, such as a spring, to elastically bias the first locker 93 in a direction of locking a second locker 94 into the locking hole 92a of the corresponding locking piece 92, such that the second locker 94

(refer to Ql) located at the other side of the cover 80 can be locked into the locking hole 92a of the corresponding locking piece 92. [102] Further, the second locker 94 is substantially flat, but one end of the first locker 93 slants to one side. In other words, the first locker 93 is formed to have one downwardly inclined end. Likewise, each of the four locking pieces 91 and 92 are formed to have one upwardly inclined end. [103] With the one end of the first locker 93 (refer to Pl) fitted to the locking hole 91a of the corresponding locking piece 91 (refer to P2) as shown in Fig. 14, the cover 80 is pressed in one direction to compress the elastic member 95. [104] As the elastic member 95 is compressed, a gap is created corresponding to movement of the cover 80, allowing the end of the second locker 94 (refer to Ql) to be

disposed in the locking hole 92a of the locking piece 92 (refer to Q2).

[105] In this state, when the cover 80 is released, the end of the second locker 94 is fitted to the locking hole 92a of the corresponding locking piece 92 while the elastic member 95 is restored. Of course, the end of the first locker 93 is in a locked state with respect to the locking hole 91a of the corresponding locking piece 91.

[106] In this way, the cover 80 can be easily coupled to the upper side of the upper molded body 10, providing an aesthetically pleasing exterior. A handle may be provided to the cover 80 or the outer covers 60a~60d, if needed. To separate the cover 80 from the upper molded body 10, the foregoing operation is performed in reverse order.

[107] Therefore, the following effects can be achieved in manufacture and assembly of the ventilation system for energy recovery according to the present invention.

[108] The upper and lower molding bodies made of a non-metal material such as

Styrofoam (polypropylene, PP) are coupled to have a structure that has the air through- holes formed to allow stable air intake and exhaust, that can guide air flow to the motors without a casing, and that can mount the heat exchanger and filters therein, thereby ensuring simplified assembly, increased productivity, and reduced manufacturing costs. Further, the fan motor supporter 40 for supporting the fan motors 50a and 50b is integrally formed with the upper molding body 10 made of plastics by insert molding, and the metallic outer covers 60a ~ 6Od are closely attached to the outer surfaces of the upper and lower molding bodies 10 and 20, thereby reducing the overall weight of the ventilation system while reducing the thickness of the outer covers 60a ~ 6Od. Instead of insert molding the fan motor supporter 40, the fan motor supporter 40 may be inserted into the upper molding body 10 by partially cutting the upper molding body 10 or may be interposed between the upper and lower molding bodies 10 and 20. In other words, the fan motor supporter 40 may be formed integrally with at least one of the upper and lower molding bodies 10 and 20. In any case, the fan motor supporter 40 is in close contact with both the upper molding body 10 and the cover 80 therebetween or both the upper molding body 10 and the lower molding body 20 therebetween, so that vibration of the fan motors 50a and 50b can be transferred to and absorbed by the upper molding body 10 or both the upper and lower molding bodies 10 and 20.

[109] Further, since the respective components are firmly and closely assembled into the ventilation system, there is no gap between the components, thereby preventing air leakage. Also, the ventilation system of the invention provides further improved assembly efficiency as compared to the conventional ventilation systems, thereby ensuring convenient assembly of the components with reduced effort and time.

[110] Particularly, in the ventilation system for energy recovery according to the present

invention, vibration or noise emanating from the fan motors 50a and 50b can be mostly absorbed by the upper and lower molded bodies 10 and 20, thereby solving problems caused by vibration or noise of the fan motors 50a and 50b.

[I l l] Operation of the ventilation system for energy recover according to the present invention will be briefly described.

[112] With the ventilation system for energy recovery loaded at a predetermined place, power is supplied to the fan motors 50a and 50b via the control box 66 to drive the fan motors 50a and 50b to generate an air flow.

[113] Then, indoor air is exhausted while flowing, for example, in a direction indicated by arrows A and A' of Fig. 2, and outdoor air is introduced into a room while flowing, for example in a direction indicated by arrows B and B' of Fig. 2.

[114] While flowing into the room, the outdoor air first undergoes heat exchange with the indoor air via the heat exchanger 30 and is then supplied into the room, thereby easily maintaining the temperature and humidity of the room.

[115] Although the present invention has been described with reference to the embodiments and drawings, it is apparent to those skilled in the art will that various modifications, additions and substitutions can be made without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Therefore, it can be understood that the modifications, additions and substitutions are included in the scope of the present invention. Industrial Applicability

[116] According to the present invention, since the ventilation system for energy recovery is configured to absorb a majority of vibration or noise emanating from a fan motor by means of upper and lower molded bodies, it is possible to solve a problem caused by vibration or noise from the fan motors. Further, since the ventilation system is configured to force outdoor air to be subjected to heat exchange with indoor air before being supplied into a room, it is advantageous in maintaining temperature and humidity of the room.