Patent Publication Number: US-9841181-B2

Title: Ceiling mounted ventilation fan with illumination

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of pending U.S. application Ser. No. 14/146,211, filed Jan. 2, 2014, which is a continuation application of U.S. application Ser. No. 13/992,881, filed Jun. 10, 2013 (now U.S. Pat. No. 8,814,513), which is a National Stage of International Patent Application No. PCT/CN2011/080333, filed Sep. 29, 2011, which claims priority to Chinese Application No. CN 2011-10037124.3, filed on Jan. 6, 2011, the disclosures of which are expressly incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a ventilation fan for push-pull ventilation systems (i.e., a ventilation fan for air supply and exhaust systems) and, more particularly, to a noise reduction structure of ceiling mounted ventilation fans with illumination for push-pull ventilation systems. 
     BACKGROUND ART 
     As such a type of ceiling mounted ventilation structure with illumination, there has conventionally been known a structure using a downlight as an example. An example of the conventional ceiling mounted ventilation structure with illumination is shown in  FIG. 7  (see, e.g., Patent Document 1). 
     As shown in  FIG. 7 , a conventional ceiling mounted ventilation structure  108  with illumination is so made up that a recess portion (dent portion)  102  is provided in a ceiling  101 , an electric bulb  105  enclosed by a moisture-proof cover  104  is set in the recess portion  102  via a rubber packing  103 , and that a ventilating opening  106  is formed at part of a peripheral wall of the recess portion  102 , where a duct  107  is connected at the ventilating opening  106 . 
     By the ceiling mounted ventilation structure  108  with illumination as shown above, the function of indoor ventilation can be fulfilled while a function as a downlight is fulfilled. 
     PATENT DOCUMENT 
     
         
         Patent Document 1: JP S57-68426 U 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     In the conventional ceiling mounted ventilation structure  108  with illumination, with the recess portion  102  formed in shape of a circular truncated conical cylinder, an inner wall surface of the recess portion  102  is used as a reflecting surface so that light derived from the electric bulb  105  is reflected by the inner wall surface of the recess portion  102  downward, i.e., toward the room inside. With such an: arrangement adopted, the function as a downlight can be enhanced in the ceiling mounted ventilation structure  108  with illumination. 
     However, because of the recess portion  102  being formed in shape of a circular truncated conical cylinder, this shape acts as a so-called megaphone, causing an issue that air flow sounds or operating sounds of the fan or the like generated in the ceiling mounted ventilation structure  108  with illumination are increased in directivity in their conduction into the room inside or that such sounds are conducted farther. 
     Accordingly, an object of the present invention, lying in solving the above-described issues, is to provide a ceiling mounted ventilation fan with illumination capable of suppressing noise conducted to room inside. 
     Solution to Problem 
     In order to achieve the object, the invention is configured as follows. 
     According to a first aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination comprising: a main housing, and a fan unit and lighting equipment installed in the main housing, wherein 
     the main housing includes a first opening connected to an air outlet of the fan unit, the first opening communicating with a duct, and a second opening formed in a lower part of the main housing so as to communicate with inside of a room, 
     the lighting equipment includes a lighting part, a lighting cover placed within the main housing so as to surround a periphery of the lighting part, the lighting cover having a reflecting surface for reflecting light from the lighting part to lead the light into the room through the second opening, and a restriction member for restricting passage of air through between the periphery of the lighting part and the lighting cover, and 
     a gap for air intake is formed between a lower end of the lighting cover and an edge of the second opening so that air introduced into the main housing through the second opening and the gap for air intake is discharged through the first opening into the duct by the fan unit. 
     According to a second aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination according to the first aspect, the lighting equipment comprises an adjustment mechanism for adjusting a height position of the lighting cover relative to the second opening of the main housing, wherein the height position of the lighting cover is adjusted by use of the adjustment mechanism thereby adjusting size of the gap for air intake. 
     According to a third aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination according to the first aspect, wherein the lighting cover is formed in such a cylindrical shape as to cover an entire side periphery of the lighting part while the lower end of the lighting cover is formed larger than an upper end thereof, and the restriction member is placed so as to substantially seal at least either one of the upper end and the lower end of the lighting cover. 
     According to a fourth aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination according to the third aspect, wherein the lighting cover is formed in such a generally circular truncated conical cylinder shape or polygonal truncated prismoidal cylinder shape that an opening of the lower end is larger than that of the upper end, and a lid member for substantially sealing the opening of the lower end is installed as the restriction member. 
     According to a fifth aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination according to the fourth aspect, wherein the lid member is detachably provided at the lower end of the lighting cover. 
     According to a sixth aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination according to any one of the first to fifth aspects, wherein a brim is formed so as to protrude from a periphery of the lower end of the lighting cover. 
     According to a seventh aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination according to any one of the first to fifth aspects, wherein on an inner surface of the main housing, a sound absorbing material is placed at least at a position facing an air inlet of the fan unit. 
     According to an eighth aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination according to any one of the first to fifth aspects, wherein the main housing further includes a third opening formed at a position separate from the second opening and communicating with the inside of the room, so that air introduced into the main housing through the second opening and the gap for air intake, together with air introduced into the main housing through the third opening is discharged into the duct through the first opening by the fan unit. 
     According to a ninth aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination comprising a main housing, and a fan unit and lighting equipment installed in the main housing, wherein 
     the main housing includes a first opening connected to an air outlet of the fan unit, the first opening communicating with a duct, and a second opening formed in a lower part of the main housing, 
     the main housing is installed in a ceiling in such a way that the indoor-side air inlet formed by an opening member provided at a ceiling opening and the second opening of the main housing are communicated with each other, 
     the lighting equipment includes a lighting part, a lighting cover placed within the main housing so as to surround a periphery of the lighting part, the lighting part having a reflecting surface for reflecting light from the lighting part to lead the light to inside of a room through the second opening and the opening member, and a restriction member for restricting passage of air through between the periphery of the lighting part and the lighting cover, and 
     a gap for air intake is formed between a lower end of the lighting cover and an edge of the opening member so that air introduced into the main housing through the opening member and the gap for air intake is discharged through the first opening into the duct by the fan unit. 
     According to a tenth aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination according to the ninth aspect, wherein the lighting equipment comprises an adjustment mechanism for adjusting a height position of the lighting cover relative to the ceiling opening, wherein the height position of the lighting cover is adjusted by use of the adjustment mechanism thereby adjusting size of the gap for air intake. 
     According to an eleventh aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination comprising a main housing, and a fan unit and lighting equipment installed in the main housing, wherein 
     the main housing includes a first opening connected to an air outlet of the fan unit, the first opening communicating with a duct, and a second opening formed in a lower part of the main housing so as to communicate with inside of a room, 
     the lighting equipment includes a lighting part, a lighting cover placed within the main housing so as to surround a periphery of the lighting part, the lighting cover having a reflecting surface for reflecting light from the lighting part to lead the light to the inside of the room through the second opening, and a restriction member for restricting passage of air through between the periphery of the lighting part and the lighting cover, 
     the lighting cover is placed so as to extend through the second opening so that a lower end of the lighting cover is protruded from the second opening toward the inside of the room, and 
     a gap for air intake is formed between the lower end of the lighting cover and an edge of the second opening so that air introduced into the main housing through the gap for air intake and the second opening is discharged through the first opening into the duct by the fan unit. 
     According to a twelfth aspect of the present invention, there is provided a ceiling mounted ventilation fan with illumination according to the eleventh aspect, wherein the lighting equipment has an adjustment mechanism for adjusting a height position of the lighting cover relative to the second opening of the main housing, wherein the height position of the lighting cover is adjusted by use of the adjustment mechanism thereby adjusting size of the gap for air intake. 
     Effects of Invention 
     According to the present invention, in the ceiling mounted ventilation fan with illumination, a restriction member for restricting passage of air through between a lighting cover and a periphery of a lighting part is provided, the lighting cover having a reflecting surface for reflecting light from the lighting part to lead the light to the inside of the room, and moreover a gap for air intake is formed between a lower end of the lighting cover and an edge of the indoor-side opening. Thus, air introduced into the main housing through the gap for air intake is discharged into the duct by the fan unit and moreover conduction of operation noises of the fan unit and the like to the indoor side with the noise directivity enhanced in the lighting cover can be suppressed by the restriction member. Accordingly, there can be provided a ceiling mounted ventilation fan with illumination capable of suppressing conduction of noises to the room inside. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a ceiling mounted ventilation fan with illumination in accordance with Embodiment 1 of the invention; 
         FIG. 2  is a sectional view of the ceiling mounted ventilation fan with illumination of Embodiment 1; 
         FIG. 3A  is a schematic view showing a placement example of a restriction member in the lighting cover; 
         FIG. 3B  is a schematic view showing a placement example of a restriction member in the lighting cover; 
         FIG. 3C  is a schematic view showing a placement example of a restriction member in the lighting cover; 
         FIG. 4  is a sectional view of a ceiling mounted ventilation fan with illumination in accordance with Embodiment 2 of the invention; 
         FIG. 5  is a sectional view of a ceiling mounted ventilation fan with illumination in accordance with Embodiment 3 of the invention; 
         FIG. 6  is a sectional view of a ceiling mounted ventilation fan with illumination in accordance with Embodiment 4 of the invention; 
         FIG. 7  is a sectional view showing a conventional ceiling mounted ventilation structure with illumination; 
         FIG. 8  is a perspective view of a ceiling mounted ventilation fan with illumination of Embodiment 4 of the invention; 
         FIG. 9  is a perspective view of lighting equipment; 
         FIG. 10  is an exploded view of the lighting equipment; and 
         FIG. 11  is an explanatory view of height adjustment of the lighting equipment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings. Hereinbelow, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
     Embodiment 1 
       FIG. 1  shows a perspective view of a ceiling mounted ventilation fan  1  with illumination in accordance with Embodiment 1 of the invention.  FIG. 2  shows a sectional view (partly sectional view) thereof. 
     As shown in  FIGS. 1 and 2 , the ceiling mounted ventilation fan  1  with illumination includes a main housing  10  that is generally shaped like a box, and a fan unit  20  and lighting equipment  30  that are placed in the main housing  10 . 
     The main housing  10  has a first opening  11  connected to an air outlet of the fan unit  20  and a second opening  12  communicating with inside of a room through a ceiling opening  3  formed on the ceiling  2 . The first opening  11  formed on a side part of the main housing  10  is connected to a duct connection part  13  so as to communicate with a duct  14  through the duct connection part  13 . Although  FIGS. 1 and 2  show an example in which the first opening  11  is formed at a side part of the main housing  10  while the second opening  12  is formed at a lower part, the case may also be such that the first opening  11  is formed at an upper part of the main housing  10 . 
     The fan unit  20  has a fan  21 , a motor  22  for rotating the fan  21 , and a fan casing  23  placed so as to surround the fan  21 . The fan unit  20  is fixed to a top inner wall of the main housing  10 . An air inlet of the fan unit  20  is opened inside the main housing  10 , and air inside the main housing  10  taken into the fan unit  20  through the air inlet is discharged through the air outlet, the first opening  11  and the duct connection part  13  into the duct  14 . Although a centrifugal fan such as multiblade fan will be described as an example of the type of the fan unit  20 , there may be employed other types of fans that are capable of achieving such a function of discharge. 
     The lighting equipment  30  includes a lamp (lighting part)  31 , a lighting cover  32  (a cover for lighting) that surrounds the lamp  31 , and a lamp mounting fixture  33  for detachably fixing the lamp  31  and the lighting cover  32  onto the inner wall of the main housing  10 . The lamp  31  and the lighting cover  32  are placed on a central axis P so that center positions thereof substantially coincide with a center of the second opening  12  of the main housing  10  as seen looking in a vertical direction. In addition to a function of detachably fixing the lamp  31  and the lighting cover  32 , the lamp mounting fixture  33  has a function of supplying the lamp  31  with electricity. As the lamp  31 , a fluorescent lamp or an LED other than so-called electric bulbs may be used. The arrangement may also be another in which an electric heater is used instead of the lamp  31  and covered by the lighting cover  32 . A relation of placement between the lamp  31 , the lighting cover  32  and the second opening  12  of the main housing  10  is not limited to such a relation that those centers substantially coincide with one another as seen looking in the vertical direction. The relation of placement has only to be such that light from the lamp  31  is cast into the room through the second opening  12 . 
     The lighting cover  32  is generally formed in shape of a circular truncated conical cylinder so that a diameter of a lower end  32   b  of the lighting cover  32  is greater than that of an upper end  32   a  thereof. The lighting cover  32  is formed so as to have a length (size in the vertical direction) that covers an overall surrounding side of a light emitting part of the lamp  31  provided inside the cover  32 . Between the lighting cover  32  and the lamp  31  is secured such a clearance as prevents contact therebetween. 
     An inner circumferential surface of the lighting cover  32  forms a reflecting surface  32   c  that reflects the light from the lamp  31  toward the second opening  12  (i.e., downward). The lighting cover  32  having such a reflecting surface  32   c  allows the light from the lamp  31  to become direct light and reflected light and to efficiently irradiate the inside of the room. 
     The lighting equipment  30  includes a lid (lid member)  34  for sealing an opening of the lower end  32   b  of the lighting cover  32 . The lid  34  is detachably attached to the lower end  32   b  of the lighting cover  32  so as not to be in contact with the lamp  31 . The lid  34  is detached from the lighting cover  32  on occasion of replacement of the lamp  31  or the like. 
     A flange  35  (opening member) that is an annular member is mounted on the ceiling opening  3 . The flange  35  serves as a dressing member that covers a lower periphery and an inner circumferential surface of the ceiling opening  3  so as to prevent the ceiling opening  3  from being directly seen from the inside of the room. The flange  35  is attached while biasing the lower periphery of the ceiling opening  3  upward through biasing members (such as wire-like springs)  36  that each have one end engaged with the main housing  10  and the other end engaged with the flange  35 . When the flange  35  is released from the ceiling opening  3 , the biasing members  36  prevent the flange  35  from falling down.  FIG. 1  shows a state in which the flange  35  has been released from the ceiling opening  3 . 
     As shown in  FIG. 2 , an annular gap S for air intake is provided between the lower end  32   b  of the lighting cover  32  and an edge of the second opening  12  of the main housing  10 , more particularly, an inside edge of the flange  35 . An introduction path for indoor air is formed so that the indoor air introduced through the ceiling opening  3  on which the flange  35  is placed is then guided through the annular gap S for air intake and the second opening  12  into the main housing  10 . 
     An annular brim  37  is formed on the lower end  32   b  of the lighting cover  32 , and the annular brim  37  is formed so as to protrude toward surroundings thereof. 
     Once the lamp  31  is turned on in the ceiling mounted ventilation fan  1  with illumination that has such a configuration, the light from the lamp  31  is introduced through the lid  34  and the ceiling opening  3  (opening of the flange  35 ) into the room and light from a circumferential surface of the side part of the lamp  31  is reflected downward by the reflecting surface  32   c  of the lighting cover  32  and is subsequently introduced through the lid  34  and the ceiling opening  3  into the room. Thus the ceiling mounted ventilation fan  1  with illumination functions as a downlight. 
     When the fan  21  is rotated by the motor  22  of the fan unit  20 , the indoor air is introduced through the ceiling opening  3  and the annular gap S for air intake into the main housing  10 . In the annular gap S for air intake, wind noises produced by the lower end  32   b  of the lighting cover  32  are reduced by the annular brim  37  formed on the lower end  32   b  of the lighting cover  32 . The air introduced into the main housing  10  is taken into the fan casing  23  and discharged from the fan unit  20  through the first opening  11  and the duct connection part  13  into the duct  14 . Thus the ceiling mounted ventilation fan  1  with illumination functions as a ventilation fan. 
     In this case, the lighting cover  32  that is placed so as to surround the lamp  31  has the cylindrical lower end  32   b  sealed with the lid  34 . Thus passage of air through between the lamp  31  and the lighting cover  32  is restricted. This reduces propagation into the room of air blow noises caused by operation of the fan unit  20  placed in the main housing  10  and the operation noises from the motor  22  with enhancement of directivity thereof that is caused by the lighting cover  32  which is generally in shape of a circular truncated conical cylinder and which functions as a megaphone. In particular, the lighting cover  32  is often generally shaped like a circular truncated conical cylinder because the cover  32  is required to have the reflecting surface  32   c  for the light from the lamp  31 . There is a high possibility that the lighting cover  32  with such a shape functions as a so-called megaphone. The provision for the lighting cover  32  of the lid  34  that restricts the passage of air effectively reduces the propagation into the room of the noises produced in the main housing  10  with the enhancement of directivity thereof. 
     Although the example provided with the lid  34  for sealing the lower end  32   b  of the lighting cover  32  has been described above, the invention is not limited only to such a configuration. Provision of members (restriction members) capable of restricting the passage of air through between the lighting cover  32  and the lamp  31  ensures the same effect as that of the provision of the lid  34 . For instance, as shown in the schematic view of the lighting equipment  30  shown in  FIG. 3A , a restriction member  41  that seals the upper end  32   a  may be provided in the lighting cover  32  with the lower end  32   b  thereof opened. Alternatively, as shown in  FIG. 3B , a restriction member  42  that seals the lower end  32   b  of the lighting cover  32  may be provided with the upper end  32   a  thereof opened. Further as shown in  FIG. 3C , there may be provided both the restriction member  41  that seals the upper end  32   a  of the lighting cover  32  and the restriction member  42  that seals the lower end  32   b.    
     Such restriction members have only to have a configuration by which the function of restricting the passage of air through between the lighting cover  32  and the lamp  31  is achieved. The configuration is not limited only to a configuration that completely shuts off the passage of air and the passage of air has only to be restricted in general. The passage of air has only to be restricted in general, even if openings required for the attachment of the lamp  31  and power supply are provided in the restriction members, for instance. 
     The lighting cover  32  may be shaped like a generally polygonal truncated prismoidal cylinder or a hemisphere, other than the generally circular truncated conical cylinder. The restriction members may integrally be formed with the lighting cover  32 . 
     The gap S for air intake has only to be formed around the lower end  32   b  of the lighting cover  32  and has only to be formed between the lower end  32   b  of the lighting cover  32  and the flange  35 , or between the lower end  32   b  and the second opening  12 , or between the lower end  32   b  and the ceiling opening  3 . 
     Sizes (area) of the gap S for air intake have only to be determined in design in consideration of specifications (air flow, static pressure and the like) of the fan unit  20 , sizes of the lamp  31  and the lighting cover  32 , a size of the ceiling opening  3 , and the like. 
     Embodiment 2 
     The present invention is not limited to the above-described embodiment, and may be carried out in other various embodiments. As an example,  FIG. 4  shows a configuration of a ceiling mounted ventilation fan  51  with illumination in accordance with Embodiment 2 of the invention. In the configuration of this ceiling mounted ventilation fan  51  with illumination of Embodiment 2 shown in  FIG. 4 , an opening  4  is additionally provided on the ceiling  2  independently of the ceiling opening  3  while a third opening  15  is provided in the main housing  10 , so that indoor air can be introduced also through the opening  4  and the third opening  15 . With the configuration like this, when the required size (area) of the gap S for air intake cannot be ensured, a shortage air-intake area can be ensured. 
     Also, as shown in  FIG. 4 , a sound absorbing material  16  is placed on an inner wall surface of the main housing  10  facing the air inlet of the fan unit  20 . With the sound absorbing material  16  placed as shown above, sounds produced by the fan unit  20  can be partly absorbed and reduced by the sound absorbing material  16 . The sound absorbing material may also be placed over the entire inner wall surface of the main housing  10 . Usable as such a sound absorbing material are those materials having a sound absorbing effect or sound-reflection suppressing effect such as porous materials and fiber materials; for example, felt material or the like is used. 
     Embodiment 3 
       FIG. 5  shows a configuration of a ceiling mounted ventilation fan  61  with illumination in accordance with Embodiment 3 of the invention. As in the ceiling mounted ventilation fan  61  with illumination of Embodiment 3 shown in  FIG. 5 , a configuration in which a whole lower part of a main housing  62  is opened is also adoptable. A first opening  63  to be connected the duct connection part  13  is formed in a side part of the main housing  62 , and a whole lower part of the main housing  62  is formed as a second opening  64 . With such a configuration, since the air inlet from the indoor side is defined by the flange  35  attached to the ceiling opening  3 , the substantially same effect as that of the ceiling mounted ventilation fan  1  with illumination of Embodiment 1 shown in  FIGS. 1 and 2  can be obtained. 
     Embodiment 4 
       FIG. 6  shows a configuration of a ceiling mounted ventilation fan  71  with illumination in accordance with Embodiment 4 of the invention. The ceiling mounted ventilation fan  71  with illumination of Embodiment 4 shown in  FIG. 6  has a configuration that differs from the foregoing individual embodiments in that a lower end  72   b  of a lighting cover  72  is placed so as to protrude toward the indoor side through the second opening  12  of the main housing  10 , the ceiling opening  3  and the flange  35 . 
     In such a configuration, an annular gap S for air intake is formed between the lower end  72   b  of the lighting cover  72  placed in protrusion toward the indoor side (i.e., placed lower than the ceiling  2 ) and the inner edge of the flange  35  (or second opening  12 ). Indoor air is introduced into the main housing  10  through this gap S for air intake and discharged into the duct  14  by the fan unit  20 . On the lower end  72   b  of the lighting cover  72 , an annular brim  73  is formed so as to protrude toward surroundings thereof. The brim  73  like this has a dressing effect that the gap S for air intake is made less easy to view from the indoor side. 
     The lighting cover  72  in a generally circular truncated conical cylinder shape is formed so that its upper end  72   a  is sealed by a sealing member  74 . Therefore, passage of air through between the lamp  31  and the lighting cover  72  is restricted, so that conduction of noises produced in the main housing  10  toward the indoor side with their directivity enhanced is suppressed. 
     Embodiment 5 
       FIG. 8  shows a configuration of a ceiling mounted ventilation fan  81  with illumination in accordance with Embodiment 5 of the invention. The ceiling mounted ventilation fan  81  with illumination of Embodiment 5 shown in  FIG. 8  differs from the ceiling mounted ventilation fan  1  with illumination of Embodiment 1 in terms of the configuration of lighting equipment  90 , with the rest of the configuration being substantially similar thereto. The following description will be given primarily about the configuration of the lighting equipment  90 .  FIG. 9  shows a perspective view of the lighting equipment  90 , and  FIG. 10  shows an exploded view thereof. 
     As shown in  FIGS. 8 to 10 , the lighting equipment  90  includes a lamp  91 , which is a vortex type fluorescent lamp, a lighting cover  92  for surrounding the lamp  91 , a lamp mounting fixture  93 , and a lid  94 . Further, the lamp mounting fixture  93  includes an adjustment mechanism  82  for variably adjusting height positions of the lamp  91  and the lighting cover  92 . 
     As shown in  FIGS. 9 and 10 , the adjustment mechanism  82  chiefly includes a generally disc-shaped engaging member  83  attached at an upper end  92   a  of the lighting cover  92 , and a spring member  84  placed within a casing  85  of the lamp mounting fixture  93  to normally bias the engaging member  83  downward. Also, the lamp  91  is detachably fitted to a lamp socket  95 , and the engaging member  83  is fixed via the lamp socket  95  to the lighting cover  92  by screwing or the like. Accordingly, the lamp  91  and the lighting cover  92  are made integrally rotatable with the engaging member  83  about a central axis P relative to the casing  85  of the lamp mounting fixture  93 . 
     In the cylindrical circumferential surface of the casing  85  of the lamp mounting fixture  93 , two kinds of engaging holes of mutually different height positions, i.e. a first engaging hole  85   a  and a second engaging hole  85   b  positioned lower in height than the first engaging hole  85   a , are formed. Meanwhile, an engaging claw  83   a  to be engaged selectively with either one of the first engaging hole  85   a  and the second engaging hole  85   b  in the casing  85  of the lamp mounting fixture  93  is formed on the circumferential edge of the generally disc-shaped engaging member  83 . As the engaging claw  83   a  is engaged selectively with either one of the first engaging hole  85   a  and the second engaging hole  85   b  by rotating the engaging member  83  together with the lamp  91  and the lighting cover  92  about the central axis P, the height positions of the lamp  91  and the lighting cover  92  can be changed. Also, since the engaging member  83  is normally biased downward by the spring member  84 , an engagement state between the first engaging hole  85   a  or the second engaging hole  85   b  and the engaging claw  83   a  is maintained, so that the height positions of the lamp  91  and the lighting cover  92  are retained. 
     Now, the adjustment of height positions of the lamp  91  and the lighting cover  92  by the adjustment mechanism  82  as shown above will be explained below with reference to the schematic view shown in  FIG. 11 . 
     Referring first to  FIG. 11(A) , in the lighting equipment  90 , the engaging claw  83   a  is in a state of being engaged with the second engaging hole  85   b . In this state, the lamp  91  and the lighting cover  92  are positioned at lower height positions by biasing force of the spring member  84 , where the lighting equipment  90  has a length of L1. 
     Referring to  FIG. 11(B) , on the other hand, in the lighting equipment  90 , the engaging claw  83   a  is in a state of being engaged with the first engaging hole  85   a . In this state, the lamp  91  and the lighting cover  92  are positioned at upper height positions, where the lighting equipment  90  has a length of L2 (L2&lt;L1). 
     With the lighting equipment  90  provided with the adjustment mechanism  82  as shown above, in a case where the ceiling  2  differs in thickness as shown in  FIGS. 11(A)  and (B) as an example, it becomes possible to adjust height positions of the lamp  91  and the lighting cover  92  (i.e., height position of the lower end  92   a  of the lighting cover  92 ) relative to the ceiling opening  3  or the second opening  12  so as to adjust the gap S for air intake to a proper size. 
     Even in cases of equal thickness of the ceiling  2 , it is also possible to adjust the quantity of air passing through the gap S for air intake by adjusting the height positions of the lamp  91  and the lighting cover  92  by the adjustment mechanism  82 . 
     In this Embodiment 5, since the lighting equipment  90  is separated from the flange  35 , it becomes possible to adjust the height positions of the lamp  91  and the lighting cover  92  relative to the flange  35 . Moving the lamp  91  and the lighting cover  92  upward by the adjustment mechanism  82  allows the gap S for air intake to be set larger. 
     This Embodiment 5 has been described on an example in which a disc-shaped rotatable engaging member  83  is used as the adjustment mechanism  82 . However, various mechanisms capable of height adjustment are also adoptable including a mechanism in which a bolt fixed to the main housing  10  in a state of vertical placement is set to support the lighting equipment  90 , and in which a nut screwed with the bolt is turned so that the support height of the lighting equipment  90  is adjusted. 
     Also, this Embodiment 5 has been described on a configuration in which the lighting cover  92  and the lid  94  can be positioned upper than the upper end of the flange  35  by the adjustment mechanism  82 . However, a similar configuration may be adopted also in the foregoing Embodiments 1 to 3. 
     Working Example 1 
     With the ceiling mounted ventilation fan  1  with illumination of Embodiment 1, noise measurement during operation was performed with respect to two types of configurations, one configuration (Working Example) in which passage of air through between the lighting cover  32  and the lamp  31  is restricted while indoor air is introduced into the main housing  10  through the gap S for air intake, and the other configuration (Comparative Example) in which the lighting cover is made up so as to eliminate the presence of any gap S for air intake while indoor air is introduced through between the lighting cover and the lamp. It is noted that a multiblade fan unit having an air flow rate of 80 CFM was used as the fan unit. 
     In a measurement room shielded from external sounds, noise measurement was performed at three points in total, specifically, at left-and-right two points laterally and horizontally 1 m distant from the ceiling mounted ventilation fan with illumination and at one lower point downwardly 1 m distant therefrom. It is noted that background noise was 15.1 dB. 
     The ceiling mounted ventilation fan with illumination of Comparative Example showed results of 36.4 dB at the left measuring point, 36.8 dB at the right measuring point, and 39.8 dB at the lower measuring point, while the ceiling mounted ventilation fan with illumination of Working Example showed results of 35.0 dB at the left measuring point, 35.3 dB at the right measuring point, and 38.6 dB at the lower measuring point. 
     From these noise measurement results, it can be understood that the ceiling mounted ventilation fan with illumination of Working Example has a higher noise suppression effect compared with Comparative Example. It can be considered that Working Example, in which the gap S for air intake is provided, is enabled to achieve noise reduction by virtue of its capability of reducing pressure loss to more extent as compared with Comparative Example as well as its suppression of the possibility that the lighting cover serves as a megaphone to cause enhancement of noise directivity. 
     It is to be noted that, by properly combining the arbitrary embodiments of the aforementioned various embodiments, the effects possessed by them can be produced. 
     Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom. 
     REFERENCE SIGNS LIST 
     
         
           1  ceiling mounted ventilation fan with illumination 
           2  ceiling 
           3  ceiling opening 
           10  main housing 
           11  first opening 
           12  second opening 
           13  duct connection part 
           14  duct 
           20  fan unit 
           21  fan 
           22  motor 
           23  fan casing 
           30  lighting equipment 
           31  lamp 
           32  lighting cover 
           32   a  upper end 
           32   b  lower end 
           32   c  reflecting surface 
           33  lamp mounting fixture 
           34  lid 
           35  flange 
           36  biasing member 
         S gap for air intake