Natural lighting structure for building with monitor roof

Abstract

To provide a natural lighting structure for a building capable of realizing optimal brightness throughout the year with a simple structure.SOLUTION: A natural lighting structure for a building is a lighting structure in a building (1) having a monitor roof (3) on a part of its roof (2). The monitor roof (3) includes: side face parts (31) intersecting a peripheral area (23) of an opening of a roof body, and provided with projected windows (4) having light transmissivity; and a ceiling part (32) connected to upper ends of the side face parts. The lighting structure comprises: a first reflector (5) disposed on an upper surface of the peripheral area of the roof body, whose regular reflectance is higher than diffusive reflectance; and a second reflector (6) disposed on a lower surface of the ceiling part of the monitor roof, whose diffusive reflectance is higher than regular reflectance.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a daylighting structure of a building, and particularly to a daylighting structure of a building having a mansard roof.

Background Art

[0002] In buildings such as factories, a mansard roof may be provided on a part of the roof. As disclosed in Japanese Unexamined Patent Application Publication No. 2015-105557 (Patent Document 1), by forming the mansard roof in a box-shaped cross section and providing an opening (window) on the side surface of the mansard roof, it is possible to ensure the daylighting property of the indoor space.

[0003] In Patent Document 1, for the purpose of improving the brightness of the indoor space, a technique has been proposed in which a reflector is provided on the general roof adjacent to the mansard roof to realize direct daylighting and indirect daylighting to the indoor space.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In buildings such as factories where the floor area of the indoor space is large, it is common to ensure the brightness of the indoor space by daylighting from the upper windows. However, in summer, glare caused by direct sunlight becomes a problem. Since the technique of Patent Document 1 is aimed at improving daylighting during snow accumulation in winter, it does not consider glare reduction in summer.

[0006] The present invention has been made to solve the above problems, and an object thereof is to provide a daylighting structure of a building that can achieve optimal brightness throughout the year with a simple configuration.

Means for Solving the Problems

[0007] The daylighting structure of a building according to an aspect of the present invention is a daylighting structure in a building having an over-roof on a part of the roof. The over-roof includes a side surface portion that intersects the peripheral region of the opening of the roof body and is provided with a protruding window having translucency, and a ceiling portion connected to the upper end of the side surface portion. The daylighting structure includes a first reflective material provided on the upper surface of the peripheral region of the opening of the roof body and having a specular reflectance higher than the diffuse reflectance, and a second reflective material provided on the lower surface of the ceiling portion of the over-roof and having a diffuse reflectance higher than the specular reflectance.

[0008] The protruding window is preferably composed of a translucent member having a high reflectance. "Having a high reflectance" typically means that the reflectance is higher than the transmittance, but for example, it may have a reflectance of 40% or more.

[0009] In addition, it is desirable that the translucent member constituting the protruding window has a property that the reflectance increases as the incident angle approaches perpendicular.

[0010] Preferably, the protruding window is positionally changeable between a fully closed posture along the vertical direction and an open posture inclined at a predetermined angle with respect to the vertical direction, and the predetermined angle is an angle that is substantially perpendicular to the solar radiation direction during the day in summer.

[0011] In a form in which the roof body is formed of a corrugated folded plate roofing material, it is desirable that the first reflective material is composed of a flat plate material fixed on the folded plate roofing material.

Advantages of the Invention

[0012] According to the present invention, an optimal brightness can be realized throughout the year with a simple configuration.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0014] Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated.

[0015] (Regarding the schematic configuration) Prior to the description of the daylighting structure for a building according to the present embodiment, a known daylighting structure will be briefly described with reference to FIG. 7.

[0016] In FIG. 7(A), a building 101 having an attic roof 3 at the central part of a roof 2 is shown. The roof 2 is, for example, a gable roof. In the following description, the roof 2 is also referred to as the roof body 2. The attic roof 3 is disposed so as to protrude upward from the roof body 2 so as to cover an opening for the attic roof 3 (hereinafter referred to as the "central opening") formed in the central part of the roof body 2 (in the case of a gable roof, the part including the ridge part). The attic roof 3 has a box-shaped cross section and windows 104 are provided on the side surfaces. In this building 101, in summer, direct sunlight shines into the indoor space S1, causing glare to the workers.

[0017] FIG. 7(B) shows a building 102 having no gable roof and only a roof 2 as a normal gable roof. In the building 102, a window 104 functioning as a high side light is provided at the upper end portion (the intersection with the roof 2) of the outer wall 10. In this building 102, it is difficult to expect natural lighting to the central portion of the plane of the indoor space S1 through the window 104, and it is difficult to secure horizontal plane illuminance.

[0018] FIG. 7(C) shows a building 103 having no gable roof and only a roof 2 as a normal gable roof. In the building 103, a window 104 functioning as a top light is provided on the roof 2. In this building 103, glare caused by direct sunlight in summer becomes a more serious problem than in the building 101 having the window 104 provided on the gable roof 3. In addition, there is a concern about deterioration of the thermal environment in the indoor space S1.

[0019] FIGS. 1 and 2 are diagrams showing the basic configuration of the daylighting structure of the building 1 according to the present embodiment. In order to facilitate understanding of the daylighting structure of the building 1, in the following description, it is assumed that the left side of the paper is the south side and the right side of the paper is the north side. Further, the extending direction of the ridge portion of the roof 2 is referred to as the beam direction, and the direction orthogonal to the ridge portion is referred to as the purlin direction.

[0020] The building 1 has the same basic configuration as the above-described building 101, and includes an outer wall 10 surrounding the indoor space S1, a roof body 2 intersecting the upper end portion of the outer wall 10, and a gable roof 3 disposed so as to cover the central opening 20 of the roof body 2. In the present embodiment, it is assumed that the beam direction of the roof body 2 is the east-west direction (the depth direction of the paper).

[0021] The roof body 2 is formed in a gentle inverted V shape, and has a first roof portion 21 inclined from the central ridge portion toward the south side (the left side of the paper) and a second roof portion 22 inclined from the ridge portion toward the north side (the right side of the paper). The central opening 20 of the roof body 2 is provided at a position including the ridge portion. Among the roof body 2, the peripheral region 23 around the central opening 20 is referred to as the "opening peripheral region 23". Each of the first roof portion 21 and the second roof portion 22 has a peripheral region 23 adjacent to the central opening 20.

[0022] The over-roof 3 has a box-shaped cross-section and includes side surfaces 31 that intersect the peripheral region 23 of the opening of the roof body 2, and a ceiling portion 32 connected to the upper ends of the side surfaces 31. The side surfaces 31 are provided on both the first roof portion 21 side and the second roof portion 22 side.

[0023] The ceiling portion 32 has a shape similar to that of the roof body 2, and has a first ceiling portion 33 that slopes southward from the ridge portion and a second ceiling portion 34 that slopes northward from the ridge portion. The inclination angles of the first ceiling portion 33 and the second ceiling portion 34 are substantially the same as the inclination angles of the first roof portion 21 and the second roof portion 22.

[0024] The side surface 31 is provided with a protruding window 4 that extends along the girder direction. That is, as shown in FIG. 2, the side surface 31 has an opening 30 that communicates the indoor space S1 and the outdoor space S2, and the protruding window 4 is provided to be able to open and close the opening 30. The light-transmitting member constituting the protruding window 4 is typically glass. It is desirable that the light-transmitting member has a high reflectance. Specifically, it is desirable that the reflectance is higher than the transmittance. Note that the light-transmitting member itself may be formed of a high-reflection material, or a sheet material such as a high-reflection film may be attached to the front surface (the outdoor side surface) or the back surface (the indoor side surface) of the light-transmitting member.

[0025] The protruding window 4 can be changed in position between a fully closed posture along the vertical direction (shown in FIG. 1) and an open posture that is inclined at a predetermined angle with respect to the vertical direction (shown in FIG. 2). The predetermined angle is desirably an angle that is substantially perpendicular to the solar radiation direction during the day in summer. The open posture at the predetermined angle is typically a fully open posture. As shown in FIG. 3 described later, the protruding window 4 is attached to a window frame 41 and has a rotation shaft 42 at its upper end portion. In the fully open posture, the lower end portion of the protruding window 4 protrudes outside the outdoor side more than the upper end portion. Note that the protruding window 4 may be inclined at a predetermined angle with respect to the vertical direction in the fully open posture and may be a so-called sliding window.

[0026] In the building 1 according to the present embodiment, as schematically shown in FIGS. 1 and 2, reflective materials 5 and 6 are provided on the upper surface of the opening peripheral region 23 of the roof body 2 and the lower surface of the ceiling portion 32 of the attic roof 3, respectively.

[0027] The reflective material (first reflective material) 5 provided on the upper surface of the opening peripheral region 23 is a specular reflective member having a higher regular reflectance than the diffuse reflectance. The reflective material 5 is composed of, for example, a sheet-like or plate-like member such as a synthetic resin material such as a mirror, glass, or acrylic. Alternatively, it may be composed of a paint having an excellent regular reflectance.

[0028] The reflective material (second reflective material) 6 provided on the lower surface of the ceiling portion 32 is a diffuse reflective member having a higher diffuse reflectance than the regular reflectance. The reflective material 6 is composed of, for example, a sheet-like or plate-like member such as a foamed resin material, glass wool, or rock wool. Alternatively, it may be composed of a paint having an excellent diffuse reflectance.

[0029] As a form not shown, the roof body 2 of the building 1 such as a factory may be formed of a corrugated folded plate roofing material. In this case, it is desirable that the reflective material 5 is composed of a flat plate material (such as a mirror) and is fixed in a state of being placed on the folded plate roofing material. This is for reflecting sunlight in a desired direction (one direction) on the surface (flat surface) of the reflective material 6. On the other hand, when the ceiling portion 32 of the attic roof 3 is formed of a folded plate roofing material, the reflective material 6 may be arranged along the corrugated shape of the ceiling portion 32. This is because the reflective material 6 is for the purpose of diffusing light. Note that the reflective material 6 may also be composed of a flat plate material (such as a foamed resin material) and fixed below the folded plate roofing material.

[0030] As described above, the daylighting structure of the building 1 according to the present embodiment has the protruding window 4 on the side surface portion 31 of the hip roof 3, and different types of reflectors 5 and 6 are provided in the outdoor opening peripheral area 23 and the indoor ceiling portion 32 adjacent to each other in the inner and outer directions (north-south direction) via the protruding window 4. Therefore, by selecting the opening and closing state of the protruding window 4, the amount of daylight entering the indoor space S1 through the opening 30 can be adjusted. That is, as will be described later, it is possible to reduce glare in summer and ensure the brightness of the indoor space S1 throughout the year.

[0031] (Daylighting method in summer) Referring to FIGS. 3 and 4, the daylighting method in summer will be described. FIG. 3 corresponds to an enlarged view of a part (the part enclosed by a circle) III of FIG. 1, and shows a state in which the opening 30 of the hip roof 3 is closed, that is, a state in which the protruding window 4 is in a fully closed position. FIG. 4 corresponds to an enlarged view of a part (the part enclosed by a circle) IV of FIG. 2, and shows a state in which the opening 30 of the hip roof 3 is released, that is, a state in which the protruding window 4 is in a fully open position.

[0032] The solar altitude during the day in summer is relatively high, for example, about 60 to 80 degrees (with respect to the horizontal plane). The incident angle θ1 on the protruding window 4 in summer is, for example, in the range of 10 degrees to 30 degrees.

[0033] Referring to FIG. 3, when the protruding window 4 is fully closed in summer, since the protruding window 4 is composed of a light-transmitting member with a high reflectivity, most of the sunlight incident on the protruding window 4 is reflected (solid line arrow L1). As a result, the amount of sunlight transmitted into the indoor space S1 can be reduced (dashed line arrow L2). That is, the amount of solar radiation taken into the indoor space S1 can be reduced.

[0034] Also, in summer, sunlight is incident on the reflector 5 disposed on the upper surface 23a of the opening peripheral region 23 at a substantially perpendicular angle. By "substantially perpendicular", an angle of about 90° ± 10° is assumed. Specifically, the incident angle θ2 of sunlight (from the south) on the reflector 5 in summer is, for example, in the range of 80° to 100°. Since the reflector 5 is composed of a specular reflection member, the sunlight incident on the reflector 5 is bounced back at a substantially perpendicular angle (solid arrow L3). As a result, the incidence of the reflected light reflected by the reflector 5 on the protruding window 4 is blocked (or suppressed).

[0035] Therefore, when the protruding window 4 is in a fully closed state in summer, the direct sunlight entering the indoor space S1 can be reduced. That is, in the indoor space S1, the glare caused by direct sunlight can be suppressed. Note that when the protruding window 4 is in a fully closed state, the solar radiation amount on the indoor space S1 is slightly more than that in the fully closed state described later, so it is effective on rainy days or cloudy days when the indoor space S1 tends to become dark.

[0036] Referring to FIG. 4, when the protruding window 4 is in a fully open state in summer, the incident angle θ2 on the protruding window 4 becomes closer to perpendicular than when it is in the fully closed state (the incident angle θ1 in FIG. 3). Therefore, the reflection amount of the sunlight incident on the protruding window 4 becomes less than that in the fully closed state (solid arrow L4), and the transmission amount of the sunlight becomes more than that in the fully closed state (dashed arrow L5). As shown in FIG. 6, this is because the reflectance is higher than the transmittance as the incident angle approaches 90°.

[0037] Therefore, although the amount of transmitted light taken into the indoor space S1 through the upper region 4a of the protruding window 4 becomes more than that in the fully closed state, since the protruding window 4 is composed of a light-transmitting member with a high reflectance, the amount of transmitted light can be reduced compared to the form composed of general window glass. In addition, the sunlight transmitted through the lower region 4b of the protruding window 4 is bounced back by the reflector 5 disposed on the upper surface 23a of the opening peripheral region 23 (solid arrow L6), so the solar radiation amount passing through the protruding window 4 can be efficiently reduced.

[0038] In addition, by setting the protruding window 4 to the fully open state during the summer, natural ventilation (temperature difference ventilation) of the indoor space S1 can be performed. Therefore, according to the present embodiment, by setting the protruding window 4 to the fully open state during the summer, it is possible to suppress the intrusion of direct sunlight into the indoor space S1 (reduce glare) and exhaust heat through the opening 30, so that the thermal environment of the indoor space S1 can be effectively improved.

[0039] (Daylighting method in winter) Referring to FIG. 5, the daylighting method in winter will be described. FIG. 5 corresponds to an enlarged view of a part (the part surrounded by a circle) III of FIG. 1, and shows a state where the opening 30 of the overhanging roof 3 is closed (the protruding window 4 is in the fully closed position).

[0040] The solar altitude during the daytime in winter is relatively low, for example, about 30 to 50 degrees (with respect to the horizontal plane). The incident angle θ4 on the protruding window 4 in winter is, for example, in the range of 40 degrees to 60 degrees.

[0041] Referring to FIG. 5, when the protruding window 4 is in the fully closed state in winter, the incident angle θ4 on the protruding window 4 is closer to the vertical than in summer (θ1 in FIG. 3). Therefore, the amount of sunlight transmitted directly to the protruding window 4 becomes larger than that in the fully closed state in summer shown in FIG. 3 (broken line arrow L7).

[0042] In addition, in winter, sunlight enters the reflector 5 arranged on the upper surface 23a of the opening peripheral region 23 at a shallow angle from the south. Specifically, the incident angle θ5 of sunlight (from the south) on the reflector 5 in winter is, for example, in the range of 30 degrees to 60 degrees. Since the reflector 5 is composed of a specular reflection member, the sunlight incident on the reflector 5 is reflected toward the protruding window 4 side (north) (solid line arrow L8). The obliquely upward reflected light enters the protruding window 4. The incident angle θ6 of the reflected light on the protruding window 4 is, for example, in the range of 40 degrees to 70 degrees.

[0043] A part of the reflected light incident on the protruding window 4 passes through the protruding window 4 and is taken into the indoor space S1. The obliquely upward transmitted light that has passed through the protruding window 4 is directly incident on the lower surface 32a (reflective material 6) of the ceiling portion 32 of the gable roof 3 (dashed arrow L9). Since the roof body 2 has a slope, the transmitted light of the protruding window 4 can be effectively delivered to the lower surface 32a of the ceiling portion 32.

[0044] When the slope of the roof body 2 is included in the range of, for example, 5 degrees to 15 degrees with respect to the horizontal plane, it is considered that the reflected light reflected by the outdoor reflective material 5 can be effectively directed to the lower surface 32a of the ceiling portion 32. As shown in FIG. 1, it is desirable that the width (length along the slope direction of the roof body 2) W of the reflective material 6 is equal to or greater than the height H of the protruding window 4. The protruding window 4 is preferably configured entirely in the height direction by a light-transmitting member. Thereby, the light reflected by the reflective material 6 can be efficiently taken into the indoor space S1.

[0045] The transmitted light that has passed through the protruding window 4 and is taken into the indoor space S1 diffusely reflects on the reflective material 6 arranged on the lower surface 32a of the ceiling portion 32 (dashed arrow L10). Since the reflective material 6 is exposed to the indoor space S1 and is arranged downward, the light reflected by the reflective material 6 diffuses over a wide range of the indoor space S1. Since the reflective material 6 is provided on the entire lower surface 32a of the ceiling portion 32 of the gable roof 3, it is possible to expect the effect of uniformly reflecting the incident transmitted light in various directions of the indoor space S1 and the effect of improving the brightness feeling of the indoor space S1 by increasing the brightness of the entire lower surface 32a.

[0046] In this way, in winter, by closing the protruding window 4 completely, the brightness of the indoor space S1 can be efficiently improved compared to the completely closed state in summer shown in FIG. 3. Since it is not necessary to open the protruding window 4 completely as shown in FIG. 4 in winter, the coldness of the indoor space S1 can be reduced.

[0047] As described above, according to the daylighting structure of the building 1 according to the present embodiment, it is possible to achieve both reduction of glare from direct sunlight in summer and improvement of the brightness of the indoor space S1 in winter. That is, with a simple configuration, optimal brightness can be realized throughout the year.

[0048] In the present embodiment, the daylighting method through the south-facing protruding window 4 has been described. However, the same effect is expected even with an east-facing or west-facing protruding window 4.

[0049] (Modification example) In the present embodiment, an example in which the protruding window 4 is provided on the side surface portion 31 extending in the girder direction has been shown. However, it may be provided on a side surface portion (not shown) extending in a direction orthogonal to the girder direction (ridge direction).

[0050] Also, an example in which the gable roof 3 is arranged across the first and second roof portions 21, 22 of the roof body 2 has been shown. However, the gable roof 3 may be arranged on either one of the first and second roof portions 21, 22. That is, the gable roof 3 may be provided at a location other than the central portion of the roof body 2.

[0051] In the present embodiment, the ceiling portion 32 of the gable roof 3 includes the first and second ceiling portions 33, 34 and is formed in a gentle inverted V shape. However, the ceiling portion 32 may be horizontal. Also, the roof body 2 includes the first and second roof portions 21, 22 and is formed in a gentle inverted V shape (gable roof). However, it is not limited to such an example, and for example, it may be a hipped roof.

[0052] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of reference numerals

[0053] 1 Building, 2 Roof, 3 Overhanging roof, 4 Protruding window, 5 First reflective material, 6 Second reflective material, 10 Outer wall, 20, 30 Opening, 23 Peripheral area of the opening, 31 Side surface part, 32 Ceiling part, S1 Indoor space, S2 Outdoor space.

Claims

1. A daylighting structure in a building having a penthouse on a part of the roof, wherein the penthouse includes a side surface portion that intersects a peripheral region of an opening of the roof body and is provided with a protruding window having translucency, and a ceiling portion connected to an upper end of the side surface portion, a first reflective material provided on an upper surface of the peripheral region of the opening of the roof body and having a specular reflectance higher than a diffuse reflectance, and a second reflective material provided on a lower surface of the ceiling portion of the penthouse and having a diffuse reflectance higher than a specular reflectance. A daylighting structure of a building.

2. The daylighting structure of the building according to claim 1, wherein the protruding window is constituted by a translucent member having a high reflectance.

3. The daylighting structure of the building according to claim 1, wherein the translucent member constituting the protruding window has a property that the reflectance increases as the incident angle approaches perpendicular.

4. The protruding window is positionally changeable between a fully closed position along the vertical direction and an open position inclined at a predetermined angle with respect to the vertical direction, and the predetermined angle is an angle that is substantially perpendicular to the solar radiation direction during the day in summer. The daylighting structure of the building according to claim 2.

5. The roof body is formed of a corrugated folded plate roofing material, and the first reflective material is constituted by a flat plate material fixed on the folded plate roofing material. The daylighting structure of the building according to claim 1.

Images