JPH10237972A - Wall construction of building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve natural ventilating properties and moisture permeability. SOLUTION: A room 3 is formed on the inside by walls such as side walls 1, roof walls 2 installed to the upper sections of the side walls 1, etc., in the building. The roof walls 2 are constituted while forming external walls 4 and internal walls 5 at that time, air passages 6, in which air is flowed, are formed among the external walls 4 and the internal walls 5, air introducing port sections 7, from which air is introduced to the air passages 6, are formed on the lower sides of the roof walls 2, and air exhaust-port sections 8 discharging air from the air passages 6 are shaped on the upper sides of the roof walls 2. The internal walls 5 are configured by using air- permeable wall bodies H, in which a plurality of porous sheets 13 having a large number of penetrated pinholes and being made of aluminum foil are laminated through core materials and air layers 15 are formed among the porous sheets 13, and the air-permeable wall bodies H are protected while being faced at intervals in the porous sheets 13 on the outsides of the air-permeable wall bodies H. Protective boards 17, to which a large number of through-holes 16 are formed, are mounted, and the vapor resistance of the porous sheets 13 on the indoor sides of the air-permeable wall bodies H is set at a large value and the vapor resistance of the porous sheets 13 on the outdoor side at a small value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wall structure of a building in which a room is formed inside a side wall, a roof wall, etc., and in particular, to perform appropriate heat insulation and moisture permeability while securing a necessary natural ventilation. The wall structure of a building that can do

[0002]

2. Description of the Related Art Conventionally, as a material for a wall of a building, a material proposed by the applicant of the present application has been known (for example, Japanese Unexamined Patent Publication No. Hei 6-306969). This is configured by laminating a plurality of porous sheets made of aluminum foil having a large number of small holes through a core material formed in a lattice shape, and forming an air layer between the porous sheets. By providing an air layer in multiple layers, heat insulation is ensured and natural ventilation can be performed by ventilating through small holes.

[0003]

By the way, even if such a wall material according to the prior art is simply applied to a wall structure of a building as it is, it is not always necessary in terms of natural ventilation and moisture permeability.
There was a fact that it was not possible to demonstrate sufficient performance. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wall structure of a building that can further improve natural ventilation and moisture permeability.

[0004]

In order to solve such problems, a wall structure of a building according to the present invention is provided for a building having a room formed therein by walls such as side walls and a roof wall provided above the side walls. In the structure of the wall, the wall includes an outer wall and an inner wall, an air passage through which air flows between the outer wall and the inner wall is provided, and the inner wall has a plurality of small holes penetrating therethrough. A plurality of sheets are laminated with a core material interposed therebetween, and the air-permeable wall is formed by forming an air layer between the porous sheets. Thus, when a temperature difference between the inside and outside is generated or a pressure difference due to the external wind pressure is generated, the indoor air is exhausted through the small holes of the porous sheet of the permeable wall, or the air of the air passage is discharged from the small holes of the porous sheet. The air is taken in, and the room is ventilated by the exhaust and the intake air.

In this case, an air inlet for introducing air into the air passage is provided below the wall, and an air outlet for discharging air from the air passage is provided above the wall. It is valid. In addition, it is effective to provide a protective board provided with a large number of through holes, while protecting the gas permeable wall by facing the porous sheet at an interval outside the gas permeable wall.

If necessary, the moisture permeability of the porous sheet on the indoor side of the air-permeable wall is increased, and the moisture permeability of the porous sheet on the outdoor side is reduced. Thereby, moisture is prevented on the indoor side surface having a high water vapor pressure in winter or the like, moisture is easily released on the outdoor side, and the occurrence of dew condensation is prevented. In this case, only the moisture permeation resistance of the porous sheet located closest to the indoor side of the air-permeable wall may be set to be larger than the moisture permeation resistance of the other porous sheets. If necessary, the porous sheet of the breathable wall is formed of aluminum foil.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wall structure of a building according to an embodiment of the present invention will be described below with reference to the accompanying drawings. 1 and 2 show a wall structure of a building according to an embodiment of the present invention. The wall structure of this building is a structure of a wall in which a room 3 is formed by walls such as a side wall 1 and a roof wall 2 provided above the side wall 1, and in the embodiment, the roof wall 2 The present invention is applied to the present invention. The roof wall 2 is composed of two inclined roof walls that are inclined left and right. The roof surface is larger than the vertical wall surface, there are no unspecified obstacles such as furniture, and even if there is excessive ventilation, the risk of cold draft due to mixed diffusion from the ceiling to the living height is small. Therefore, it is considered to be an effective site for providing a natural ventilation function.

The roof wall 2 has an outer wall 4 and an inner wall 5. An air passage 6 through which air flows is provided between the outer wall 4 and the inner wall 5. An air inlet 7 for introducing air into the air passage 6 is provided below the eaves below the roof wall 2, and air is supplied from the air passage 6 to the roof top above the roof wall 2. An air outlet 8 for discharging air is provided. Reference numeral 9 denotes a duct-shaped rooftop provided along the top of the roof and having left and right ventilation ports 10 communicating with the air passage 6. Reference numeral 11 denotes a plurality of valve plates which are provided in the roof 9 and whose opening is variably opened / closed in accordance with the wind pressure of the external wind flowing from the ventilation opening 10 to adjust the flow of the left and right winds. In the embodiment, it is assumed that the rain is not included, and the range from the ventilation layer under the rain to the indoor surface of the wall is defined as the range of the wall structure.

As shown in FIG. 2, the inner wall 5 is formed by laminating a plurality of porous sheets 13 having a large number of small holes 12 therethrough through a core material 14 and forming an air layer 15 between the porous sheets 13. It is configured using a wall H. Breathable wall H
Is formed of aluminum foil. The core material 14 is formed in a lattice shape, a honeycomb shape, or a net shape using wood or the like. The number of the porous sheets 13 is, for example, 2
The thickness of the core material 14 is set so that the width of the air layer 15 is set to an appropriate numerical value in the range of, for example, 3 to 20 mm. And it is formed so that the whole thickness may be in the range of, for example, 30 to 110 mm. Also, on the outside of the permeable wall H,
The air permeable wall H faces the porous sheet 13 at an interval.
And a protection board 17 provided with a large number of through holes 16 is provided. The thickness of the protection board 17 is set to, for example, 2 to 5 mm, and the diameter of the through holes 16 is set to, for example, 8 to 16 mm and the interval is set to 40 to 60 mm.

Further, the moisture permeation resistance of the porous sheet 13 on the indoor side of the permeable wall H is set to be larger than the moisture permeation resistance of the porous sheet 13 on the outdoor side. In the embodiment,
The porous sheet 13 located at the most indoor side of the permeable wall H
Only the moisture permeation resistance of the (first sheet) is set to be larger than the moisture permeation resistance of the other porous sheets (the second to n-th sheets). That is, the porous sheet 1 located closest to the indoor side of the breathable wall H
Only the moisture permeability coefficient of No. 3 is set to be smaller than the moisture permeability coefficients of the other porous sheets 13. Specifically, since the air-permeable wall H has the multilayer air layer 15 made of the porous sheet 13,
The equivalent opening area per unit area of the entire wall is determined by the sum of the air resistance of each sheet. On the other hand, the moisture permeation resistance distribution inside the wall is effective in preventing internal dew condensation if the resistance is maximized on the indoor side and the structure is easy to release moisture outdoors. Then, since the moisture permeability coefficient is proportional to the opening ratio, the opening ratio of the porous sheet 13 closest to the room is reduced, and the air permeability resistance of the wall is borne. Therefore, the equivalent opening area per unit area of the entire wall is determined by the air permeability of the porous sheet closest to the room. For example, the hole diameter of the first porous sheet 13 from the indoor side is 0.8 to 1.2 mm and the hole interval is 19 to 2 mm.
7.0 mm, the hole diameter of the second and subsequent porous sheets 13 is 0.2 to 0.3 mm, the hole interval is 0.8 to 1.2 mm, and the like. Only the moisture permeation resistance of the porous sheet 13 is set to be higher than the moisture permeation resistance of the other porous sheets 13.

Therefore, according to the wall structure of the building according to this embodiment, the ventilation driving force is an external wind and an internal / external temperature difference. In temperature difference ventilation when the external wind is weak, air flows in from the lower part of the roof surface and flows out from the upper part due to the difference in altitude of the roof wall. When the external wind is 2 to 3 m / s or more, the differential pressure due to the external wind pressure is more prominent than the internal / external temperature difference, so that the external wind is used as the driving force, and the air flows from one roof surface to the other to ventilate the room. Is done. Thus, ventilation is secured only on the roof surface without expecting ventilation on walls and floors. That is, when a temperature difference between the inside and outside is generated or a pressure difference due to an external wind pressure is generated, the indoor air is exhausted through the small holes 12 of the porous sheet 13 of the permeable wall H, or the air of the air passage 6 is removed from the porous sheet 13. Is sucked through the small holes 12 of
The ventilation and ventilation of the room are performed by the exhaust air and the intake air.

In this case, the permeable wall H is formed of the porous sheet 13.
The multi-layer air layer 15 allows ventilation to be performed gently. Therefore, while having sufficient heat insulation performance, ventilation and moisture permeation are performed on the entire wall surface, and the room temperature distribution that does not cause inconsistency is felt. Is formed. Further, in this case, internal dew condensation hardly occurs in winter or the like. That is, since only the moisture permeation resistance of the porous sheet 13 located closest to the indoor side of the air permeable wall H is set to be higher than the moisture permeation resistance of the other porous sheets 13, the indoor side having a high water vapor pressure in winter Moisture is prevented on the surface, and moisture is easily released on the outdoor side, thereby preventing the occurrence of dew condensation.

[0013]

Next, an embodiment of the present invention will be described. [Example 1] This example is directed to a building in an "area where the temperature is high and humid in summer and heating is required even in winter when the temperature does not drop below freezing", and the hole diameter and hole interval of the perforated sheet are used. Depending on the number of sheets, the number of parts, and the thickness of the members, the following functions can be obtained. (1) A minimum necessary ventilation volume can always be obtained in a natural state without using air conditioning equipment. (2) It has sufficient heat insulation performance. (3) Provide ventilation and moisture permeation on the entire wall. (4) No actual harm due to internal condensation. (5) Form an indoor temperature distribution that does not give a sense of independence. Was designed to satisfy at the same time.

As shown in FIG. 3, the total floor area is 120 m ² ,
A two-story house with a five-slope gabled roof was set up, and Fig. 1
As shown in FIG. 5, the roof wall 2 is
The outer wall 4 and the inner wall 5 are provided with the air passage 6 interposed therebetween. In the calculation of ventilation, there is no gap between the wall and the floor, and the room is treated as one room. The wind speed conditions when the building secures the required ventilation volume are as follows.
It was set to 3 m / s from the mode value of wind speed in the standard weather data of Tokyo from February to January. Set the wind pressure coefficient of the roof surface to
2. If a uniform distribution is set at -0.5 on the leeward side, the differential pressure on the sloped roof surface is 2.0 Pa. In addition, 20 ° C
Considering that there is a difference of 2.2 Pa between the ridge and eaves due to the temperature difference between inside and outside (0 ° C outdoors, 20 ° C indoors), the ventilation rate is 0.5 times / h (196.5m ³ / h) Equivalent opening area per unit area of the sloped roof surface such that
αA) was 9.2 cm ² / m ² .

Using the obtained αA, indoor air pollution in winter was examined. From the wind speed value of the standard weather data in Tokyo from December to January, the air permeability Q _i (m ³ / h, i represents time) of the roof surface every hour was calculated from the following formula assuming a single-room model. The amount of change in indoor CO ₂ concentration Δpi _{, i + 1} (ppm / h) at each time was calculated. The initial value of the CO ₂ concentration was 700 ppm.

[0016]

(Equation 1)

Here, k: the amount of CO ₂ generated in the room (family 4
Taking into account the generation by human and equipment 0.07 m ³ / h and the) p _0: outdoor CO ₂ concentration (= 300ppm) Q _r: chamber volume (393m ³⁾ As a result, indoor exceeding short stay OEL 1000ppm Only 10 hours of the total 2160 hours showed concentration.

Next, considering the relationship between the pore diameter and the air permeability, the air permeability wall is a multi-layer air layer made of a porous sheet, so that αA of the entire wall is determined by the sum of the air resistance of each sheet. You. On the other hand, the moisture permeation resistance distribution inside the wall is effective in preventing internal dew condensation if the resistance is maximized on the indoor side and the structure is easy to release moisture outdoors. Therefore, since the moisture permeability coefficient is proportional to the opening ratio, the opening ratio of the sheet on the indoor side is reduced to bear the air permeability resistance of the wall. Therefore, the αA of the wall is determined by the air permeability of the sheet closest to the room. 4 to 6 were prepared based on the relationship between the Reynolds number (hereinafter referred to as Re) of the blade-shaped orifice and the relationship between the opening ratio and the flow coefficient in order to examine the effect of the hole diameter of the porous sheet on the air permeability. At this time, an extrapolated value was used for Re <1.
In the range of Re <100, the flow coefficient monotonically increases with respect to Re. Therefore, when the aperture ratios are equal, as shown in FIGS. Therefore, the air permeability increases.

However, when the opening ratio is set so that the required air permeability of 5.9 m ³ / hm ² is obtained at the wind pressure of 2.0 Pa used for the design of the required ventilation, as shown in FIG. At a wind pressure of 22.2 Pa corresponding to a wind speed of 10 m / s at which the excess frequency becomes 0% at a height of 10 m, a sheet having a hole diameter of 0.1 mm exhibits a gas permeability 1.9 times that of a sheet having a hole diameter of 1.0 mm.
In a sheet having a hole diameter of 4.0 mm, Re exceeds 1000 at a wind pressure of 22.2 Pa, which is a value immediately before a turbulent flow. Therefore, it is concluded that a hole diameter of 1.0 to 3.0 mm is most appropriate from consideration of heat insulation. In this example, optimal values were examined for the αA of the air-permeable wall and the pore size of the porous sheet, and were determined to be 9.2 cm ² / m ² and 1.0 to 3.0 mm, respectively.

[Embodiment 2] In this embodiment, the amount of air, heat, and moisture transfer in the plane direction of the wall is checked in order to confirm the thermal characteristics and the internal dew condensation characteristics of the wall when air is permeable by an external wind. Assuming that is small enough to be ignored as compared with the amount of permeation, a study by one-dimensional numerical calculation was performed to obtain a design value of the permeable wall. FIG. 7 shows a mass point model of a multi-layer air layer made of the porous sheet used in this example. The set temperature and humidity conditions are as follows: 20 ° C outdoors, assuming the nighttime of winter in Tokyo.
60%, room temperature 0 ° C, 60%.

For reference, a calculation formula for calculating the movement amount of air, heat, and humidity is shown. (1) Air movement Compared to the indoor and outdoor differential pressure generated on both surfaces of the wall, the buoyancy due to the temperature difference of the air in the air layer is considered to be negligible, and the amount of air passing through the wall V [m ³ / s · m ^2] ]

[0022]

(Equation 2)

[0023]

(Equation 3)

[0024] The flow coefficient c [-] of the micropores of the aluminum foil is assumed to be a blade-type orifice,
Consider the number and the area ratio dependence of the flow cross section. Symbol A: Opening area per unit area [m ² / m ² ], ρ: Air density (= 1.293 / (1 + 0.00367)
T)) [Kg / m ³ ] P: Atmospheric pressure [Pa] Subscript r: indoor, o: outdoor, t: ceiling height

(2) Heat transfer The convective heat transfer coefficient α _c [W / m ² · ° C.] on the surface of the aluminum foil is based on the forced convective laminar heat inside the flow pipe, assuming that the flow of air in the air layer is laminar. It is determined from the transfer equation and the Nusselt number Nu. _{Nu = α c · d / λ} = 7.54 ∴α c = 3.77λ / D (∵d = 4D / 2 = 2D) radiation heat transfer coefficient between the opposing aluminum foil surface α _r [W / m
² ° C] is determined by the following equation. α _{r j, j + 1} = ε _{j, j + 1} σ [(Ts _j +273.15) +
(Ts _{j + 1} +273.15)] × [(Ts _j +273.15)
15) ² + (Ts _{j + 1} +273.15) ² ] 1 / ε _{j, j + 1} = 1 / ε _j + 1 / ε _{j + 1} −1 Heat transfer E [W / m ^{2 due} to air movement [° C] is obtained from the following equation. E _{k, k + 1} = VCpρ (T _k −T _{k + 1} ) symbol d: equivalent diameter of pipe section [m] D: air layer thickness [m] ε _j : emissivity of aluminum foil j [-] Ts _j : Surface temperature of the aluminum foil j [° C.] σ: Stefan-Boltzmann constant (= 5.67 × 10
^-8 ) [W / m ² · K ⁴ ] Cp: Specific heat at constant pressure [J / g · ° C] T: Temperature of air layer k [° C]

(3) Moisture movement Moisture movement Wa [g due to the movement of k + 1 air from the air layer k
/ S · m ² ], and the moisture transfer Wp due to the water vapor pressure difference
[G / s · m ² ] uses the following equation. Wa _{k, k + 1} = VX _k

[0027]

(Equation 4)

Symbol X _k : absolute volume humidity of air layer k [g / m ³ ] Ps: moisture permeability coefficient of perforated aluminum foil [g / m ² · h · mm]
Hg] Pv: moisture permeability coefficient [g / m ² · h · mmHg] of the air layer sandwiched between two perforated aluminum foils

Next, the equivalent heat transmission coefficient of the permeable wall will be described. FIG. 8 shows 4.8 m ³ / hm ^{2 on the} wall.
The figure shows the relationship between the wall thickness, the number of aluminum foils, and the equivalent heat transmission coefficient when there is an airflow in the outflow and inflow directions (maximum airflow when there is no wind). Aluminum foil number is 10
As the number of sheets increases, the equivalent heat transmission coefficient at each wall thickness almost reaches a plateau, and the degree of influence on the heat insulation performance depends more on the member thickness than on the number of aluminum foils. However,
When the wall thickness is aluminum foil of 11 sheets, even if the 6 cm, at the time of outflow ^{0.38w / m 2 ℃, 0.34w /} m 2 ℃ with time flows
Therefore, only this specification will be dealt with hereafter.

On the other hand, FIG. 9 shows a change in the equivalent heat transmission coefficient when the air permeability increases. At the outflow side, the heat of the air that has entered the wall due to airflow from the room is recovered in the wall, and as a result, the temperature difference between the indoor surface temperature of the wall and room temperature is reduced. On the other hand, on the inflow side, cold air that has entered from the outside flows into the room while receiving heat from the wall, but as the amount of inflow air increases, the rate of increase in the amount of recovered heat is greater than the amount of heat loss from the wall. Due to the high heat transfer rate, the corresponding heat transfer coefficient becomes low. The equivalent heat transmission coefficient shows almost the same value irrespective of the direction of air permeability, and the air permeability is 7 m ³ / hm ²
0 in case of (corresponding to 3 m / s of external wind used for ventilation design)
21 to 0.25 w / m ² ° C.

The relationship between the inflow air permeability and the heat recovery performance will be described. FIG. 10 shows the amount of air permeation in the inflow direction, the inflow temperature at that time, and the amount of heat recovered by air permeation in the wall. In FIG. 9, the equivalent heat transmission rate decreases as the air permeability increases, but it can be seen that this is because the amount of heat recovery increases. On the other hand, an increase in the amount of air permeation also causes a decrease in the inflow air temperature, but the maximum value of the inflow ventilation amount to the wall 22.
Even at m ³ / hm ² (corresponding to an external wind of 10 m / s), the inflow temperature reaches as high as 12 ° C. However, the cold draft of the inflow temperature needs to be considered separately.

Next, the relationship between the outflow air permeability and the occurrence of internal condensation will be described. In order to prevent internal dew condensation, it is preferable to provide a moisture-proof structure on the indoor surface having a high water vapor pressure in winter and a wall structure that facilitates moisture release on the outdoor side. Therefore, in the breathable wall, first, only the first sheet from the indoor side of the porous sheet is reduced in moisture permeability coefficient, and the second to eleventh sheets are increased.
FIG. 11 shows that the specification of the first aluminum foil (hole diameter 0.1 mm, hole interval 1.3 mm) and the opening ratio (5.0%) of the second to eleventh sheets from the indoor side are unchanged. The relationship between the amount of air permeation and the occurrence of dew is shown for each sheet by changing the moisture permeability coefficient. At first, the moisture permeability of the 2nd to 11th aluminum foils is the same as that of the first aluminum foil.
It reaches a plateau at 2.4 to 2.8 g / m ² hmmHg and thereafter tends to be easily dewed.

Next, the specifications of the second to eleventh aluminum foils (hole diameter 0.25 mm, hole interval 1.0 mm, moisture permeability coefficient 3.0 g)
/ M ² hmmHg) and the equivalent opening area per unit area of the first sheet (10 cm ² / m ² ), and the result of changing the moisture permeability coefficient of the first sheet is shown in FIG. As compared with the case where the moisture permeability coefficient of the second to eleventh sheets is increased, the effect on the prevention of dew condensation by reducing the moisture permeability coefficient of the first sheet is remarkable, and 0.05 g / m ² hmmHg (pore diameter 1). 2.0 mm, hole interval 22.8 mm) or less, the air permeability is 7 m ³ / hm.
² (corresponding to an external wind speed of about 3 m / s), no condensation occurs.

As described above, in Example 2, the thermal characteristics of the wall due to air permeability and the possibility of internal dew condensation were examined, and detailed design values of the permeable wall were obtained. As a result, the wall thickness was 6 cm, the number of aluminum foils was 11, the hole diameter of the first aluminum foil from the indoor side was 1.0 mm, the hole interval was 23.0 mm,
The hole diameter of the eleventh aluminum foil is 0.25 mm, and the hole interval is 1.
It was 0 mm.

[Embodiment 3] In this embodiment, a specimen having a permeable wall is manufactured, and an external wind speed is imitated in an experiment in an environment control laboratory to simulate the change, natural ventilation, and permeability. The relationship between heat recovery performance due to air and the occurrence of internal condensation was determined. In the apparatus according to this example, as shown in FIG. 13, a real-table experimental house having a five-dimensional sloped roof was installed in an environmental control laboratory. A 4950 mm x 1650 mm variable temperature panel at the center of the floor of the environmental control laboratory was used as the floor of the experimental house and used for room temperature control. The walls of the experimental house were made airtight and dehumidified by polyethylene plywood on the indoor side surface, and foamed polystyrene (JIS A9511, Class B 2) was used for insulation.
Class) 200 mm was used.

The air-permeable wall has an outer dimension of 1840 mm ×
453 mm x 120 mm specifications were used. Thickness 1
A core material forming a 5 mm air layer between 11 5 μm perforated porous sheets is made of a 5 mm square material having a lattice spacing of 15 mm.
Waterproof coating was performed with a 0 mm wooden lattice to prevent moisture absorption and desorption. The core material and the porous sheet were in close contact with each other, and air and moisture were moved only in the transmission direction. An air layer of 30 mm is provided on the indoor side and the outdoor side of the multilayer air layer, and the outermost layer has a thickness of 3 m.
m (hole diameter: 12 mm, hole interval: 50 mm, aperture ratio: 4.5%).

In this apparatus, according to experiments, when the direction of air permeability is opposite between the ridge portion and the eave portion of the sloped roof due to the effect of the temperature difference between the inside and outside, the temperature and water vapor pressure distributions are the most in the ridge portion and the eave portion. There was a large difference, and the part between them tended to be monotonic. Therefore, in consideration of the influence of heat transfer in the peripheral surface direction, the measurement position was set in the second lattice of the core material from the end of the test specimen (position of 200 to 250 mm from the end). That is, measurement points 1 and 2 indicated by numerals in FIG. FIG. 14 shows the sensor installation status at each measurement position. The measurement items were (1) wall temperature,
(2) Relative humidity distribution in the wall. As the setting conditions for this experiment, the outside air was assumed to be 5 ° C, 6
The room temperature was set at 25 ° C. and 60%. The wind speed condition is 0 m / s, and the excess risk factor in Tokyo is almost 0% 10
up to m / s. The wind pressure coefficient is set to 0.2 on the windward side and −0.5 on the leeward side, and a corresponding wind pressure of 0 ± 23 Pa is given. This is adjusted by sucking or blowing air through a hole (φ68 mm) formed in the wall of the experimental house.

In the natural ventilation performance of this device, first, the air permeability of the wall was measured. Both indoor and outdoor temperatures are set to 20 ° C., and the wall pressure difference is -23 to 23 Pa.
The pressure was changed stepwise at pressures corresponding to the wind speed of 1 m / s in the range (FIG. 15). The equivalent opening area per unit area at the wind speed of 3 m / s used for the design is 6 cm ² / m ² ,
At 10 m / s, it was 7.53 cm ² / m ² . Next, the differential pressure and air permeability distribution on the sloped roof surface were measured. FIG. 16 shows the distribution of air permeability in the direction of roof surface inclination at no wind and at a wind speed of 3 m / s. When there is no wind, the difference in temperature between inside and outside is the driving force for ventilation. Therefore, outside air flows into the eaves on the roof surface and indoor air flows out from the ridge. When the wind speed is 3 m / s, there is almost no difference in air permeability between the eaves and the ridge part.
It was 3.9 m ³ / hm ² . Assuming that this is used in an actual building, the air permeability is 102 m ³ / h, which corresponds to a ventilation rate of 0.26 times / h, but the equivalent opening area per unit area of the test specimen is smaller than the design value. Considering that it was a little small, the system has the capacity to supply the required ventilation.

A test was also conducted on the heat recovery performance when external air flows in due to external wind pressure. The temperature distribution in the wall was as shown in FIG. When there is no wind outside, the temperature of the ridge is the highest due to the influence of the airflow direction, and then the center and the eaves have the lowest temperature distribution. Therefore, it is understood that the inflow air temperature should be evaluated for the eaves portion. On the other hand, when the wind speed is 3 m / s or more, as shown in FIGS.
The entire roof surface is almost uniformly distributed. Further, the relationship between the air permeability and the heat recovery is as shown in FIG. FIG.
Shows the relationship between the inflow air permeability and the temperature change that has increased due to the heat recovery of the air. According to the experimental results, the air permeability was 19.1.
m ³ / hm ² (corresponding to wind speed of 10 m / s)
The temperature rose by as much as 1.2 ° C. 77 heat recovery
w / m ² was obtained.

FIG. 19 shows the presence or absence of internal dew formation when the indoor air flows out due to the external wind pressure. FIG. 19 shows the relationship between the wall temperature distribution and the dew point temperature distribution when there is an external wind pressure in the outflow direction. It was confirmed that no dew was formed even under the condition of an external wind velocity of 10 m / s with an air permeability of 7 m ³ / hm ² or more, which is a design condition.
As a result, in the examples, it is necessary to have the ability to secure the necessary ventilation volume, to obtain a sufficient temperature rise by heat recovery in the ventilation, and to prevent internal dew condensation even at an external wind speed of 10 m / s. confirmed.

In the above embodiments and examples, the porous sheet is formed of aluminum foil. However, the present invention is not limited to this, and other metal sheets or resin sheets may be used. You can do it. Further, in the above-described embodiments and examples, the moisture-permeation resistance of only one porous sheet on the indoor side of the air-permeable wall is set larger than the others, but is not necessarily limited to this. Instead, the number of perforated sheets for increasing the moisture permeation resistance may be changed, or the moisture permeation resistance may be gradually reduced toward the outside of the room. In addition, in the above-described embodiment and examples, the present invention is applied to the roof wall. However, the present invention is not limited to this, and may be applied to the side wall, and may be appropriately changed. Further, the dimensions of the respective parts are not limited to those described above, and may be set in any manner so as to satisfy the conditions. Further, it goes without saying that the overall shape of the wall structure of the building is not limited to the above.

[0042]

As described above, according to the building wall structure of the present invention, an air passage is provided between an outer wall and an inner wall, and a plurality of porous sheets are laminated on the inner wall to form a multi-layer air layer. Because it is configured using a permeable wall, the indoor air can be ventilated by the internal and external temperature difference and the differential pressure due to the external wind pressure, and the permeable wall has a multilayer air layer made of a porous sheet. Therefore, it is possible to provide ventilation and moisture permeability over the entire wall surface while having sufficient heat insulation performance, and to provide an indoor temperature distribution that does not give a sense of independence.

When an air inlet for introducing air into the air passage is provided below the wall and an air outlet for discharging air from the air passage above the wall is provided, Since fresh air can be introduced from the air inlet and exhausted from the air outlet, air can be constantly ventilated, and heat can be transmitted to the air flowing through the air passage and released, thereby reducing the indoor temperature. It is possible to suppress a rise and provide a comfortable space. Furthermore, while protecting the gas permeable wall by facing the porous sheet at an interval outside the gas permeable wall, and having a protective board provided with a large number of through holes, it is possible to secure ventilation while maintaining There is an effect that the breathable wall can be protected.

Further, when the moisture permeability of the porous sheet on the indoor side of the permeable wall is set to be larger than the moisture permeability resistance of the porous sheet on the outdoor side, the indoor surface having a high water vapor pressure in winter or the like. Therefore, moisture can be easily released on the outdoor side, so that the effect of preventing the occurrence of dew condensation can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a wall structure of a building according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a permeable wall of a building wall structure according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a building according to the first embodiment of the present invention.

FIG. 4 is a graph showing a test result according to Example 1 of the present invention and showing an influence of a pore diameter on a flow coefficient.

FIG. 5 is a graph showing a test result according to Example 1 of the present invention and showing an influence of a pore diameter on an air permeability.

FIG. 6 is a graph showing a test result according to Example 1 of the present invention and showing an influence of a pore diameter of a porous sheet providing a required ventilation rate on a change in air permeability.

FIG. 7 is a diagram showing a one-dimensional mass point system model of a breathable wall according to a second embodiment of the present invention.

FIG. 8 is a graph showing the test results according to Example 2 of the present invention and showing the relationship between the member thickness / the number of aluminum foils and the equivalent heat transmission coefficient.

FIG. 9 is a graph showing the test results according to Example 2 of the present invention and showing the effect of the air permeability on the equivalent heat transfer coefficient.

FIG. 10 is a graph showing test results according to Example 2 of the present invention and showing changes in the inflow air temperature and the heat recovery amount depending on the air permeability.

FIG. 11 shows test results according to Example 2 of the present invention.
It is a graph which shows the relationship between the moisture permeability coefficient of the 11th aluminum foil, and dew condensation.

FIG. 12 shows test results according to Example 2 of the present invention,
It is a graph which shows the relationship between the moisture permeability coefficient of the 2nd aluminum foil, and dew condensation.

FIG. 13 is a sectional view showing a laboratory according to Example 3 of the present invention.

FIG. 14 is a diagram illustrating measurement items and measurement positions according to a third embodiment of the present invention.

FIG. 15 is a graph showing a test result according to Example 3 of the present invention and showing a relationship between a change in differential pressure and an air permeability.

FIG. 16 is a graph showing the test results according to Example 3 of the present invention and showing the amount of air permeation of the wall by the external wind.

FIG. 17 is a graph showing a test result according to Example 3 of the present invention and showing an internal temperature distribution of a wall body.

FIG. 18 is a graph showing a test result according to Example 3 of the present invention and showing a temperature change amount due to heat recovery.

FIG. 19 is a graph showing test results according to Example 3 of the present invention and showing whether or not internal dew has occurred due to external wind.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Side wall 2 Roof wall 3 Room 4 Outer wall 5 Inner wall 6 Air passage 7 Air introduction port 8 Air exhaust port 9 Over roof 10 Ventilation port 11 Valve plate H Breathable wall 12 Small hole 13 Perforated sheet 14 Core material 15 Air layer 16 through hole 17 protection board

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Inako Tanaka 1-15-5 Minami Tsukushino, Machida-shi, Tokyo 201 Tsutsukino 201

Claims (6)

[Claims] 1. A structure of a wall of a building in which a room is formed by a wall such as a side wall and a roof wall provided on an upper part of the side wall, wherein the wall comprises an outer wall and an inner wall, And an air passage through which air flows between the inner wall and the inner wall,
A wall structure for a building, comprising a plurality of porous sheets having a large number of small holes penetrating through a core material, and using an air-permeable wall in which an air layer is formed between the porous sheets. 2. An air inlet for introducing air into the air passage below the wall, and an air outlet for discharging air from the air passage above the wall. The wall structure of a building according to claim 1, wherein 3. The air-permeable wall faces the porous sheet at an interval outside the air-permeable wall to protect the air-permeable wall, and
The building wall structure according to claim 1, further comprising a protection board provided with a plurality of through holes. 4. The air permeability of the porous sheet on the indoor side of the air permeable wall is increased, and the moisture permeability of the porous sheet on the outdoor side is reduced.
The described wall structure of the building. 5. The building according to claim 4, wherein only the moisture permeation resistance of the perforated sheet located closest to the indoor side of the air-permeable wall is set to be larger than the moisture permeation resistance of the other perforated sheets. Wall structure. 6. The wall structure of a building according to claim 1, wherein the porous sheet of the permeable wall is made of aluminum foil.