ES2588856B1 - Panel for indirect evaporative cooling of facades - Google Patents

Abstract

Panel for indirect evaporative cooling of facades that has several tanks (1), (11) interconnected and that can be filled by gravity by overflowing the upper panels. The cooling is caused by the evaporation of the contained liquid, preferably water, when filtered through the porous walls that separate the deposits (1), (11) from ducts called alveoli (2), through which air can flow. The geometry of these alveoli (2) consists of narrowings, helical grooves (4) and asymmetric triangular dimples (14) with projections (15) that improve evaporative cooling by controlling air flow. The outer part of the panel has another set of inclined stretch marks (5) with hydrophilic and photocatalytic treatment that control differential washing, creating a chiaroscuro pattern that can repel some insects and improve thermal and aesthetic efficiency over time in contaminated environments .

Description

DESCRIPTION

Panel for indirect evaporative cooling of facades. 5

SECTOR OF THE TECHNIQUE

The invention falls within the construction sector. It is a constructive facade solution that collaborates in the air conditioning of the building and its surroundings. 10

STATE OF THE TECHNIQUE

Evaporative cooling Indirect: Does not introduce moist air into the inhabited area. Thermal exchange does not imply mass exchange (water vapor). They have the advantage of maintaining hygrometric comfort conditions inside the building over time.

Evaporative cooling on facades:

Gravity conditions the presence of the liquid to evaporate, usually water, in a vertical plane. In this sense, the known systems could be divided into: Fluids, which do not retain water in the vertical plane and accumulators, which have deposits or equivalent retention systems.

In flowing systems, evaporation occurs by direct contact between water and air. They can have a support surface on which the water flows, or not, for example by free dripping, micronization, etc. The function of the support, if any, is to increase the water-air contact surface. The advantages compared to systems with accumulation are the saving in weight and the limited limitations of the supports, which if they exist, should only be resistant to contact with water. 30

Its disadvantages are: The need for a constant supply that also has to adjust to the climatic variables at every moment, absence of thermal inertia, continuous noise of water flowing or dripping, vulnerability to wind that can disperse water and spread infections contracted to through the inhalation of contaminated water such as legionella. 35

Systems with retention must solve the contact of water with air to achieve evaporation. The known method is that the deposits have a porous membrane or wall that allows evaporation through it.

The advantages of systems with retention are: Greater thermal inertia, they do not require a constant supply that implies less need for pumping. Less or no 40 water recirculation. They are more autonomous systems that passively adapt automatically to external conditions.

Its disadvantages: Its weight increases proportionally to retained water. Deposits or their equivalent require more specific materials than flowing systems, as they have to withstand water, hydrostatic pressure and allow evaporation through them.

Deposit materials:

The materials known for this function are textiles, ceramics or gels; without proof of the use of mortars. Both ceramic materials and mortars can have a capillary network in their internal structure that contributes to evaporation. In it, the water runs slowly in all directions thanks to the surface tension between the water and the material, and can even ascend through the 5 walls of the tank and exceed the water level, increasing the evaporative surface.

Lime mortar: In a facade panel that essentially seeks to counteract overheating in hot weather conditions, the finishing material is very relevant. The whitewashing of facades was common in popular architecture as a measure to counteract the heat, even if they failed to understand the physical principles that governed their behavior.

Lime behaves as a cold selective surface, this means that it has a great capacity to radiate energy to other long-wave bodies at room temperature, but at the same time it reflects the radiation received in the visible spectrum 15 (white surface).

Geosilex®: It is a lime obtained by recycling by-products from the manufacture of acetylene. Like other limes, it has the property of incorporating atmospheric CO2 into a process that can last for years according to its formulation, increasing its mass up to 20% at the end of the carbonation process. twenty

Indirect evaporative cooling panels on facades:

"Gres-Bot. Bioclimatic ceramics" Spain. (2010):

Passive evaporative cooling by means of ceramic pieces.

It consists of a series of horizontal square tubes, manufactured by extrusion and 25 sealed at their ends in which water is provided through sealed sleeves that connect the panels in series. Water circulation is regulated through thermostatic valves and solenoid valves. The system can be used as a radiant wall during winter by connecting it to solar panels and support boiler, the evaporative cooling in this mode of operation, according to its authors, is canceled 30 by stagnating the air above the water level and by Adding sand would increase thermal inertia.

"Casa Patio" 2.12 Andalucía Team España (2012):

Indirect evaporative cooling panel for the façade, based on extruded porous ceramic 35, humidified by means of a sleeve system that drips over the edge of the pieces. The outer surface has a ribbed texture that increases the evaporation surface.

"Aislater" Vera B., Gordo J. A. Spain. (2013): 40

Ceramic panel for the improvement of the external insulation of buildings. It allows indirect evaporative cooling by evaporating the water retained in the horizontal grooves of the panels.

"Kaikaku System", Spain: 45

Inner sheet of façade based on large-format extruded ceramic brick in which its exterior openings have a larger size to allow ventilation.

Optionally it proposes a drip irrigation system in the coronation of the wall for indirect evaporative cooling of its outer face.

"Hydroceramic" Rathee A., Mitrofanova E., Santayanon P. Spain (2014):

Panel for direct and indirect evaporative cooling, developed by students 5 of the Advanced Architecture Institute of Catalonia (Hydroceramic_hydrogel.), Which combines two ceramic outer layers with hydrogel spheres retained by means of a textile that collaborates in the diffusion of moisture. The system takes advantage of the properties of thermal inertia, absorption and water supply of the hydrogel. It proposes the collection of environmental humidity and rainwater as a supply. 10

Self-cleaning surfaces:

In 2001 Pilkinton introduced Pilkington Activ ™, a self-cleaning window thanks to a thin layer of titanium dioxide, which due to its hydrophilic and photocatalytic properties decomposed the dirt and allowed rainwater to drag it from its surface, reducing the costs of cleaning and maintenance. Subsequent applications have had the same objective, expanded the construction materials on which it is used: paints, ceramics, concrete, tiles, pavers, traffic signs, etc.

The application of photocatalytic treatments on facades presents some deficiencies 20 of an aesthetic nature in terms of the lack of uniformity in their cleaning, generally due to an inhomogeneous exposure to rain and solar radiation. There is no knowledge that the presence of residual dirt is intentional.

Titanium dioxide (TiO2):

It is a very stable common crystalline formation. It is recyclable and synthesizable. It is usually used as a bleach and catalyst. It reflects practically all the light it receives.

When exposed to sunlight it becomes hydrophilic and its contact angle with water goes from 72 ± 1 ° to 0 ± 1 ° creating a continuous film of water if it gets wet. The behavior with oil is similar. The phenomenon occurs both in TiO2 in Anatase form and in Rutile and is maintained over time for several days after receiving ultraviolet radiation. After this period, it gradually decreases, but it regenerates as soon as it is exposed again.

Insect repellents: 35

The studies and experiments of (HORVÁTH et al. 2004, 2008, 2010 and 2012). demonstrate the ability of the black and white striped pattern of zebras to repel horseflies and other insect species. Stripe patterns that alternate orthogonal directions are more dissuasive than those with a single direction. 40

Insects have compound eyes sensitive to polarized light, while the human eye is barely able to perceive it.

The known systems to scare away insects based on light are active emitters: (MÁRKA et al. 2012) US Pat. 20120032096 A1.

There is no known system that uses differential washing to create an optical effect that repels insects.

Other references:

ABBA M. B. "Pot-in-pot refrigerator, clay pot cooler" Nigeria. (1990).

DÍEZ A., CHAPARRO I., GARCÍA B., GOZALO J. "Atlas House". Solar decathlon. ETSA UPV (2010) 5

FLOWERS. "Ceramic bricks acting as a semi-indirect evaporative cooler". (2008).

HE J., HOYANO A. “Experimental study of cooling effects of a passive evaporative 10 cooling wall constructed of porous ceramics with high water soaking-up ability”.

Tokyo Institute of Technology. Yokohama Japan (2008).

HORVÁTH G, VARJÚ D. "Polarized Light in Animal Vision. Polarization Patterns in Nature". Springer-Verlag ISBN: 3-540-40457-0. (2004). fifteen

HORVÁTH G., MAJER J., HORVÁTH L., SZIVÁK I. KRISKA G. "Ventral polarization vision in tabanids, horseflies and deerflies (Diptera, Tabanidae) are attracted to horizontally polarized light". Naturwissenschaften 95, 1093-1100. (2008)

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HORVÁTH G., BLAHÓ M., KRISKA G., HEGEDÜS R., GERICS B., FARKAS R., ÅKESSON S. "An unexpected advantage of whiteness in horses, the most horsefly-proof horse has a depolarizing white coat". Proc. R. Soc. B 277, 1643-1650. London. (2010).

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HORVÁTH G., EGRI Á., BLAHÓ M., KRISKA G., FARKAS R., GYURKOVSZKY M., ÅKESSON S. "Polarotactic tabanids find striped patterns with brightness and / or polarization modulation least attractive: an advantage of zebra stripes". J. Exp. Biol. 215, 736-745. (2012).

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MAISOTSENKO V. "Indirect Evaporative Cooling" (2007).

MÁRKA S., MÁRKA Z. Á., BARTOS I. "Optical Barrier to Pests" (2012) Patent: US 20120032096 A1

 35

MELERO S. "Study of the efficiency of evaporative cooling in porous ceramic pieces for application in architecture". (2010).

WANG R. "Photogeneration of Highly Amphiphilic TiO2 Surfaces" Advanced Materials (1999) 40

WSP ENVIRONMENTAL LTD "EVAPCOOL: Passive Downdraught Cooling Systems Using Porous Ceramic Evaporators". (2003).

EXPLANATION OF THE INVENTION

The present invention is a panel to be used primarily as a facade, either in new construction or rehabilitation, with the capacity to perform indirect evaporative cooling, improving the energy efficiency of the building envelope. 5 It also combines a series of elements that increase surface convection and can vary the hue of the outer face.

Mounting:

The panel is designed to be stacked on the facade as an outer sheet; fixed 10 by means of staples, keys, profiles or other existing analog system to an inner sheet or other type of structure that serves as support.

Evaporative System:

The panel has several tanks that will preferably be filled with water. 15 The walls of these deposits that are oriented outwards are porous like a botijo, retaining water but allowing evaporative cooling. In the absence of other external conditions, the temperature of this water drops to reach the wet bulb temperature, which in hot and dry climates is well below room temperature. Water is one of the 20 elements with the highest specific heat, which gives the enclosure great stability thanks to the thermal inertia of the tanks when they are full. This cooled mass tends to counteract external gains (high external temperature and solar radiation), and internal (internal loads) making cooling systems dispensable, or minimizing their consumption. The cooling capacity of the panels extends beyond the depletion of the deposits, since the water embedded in the porous walls of the deposits will continue to evaporate until this remnant is consumed.

To improve thermal performance and reduce water consumption, the panel can have a series of vertical hollow channels called 30 cells in the outer face. The deposits are thus protected from direct solar radiation and the air contained in the alveoli acts as a thermal mattress. However, the movement of the air inside the alveoli has a different pattern, if not opposite, to that of a ventilated chamber. In evaporative mode the incident solar radiation ceases to be the determining factor in fluid dynamic behavior and becomes the relative humidity.

Filling System:

The deposits of each panel are cascaded by sequential overflow of the one above. This simple gravity method is performed at atmospheric pressure. The hydrostatic pressure only then depends on the height of the tanks, so the system can be stacked unlimitedly without increasing it and saves the sleeves, valves, nozzles and similar elements for the distribution of water to the lower panels.

The tanks are interconnected at their upper end so that all 45 can be filled regardless of which one receives supply. Upon reaching a maximum level, the excess water overflows through ducts that act as a sump and channel the water by gravity to the panel below. That is to say that by

a single supply point at the upper end of the facade, an unlimited amount of vertically arranged panels can be filled. The panels have a modulation that allows them to be thrown into thirds, which adds some ability to distribute the water horizontally.

 5

Seasonal Operation:

The panel includes two operating modes that allow it to adapt to climatic variations. Winter mode or insulating mode, in which the tanks are empty and therefore there is no evaporative cooling; and summer mode or evaporative mode, in which the deposits are sporadically refilled, with water evaporation and evaporative cooling similar to a botijo being produced.

Advantages of deposits:

The arrangement of deposits against other systems without accumulation provides, in addition to the aforementioned thermal inertia, an autonomy to the panel that allows it to prolong its operation without receiving a constant supply. This expands the sources of supply, being able to contemplate in addition to the water of network, the rain, recycled water or atmospheric condensation among others.

Temperature reduction in summer conditions: 20

The panel uses several mechanisms to reduce its temperature and combat external heat under conditions of excessive solar radiation. The most important is evaporative cooling, but others are added such as:

Solar reflection: The preferred material of the invention is lime mortar, to which a titanium dioxide treatment is promptly incorporated. Both materials 25 have a high reflectance and their surface temperature is less affected by solar radiation than most materials used as a facade finish.

As mentioned in the prior art, lime behaves like a cold surface, reflecting the visible spectrum but with a high long-wave or far-infrared emittance, which is ideal for counteracting the superheating of the envelope.

Increasing convection: The ability of a facade to return heat from solar radiation to the atmosphere depends, among other factors, on the surface of contact with the air. While the majority of facade panels on the market are flat, the invention has a wavy outer surface. This implies a larger convective exchange surface. At the same time, presenting different angles of exposure to the sun's rays, there is a differential heating of its surface, generating convective currents from the shaded or less exposed areas and therefore at a lower temperature, towards the most exposed, helping to reduce its surface temperature 40

Hue variation:

The hue of the facade determines its ability to absorb or reflect solar radiation. In warm climates, ideally from an energy point of view, it is a light colored facade that has a great albedo and avoids overheating its surface, while in cold climates, the opposite situation would be desirable. The invention uses the accumulation and differential washing of air pollution to modify its hue and thus adapt to change

seasonal. This capacity is conditioned by the presence of water in the reservoirs, linking to the aforementioned summer / winter operating modes.

The panel incorporates inclined striations perpendicular to each other, of semicircular, semi-elliptical or triangular section on its outer face that, when presenting surfaces with a certain horizontal component, encourage the deposition of contaminating particles on them, obscuring the façade and thereby increasing its capacity to absorb solar radiation. The upper half of these stretch marks have a photocatalytic treatment capable of decomposing mainly nitrous oxides produced by industry, heating and transport systems based on the combustion of fossil fuels. The hydrophilic property of the photocatalytic treatment results in a migration of the contamination deposited on the upper half of the stretch marks, which tends to deposit and concentrate on the lower face that lacks treatment. Thus, when the tanks are filled in summer mode, the water that oozes by horizontal capillarity through the porous material, reaches up to 15 the upper face of the stretch marks, activating the hydrophilic effect that produces a differential wash of the deposited contamination. The upper half of the stretch marks regains its original clear hue, reflecting solar radiation that in summer has a more vertical component than in winter.

Pollution and the compounds derived from its photocatalytic oxidation, which have been displaced towards the underside of the stretch marks, obscure the facade at negative angles in which the sun will affect when its trajectory is more horizontal, as occurs in winter.

DESCRIPTION OF THE FIGURES 25

For a better understanding of the invention, the present specification is accompanied by a description of the figures in an illustrative and non-limiting manner:

Figure 1.- Shows the panel in axonometric view where its front, side and upper part is shown. 30

Figure 2.- Shows a horizontal section at its upper end.

Figure 3.- Shows a vertical section in the middle of a socket in which the narrowing and internal geometry of the same is represented.

Figure 4.- It shows a vertical section in the middle of one of the tanks, in which the overflow of a tank is represented and the channel through which the water would descend to the part immediately below, once the upper one has been filled to the maximum It is also represented the open pore matrix that, as a sponge, would house the liquid contained in the deposits.

Figure 5.- Shows the front elevation of the piece in which the spike-shaped texture that channels the runoff water to the concave vertices of the front panel is represented.

Figure 6.- Shows a horizontal section of the encounter between two panels.

Figure 7.- Shows the distribution of dimples along the vertex of the stretch marks.

Figure 8.- Shows one of the dimples that texture the inner face of the walls of the alveoli, seen in elevation. Four. Five

Figure 9.- Shows one of the dimples that texture the walls of the alveoli, seen in vertical section.

Below is a list of the different elements represented in the figures that make up the invention:

1 = Central deposits.

2 = Alveoli.

3 = Drainage channel. 5

4 = Helical striae on inner faces of the alveoli.

5 = Inclined stretch marks with hydrophilic and photocatalytic treatment based on TiO2.

6 = Notch on the dividing wall of the tanks that interconnects them at a lower level than the drainage sinks.

7 = Side machining of the panels. 10

8 = Sump in the upper end of the tanks that communicates with the drainage channel.

9 = Goton.

10 = Hollow channel.

11 = Lateral deposits. fifteen

12 = Exit hole of the drainage channel.

13 = Upper vertex of an asymmetric triangular dimple.

14 = Asymmetric triangular dimples.

15 = Highlights on the lower side of the triangle, not perpendicular to the flow.

16 = Vertical ribs. twenty

17 = Upper half of the stretch mark with photocatalytic treatment based on titanium dioxide.

18 = Elbow.

α = Angle that forms the projection with the perpendicular to the flow, 20 ° <α <50 °.

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EMBODIMENT OF THE INVENTION:

The panel for indirect evaporative cooling of facades comprises a series of deposits (1), (11) of porous walls, impervious to the passage of liquid to evaporate but permeable to the passage of steam. The liquid to evaporate is preferably water. The 30 tanks (1), (11) are arranged on the inner side of the panel, separated from each other by walls of a structural nature but interconnected horizontally at their upper end by notches (6) on the partition wall of the tanks (1) , (eleven). in a way that guarantees the filling of all deposits (1), (11) regardless of which one receives supply. This is an advantage over 35 systems that do not allow horizontal water distribution. The deposits (1), (11) can be simply hollow or contain an open pore matrix, that is, a spongy structure with multiple interconnected cavities that can be occupied by air or water. The preferred material of the open pore matrix is ceramic foam. Its functions are: Percolate the water during the filling operation, acting as a filter and increasing the dissolved oxygen; as well as protect it from light and insects.

The panel incorporates an overflow system consisting of: A sump (8) at the upper end above the notches (6) of the tank partition wall (1), (11) and a drainage channel (3) comprising an elbow (18) and an outlet (12) 45 with a drip (9). When stacked, the exit hole (12) of a panel is positioned vertically in one of the tanks (1), (11) of the panel below.

The system allows the replacement of a panel while the rest are full and cooling, except in strong wind conditions.

The outer face of the panels has a series of hollow channels through which air can flow, called alveoli (2) of section: triangular, circular, elliptical or ovoid. The walls that separate the deposits (1), (11), from the alveoli (2) are 5 porous and through them the evaporation of the water takes place. The air contained in the alveoli cools and, as it becomes denser, a downward movement begins that renews the air, encouraging the entry of new dry air that perpetuates the system's operation. The thermal mattress that forms, improves the benefits with respect to evaporative façade systems without a chamber, where the convection of its 10 elements is carried out against an air at outside temperature and also receives thermal gains by solar radiation.

The system is seasonally versatile, operating in two modes according to outdoor weather conditions: 15

- Winter mode or insulating mode: The tanks (1), (11) are dry, the open pore matrix inside reduces air movement, giving it insulating properties. The low outside temperature and the different geometries of the surface of the alveoli (2) limit convection.

- Summer mode or evaporative mode: The tanks (1), (11) are filled with water, which evaporates through the porous walls. The water, the walls of the tanks and the air in contact with them cool, forming a thermal mattress against the outside heat.

Outdoor air conditioning:

During the warm months, when the system is cooling, you can take advantage of the downward air flow for the air conditioning of outdoor spaces and the creation of cold air curtains, reducing the heat gain in the accesses of the buildings.

Its use is also possible as pre-conditioning of the air of other conventional systems (heat pumps, air handling units, etc.) whose performance is implemented by exchanging energy with an environment at a temperature more favorable for its performance and at the same time the condensation water could be used to feed the tanks (1), (11).

Materials: The preferred material of the invention is reinforced lime mortar, being able to incorporate lime obtained from the recycling of industrial by-products (Geosilex®), permeable to water vapor (μ ≤15). The progressive carbonation of lime compensates for the eventual appearance of microcracks derived from the absorption and drying processes. The binder is subjected to contractions during the drying cycles, while the aggregate does not, generating tensions that can produce 40 mechanical resistance losses due to fatigue or leaks in the tanks (1), (11) in the long term.

The preferred manufacturing system, but not the only one, is three-dimensional mortar printing and can incorporate reinforcement reinforcement in the dough. The versatility of the invention to be manufactured primarily based on mortar expands the production possibilities and can save money on ceramic materials.

The back wall of the panel can be waterproofed by a liquid sealant.

The ceramic foam that can occupy the tanks (1), (11) is a high porosity cellular material used in multiple industrial applications. Its properties are low thermal conductivity, high permeability, high temperature stability, thermal stability and resistance to thermal shock. 5

The inner faces of the alveoli (2) have geometries that improve their operation:

Helical stretch marks (4):

They increase the evaporative surface and induce a rotational movement in the air stream 10 that runs through the alveoli (2), channeling the dry air near the outer face of the panel towards the damp walls of the tanks (1), (11) to renew the saturated humidity air near the evaporative surface.

Alternate Narrows: 15

The alveoli (2) narrow in their central section forming a hyperboloid that accelerates and modulates the air flow.

Asymmetric triangular dimples (14) with projections (15):

At the apex of the helical grooves (4) a series of asymmetric triangular dimples 20 (14) are aligned, which have an upper vertex (13) facing up, and a shoulder (15) at the opposite end that forms an angle (α) between 20 ° and 50 ° perpendicular to the axis of the socket (2). This axis is parallel to the direction of the air flow (which will usually be vertical and descending in evaporative mode). 25

The function of asymmetric triangular dimples (14) is to improve the surface evaporation capacity. The air flow streamlines that run through the socket (2) accommodate the smooth change of direction introduced by the upper vertex (13), but upon reaching the shoulder (15) the change in direction is more abrupt, and may lead to to the detachment of the boundary layer and the generation of a turbulent wake that would mix the saturated humidity air located in the boundary layer with the farthest and driest, accelerating the dispersion of water vapor.

The function of the projections (15) and the asymmetry of the asymmetric triangular dimples (14) is to divert the flow laterally in favor of the rotational movement induced by the helical grooves (4), collaborating in displacing the saturated humidity air of the 35 walls from the tanks (1), (11) towards the outer face of the panel.

Outer face:

Vertical ribs (16):

The outer face of the panel consists of a wavy geometry similar to that of some 40 cactus species. As in these plants, the protruding parts are called vertical ribs (16) and have a similar function. They protrude outwards with respect to the deposits, producing self-thrown shadows so that when the sun hits the plane of the facade with a tangential angle, thermal gradients are created that increase the convection and increase the capacity of the facade to dissipate the incident radiation back into the atmosphere.

The inclined stretch marks (5) and the variation of the absorptivity of the evaporative panels according to the solar angle:

The panels reflect a higher proportion of solar radiation in summer than in winter varying their hue. To achieve this, they use air pollution, accumulating it during winter and redistributing it during summer 5 by means of a differential washing towards areas where the sun does not directly affect or does so in a smaller proportion compared to winter.

The vertical ribs (16) have a series of inclined grooves (5) on the outer face of the semicircular, semi-elliptical or triangular section panel with a titanium dioxide (TiO2) treatment in the mortar mass in a thickness ≥0 , 7mm in the upper half 10 (17) of said stretch marks (5) which gives its surface photocatalytic and hydrophilic properties. The urban pollution molecules (mainly NOx) that are deposited on the treated surface, are decomposed by the photocatalytic action of TiO2 in the form of CO2 and nitrates. Decomposed pollutants are dragged through the water towards the lower half of the inclined stretch marks, while the upper half and more exposed to light is cleaner, forming a geometric chiaroscuro pattern. In addition to an aesthetic advantage, the panel varies its absorptivity on a seasonal basis, absorbing more radiation in winter and reflecting it in greater proportion during the summer, which implies energy savings in both heating and cooling. twenty

To achieve greater control of seasonal color variation, panel facades for indirect evaporative cooling will preferably have eaves and cornices. The water needed for washing is provided by the oozing of the tanks (1), (11) during the summer, when they are filled in evaporative mode. The described differential washing makes the upper part of the stretch marks 25 cleaner than the lower. As the lime mortar, the preferred material of the invention, and the TiO2 have a low absorbency, they reflect most of the radiation incident in the clean areas, which are the ones that receive the most radiation in summer; while in winter, when the sun's rays are more horizontal, the proportion of solar rays that affect the areas obscured by differential washing increases, increasing the absorption of the facade and therefore its surface temperature.

Aesthetic advantages:

The inclined stretch marks (5) of the outer face of the panel control the surface runoff 35 producing a foreseeable differential washing that concentrates the contamination sediments in the lower half of the stretch marks (5) improving the aesthetic qualities over time.

Vegetation: 40

The panel can be vegetated between the inclined stretch marks (5). The plants absorb the moisture that emerges between the alveoli (2) when the tanks (1), (11) are full. Although they are empty, the "V" shape of the stretch marks (5) concentrates the rainwater and dew on the vertices as well as the nitrates from the photocatalytic reaction, serving as sustenance for small plants or lichens. Four. Five

Insect repellent:

The treatment based on titanium dioxide (TiO2) in the upper half (17) of the inclined grooves (5) of the outer face of the panel makes them reflective to the light and reduces the accumulation of dirt with respect to the rest of the panel, producing a differential wash that results in a pattern of chiaroscuro bands similar to those of zebras. The created optical effect repels certain species of insects. 5

The inclined stretch marks (5) follow two directions perpendicular to each other, which increases the deterrent effect of the pests with respect to patterns with only one direction.

Acoustics: 10

Both the vertical ribs (16) and the inclined striations (5) improve urban acoustics, absorbing wavelengths of the same size as their undulations and dispersing those of shorter length, reducing the cannon effect.

Preferred fixing mode: 15

The panels are anchored on an insulated facade and preferably waterproofed by 4 metal clips, the upper two are shared with the panel located above and the lower two with below.

Side panel joint: 20

To improve the sealing, the panels have a tongue and groove (7) on their side faces. The first pair of notches leave a hollow channel (10) through which the water that could infiltrate from the outside, would find a widening that would not allow it to take advantage of the surface tension to continue progressing inwards and would descend by gravity. 25

Packing and filling of the panels:

If the panels are arranged in a grid, the upper overflow will fill only the one below. But being modular and having two drainage holes (12), it is also possible to squeeze them, which allows each panel to overflow 30 on the two below.

The water supply system for the panels is not the subject of the present invention, but for a better understanding of it it is indicated that it mainly comes from rainwater accumulation deposits on the roof, recycled gray water in the same building by means ultrafiltration or similar 35 present in the market and / or condensation water.

The filling system can be manual or automatic. The monitoring of the installed façade will allow the estimation of consumption. A gutter at the lower end collects water that may overflow from the lower row of panels.

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Dimensions:

The panel works in a wide range of dimensions. The ones that achieve the highest performance compatible with existing blocks in the market are proposed.

Width: 40cm Height: 20cm Depth: 18cm.

Four. Five

Claims (9)

1. Panel for indirect evaporative cooling of facades characterized by a series of deposits (1), (11) of porous walls, impervious to the passage of liquid to evaporate but permeable to the passage of steam. The liquid to evaporate is preferably water. The tanks (1), (11) are arranged on the inner face of the panel, separated from each other by structural walls but interconnected horizontally at their upper end by notches (6) on the partition wall of the tanks (1), (eleven). The deposits (1), (11) may simply be hollow or contain an open pore matrix. 10 The panel incorporates an overflow system consisting of: A sump (8) at the upper end above the notches (6) of the tank partition wall (1), (11) and a drainage channel (3) comprising an elbow (18) and an exit hole (12) with a drip (9). The preferred material of the porous walls of the tanks (1), (11) is 15 reinforced lime mortar, being able to incorporate other limes obtained from the recycling of industrial by-products, permeable to water vapor. 2. Panel for indirect evaporative cooling of facades according to claim 1 characterized by having a series of hollow channels through which the air can flow, called sockets (2) located on the outer face of the panel, of 20 section: triangular, circular, elliptical or ovoid. The alveoli (2) can narrow in their central section forming a hyperboloid. 3. Panel for indirect evaporative cooling of facades according to claim 1 characterized in that the open pore matrix of the tanks (1), (11) is made of ceramic foam. 4. Panel for indirect evaporative cooling of facades according to claim 2 characterized in that the cells (2) externally form a series of protrusions called vertical ribs (16) that protrude outwards with respect to the tanks (1), (11). 30 5. Panel for indirect evaporative cooling of facades according to claim 1 characterized in that the walls of the tanks (1), (11) are made of lime mortar. 6. Panel for indirect evaporative cooling of facades according to claim 1 characterized in that the outlet orifice (12) of the overflow system is aligned in the vertical of the tanks (1), (11). 7. Panel for indirect evaporative cooling of facades according to claim 2 characterized in that the cells (2) have helical grooves (4) on their inner faces. 8. Panel for indirect evaporative cooling of facades according to claim 40 7 characterized in that the helical grooves (4) have at their vertex an alignment of asymmetric triangular dimples (14) having an upper vertex (13) facing up and a projection (15) at the opposite end that forms an angle (α) between 20 ° and 50 ° with the perpendicular to the axis of the socket (2). Four. Five 9. Panel for indirect evaporative cooling of facades according to claim 1 characterized by inclined striations (5) perpendicular to each other, of semicircular, semi-elliptical or triangular section along the outer face of the panel. The inclined striations (5) have in their upper half (17) a photocatalyst surface treatment, preferably based on titanium dioxide.