EP2521883A1

EP2521883A1 - Method and device for regulating the temperature inside a dwelling

Info

Publication number: EP2521883A1
Application number: EP10809319A
Authority: EP
Inventors: Edouard Serras
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-01-05
Filing date: 2010-12-28
Publication date: 2012-11-14
Also published as: FR2954970A3; FR2954969B1; US20130040551A1; FR2954970B3; WO2011083257A1; FR2954969A1

Abstract

Method and device for regulating the temperature in a dwelling having microporous walls (10) and having external thermal insulation (12), by circulation of external air in a wall (10) and/or between a wall (10) and its thermal insulation (12) depending on the moisture content of the external air, and the moisture content of the wall and on the heating or cooling of the wall (10), the temperature of which is measured by means of sensors (30, 30') mounted facing the wall and/or in the wall (10).

Description

Method and device for regulating temperature inside a residential building

The invention relates to a method and a device for regulating the temperature in a residential building comprising walls with a microporous structure and an external thermal insulation.

It is known, in particular from the document FR 2417726-A1, to provide housing constructions with an external thermal insulation which provides an intermediate space between the insulation and the walls, and to circulate heated outside air or cooled in this intermediate space to heat or cool the walls, depending on the case, the outside air being heated or cooled by means of heating or cooling of a conventional type and the walls in contact with this air acting as walls radiating to heat or cool the interior of the building.

This known technique is however not very effective and does not regulate the temperature in a residential building by achieving significant energy savings.

Applicant PCT / FR2009 / 000834 also discloses a method and a device for regulating the temperature inside a building with external thermal insulation and whose walls have a microporous structure, temperature regulation by measuring or estimating the temperature of the outside air and its relative humidity, as well as their variations during the day and the night during the seasons, and by determining the periods of the day and the night during which the circulation outside air in the space between the thermal insulation and a wall allows the best to cool or heat the wall as needed, taking into account the humidity of the outside air and that of the air. air in the building in contact with the microporous wall and variations in temperature and humidity of the microporous wall. This technique makes it possible to heat or cool the walls of a residential building by circulating outside air that has not previously been passed through a conventional heating or cooling means, which makes it possible to greatly reduce the consumption of energy needed to regulate the temperature inside the building.

The present invention is intended to improve this technique and increase the energy savings it provides.

To this end, it proposes a method of regulating the temperature in a dwelling building with microporous walls and with external thermal insulation, characterized in that it consists in determining the periods and the speeds at which air is circulated. outside in a wall and / or between a wall and its thermal insulation according to the hygrometry of the outside air, the hygrometry of the wall and the surface temperature variations of the wall and / or inside the wall .

The invention is based on the fact that the adsorption of moisture in the form of water vapor by the microporous wall results in a rise in the temperature of the wall, this adsorption continuing as long as the wall is not saturated. in water vapor, this wall can be full or formed with air circulation channels.

Thus, for example in winter, it is possible to circulate in the microporous wall and / or between the microporous wall and its thermal insulation, cold external air with high hygrometry, the moisture of which is adsorbed by the surface of the wall. heats the wall, stop the flow of air when the surface temperature of the wall reaches a maximum value corresponding to a surface saturation of water vapor and circulate outside air at high humidity in this space when the temperature of the wall has decreased to a minimum value, this decrease being due to the diffusion of water vapor inside the wall.

It is also possible, for example in summer, to circulate in the wall and / or between the wall and its insulation of the hot outside air with hygrometry relatively small to absorb the water vapor contained in the microporous wall and thus cool the wall, stop the flow of outside air when the surface temperature of the wall reaches a minimum value and re-circulate the outside air at low humidity when the surface temperature of the microporous wall has increased to a maximum value, by diffusion of water vapor and heat transfer from the inside to the outside through the wall.

The periods of circulation of outside air and those of stop of this circulation have different durations, for example of a few minutes or tens of minutes for the first and several hours for the seconds.

According to an important characteristic of the invention, the speed of the air in the space between the wall and its external insulation is set to a low value, for example of the order of 0.05m / s, for heating or cooling. the wall by adsorption or desorption of water vapor, or at a value greater than about 0.5m / s to heat or cool the wall by convection.

It is thus possible, depending on the climatic conditions, to heat or cool the microporous walls, either by thermal convection by circulating the outside air at a relatively high speed along the walls, or by adsorption or desorption of water by circulating the outside air at relatively low speed along the walls.

Alternatively, in the second case, it is possible to circulate outside air at a relatively high speed in the space between the wall and its external insulation and to stop this flow of air when the volume of air contained in said space has increased. was renewed, and then circulate outside air in said space after a predetermined period of time, for example a few tens of minutes, to renew again the volume of air contained in the space.

In this variant, the space between the wall and its external insulation is filled with "new" outside air, this space is closed for the necessary time. condensation or vaporization of the wall water or outside air, it refills the aforementioned space of "new" outdoor air, and so on.

In another variant of the invention, the outside air is allowed to circulate freely in the aforementioned space by limiting the speed of the air in this space to a low value, for example less than 1 m / s, to maintain the temperature inside the building at a substantially constant value over a long period of time, for example of several days or more.

When certain conditions of temperature and hygrometry are favorable, one can indeed open the space between a wall and its external insulation and let the outside air circulate freely in this space by natural convection. This should be done in order to maintain a constant temperature in the building for several days or weeks, if care is taken to limit the air velocity in the space mentioned above, for example by adjusting it to less than 1 m / s, so that the thermal regulation by adsorption / desorption of water vapor is preponderant compared to heat exchanges by convection.

Advantageously, the method according to the invention also consists in calculating the hygrometry of the outside air from its dry temperature, date and time.

It also consists of calculating or estimating the hygrometry of the wall from the wall temperatures and a preliminary calibration.

This avoids the use of relative humidity probes that are extremely expensive, have a relatively short life and are very sensitive to pollution problems that greatly degrade their accuracy.

The invention also proposes a device for regulating the temperature inside a residential building with microporous walls and with external thermal insulation, comprising outside air circulation spaces formed between microporous walls and their thermal insulation. , characterized in that it comprises means for controlling the circulation of outside air and the speed of circulation of this air in said spaces, these control means receiving as input measurements of the microporous wall temperatures to control the circulation of outside air in the space between a microporous wall and its thermal insulation as a function of the temperature variations of the microporous wall, its hygrometry and the hygrometry of the outside air.

According to another characteristic of the invention, this device comprises means for instantaneous measurement of the surface temperature of the microporous walls.

Advantageously, these means for measuring the temperature of the microporous walls comprise infrared sensors.

Preferably, the means for measuring the temperature of the microporous walls are mounted in the abovementioned spaces facing the outer surface of the walls, in particular at the lower and upper ends of these spaces.

It is also possible to mount temperature sensor strips in holes drilled in the walls over substantially their entire thickness to continuously measure the temperatures in the walls and follow their evolution. This makes it possible to directly control the temperature control device according to the invention without first having to define the hygrometric and thermal behavior characteristics of the wall materials.

Fans may be provided if necessary to circulate the outside air and external air inlet or outlet means are mounted at a vertical or horizontal end of the aforesaid spaces and comprise vertical or horizontal tubes of which a longitudinal end comprises means for adjusting the air inlet section, for example a diaphragm, these tubes comprising air outlet orifices distributed along their length. When the height of the space between the wall and its insulation is sufficient, the outside air can circulate there by natural convection without it being necessary to use the aforementioned fans.

In a particularly advantageous embodiment, the microporous walls comprise passages or channels of external air circulation, these walls being in particular formed of panels or juxtaposed elements, such as for example hollow bricks or the like, having passages unobstructed air and aligned with each other which communicate with the aforesaid spaces between the walls and their outer insulation, which makes it possible to multiply the microporous wall surfaces in contact with the outside air and to increase in a very important way the performance of the invention in terms of energy saving.

In practice, the device according to the invention can be combined with a dual flow controlled mechanical ventilation system (VMC), comprising auxiliary heating means of low power (a few kilowatts) depending on the dimensions of the building, its geographical location and its exposure.

In general, the invention reduces by at least 85% the energy consumed for the thermal regulation of the interior of a residential building.

The invention will be better understood and other characteristics, details and advantages thereof will appear more clearly on reading the description which follows, given by way of example with reference to the appended drawings in which:

Figure 1 is a partial schematic sectional view of a residential building according to the invention;

Figure 2 is a schematic top view of an external air intake device;

Fig. 3 is a graph showing the variations in dry temperature and relative humidity of outdoor air during a summer day; Figures 4 and 5 are perspective views of hollow bricks;

Figure 6 is a sectional view along the line VI-VI of Figure 1, in an alternative embodiment of the invention.

Referring first to Figure 1, which schematically shows a portion of a residential building according to the invention, the building comprising outer walls 1 0 microporous structure, which are equipped with an external thermal insulation 1 2 providing with the outer face of walls 10 spaces 14 in which can be circulated outside air, that is to say air taken from the outside of the building.

The walls 10 microporous structure are made for example conventionally using common products such as bricks, stones, blocks, etc. ....

The thermal insulation 12 which is attached to the outer face of the walls 10 is of any suitable type and is placed so as to arrange with the walls 10 the spaces 14, which have a thickness of a few centimeters and which extend over the entire surface of the walls 10, preferably.

Means 1 6 for air intake and 1 8 air outlet are provided at the lower and upper ends of the spaces 14, the air intake means 1 6 having for example a horizontal tube 20 which extends The end 24 of the tube is closed, while its other end is equipped with a row of orifices 22 distributed along its length as shown in FIG. a controlled means 26 for adjusting the inlet section of the air in the tube 20, this means 26 being for example of the circular diaphragm type.

A fan 28 may be mounted or connected to this end of the tube 20, to supply external air through the means 26 for adjusting the inlet section.

Similarly, the air outlet means 18 provided at the upper end of the space 14 may comprise a perforated tube 20 similar to that represented in FIG. 2, one end of this tube being closed and its other end being connected to an air outlet mouth.

This air outlet means 18 may be equipped with a suction fan, which will replace the fan 28 fitted to the air intake means 16 or will reinforce the action of this fan 28.

Alternatively, the outside air can circulate by natural convection in the space 14, the fans are not powered.

In any case, provision is also made for means for regulating the speed of circulation of the outside air in the space 14, these means comprising, for example, diaphragms with an adjustable section which can also be used to open and close the entries or the air outlets of space 14.

At least one temperature sensor 30 is mounted in the intermediate space 14 to measure the temperature of the outer surface of the wall 10.

Preferably, the temperature sensor 30 allows an instantaneous measurement of the temperature and is advantageously of the infrared type. It is then mounted on the face 32 of the thermal insulation 12, to be opposite the outer surface of the wall 10.

In the embodiment shown in FIG. 1, the outside air circulation space 14 is equipped with two temperature sensors 30, one at the lower end of this space and the other at its upper end, this makes it possible to measure the temperature difference of the wall between its lower end and its upper end.

Alternatively or additionally, it is possible to mount in horizontal holes of walls 1 0, for example at the upper and lower ends of spaces 14, linear bars 30 'of temperature sensors for measuring temperatures and their variations in temperature. thickness of the walls, these captors being preferably of the infrared type and distributed along the thickness of the walls, being separated by a distance of one to two centimeters for example. The temperature sensor or sensors 30, 30 'are connected to inputs of a control circuit 34 which will regulate the inlet sections of the tubes 20 and the operation of the fans 28 to circulate outside air on the surface. exterior of a wall 10 or several walls 10 of the building according to the hygrometry of the outside air and the variation in time of the temperature or temperatures of the wall or walls 10.

The hygrometry or relative humidity of the outside air is not measured directly for the reasons indicated above, the known probes of hygrometry measurement being extremely expensive, sensitive to air pollution and having a lifetime relatively weak. It is possible to determine this hygrometry by calculation, for a given date and time.

It is known that the absolute humidity of the ambient air does not vary measurably over a day and that it varies almost sinusoidally during the year around an average value equal to 0.0072. kg of water / kg of dry air with a maximum value of 0,01 kg of water / kg of ambient dry air and a minimum value of 0,004 kg / of water / kg of dry air ambient (these values being measured in summer in the center of France).

The hygrometric degree of air (or relative humidity of the air) is given by the ratio between the vapor pressure of the air and the saturation vapor pressure at the dry air temperature and can be calculated according to the absolute humidity of the air, the atmospheric pressure and the saturation vapor pressure by a formula of the type:

w.Po / (a + w) .pvs

where w is the absolute humidity of the air, Po is the atmospheric pressure, a is a constant and Pvs is the saturation vapor pressure, which is a known function of the dry air temperature.

It is thus possible, at a given date and at a given hour, to calculate the hygrometric degree of the air from the measurement of the dry air temperature. and information stored in memory of seasonal variations in the absolute humidity of the air in the area where a residential building is constructed.

As schematically shown in FIG. 3, the hygrometric degree of the air et and the dry temperature T of the air vary in a contrary manner during a day, the curves of FIG. 3 being taken at the neck. in a summer day where the weather varies between a minimum of 15 degrees at 5 o'clock in the morning and a maximum of 27 degrees at 15 o'clock, the relative humidity of the air varying between about 0.9 at 5 am and 0.45 at about 3 pm

If, for example, it is assumed that, during the winter, the outside air temperature is 5 ° C and its hygrometric degree £ is 90%, the circulation of the outside air at low speed (e.g. approximately 0.05m / s) in the space 14 on the outer surface of the wall 10 will result in an adsorption of water vapor by the outer surface of the wall as long as this surface is not saturated with steam. water. This adsorption of water vapor by the surface of the wall 10 results in an increase in its temperature, which increases for example from 20 ° C. to 23 ° C., the temperature of 23 ° C. being reached when the surface of the wall 1 0 is saturated with water vapor. The water vapor then passes into the capillaries of the interior of the wall and the heat of the surface of the wall is diffused inside the wall.

When the surface temperature of the wall 10 has reached 23 ° C and begins to decrease, it stops the flow of outside air in the space 14. There is then a cooling of the wall 10, the heat is absorbed gradually by the interior of the building. When the temperature of the wall 10 has decreased to 20 ° C, it starts again to circulate at a low speed of the outside air at high humidity in space 14, until the surface temperature of the wall rises to around 23 ° vs.

The average thermal flux absorbed by the wall over an air circulation period of 15 minutes is, in one exemplary embodiment, the order of 13W / m ² , which corresponds to an energy of about 3Wh / m ² . If during the course of a day this thermal input is made three times over a total surface area of approximately 200m ² , the energy supplied to the building is of the order of 2kWh.

It is during the hours of the night, when the hygrometric degree of the outside air is the highest, that the outside air will be circulated in the space 14 to warm the wall 10, in winter.

Conversely, in summer, when it is necessary to lower the temperature of the wall 10, it controls the circulation of outside air at low speed in the space 14 during the hot hours of the day when the hygrometric degree of the outside air is the weaker. The circulation of the outside air on the outer surface of the wall 1 0 then causes a desorption of water vapor by the surface of the wall 1 0, which results in a lowering of its temperature and therefore by a decrease in the temperature from the wall and inside the building.

The temperature of the outer surface of the wall 10 can thus, for example, go from 23 ° C to 20 ° C. The flow of outside air is then stopped in the space 14, until the surface temperature of the wall 10 has risen to 23 ° C., for example, and then the air circulates again. outside in space 14.

In the cases described above, the speed of circulation of the outside air in a space 14 is set to a relatively low value, for example of the order of a few centimeters per second, to reduce the convective effect of the circulation. air in the space 14, which opposes the heat transfer by adsorption-desorption of water vapor in the wall.

Typically, the periods of circulation of outside air in space 14 have durations of a few tens of minutes, for example from 10 to 20 m in utes, and alternate with periods of stopping of this circulation which are much more long and for example several hours. It is also possible to proceed by renewing the volume of air in the space 14, that is to fill the "new" outside air space, and then to close it for a certain time (of 10 or 15 or 30 minutes per minute). for example, depending on weather conditions), open it and refill it with "new" outdoor air, close it, etc. When the circulation of air in the space 14 is stopped, the water vapor diffuses by osmosis in this space and in the cavities of the elements forming the wall 10.

In a warm and humid atmosphere, the following procedure can be used to cool a wall 10: during the night, when the outside air is at a minimum temperature, for example of the order of 20 ° C, circulates in the space 1 4 at a relatively high speed, for example of the order of 0.5 to 1 m / s. This is manifested at the beginning by a small temperature rise of the wall 10 which adsorbs water vapor, then by a cooling of the wall 10 in contact with the outside air which circulates continuously on the wall. It is thus possible to lower the temperature of the chamber during the night to 20 ° C., and this cooling is sufficient to maintain a pleasant temperature inside the building during the day, the wall 10 gradually warming up to midnight where it can then be brought back to a temperature of about 20 ° C.

This method of heating and cooling the walls of a residential building also allows the interior of the building to have a relative air humidity of between 60 and 70%, which corresponds to a sensation maximum comfort and well-being.

With the bars 30 'of temperature sensors, it is possible to measure and monitor the variations and temperature gradients inside a wall 10 and to directly control the flow of outside air on the wall without being necessary. re to know the thermal and hygrometric characteristics of the wall.

The circuit 34 which controls the circulation of the outside air in the spaces 14 also controls the operation of a controlled mechanical ventilation system 36 with a double flow, which can be associated with low power auxiliary heating means, if necessary, or a reversible heat pump for heating or cooling the building interior in a complementary manner.

Simulations and measurements have made it possible to verify that the invention gives the wall 10 a very great thermal inertia and a power of regulation of the temperature and hygrometry inside the building. As already indicated, it reduces by at least 85% the energy consumed for the thermal regulation in the building.

The performances are further improved in the variant embodiment of FIGS. 4 to 6.

In this variant, the microporous wall 10 is made of hollow bricks, such as that 40 shown in FIG. 5, which are laid in superposed and staggered rows, these bricks comprising parallel and rectilinear internal channels 42 which open at the ends of the bricks and which are horizontal in the bricks 40 or vertical in the bricks 44 of Figure 4.

In the wall 1 0, the channels 42 of alie bricks are aligned with each other and in the extension of each other. Mortar joints are provided between the rows of bricks, but not between the bricks of the same row so that the aligned channels can communicate with each other and with the spaces 14 between the walls 10 and their insulation. exterior.

Thus, the flow of outside air between the wall 1 0 and its insulation 12 causes an outside air circulation in the channels 42 of the bricks 40 of the wall 10, the outside air entering the channels 42 and out of these channels by suction by the spaces 46 left free between the juxtaposed bricks.

Vertical ducts or collectors for supplying and discharging outside air may also be provided at the longitudinal ends of the wall, in order to circulate the outside air from one end of the wall to the other in the aligned channels 42. Thus, the outside air, dry or moist depending on the case, is in contact with a surface equal to the sum of the walls of the walls of the channels 42, which is several times greater than the vertical surface of the wall 10 (for example 5 times greater ), which increases the efficiency of the invention in a very important way.

It is possible in this variant to reduce the thickness of the space 14 between the wall 10 and its insulation 12, and even to cancel this thickness. In this case, the outside air circulates only inside the wall 10 in the channels 42, under the same conditions as those already described with reference to FIGS. 1 to 3, that is to say with a low speed and for a short time, to yield moisture to the wall 10 and warm the wall or to absorb moisture from the wall 10 and cool it.

The wall 10 can also be made by juxtaposing the bricks 44 of Figure 4, in which the channels 42 are vertical. In this case, the outside air flows vertically in the wall 10, and horizontal collectors of supply and external air outlet can be provided respectively at the lower and upper ends of the wall.

In another embodiment of the invention, the wall 10 is formed of panels having horizontal or vertical air circulation channels, these panels being prefabricated or made for example by lost formwork methods.

The mu r 10 is also realis ed in a microporous material cls (fri er, bricks, concrete, ...) whose croporos ity can t possibly be adjusted for example by addition of a pozzolanic material to concrete.

Claims

1. Device for regulating the temperature inside a microporous walled dwelling building (10) and with external thermal insulation (12), comprising outside air circulation spaces between the microporous walls (10) and their thermal insulation (12), characterized in that it comprises means (34) for controlling the flow of outside air and the speed of circulation of this air in said spaces, these control means receiving as input measurements of microporous wall temperatures (10) for controlling the flow of outside air into the space (14) between a microporous wall and its thermal insulation (12) as a function of the temperature variations of the microporous wall, its hygrometry and the hygrometry of the outside air.

2. Device according to claim 1, characterized in that it comprises means (30) for instantaneous measurement of the surface temperature of the microporous walls (10).

3. Device according to claim 2, characterized in that the means for measuring the temperature of the microporous walls comprise infrared sensors.

4. Device according to claim 2 or 3, characterized in that the means (30) for measuring the surface temperature of the walls (10) are mounted in the aforementioned spaces (14) facing the outer surface of the walls (10). ).

5. Device according to one of the preceding claims, characterized in that strips (30 ') of temperature sensors are mounted in holes formed in the walls (10) over substantially their entire thickness.

6. Device according to one of the preceding claims, characterized in that the microporous wall (10) comprises passages or channels (42) of external air circulation, communicating with the spaces (14) between the microporous walls and their outer insulation.

7. Device according to claim 6, characterized in that the microporous walls (10) are formed of panels or juxtaposed elements having air passages, such as hollow bricks (40, 44), the air passages said elements being unobstructed and aligned with each other from one element to the next element.

8. Device according to one of the preceding claims, characterized in that the external air flow means comprise fans (28) and means (20) for admission and / or external air outlet mounted to a vertical or horizontal end of the walls (10) and comprising horizontal tubes (20) or vertical tubes, a long end of which comprises a means (26) for adjusting the air inlet section, for example diaphragm, the tubes ( 20) having orifices (22) of air outlet distributed along their length.

9. A method for regulating the temperature in a microporous walled dwelling building (10) and with external thermal insulation (12), comprising spaces (14) for the circulation of outside air formed between the walls (10) and their thermal insulation (12), characterized in that it consists in determining the periods and speeds at which outside air is circulated in a space (1 4) above between a wall (1 0) and its thermal insulation in depending on the hygrometry of the outside air, the hygrometry of the wall and temperature variations on the surface of the wall (10) and / or inside the wall.

10. The method of claim 9, characterized in that the speed of the air in said space (14) is set to a low value, for example of the order of 0.05m / s, to heat or cool the wall (1 0) by adsorption or desorption of water vapor, or at a value greater than about 0.5m / s to heat or cool the wall (10) by convection.

1 1. A method according to claim 9 or 10, characterized in that it consists in circulating in said space (14) outside air and stop this circulation of air when the volume of air contained in said space (14) has been renewed, then to circulate outside air in said space (14) after a predetermined time interval, for example a few tens of minutes. minutes, to renew again the volume of air contained in the space (14).

12. Method according to one of claims 9 to 1 1, characterized in that it also consists, under certain conditions of temperature and hygrometry, to let the outside air freely circulate in said space (14) by limiting the air velocity in this space to a value less than 1 m / s, to maintain the temperature inside the building at a substantially constant value over a long period of time, for example several days.

13. Method according to one of claims 9 to 12, characterized in that it consists in calculating the hygrometry of the outside air from its dry temperature, date and time, for a given region. , and to calculate or estimate the hygrometry of the wall.