US20170003048A1

US20170003048A1 - Device for ventilating a room, device for protecting a site and method for ventilating a site

Info

Publication number: US20170003048A1
Application number: US15/106,310
Authority: US
Inventors: Laurent Pichard; Stéphane Di Marco
Original assignee: Finsecur SAS
Current assignee: Finsecur SAS
Priority date: 2013-12-23
Filing date: 2014-12-23
Publication date: 2017-01-05
Also published as: WO2015097258A1; EP3087556A1; EP3087556B1

Abstract

A device for ventilating a room includes an actuator configured to open an opening panel of the room and a pairer to pair with an alarm control unit. A controller to control the actuator, configured to control the opening or the closing of the opening panel in accordance with a received signal. A transmitter to communicate wirelessly with the alarm control unit configured to receive a smoke evacuation signal. A battery to store electrical energy, charged by an electrical power supply, configured to power the actuator during the opening of the opening panel following the receipt of a smoke evacuation signal.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a device for ventilating a room, a device for protecting a site, and a method for ventilating a site. It applies, in particular, to the protection against risks of fires at public or business sites.

STATE OF THE ART

For the rest of the document, the term “supercapacitor” will refer to a capacitor whose power density and energy density fall between batteries and conventional electrolytic capacitors.
In certain systems for protecting an area against fires, smoke vents are positioned high up in the area to allow the smoke contained in this room to be evacuated during a fire. The opening of these vents is controlled by an alarm control unit after this control unit has detected a fire in the area protected by these systems.
These systems have several drawbacks.
Firstly, because of standards imposing rapid opening of the vents, actuators causing each vent of the device to be opened require significant amperage, of the order of one ampere. When several devices are present, the total amperage demanded requires installing cables with substantial cross-sections. In order to remedy this disadvantage, some systems comprise an electrical cabinet connected by cables to each vent of the device. However, these electrical cabinets use a lot of space and the cables used impose a considerable constraint on the installation of the system due to the dimensions of these cables.
Secondly, maintenance standards for these systems require each vent to undergo maintenance once a year. This maintenance includes, in particular, opening and closing the vent to verify the proper operation of this vent. In current systems, these tests are performed manually, which does not make it possible to reliably establish that, for each part of the system, the length of time between two tests complies with regulatory obligations.
In some current systems, vents are connected wirelessly to the control unit. The disadvantage of current wireless technology is that the wireless transmission between a vent and a control unit is fragile, given the distances that can separate the control unit from the vent. In addition, the surrounding electromagnetic noise may be a source of transmission faults between a vent and the control unit. For these reasons, these systems are either used in smaller rooms or comprise a plurality of control units, making it possible to limit these transmission problems, or repeaters that relay the transmitted signals, which increases maintenance costs and the risks of equipment failure. In addition, these current systems have one-way downward communication from the alarm control unit, which prevents the alarm control unit obtaining any information whatsoever from the vent.

SUBJECT OF THE INVENTION

The present invention aims to remedy all or part of these drawbacks. To this end, according to a first aspect, the present invention envisages a device for ventilating a room, which comprises:

- an actuator configured to open an opening panel of the room;
- a means for pairing with an alarm control unit;
- a means for controlling the actuator, configured to control the opening or closing of the opening panel according to a received signal;
- a means for communicating wirelessly with the alarm control unit configured to receive a smoke evacuation signal;
- a means for storing electrical energy, charged by an electrical power supply source, configured to power the actuator during the opening of the opening panel after a smoke evacuation signal has been received.

Thanks to these provisions, when a smoke evacuation signal is received by the communication means, the actuator is activated so as to open the room. In order to power this actuator, the energy storage means discharges the electrical energy stored during the charging of this storage means by the electrical power supply source. In this way, it is possible to use conventional electrical cables not imposing space constraints when implementing the device in a room. Similarly, this device does not require an electrical cabinet to be used, which reduces the device's installation costs and the space required for this installation.
In some embodiments:

- the communication means is configured to receive a ventilation signal;
- the actuator control means is configured to command the opening of the opening panel according to the ventilation signal received; and
- the power supply source is configured to power the actuator during the opening of the opening panel.

These embodiments have the advantage of making it possible, depending on the signal received, for the actuator to be powered by the storage means on receipt of a smoke evacuation signal representative of the detection of a fire by the alarm control unit. It is also possible for the actuator to be powered by the power supply source during an opening of the opening panel in response to a ventilation signal.
In some embodiments, the ventilation signal comprises a piece of information representative of a degree of opening for the opening panel, the control means being configured to command a degree of opening of the opening panel according to the piece of information representative of a degree of opening of the opening panel.
The advantage of these embodiments is that they make it possible to regulate the degree of opening of the opening panel according to an opening degree determined by a user and transmitted in the ventilation signal.
In some embodiments, the communication means is a means for spread-spectrum wireless communication with the alarm control unit.
These embodiments have the advantage of enabling robust communication with regard to a degree of electromagnetic noise between the alarm control unit and the communication means.
In some embodiments, the device that is the subject of the present invention comprises:

- a sensor of a value representative of a physical magnitude;
- a detector configured to determine a piece of information relative to the opening panel as a function of the captured value,
  the communication means being configured to transmit a signal representative of the piece of information detected to the alarm control unit.

The advantage of these embodiments is that they make it possible, for example, to transmit to the alarm control unit a piece of information representative of whether the opening panel is open or not.
In some embodiments, the detector is configured to determine a piece of information representative of the degree of opening of the opening panel as a function of the captured value.
These embodiments have the advantage of enabling more precise information to be transmitted to the alarm control unit.
In some embodiments:

- the actuator comprises a rotary motor;
- the sensor is a rev counter for the motor; and
- the detector detects a degree of opening of the opening panel according to the number of motor revolutions counted.

The advantage of these embodiments is that they enable the opening degree of the opening panel to be detected accurately.
In some embodiments, the motor is a brushless motor and the sensor is a Hall Effect sensor.
These embodiments have the advantage of enabling the opening degree of the opening panel to be detected accurately.
In some embodiments, the device that is the subject of the present invention comprises a means for measuring a length of time since a change to a physical magnitude captured by the sensor, the communication means being configured to emit a warning signal when the length of time measured is longer than a predefined limit time.
The advantage of these embodiments is that they make it possible to identify the need for carrying out maintenance of the device when, for example, the opening panel was last opened more than one year ago.
In some embodiments, the energy storage means is a supercapacitor.
These embodiments have the advantage of enabling the rapid return, compared to a battery, of the energy stored in the supercapacitor.
In some embodiments, the device that is the subject of the present invention comprises:

- a sensor of a value representative of a physical magnitude of the device's environment;
- a fire detector configured to detect a fire as a function of the value captured; the communication means being configured to send the alarm control unit a signal representative of the detection of a fire.

The advantage of these embodiments is that they allow a reduction in the costs of a fire detection system comprising the device that is the subject of the present invention by combining the device, a sensor and a fire detector.
In some embodiments, the device that is the subject of the present invention comprises:

- a means for verifying the working condition of the communication means according to a signal received, from the alarm control unit, by the communication means after the verification means has commanded the communication means to emit a standard piece of information to the alarm control unit; and
- a means for activating a visual and/or sound alarm as a function of the signal received.

These embodiments enable a user to identify a communication fault between the alarm control unit and the device according to the visual and/or sound alarm.
In some embodiments, the device comprises a means for verifying the working condition of a sensor, configured to command the communication means to emit a piece of information representative of the working condition of the sensor.
The advantage of these embodiments is that they make it possible, for example, to transmit to the alarm control unit a signal representative of an operating fault of a sensor.
According to a second aspect, the present invention envisages a device for protecting a site, which comprises:

- at least one room ventilation device that is the subject of the present invention;
- an alarm control unit paired with each room ventilation device, configured to transmit a smoke evacuation signal when a fire is detected;
- a ventilation control unit configured to transmit a ventilation signal to at least one ventilation device;
- a common power supply source powering each ventilation device.

As the aims, advantages and features of the site protection device that is the subject of the present invention are similar to those of the room ventilation device that is the subject of the present invention, they are not repeated here.
According to a third aspect, the present invention envisages a method for ventilating a site by a plurality of ventilation devices, each equipped with an opening actuator for an opening panel, which comprises:

- a step of charging, in each ventilation device, an energy storage means associated to said ventilation device, by powering the electrical energy storage means with an electrical power supply source common to the ventilation devices;
- a step of each device waiting for an ‘open’ or ‘close’ control signal for the opening panels, received from either an alarm control unit or from a ventilation control unit;
- if an ‘open’ or ‘close’ control signal for the opening panels is received from the ventilation control unit, a step of successively opening or closing opening panels, powering the actuators by the power supply common to the ventilation devices, the amperage output by the common power supply being less than the sum of the amperages necessary to simultaneously power the actuators; and
- if an ‘open’ control signal for the opening panels is received from the alarm control unit, a step of simultaneously opening the opening panels, powering the actuator of each device with the energy storage means associated to said device.

As the aims, advantages and features of the method that is the subject of the present invention are similar to those of the device that is the subject of the present invention, they are not repeated here.

BRIEF DESCRIPTION OF THE FIGURES

Other advantages, aims and particular features of the invention will become apparent from the non-limiting description that follows of at least one particular embodiment of the devices and the method that are the subjects of the present invention, with reference to drawings included in an appendix, wherein:

FIG. 1 represents, schematically, a first particular embodiment of the device for ventilating a room that is the subject of the present invention,

FIG. 2 represents, schematically, a particular embodiment of the device for protecting a site that is the subject of the present invention;

FIG. 3 represents, in the form of a logical diagram, steps in a particular embodiment of the method that is the subject of the present invention.

DESCRIPTION OF EXAMPLES OF REALIZATION OF THE INVENTION

The present description is given as a non-limiting example. FIG. 1, which is not to scale, shows an embodiment of the device 10 that is the subject of the present invention. This device 10 comprises:

- an actuator 105, configured to open an opening panel 110 of the room, that comprises a rotary motor 150;
- a means 115 for pairing with an alarm control unit;
- a means 120 for controlling the actuator 105;
- a means 125 for communicating wirelessly with the alarm control unit;
- a means 130 for storing electrical energy, charged by an electrical power supply source 135;
- a sensor 140 of a value representative of a physical magnitude;
- a detector 145 configured to determine a piece of information relative to the opening panel 110 as a function of the captured value;
- a means 155 for measuring a length of time since a change to a physical magnitude captured by the sensor 140;
- a sensor 160 of a value representative of a physical magnitude of the device's environment;
- a fire detector 165;
- a means 170 for verifying the working condition of the communication means 125;
- a means 175 for activating a visual and/or sound alarm 180 as a function of the signal received; and
- a means 185 for verifying the working condition of a sensor, 140 and 160.

The actuator 105 is, for example, a mechanical actuator comprising a cylindrical tube in which a piston is set in motion by the action of a rotary motor 150. This rotary motor 150 is, for example, a brushless motor. When the piston of the actuator 105 is deployed, the opening panel 110 is opened, and the smoke contained in the room comprising the opening panel 110 can leave this room.
The actuator 105 is controlled by a means 120 for controlling the actuator 105. When a signal to open the opening panel 110 is received by the communication means 125, this control means 120 transmits to the motor 150 a command to activate the actuator 105 so as to open the opening panel 110. Conversely, this control means 120 transmits to the motor 150 a command to close the opening panel 110 when a close command is received by the communication means 125.
The communication means 125 is, for example, a wireless antenna utilizing spread-spectrum transmission technology. In order to utilize spread-spectrum communication, the communication means 125 is based on the device 10 being paired with the alarm control unit. This pairing utilizes a pairing means 115.
The pairing means 115 is, for example, an electronic circuit configured to receive a pairing command emitted by the alarm control unit from the transmission means 125. This pairing command also comprises, for example, a pseudo-random sequence of values “1” and “−1” generated once by the alarm control unit, during the pairing of the alarm control unit with the device 10.
The pairing means 115 compels the communication means 125 to logically multiply the data emitted by the communication means 125 with the pseudo-random sequence. In this way, the spectrum of the emitted signal is spread over a plurality of frequencies, the strength of each portion of the signal over a frequency becoming weaker than the strength of the ambient electromagnetic noise. In addition, the pairing means 115 compels the communication means 125 to correlate the signals received by the communication means 125 with the pseudo-random sequence so as to extract the usable signal from the electromagnetic noise. In some variants, the communication means 125 uses other known spread-spectrum techniques such as, for example, frequency-hopping spread-spectrum. The pairing is performed when the following steps:

- generating a pseudo-random sequence;
- communicating the sequence from the alarm control unit to the device 10; and
- pairing command by the pairing means 120, have been performed.

The pairing means 115 is configured to wirelessly emit a pairing request signal until the device 10 is paired. When the alarm control unit receives the request signal, the alarm control unit emits a signal for the device 10 comprising the pseudo-random sequence. In some variants, the alarm control unit emits a pairing request signal and the device, in response to receiving this request, emits a signal accepting the pairing request. In these variants, the alarm control unit emits a signal comprising the pseudo-random sequence, for the device, on receiving the acceptance signal.
The communication means 125 receives, for example, two types of ‘open’ signals:

- a smoke evacuation signal; and
- a room ventilation signal.

A smoke evacuation signal corresponds to an alarm signal emitted by the alarm control unit. This signal is representative of the detection, by the alarm control unit, of a fire as a function of data transmitted by the fire detectors associated to sensors.
A room ventilation signal corresponds to a signal emitted by a ventilation control unit, which can also be the alarm control unit. This ventilation control unit is, for example, a portable communicating terminal such as a tablet making it possible to command the alarm control unit to emit a ventilation signal. The ventilation signal comprises a piece of information representative of a degree of opening for the opening panel 110.
The communication means 125 transmits the two types of signals to the control means 120 of the actuator 105.
When the control means 120 receives a ventilation signal, the control means 120 commands the activation of the actuator 105 resulting in the slow opening of the opening panel 110. As this operation requires low electrical amperage, the motor 150 activating the actuator 105 draws its power supply from an electrical power supply source 135 that is, for example, a mains power supply. In addition, the control means 120 is configured to control a degree of opening of the opening panel 110 according to the piece of information representative of an opening degree for the opening panel 110 in the ventilation signal.
When the control means 120 receives a smoke evacuation signal, the control means 120 commands the actuator 105 to open the opening panel 110 quickly. As this quick opening requires high electrical amperage, the control means 120 commands an electrical energy storage means 130 to power the motor 150.
The electrical energy storage means 130 is, for example, a supercapacitor charged by the electrical power supply source 135. This storage means 130 is charged by the electrical power supply 135 while the control means 120 is not commanding the storage means 130 to power the motor 150. In this way, the storage means 130 acts as a safety system for the device 10.
The sensor 140 of a value representative of a physical magnitude is, for example, a Hall Effect sensor positioned near the brushless motor 150. The sensor 140 counts the number of revolutions made by the motor 150 and the direction of each of the revolutions counted.
The detector 145 is, for example, an electronic circuit configured to determine a piece of information relative to the opening panel 110 according to the number of revolutions counted by the sensor 140. Thus, if a captured number of revolutions made by the motor 150 in a direction corresponding to opening the opening panel 110 is greater than a captured number of revolutions made by the motor 150 in a direction corresponding to closing the opening panel 110, the detector 145 detects that the opening panel 110 is open. In addition, the detector 145 detects a degree of opening of the opening panel 110 according to a difference between the number of revolutions captured by the sensor 140 in each direction of the motor 150.
The communication means 125 is configured to transmit a signal representative of the detected degree of opening of the opening panel 110 to the alarm control unit.
The means for measuring 155 a length of time since a change to a physical magnitude captured by the sensor 140 is, for example, an electronic clock. This electronic clock is configured to measure a length of time beginning when a captured physical magnitude is changed. Once this physical magnitude is changed, the length of time measured is reset. When the length of time measured is longer than a predefined limit time, the measurement means 155 transmits a signal representative of the predefined limit time being exceeded to the communication means 125.
In that case, the communication means 125 is configured to transmit a signal representative of the predefined value time being exceeded.
The sensor 160 of a value representative of a physical magnitude of the device's environment is, for example, an optical smoke detector.
The fire detector 165 is, for example, an electronic circuit. This electronic circuit is configured to detect a fire as a function of an amount of smoke in the air captured by the sensor 160 for example.
The communication means 125 is configured to send the alarm control unit a signal representative of the detection of a fire when the detector 165 detects a fire.
The means 170 for verifying the working condition of the communication means 125 is, for example, an electronic circuit. This electronic circuit verifies the working condition of the communication means 125 according to a signal received, from the alarm control unit, by the communication means 125 after the verification means 170 has commanded the communication means 125 to emit a standard piece of information to the alarm control unit. If no signal is received from the alarm control unit, the verification means 170 determines that the communication means 125 is faulty. In some variants, if no signal is received, the verification means 170 performs a second verification as confirmation. If the signal received conforms to the expected signal, for example comprising a specific code transmitted by the communication means 125 to the alarm control unit, the verification means 170 determines that the communication means 125 is working.
The verification means 170 is configured to perform a verification when a length of time since the reception of a last signal emitted by the alarm control unit is longer than a predefined limit time. This provision makes it possible to verify the state of the pairing between the device 10 and the alarm control unit.
When the verification means 170 determines that the communication means 125 is faulty, the verification means 170 commands the means 175 for activating a visual and/or sound alarm 180 to activate the visual and/or sound alarm 180. This activation means 175 is, for example, an electronic circuit configured to emit a command to blink or to emit a periodic sound signal according to the type of alarm 180 controlled. The visual and/or sound alarm 180 is, for example, a light-emitting diode, possibly associated with a loudspeaker.
The means 185 for verifying the working condition of the sensors 140 and 160 is, for example, an electronic circuit configured to send to the sensors 140 and 160 a signal representative of a physical magnitude and to measure the reaction of each sensor 140 and 160. If the reaction of at least one sensor, 140 and/or 160, conforms to a reaction expected by the verification means 185, the verification means 185 determines that each said sensor, 140 and/or 160, is in working condition. Conversely, if the reaction of at least one sensor, 140 and/or 160, does not conform to a reaction expected by the verification means 185, the verification means 185 determines that each said sensor, 140 and/or 160, is faulty.
The verification means 185 is configured to command the communication means 125 to send the alarm control unit a piece of information representative of the working condition of each sensor 140 and 160.
FIG. 2, which is not to scale, shows an embodiment of the device 20 for protecting a site that is the subject of the present invention. This device 20 comprises:

- two devices 10 for ventilating a room, as described in FIG. 1;
- an alarm control unit 205 paired with each room ventilation device 10, configured to transmit a smoke evacuation signal when a fire is detected;
- a ventilation control unit 210 configured to transmit a ventilation signal to at least one ventilation device 10;
- a common power supply source 215 powering each ventilation device 10.

The two devices 10 are powered by a common power supply source 215. This power supply source 215 is, for example, a mains power supply connected to each energy storage means, not shown, of each ventilation device 10.
The alarm control unit 205 is, for example, an electronic circuit connected wirelessly to sensors, not shown, of values representative of physical magnitudes. These sensors transmit the values captured to the alarm control unit 205 and, according to these captured values, the alarm control unit 205 detects, or not, a fire. Such a captured physical magnitude is, for example, a density of smoke in the ambient air. If this smoke density is greater than a limit value predefined by the alarm control unit 205, the alarm control unit 205 detects the presence of a fire in the site. When a fire is detected, the alarm control unit 205 transmits a smoke evacuation signal to each ventilation device 10.
Each ventilation device 10 powers the opening of an opening panel, not shown, by means of an actuator, not shown, by the storage means previously charged by the common power supply source 215.
The ventilation control unit 210 is, for example an electronic circuit associated to the alarm control unit 205. The ventilation control unit 210 communicates with a user interface, not shown, located remotely, or not, from the ventilation control unit 210. This user interface allows a user to control a degree of opening of at least one opening panel. Depending on the degree of opening of at least one opening panel entered by a user, the ventilation control unit 210 transmits a ventilation signal to each ventilation device 10 controlling an actuator configured to open each said opening panel.
Each ventilation device 10 receiving a ventilation signal powers the opening of the opening panel of the ventilation device 10 by means of the common power supply source 215. When at least two ventilation devices 10 must be activated, the ventilation control unit 210 orders the consecutive activation of each ventilation device 10 that has to be activated. In this way, the electrical amperage necessary to activate one or more devices 10 is not greater than the electrical amperage available at the common power supply source 205. In some variants, the device 20 comprises more than two devices 10 and the electrical amperage available at the ventilation control unit 210 makes it possible, for example, to power only two ventilation devices 10 simultaneously. In these variants, the ventilation control unit 210 commands the simultaneous opening of two ventilation devices 10 first and then, subsequently, the opening of the third ventilation device 10.
In this embodiment, with a standard power supply source 215, it is possible to command a simultaneous, quick opening of the opening panels “in parallel”, or a consecutive opening of the opening panels “in series” when no fire risk has been detected.
FIG. 3 shows a logical diagram of particular steps of the method 30 that is the subject of the present invention. This method 30 for ventilating a site by a plurality of ventilation devices, each equipped with an actuator for opening an opening panel, comprises:

- a step 305 of charging, in each ventilation device, an energy storage means associated with said ventilation device, by powering the electrical energy storage means with an electrical power supply source common to the ventilation devices;
- a step 310 of each device waiting for an ‘open’ or ‘close’ control signal for the opening panels, received from either an alarm control unit or from a ventilation control unit;
- if an ‘open’ or ‘close’ control signal for the opening panels is received from the ventilation control unit, a step 315 of successively opening or closing opening panels, powering the actuators by the power supply common to the ventilation devices, the amperage output by the common power supply being less than the sum of the amperages necessary to simultaneously power the actuators; and
- if an ‘open’ control signal for the opening panels is received from the alarm control unit, a step 320 of simultaneously opening the opening panels, powering the actuator of each device with the energy storage means associated to said device.

The charging step 305 is realized, for example, by wiring each ventilation device to a common power supply source. This common power supply source is, for example, the mains power supply. In addition, this power supply source is configured to power an actuator for opening an opening panel of a device when said device receives a ventilation signal. This charging step 305 is also realized by wiring a supercapacitor to each ventilation device. This supercapacitor is powered by the common power supply source and is charged by means of this power supply source. In addition, each energy storage means is configured to power an actuator for opening an opening panel of the ventilation device when said device receives a smoke evacuation signal.
The waiting step 310 is realized, for example, by utilizing a wireless communication means of each ventilation device connected to the alarm control unit. This communication means is configured to receive a signal to open the opening panel of the device. This ‘open’ signal is either:

- a smoke evacuation signal; or
- a ventilation signal.

The step 315 of successively opening or closing opening panels is carried out, for example, by utilizing each actuator associated to an opening panel to be opened powered by the common power supply source.
The simultaneous opening step 320 is carried out, for example, by utilizing each actuator associated to an opening panel to be opened powered by the energy storage means associated to the device comprising the actuator.

Claims

1-15. (canceled)

16. Device for ventilating a room, comprising:

an actuator configured to open an opening panel of the room;

a pairer to pair the device with an alarm control unit;

a controller to control the actuator, configured to control an opening or closing of the opening panel in accordance with a received signal;

a transmitter to communicate wirelessly with the alarm control unit configured to receive a smoke evacuation signal; and

a battery to locally store electrical energy, charged by a remote electrical power supply, configured to power the actuator, with an electrical current that is higher than an electrical current delivered by the remote electrical power supply, during the opening of the opening panel immediately following the receipt of a smoke evacuation signal.

17. The device according to claim 16, wherein the transmitter is configured to receive a ventilation signal; wherein the controller is configured to command the opening of the opening panel according to the ventilation signal received; and wherein the remove electrical power supply is configured to power the actuator during the opening of the opening panel.

18. The device according to claim 17, wherein the ventilation signal comprises a piece of information representative of a degree of opening for the opening panel; wherein the controller is configured to command the degree of opening of the opening panel according to the piece of information representative of the degree of opening of the opening panel.

19. The device according to claim 16, wherein the transmitter is a spread-spectrum wireless transmitter.

20. The device according to claim 16, comprising:

a sensor to capture a value representative of a physical magnitude;

a detector configured to determine a piece of information relative to the opening panel as a function of the captured value; and

wherein the transmitter is configured to transmit a signal representative of the determined piece of information to the alarm control unit.

21. The device according to claim 20, wherein the detector is configured to determine a piece of information representative of the degree of opening of the opening panel as a function of the captured value.

22. The device according to claim 20, wherein the actuator comprises a rotary motor;

wherein the sensor is a revolution counter for the rotary motor; and wherein the detector detects a degree of opening of the opening panel according to the number of motor revolutions counted.

23. The device according to claim 22, wherein the rotary motor is a brushless motor and the sensor is a Hall Effect sensor.

24. The device according to claim 20, further comprising a clock to measure a length of time since a change to the physical magnitude captured by the sensor; and wherein the transmitter is configured to emit a warning signal when the length of time measured is longer than a predefined limit time.

25. The device according to claim 20, further comprising a verifier to verify a working condition of the sensor and configured to command the transmitter to emit a piece of information representative of the working condition of the sensor.

26. The device according to claim 16, wherein the battery is a supercapacitor.

27. The device according to claim 16, further comprising: a sensor to capture a value representative of a physical magnitude of the device's environment; and a fire detector configured to detect a fire as a function of the captured value; and wherein the transmitter is configured to send a signal representative of a detection of the fire to the alarm control unit.

28. The device according to claim 16, further comprising: a verifier to verify a working condition of the transmitter as a function of a signal received, from the alarm control unit, by the transmitter after the verifier has commanded the transmitter to emit a standard piece of information to the alarm control unit; and an activator to activate at least one of a visual alarm and a sound alarm as a function of the signal received.

29. The device for protecting a site, comprising at least two devices for ventilating a room according to claim 16; and further comprising:

an alarm control unit paired with each room ventilation device configured to transmit a smoke evacuation signal when a fire is detected, the actuators of the two devices for ventilating being simultaneously powered;

a ventilation control unit configured to transmit a ventilation signal to at least one ventilation device, the actuators of the two devices for ventilating being successively powered;

a common power supply source to power each ventilation device, the common power supply being remotely positioned from at least one device for ventilating and being configured to deliver an electrical current for charging the batteries of the devices for ventilating that is less than a sum of the electrical current required for simultaneously powering the actuators to simultaneously open the opening panels.

30. A method for ventilating a site by a plurality of ventilation devices, each equipped with an actuator for opening an opening panel, comprising the steps of:

charging, in each ventilation device, a battery integrated inside said each ventilation device, by powering the battery with a remote electrical power supply source common to the ventilation devices;

receiving an open or close control signal for the opening panels by said each ventilation device from either an alarm control unit or a ventilation control unit;

successively opening or closing the opening panels and powering the actuators by the remote electrical power supply source common to the ventilation devices in response to a reception of the open or close control signal from the ventilation control unit, an amperage output by the common power supply being less than a sum of amperages required to simultaneously power the actuators; and

simultaneously opening the opening panels in response a reception of the open control signal from the alarm control unit, each battery powering the corresponding actuator, with an electrical current that is higher than an electrical current delivered by the remote electrical power supply source, during the opening of the opening panels immediately following the receipt of a smoke evacuation signal.