GB2349472A - A ventilation or air extraction system comprising means to log and transmit operational data - Google Patents

Abstract

A ventilation or air extraction system comprises a fan unit (10) and a power control means (18) for receiving electrical power from a mains or other electrical supply and passing electrical power to the fan unit: the system includes a data logger (22) for making a record of information related to the operation of the system, particularly the length of time over which the power control means receives power from the electrical supply, and a telemetry communication unit (23) for transmitting a data signal incorporating the record of information made by the data logger. Also disclosed is a means for indicating abnormal fan speed in relation to the power supplied to the fan drive unit.

Description

Ventilation or Extraction Systems The present invention relates to ventilation or air extraction systems for dwellings or other buildings.

It is known to provide a dwelling with a ventilation system which comprises a fan unit mounted in the loft or roof space of the building and arranged to discharge air into the living space of the building. This places the living space under a slight positive pressure and forces air to flow out of the building through gaps in windows, doors etc.: the effect is that the living space is subjected continuously to a ventilating flow of air, which acts to remove or prevent the build up of condensation. Such ventilation systems are often installed in tenanted dwellings by the landlord, to overcome the tendency in some buildings for damp conditions to develop.

However, it has been found on occasions that a tenant may switch the ventilating system off. In order to monitor tenant acceptability, it has been known for the ventilating system to be provided with a logger which records the length of time for which the fan unit has been powered up and/or the length of time for which the fan has been running: however, it is then necessary for an engineer to visit each dwelling periodically in order to access the logger, read and record the logger's recording and reset the logger.

It is also known to provide dwellings or other buildings with an air extraction system, which serves to expel air from within the living space on a continuous basis.

In accordance with the present invention, there is provided a ventilation or air extraction system which comprises a fan unit and a power control means for receiving electrical power from a mains or other electrical supply and passing electrical power to the fan unit, the system having a data logger for making a record of information related to the operation of the system, and a telemetry communication unit for transmitting a data signal incorporating the record of information made by the data logger.

This system enables information to be obtained concerning its operation, without the need to enter the premises in which the system is installed. Thus, the system can be interrogated remotely either by a hand-held interrogation unit or by an interrogation unit positioned onboard a vehicle.

Preferably the ventilation or air extraction system is assigned a unique identity code. The system may be arranged to transmit its data signal in response to reception of an interrogation signal which includes the identity code of the system. Alternatively, the system may be arranged to respond to reception of a security code, which identifies a valid interrogation unit, by transmitting its data signal including its own identity code.

In particular, the data logger may make a record of the time, or total time, within a predetermined duration, over which the power control means receives power from the mains or other electrical supply, and/or a record of the time, or total time, over which the fan unit runs: the data signal transmitted by the telemetry communication unit includes the record of"powered up"duration and/or the record of"fan running"duration. Preferably the record transmitted is of the duration (or total duration) over which the system has been powered up, and/or the duration (or total duration) over which the fan has been running, since the last occasion that the data logger was interrogated or reset.

Additionally or instead, particularly in the case of the ventilation system, the data logger may make a record of the temperature determined by one or more temperature sensors with which the system is provided, the sensed temperature of the or each sensor being recorded at intervals or an average temperature of each sensor being recorded. Such temperature sensors may be provided in any one or more of the roof space, the living space and exterior of the building.

The data logger may record additional information, which is also included in the data signal which it transmits.

Preferably the data logger is arranged to monitor the rotary speed of the fan or drive motor of the fan unit to determine if this speed becomes abnormal: in particular, the data logger may determine if the rotary speed rises above a predetermined threshold speed value, as occurs when the air filter of the fan unit becomes excessively dirty and therefore clogged. The transmitted data signal may include data as to the current fan or motor speed or simply indicate that the fan or motor speed has risen above the predetermined threshold speed value.

When a ventilation or extraction system is first installed in a dwelling, the occupiers may find difficulty becoming accustomed to it operating in their home. In order to overcome this, preferably the system of the present invention is arranged to run at a relatively low rotary speed when first installed, then progressively increase its running speed over a period of time e. g. of several days. In this way, the occupiers of the dwelling become gradually accustomed to the system operating in their home.

In the case of the ventilation system, preferably this is provided with one or more sensors of abnormal ambient conditions, arranged for stopping the fan unit running when such a condition is detected. For example, any one or more of the following sensors may be provided: carbon monoxide sensor, smoke detector, temperature sensor (particularly to detect excessive temperature indicating a fire). The sensor or sensors may be positioned in the living space of the dwelling and/or in the roof space: in particular a carbon monoxide sensor positioned in the roof space protects against the possibility of any carbon monoxide, which might come from a boiler flue passing through the loft, being pumped back into the dwelling by the ventilation system.

It will be appreciated that the feature of monitoring the fan or drive motor speed, for example in order to detect a clogged filter, is advantageously applicable to any ventilation or extraction fan installation. Therefore, also in accordance with the present invention, there is provided a fan unit which comprises a drive motor, a fan driven by the drive motor, an air filter through which air flows in use of the fan unit, and means for monitoring the rotary speed of the drive motor and/or fan and for providing an indicating signal in the event that said rotary speed becomes abnormal having regard to the value of electrical power being supplied to the drive motor. This indicating signal may be provided if the fan or motor speed rises above a predetermined threshold speed value: instead or in addition, the fan unit may be arranged to provide an indicating signal if the fan or motor speed falls below a lower threshold speed value.

Embodiments of the present invention will now be described by way of examples only and with reference to the accompanying drawings, in which; FIGURE 1 is a schematic diagram showing a dwelling having a ventilation system in accordance with the present invention installed in it; and FIGURE 2 is a diagram showing a wall of dwelling, the wall having an air extraction system in accordance with the present invention installed in it.

Referring to Figure 1 of the drawing, there is shown a ventilation system installed in a dwelling and arranged to introduce air into the living space S of the dwelling and so place the living space under a small positive pressure. The ventilation system comprises a fan unit 10 which is mounted in the loft or roof space L of the dwelling and has its outlet coupled to a duct 12 which leads to a diffuser 14 in the ceiling of the living space S immediately below the roof space L. The fan unit 10 has an inlet coupled to a duct 16 which, in the example shown, serves to draw air in from the interior of the roof space L: instead, the duct 16 may run from the exterior of the building, e. g. from under the eaves, as shown by dotted lines at 16a, or from any other convenient location.

The ventilating system includes a controller 18 which includes a power unit 20 which is connected to the mains electricity supply of the building and supplies power, either continuously or intermittently, to the drive motor of the fan unit 10. Thus, in use, the fan unit 10 draws its power from the mains electricity supply via the power unit 20 and acts to draw air in through the inlet duct 16 or 16a and discharges this air into the living space S via the outlet duct 12 and the diffuser 14. This places the living space under a slight positive pressure such that air is forced to flow out of the dwelling through gaps in the windows, doors etc., with the effect of subjecting the living space S to a ventilating flow of air which acts to remove or prevent the build up of condensation within the living space.

The controller 18 of the ventilating system also includes a data logger 22 and a radio telemetry unit 23, the aerial of which is indicated diagrammatically at 24. The data logger monitors the power unit 20 to log the duration over which power is available to this unit from the mains supply, and/or the duration over which the fan is running: accordingly, the logger monitors for whether the system has been switched off, disconnected from the mains or otherwise suffered a loss of power for any extended period The ventilation system is arranged for interrogation of its data logger from the exterior of the building, using either a hand-held or vehicle-based interrogation unit. In use, the interrogation unit transmits a radio signal which includes a unique identity code of the ventilating system installed in the dwelling. In response to reception of an interrogation signal with the correct identity code, the data logger of the ventilating system transmits a reply signal which includes data indicating the time period for which the fan unit has been powered up and/or the time period over which the fan has been running, at least since the last time the data logger was interrogated or reset.

The data logger 22 of the control system may record additional information, which is also included in the reply signal which it sends when interrogated. For example, the data logger is preferably arranged to monitor the rotary speed of the fan unit drive motor and either transmit data as to the current motor speed or a signal indicating that the motor speed has become abnormal, either when it has risen above an upper threshold speed value and/or fallen below a lower threshold speed value. In this way, for example, the interrogation unit may become aware if the motor speed has become too fast, due to the air filter of the fan unit having become too dirty.

The ventilation system is also provided with a sensor unit 30 which is mounted within the living space S of the dwelling. Preferably this sensor unit includes a temperature sensor, a carbon monoxide sensor and a smoke detector: in the event of excessive temperature (indicating fire conditions) or the presence of carbon monoxide or smoke, the sensor unit 30 signals the controller 18 to stop the fan unit 10.

A similar sensor unit may also be mounted in the roof space L of the dwelling, particularly to stop the fan unit 10 should carbon monoxide be detected, e. g. coming from a boiler flue passing through the loft, and so prevent this carbon monoxide being drawn in by the fan unit 10 and discharged into the living space S.

The controller 18 is arranged to respond to the temperature sensed in the living space and to the temperature of the available inlet air (e. g. in loft), and to alter the speed of the fan motor, in the event of predetermined temperature differentials, with a view to achieving or maintaining an optimum temperature in the living space.

Preferably the data logger 22 is arranged to record periodically (e. g. at 30 minute intervals) the temperature determined by at least one temperature sensor, e. g. temperature sensors positioned in the roof space L, and/or in the living space S and/or exterior to the building. In particular, the data logger may record the average of the loft temperature and/or the average of the living space temperature, over a predetermined period of time e. g. 24 hours and/or 7 days. The recorded temperature information is transmitted to the interrogation unit and can then be analysed to check whether the ventilating system has achieved appropriate or optimum performance over the period concerned. The actual air flow rate may also be recorded.

The interrogation unit can also be arranged to write information into the data logger, and also reprogram the controller of the ventilating system. In particular, the controller may be reset to run the fan motor at a different speed and so alter the volume rate of flow of air through the system. Further, the temperature control strategy of the controller may be altered, e. g. the temperature differential, between the living space and available inlet air, at which the fan speed is changed may be altered.

As previously mentioned, the controller 18 of the ventilating system may be arranged to run the fan unit 10 at a relatively low rotary speed when the system is first installed and then commissioned, but then progressively increase the running speed over a period of time, say a week.

In this way, the occupiers of the dwelling will become gradually accustomed to the system operating in their home.

Although the fan unit 10 has been shown and described as mounted in the loft space L of a building, it may instead be mounted within the living space of a building, for example in an apartment, typically mounted on a wall of a room and drawing air in from the exterior through a duct.

Referring to Figure 2, there is shown an air extraction system which comprises a fan unit 40 mounted in a duct through the exterior wall of a building, to draw in air from within the living space S of the building and expel this air to the exterior of the building. The extraction system further comprises a controller 48 which includes a power unit 50 connected to the mains electricity supply of the building for supplying power to the drive motor of the fan unit 40. The controller 48 also includes a data logger 52 and a radio telemetry unit 53, the aerial of which is indicated diagrammatically at 54.

In the example shown, the extraction system is arranged for the fan unit 40 to run at a low speed, either continuously or intermittently, so that a trickle of air is expelled from the living space of the building. The controller 48 includes a manual switch, operable for increasing the speed of the fan unit 40 when desired. Further, a humidity sensor 56 is connected to the controller 48, for the controller 48 to increase the speed of the fan unit 40 when sensor 56 senses air humidity of greater than a predetermined threshold.

The data logger 52 monitors the power unit 50 to log the duration over which power is available to this unit, thus checking whether the system has been switched off, disconnected from the mains or otherwise suffered a loss of power for any extended period. The data logger 52 also or instead monitors and logs the duration over which the fan is running. In addition, the data logger monitors the rotary speed of the fan unit 40, at least under its trickle condition, in order to initiate a warning signal if this speed rises able an upper threshold value or falls below a lower threshold value.

The extraction system of Figure 2 is arranged for interrogation of its data logger from the outside of the building, using a remote interrogation unit in the same way as the ventilation system of Figure 1, in order to transmit data indicating the time period (or total of the time periods) over which the fan unit has been powered up and/or the time period (or total of the time periods) over which the fan unit has been running, at least since the data logger was last interrogated or reset. Additionally, the transmitted data indicates if the running speed of the fan unit has become abnormal, indicative of a clogged filter or other fault condition. Further, the interrogation unit may be arranged to write information into the data logger, and also reprogram the controller of the extraction system: in particular, the running speed of the fan motor may be adjusted in order to alter the volume flow rate; also the level of humidity, at which the fan motor is increased, may be adjusted.

Claims (9)

1. Claims 1) A ventilation or air extraction system which comprises a fan unit and a power control means for receiving electrical power from a mains or other electrical supply and passing electrical power to the fan unit, the system having a data logger for making a record of information related to the operation of the system, and a telemetry communication unit for transmitting a data signal incorporating the record of information made by the data logger.
2. 2) A system as claimed in claim 1, in which said data logger is arranged to make a record of the time, or total time, within a predetermined duration, over which the power control means receives power from said mains or other electrical supply.
3. 3) A system as claimed in claim 1 or 2, in which said data logger is arranged to make a record of the time, or total time, within a predetermined duration, over which the fan unit runs.
4. 4) A system as claimed in any preceding claim, in which said data logger is arranged to make a record of the temperature sensed by one or more temperature sensors, the sensed temperature or temperatures being recorded at intervals of time or an average temperature being recorded.
5. 5) A system as claimed in any preceding claim, in which said data logger is arranged to monitor the rotary speed of the fan or drive motor of the fan unit and make a record of information related thereto.
6. 6) A system as claimed in any preceding claim, in which said telemetry communication unit is arranged for writing information into the data logger and/or for reprogramming said power control means.
7. 7) A system as claimed in any preceding claim, in which said power control means is arranged to run said fan unit at a relatively low rotary speed when the system is initially commissioned, then to increase the running speed over a period of time.
8. 8) A fan unit which comprises a drive motor, a fan driven by said drive motor, an air filter through which air flows in use of the fan unit, and means for monitoring the rotary speed of the drive motor and/or fan for providing an indicating signal in the event that said rotary speed becomes abnormal having regard to the value of electrical power being supplied to the drive motor.
9. 9) A ventilation or air extraction system substantially as herein described with reference to Figure 1 or 2 of the accompanying drawings.