GB2090966A

GB2090966A - Ventilation system for bathrooms and toilets

Info

Publication number: GB2090966A
Application number: GB8134426A
Authority: GB
Original assignee: Maico Elektroapparate Fabrik GmbH
Current assignee: Maico Elektroapparate Fabrik GmbH
Priority date: 1980-11-15
Filing date: 1981-11-16
Publication date: 1982-07-21
Also published as: DK505381A; CH654647A5; DE3043191A1; GB2090966B; SE8106586L

Abstract

A system for the central ventilation of rooms of a building, preferably of bathrooms and toilets, by means of an air conveying device 12, 13, the rotational speed of which can be adjusted in stages and which is connected via a duct system to air outlets of the relevant rooms for the extraction of used air, which air outlets comprise adjustable air-core choke devices (20) which are normally in predetermined first positions for strong throttling of the used air in order to maintain basic volumetric flows of the used air and can be switched to second positions for increased ventilation. In order to ventilate the rooms as required, a store (25) is associated with the air-core choke devices (20), the content of which store is in each case increased by one stage as a result of the individual air- core choke device being switched into the second position and in each case lowered by one stage as a result of the individual air-core choke device being switched into the first position, the air conveying device being switched over into its different rotational speed stages as a predetermined function of the content of the store. <IMAGE>

Description

SPECIFICATION Ventilation system The invention relates to a system for the central ventilation of rooms, especially of the bathrooms and toilets of a building, according to the classifying part of claim 1.

It was previously usual for the air conveying device in systems of this type to have a total of two rotational speed stages, which were alternately switched in according to a time programme by means of a time switch clock.

During periods in which the relevant rooms were not greatly used the lower rotational speed was switched in and the higher rotational speed was intended for the periods in which these rooms were used more, so as to obtain increased ventilation. As the air-core choke devices are not completely closed in their first positions, the low rotational speed of the air conveying device ensures that the ventilation of the relevant rooms is at a minimum.

However, as the air conveying device constantly operates at its highest rotational speed during the remaining periods, it suclts out essentially more used air when all the air-core choke devices are in -their first positions than during the periods in which the rooms are not greatly used. This leads to considerable heat losses when the building is being heated. The power requirements of the air conveying device are also constantly high during the periods which are programmed for considerable use.

Furthermore, it is also possible, for some reason or other, for the rooms in question to be used to a greater extent during the periods which are not programmed for much use, in which case the basic ventilation is no longer adequate.

One object of the invention is therefore to ventilate, as required, the rooms of a building whose used air outlets are connected to the air conveying device by simple measures which can inexpensively be put into practice.

The system according to the invention provides ventilation, as required, of the relevant rooms of a building. These rooms may preferably be bathrooms and/or toilets and possibly other damp rooms. This enables considerable amounts of energy to be saved with respect to the above systems hitherto usually used. The measures listed in the characterising part of claim 1 may also be put into effect in a simple and inexpensive manner and it is also unnecessary for this system according to the invention to be connected to a time switch clock.

The store may preferably be an electric or electronic storage circuit. However other constructions are also conceivable. The evaluation device may also preferably be an electric or electronic evaluation circuit.

The instantaneous content of the store corresponds in each case to the number of rooms which require a considerable amount of ventilation. The evaluation device, which preferably triggers the rotational speed adjustment via a control device, but may also do so directly, can in particular be suitably formed such that at least each rotational speed stage of the air conveying device lying above the lowest rotational speed stage comprises a content difference of the store of at least two stages, as as result of which the number of necessary rotational speed stages of the air conveying device is considerably smaller than the number of rooms to be ventilated by this system.In accordance with a preferred embodiment of the invention it is also possible, for the same purpose, for the lowest rotational speed stage of the air conveying device to comprise a content difference of the store of at least two stages, the lowest stage of which commences when all the air conveying devices are switched into their first positions, as the lowest rotational speed of the air conveying device is frequently also still sufficient to ventilate at least one room to a considerable degree; this may preferably be one to two rooms. In order to reduce the rotational speed stages, it is also possible, in an advantageous manner, for the highest rotational speed stage of the air conveying device to comprise a content difference of the store which is greater than the content difference(s) associated with the lower rotational speed stage(s).It is in fact very rare, at least when there are a considerable number of rooms, for all the rooms to be used at the same time, so that, on the rare occasions when all the rooms are simultaneously used, a somewhat smaller amount of air can be removed from these rooms without inconvenience.

It is often sufficient for the air conveying device to be adjustable to only two different rotational speeds, particularly when there are not many rooms to be ventilated. However in fairly large buildings, in which there is a relatively high number of rooms to be ventilated, it is advisable for the air conveying device to be adjustable to more than two rotational speed stages, preferably to at least four rotational speed stages. If, for example, each rotational speed stage comprises a content difference of the store of two stages, 9 rooms are ventilated. If even greater store content differences are associated with all or individual rotational speed stages, a correspondingly greater number of rooms in a building can be connected to the air conveying device.

The different rotational speed stages of the air conveying device can be adjusted by known measures. The electric drive motor of the air conveying device may preferably be an asynchronous motor, which can be supplied with different supply voltages by means of a regulating transformer in order to adjust its rotational speed, or it may be a motor with commutable poles, etc.

In a preferred embodiment the store comprises limit switches arranged on the air conveying devices, preferably microswitches with switching hysteresis, the closed state of the individual microswitch raising the store content by one stage. These limit switches can be directly connected and disconnected by throttling members of the air conveying device or by the actuating drive thereof.

The air-core choke devices and their actuating drives can be formed in a known manner. The aircore choke devices may preferably be slatted flaps and a stop or another means prevents the shutter closing completely.

The actuating drive of the air-core choke device may be of conventional type and preferably comprises heated bimetal for adjusting the throttling member(s), whose heating coil is usually switched off and switched on in order to move the air-core device into its second position. The aircore choke device can be switched into the first and second positions by the light switch of a room, particularly in the case of windowless rooms. The hasp of the entrance doors of toilets can be connected to a switch for switching in the first and second positions, or another, preferably manually operable switch can be provided for switching in the first and second positions.

If a limit switch with switching hysteresis is arranged on the air conveying device, the throttle positions of the air-core choke device in which the limit switch is switched on and off differ, thus resulting in it being disconnected with a corresponding time delay after the air-core choke device has been switched over into the first position. This time delay may preferably be several minutes on account of a correspondingly slow adjustment of its throttling member(s), which is desirable at least in toilets.

An embodiment of the invention will now be described by way of example only and with reference to the accompanying drawing. The single figure shows a longitudinal section through a vertical shaft 10 of a building in which a duct system 11, used to ventilate four rooms 21, is disposed and to whose outlet a roof ventilator serving as an air conveying device 12 for the exhaust air is connected, the electric drive motor 1 3 of which roof ventilator can be switched to four different rotational speed stages by means of a control device 34 adjusting its supply voltages.

The drawing also includes an embodiment of an electric circuit used to adjust the rotational speed of this air conveying device 12.

The duct system 11 is provided with a vertical main duct 16, in which an injector 17 is arranged for each floor of the building and from which a branch duct 1 9 in each case leads to a used air outlet 18 of a room 21 which is to be ventilated and which may preferably be a bathroom or toilet.

All the used air in the illustrated system is exhaust air.

Each used air outlet 18 is provided with an aircore choke device 20, which can be moved between a first and a second position by an actuating drive, which is not shown, the first position of the air-core choke device throttling the air to a considerable degree and the second position corresponding to its completely open position.

Each air-core choke device 20 is provided with a limit switch 22, which is formed as a microswitch and which, in order to provide a better overall view, has been drawn at a distance from the air-core choke device 20, although it is incorporated in the frame of the air-core choke device 20 and in this case preferably actuated by the adjusting lever which adjusts the lamellae of the air-core choke device. In a manner which is known per Se, the adjusting lever may preferably be actuated by a heated bimetal or possibly also by another, preferably slow servomotor. The heating coil of the bimetal is switched on and off by means of an associated switch, which is switched on when the relevant room 21 is used and switched off again when the room is vacated.

An electric storage circuit 25 associated with the air-core choke devices 20 is provided in this embodiment with the microswitches 22 in series with a respective resistor 27 in branch circuits which are connected in parallel with one another and which are inserted in a circuit 35, supplied by a direct current source 26. Another branch circuit, connected in parallel, is provided and comprises a resistor 27' but no switch. The resistors 27 and 27' may advantageously be of the same size.

A chain of four relays 30-33 is inserted in series in the supply line 28 for this storage circuit 25 as an evaluation circuit for the storage circuit 25, the switch contacts 30' to 33' of which relays are connected to the control device 34 which can alternatively switch in a total of four rotational speed stages of the air conveying device 1 2 by means of switching means controlled by the relay contacts 30' to 33' by alternatively applying the four different output voltages of a regulating transformer 14 to the motor 13 as the supply voltage.

The lowest rotational speed of the air conveying device 1 2 is switched in if only the relay contact 30' of the first relay 30 is closed. The second rotational speed stage of the air conveying device 12 is switched in if the relay contact 31' of the second relay 31 is also closed. The third rotational speed stage of the air conveying device is switched in if the relay contact 32' of the third relay 32 is closed and the fourth rotational speed stage, i.e. the highest rotational speed of the air conveying device 12 is switched in if the relay contact 33' of the fourth relay 33 is closed.

Current constantly flows through the resistor 27' as long as the on-off switch 36 of the circuit 35 is switched on. The starting current, upon the attainment of which the first relay 30 responds by closing its relay contact 30', is such that this relay contact 30' is constantly closed as long as the main switch 36 is switched on. When the main switch 36 is switched on, the air conveying device 12 thus operates at least at its lowest rotational speed, is therefore at least switched in to the first rotational speed stage, but can be switched over to the higher rotational speed stages by closing the microswitches 22. For this purpose the starting currents, to which the relays 31,32 and 33 respond, are of different sizes such that the second relay contact 31' is only closed as long as at least one of the four microswitches 22 is closed.It remains closed when other microswitches 22 are switched on, but it is opened again as soon as all the microswitches 22 are opened. The relay contact 32' of the third relay 32 is only closed if at least three microswitches 22 are closed and the relay contact 33' of the fourth relay 33 is only closed if at least three microswitches 22 are closed. The first, lowest rotational speed stage is therefore set if no microswitch 22 is closed and therefore none of the rooms 21 are being used. If a single room 21 is used, only one of the four microswitches 22 is closed, as a result of which the second rotational speed stage of the air conveying device 12 is switched in.If two rooms 21 are used and therefore two microswitches 22 closed, the third rotational speed stage is correspondingly switched in and if three or all four of these rooms 21 are used and three or all four microswitches 22 correspondingly closed, the fourth rotational speed stage is switched in. The third rotational speed stage is again accordingly switched in if only two microswitches 22 are closed and the second rotational speed stage is switched over to if only one microswitch 22 is closed and the lowest rotational speed stage is switched in if all microswitches 22 are again opened.In the case which has just been described the first to the third rotational speed stages thus comprise a content difference of the storage circuit 25 of one stage in each case, whereas the fourth rotational speed stage comprises a content difference of the storage circuit of two stages. The starting currents, which vary in size, of the relays 31 to 33, may also be different. They can, for example, be such that the first rotational speed stage also remains switched in when one microswitch is closed and the higher rotational speed stages are switched over to when two, three and four microswitches 22 are closed. In this case the first rotational speed stage thus comprises a content difference of the storage circuit 25 of two stages and the other rotational speed stages a content difference of one stage in each case.

When it is closed each microswitch 22 increases by one stage the instantaneous content of the storage circuit 25 formed by the current flowing through the relays 30 to 33 and lowers it by one stage when it is opened again.

Since, in the illustrated system, the adjustment of the content of the storage circuit 25 by one stage tal < es place in a time-delayed manner relative to the moment when the relevant air-core choke device 20 is switched over from one position to the other, the content of the storage circuit 25 is never adjusted, if the relevant air-core choke device 20 is again already switched over into one position, before the store content is adjusted, i.e. the relevant microswitch 22 is opened or closed.

When the main switch 36 is opened, the opening of the relay contact 30 triggers the disconnection of the air conveying device 12, so that no additional switch is necessary for this.

Claims

1. A system for the central ventilation of rooms of a building, preferably of bathrooms and toilets, by means of an air conveying device, preferably by means of a roof ventilator or fan, the rotational speed of which can be adjusted in stages, the air conveying device being connected via a duct system to air outlets of the relevant rooms for the extraction of used air, which air outlets are provided with air-core choke devices which can be adjusted by actuating drives and which are normally in predetermined first positions for strong throttling of the used air in order to maintain basic volumetric flows of the used air and can be switched into second positions, which correspond to their completely, or almost completely open positions, for increased ventilation, characterised in that a store is associated with the air-core choke devices the content of which store can be increased and lowered in predetermined stages, that the content of the store is in each case increased by one stage as a result of the individual air-core choke device being switched into the second position and in each case lowered by one stage as a result of the individual air-core choke device being switched into the first position and that an evaluation device is provided which detects the momentary content of the store and causes the air conveying device to be switched over to its different rotational speed stages as a predetermined function of the content of the store.

2. A system according to claim 1, characterised in that the adjustment of the store by one stage takes place in a time-delayed manner relative to the moment when the relevant air-core choke device is switched over from one position to the other and that the content of the store is never adjusted, if the relevant air-core choke device is again already switched over into one position, before the store content is adjusted.

3. A system according to claim 1 or 2, characterised in that each rotational speed stage lying above the lowest rotational speed stage of the air conveying device comprises a content difference of the store of at least two stages.

4. A system according to one of the preceding claims, characterised in that the lowest rotational speed stage of the air conveying device comprises a content difference of the store of at least two stages.

5. A system according to one of the preceding claims, characterised in that a limit switch, serving to alter the content of the store in stages, is arranged on each air-core choke device and is preferably only switched on when the air-core choke device has almost reached its second position and is only switched off again as a result of the air-core choke device being switched over to its first position.

6. A system according to claim 5, characterised in that the limit switch is a microswitch with switching hysteresis.

7. A system according to one of the preceding claims, characterised in that the air conveying device can be switched to at least three different rotational speed stages.

8. A system according to one of the preceding claims, characterised in that the highest rotational speed stage of the air conveying device comprises a content difference of the store which is greater than the content difference or differences associated with the lower rotational speed stage or stages.

9. A system according to one of the preceding claims, characterised in that the store is an electric or electronic store, is preferably formed by branch circuits of an electric circuit connected in parallel and the evaluation device is an electric or electronic evaluation circuit.

10. A system for the central ventilation of rooms of a building substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.