The present invention relates to a room with an arrangement for air exchange according to the introductory portion of the independent claim.

Background of the invention

Rooms with arrangements for air exchange may be used in many different ways, such as cleanrooms or fame rooms. If the air exchange ceases, poisonous or explosive substances will no longer be removed from the operator in a fame room and pharmaceutical substances that are being prepared in a cleanroom may be contaminated. It is therefore important that the operator is immediately and clearly made aware air exchange has ceased.

An object of the invention is therefore to provide a room with an arrangement for air exchange which indicates that air exchange has ceased.

These and other objects are attained by a room with an arrangement for air exchange according to the characterising portion of the independent claim.

Summary of the invention

The invention relates to a room 1 to which an arrangement 3, 12 is connected that provides air exchange between the interior of the room and its surroundings. The room is provided with room lighting 11 and a control unit that switches the room lighting off when no air exchange occurs. This has the advantage that an operator receives a clear and immediate indication that air exchange has ceased.

In an advantageous embodiment, the arrangement 3, 12 that provides air exchange between the interior of the room and its surroundings is constituted by a fan 12, and the control unit switches the room lighting off when the fen is not running.

In yet another advantageous embodiment the room comprises at least one pressure gauge lOa-c arranged such that measurement values for at least one pressure difference is generated that reflects air exchange between the interior of the room and its surroundings, where the control unit switches the room lighting off when a pressure difference is not present.

The invention further relates to such a room that is constituted by a fume room.

Brief description of the drawings

Fig. 1 shows a fiime room according to the invention with the lighting switched off Fig. 2 shows the fume room with the lighting switched on Description of a preferred embodiment

A fume room is an arrangement similar to a fiime hood or a fume cabinet, but so large that an operator may work inside the fiime room. Fume rooms are used when handling dangerous, infectious or irritable substances that emit gases or particles that have to be removed from the operator. If the suction is disabled, the substances will not be removed from the operator, and it is important that the operator is immediately made aware of this. A clear indication is that the lighting 1 1 in the fume room is switched off.

Fig. 1 shows a fume room according to the invention with the lighting switched off. The fume room is constituted by a rectilinear volume delineated by four outer walls, a floor 12 and a ceiling 12, and it further comprises an inner wall 8. The fume room is divided into two sections by the inner wall 8, where the larger section constitutes an operator space 2 and the smaller section is a fan and filter space 3. Inside the fan and filter space 3, three fans 12 are arranged that draws air through the perforations 5 in the inner wall, through a filter and the purified air is then emitted through a rear wall 9 that is provided with perforations too.

Air is drawn through a perforated front wall 10 into the operator space, and the air the moves through the operator space towards the inner wall, such that an exchange of air and continuous air movement always takes place in the space. The purpose of this is that potentially

contaminated air rapidly is replaced and sucked away from the operator. The air movement causes a pressure difference between the operator space and the surroundings, a pressure difference between the operator space and the fan and filter space 3, and a pressure difference between the surroundings and the fan and filter space 3. The fume room is provided with three pressure gauges lOa-c, a first pressure gauge 10a in the operator space, a second pressure gauge 10b in the fan and filter space and a third pressure gauge 10c on the exterior of the fume room for gauging the pressure in the surroundings. If aitr movement in the fume room takes place, a pressure difference occurs between all the pressure gauges, and the lighting may be switched on. In the figure, the fans 12 are not running, so no air movement takes place and no pressure difference between the pressure gauges is present. The fume room is provided with a control unit that switches off the lighting 11 when no air movement takes place. The control unit may use input signals indicating that the fans are standing still or that no pressure difference between the pressure gauges is present, in order to switch the lighting 11 off.

Fig. 2 shows the fume room when the fans are running and the lighting is switched on. When the fans are running, a pressure difference between the pressure gauges occurs, and this information may be used by the control unit to control the lighting.

The described embodiment refers to a fiime room, but obviously the invention may be applied to cleanrooms, or other spaces with air being supplied or drawn from it. The fiime room is here provided with fans, but these may obviously be replaced by pumps or any other type of device that causes air movement. The fan system does not have to be arranged in the fume room, but may be placed somewhere else and connected to the fiime room. The pressure gauges in the presented embodiment gauges absolute pressure and the pressure difference between them is calculated as the difference in pressure between them. Alternatively, pressure gauges may be used that measure pressure difference between two spaces directly.