The present invention relates to a warning device, more specifi- cally to a warning device for warning against conditions favourable for the growth of mould and fungus on a moist permeable surface, said device comprising a housing of a gas impervious material with at least a first compartment, in which the electronic components of the warning device and the power source for the components are located.

It is well known that mould and fungus occurring on in buildings may pose a health risk to people occupying the building e.g. residing or working in it. Mould and fungus typically occur on surfaces, whenever the conditions on the surface are favourable for their growth. The most important condition is the humidity on the surface but temperature and of the factors also have an influence on the growth of mould and fungus.

It is therefore desirable to monitor the humidity of the surface, at least in places where the growth of mould and fungus can be expected. Such places are typically cold places such as on the inside of external walls, around windows, but also badly ventilated places, places where a lot of moisture is introduced, such as bathrooms and kitchens and external walls susceptible to the ingress of water from the exterior.

Devices for such monitoring and warning are well known in the art, and e.g. disclosed in EP-A-1302831, US-A-2005/0156746 and EP-A- 1621901.

These warning devices respond to humidity in the surrounding air and in the vicinity of the surface on which the warning device is mounted. Since these devices respond generally to the humidity of the air, warnings are often given in connection with cooking, showering and other common activities which produce increased levels of humidity. These situations need not pose any problem for persons, who are well aware of this and consequently take appropriate measures, such as airing the room by e.g. opening windows or the like, and keeping the room temperature sufficiently high to reduce condensation on cold surfaces. In fact, these warnings may be considered false positives and constitute a nuisance rather than a helpful warning.

Furthermore these warnings may actually divert the attention of the persons from the fact that occurring mould and fungus is not actually caused by the above mentioned common activities, such as cooking, showering and the like, which produce increased levels of humidity. In some cases the high humidity on the surface is not so much caused by condensation, but rather by ingress of moist through the surface, e.g. through a porous wall. In this case the persons' countermeasures such as airing may be futile, and even lead to frustrations over the fact that the countermeasures does not work.

Based on this, it is the object of the present invention to provide a warning device, which responds to moist on a surface, such as a wall, which is not caused by condensation of moist from the ambient air but primarily by moist permeating the surface.

According to the present invention this object is achieved by a warning device according to the opening paragraph, characterized in that the warning device comprises sealing means adapted to engage said moist permeable surface in order to provide a closed cavity within said housing of gas impervious material.

By providing a closed cavity ingress of moist is only possible through said surface, which, in turn, excludes a response to moisture in the ambient air. This provides a reliable detection of moist permeating the surface, and may reduce the number of warnings which may be perceived as false positives.

According to a preferred embodiment of the invention, said warning device comprises at least one gas pervious barrier, said gas pervious separating the first compartment from a second compartment, where said second compartment is closed by said moist permeable surface, so as to form said closed cavity. This protects the electronics from direct access by the user, whilst still allowing the moist to access the electronics, for detection.

According to another embodiment of the invention, said housing of a gas impervious material comprises a double wall. This further prevents penetration of moist from the ambient air, and thus reduces the risk of influencing the desired detection of moist permeation through the surface.

According to a further embodiment of the invention, the warning device comprises means for issuing an optical warning. An optical warn- ing is an efficient way of warning, which may be achieved with very low power consumption, e.g. using Light Emitting Diodes (LEDs).

According to yet a further embodiment of the invention, the gas impervious material is a translucent material. This allows the optical warning to be visible through the gas impervious material. This, in turn, protects against undesired penetration of moist from the ambient air, because the integrity of the housing of gas impervious material need not be breached.

According to a particularly preferred embodiment of the invention, however, the gas impervious material comprises areas of reduced material thickness. This provides efficient visibility of the optical warning, low power consumption, and a good aesthetic appearance of the warning device from the exterior.

According to yet another embodiment of the invention, the warning device comprises means for issuing an acoustic warning. An acoustic warning in addition to or instead of an optical warning, is advantageous in that it may be perceived, even if the warning device is located in an inconspicuous place, e.g. on a wall behind a sofa.

According a further embodiment of the invention, the warning device comprises switch means located within said first compartment and adapted to clear an issued warning upon user activation from the exterior of said closed cavity. From a purely technical point of view, possibility of clearing an issued warning may be desirable in order to reduce power consumption viewpoint. However, a persisting acoustic warning may be considered a nuisance, e.g. if the warning occurs at nighttime in a bedroom, and being able to just clear the alarm by e.g. pushing the housing of gas impervious material would come in handy.

According to still another embodiment of the invention, warning device according to any one of the preceding claims wherein said electronics comprises a pressure sensor. This allows the integrity of the closed cavity within said housing of gas impervious material to be checked. If the integrity of the closed cavity is all right, pressing the housing of gas impervious material would lead to a detectable pressure increase verifying this. If there is a leak, e.g. if the sealing against the surface is insufficient, then pressing the housing would not lead to the expected pressure increase, thus indicating that the closed cavity is open to ingress of moist other than that permeating through the surface.

The invention will now be described in greater detail based on non-limiting exemplary embodiments and with reference to the sche- matic drawings, on which :

Fig. 1 is an exploded view of a first embodiment of the warning device according to the in invention,

Fig. 2a is a bottom plan view of the warning device of Fig. 1,

Fig. 2b is a side view of the warning device of Fig. 1,

Fig. 2c is a top plan view of the warning device of Fig. 1,

Fig. 3 is a cross-sectional view of the warning device of Fig. 1 taken along the line III-III in Fig. 2b,

Fig. 4 is an exploded view of a second embodiment of the warning device according to the in invention,

Fig. 5a is a bottom plan view of the warning device of Fig. 4,

Fig. 5b is a side view of the warning device of Fig. 4,

Fig. 5c is a top plan view of the warning device of Fig. 4,

Fig. 6 is a cross-sectional view of the warning device of Fig. 4 taken along the line VI-VI in Fig. 5b,

Fig. 7 is a perspective view of the inside of a housing part of the warning device of Fig. 4,

Fig. 8 is an exploded view of a third embodiment of the warning device according to the in invention,

Fig. 9a is a bottom plan view of the warning device of Fig. 8, Fig. 9b is a side view of the warning device of Fig. 8,

Fig. 9c is a top plan view of the warning device of Fig. 8,

Fig. 10 is a cross-sectional view of the warning device of Fig. 8 taken along the line X-X in Fig. 9b,

Fig. 11 is an exploded view of a fourth embodiment of the warn- ing device according to the in invention,

Fig. 12a is a bottom plan view of the warning device of Fig. 11, Fig. 12b is a side view of the warning device of Fig. 11,

Fig. 12c is a top plan view of the warning device of Fig. 11, Fig. 13 is a cross-sectional view of the warning device of Fig. 11 taken along the line XIII-XIII in Fig. 12b, and

Fig. 14 is a diagram showing warning zones corresponding to various values of relative humidity vs. temperature.

Turning first to Fig. 1 an exploded view of a first embodiment of a warning device 1 according to the invention is shown. The warning device 1 comprises a housing 2 of a gas impervious material, such as a plastic material. For reasons which will be explained further below, the gas impervious material of the housing 2 is preferably also translucent. The housing 2 has a generally rotational symmetric shell shape, so as to provide an internal compartment in which a printed circuit board 3 carrying at least some of the electronic components of the warning device 1 is accommodated. The warning device 1 comprises an o-ring 4 serving as sealing means adapted to engage on one side a moist permeable surface such as a wall (not shown) on which the warning device 1 is to be mounted. The o-ring is preferably of an elastomeric material such as natural or synthetic rubber. The warning device 1 further comprises a generally circular gas pervious barrier 5, such as a metal plate with perforations 6 in order to make it gas pervious. The other side of the o-ring 4 engages the gas pervious barrier 5. As can be seen in Fig. 3, the gas pervious barrier 5 preferably has a recess 16 at the periphery in order to accommodate and ensure correct location of the o-ring 4. The perforations 6 are generally located centrally, so as to be surrounded by the o- ring 4 and keep the outer parts of the gas pervious barrier 5 at the periphery gas impervious. The edge of the gas pervious barrier 5 is adapted to engage slits 7 in the housing 2 so as to connect the two. The width of the edge of the gas pervious barrier 5 and the width of the slits 7 are adapted to each other so as to allow the edge to seal the slit against ingress of moisture. However, as can be seen in Fig. 3, the housing 2 preferably comprises a double wall comprising an outer wall 9 and an inner wall 10, in order to further increase the sealing between the gas pervious barrier 5 and the housing 2. The outer wall 9 comprises the slit 7, in which the edge of the gas pervious barrier 5 engages. The inner wall 10 engages the surface of the gas pervious barrier 5 in a perpendicular direction.

When the warning device 1 in the assembled state shown in Fig. 2a-2c is mounted on a moist permeable surface, e.g. by means of a screw or a bolt (not shown) through a central hole 8 in the gas pervious barrier 5, the gas pervious barrier 5 separates the warning device 1 into two compartments, i.e. a first compartment, in which the printed circuit board 3 is accommodated, and a second compartment, sealed against the moist permeable mounting surface by the o-ring 4. Thereby a subdivided, closed cavity is formed within said warning device 1, delimited by the moist permeable surface, the o-ring 4, the outer parts of the gas pervious barrier 5 and the housing 2.

Since the cavity is enclosed by gas impervious parts on all sides except the moist permeable surface, the only moist which will enter into the cavity will enter via the moist permeable surface, except of course a negligible amount trapped when the housing 2 is mounted on the barrier 5, after the latter has been mounted on the surface. Accordingly, the humidity measured by the electronics in the first compartment will originate from the moist permeable surface and the humidity within the cavity will be in equilibrium with the humidity of the material forming the moist permeable surface.

Turning now to Figs. 4 to 7 a second embodiment of a warning device 1 according to the invention is shown. For easy reference, parts identical with or corresponding to parts described in connection with the first embodiment above, will have same reference numerals.

Like the first embodiment of the warning device of Fig. 1 the second embodiment of the warning device 1 shown in Fig 4, comprises a housing 2, a printed circuit board 3 a gas pervious barrier 5 and a sealing member 4. The materials are preferably the same as mentioned in connection with the first embodiment of the warning device 1.

Unlike the first embodiment where the gas pervious barrier 5 is to be mounted on the moist permeable surface with the interposed sealing member 4 and the cavity formed by the subsequent mounting of the housing 2, the barrier member 4 is secured to the housing 2, prior to the mounting on the moist permeable surface, e.g. during manufacture. The gas pervious barrier has holes 11 through which screws or bolts 12 may pass and engage suitable receiving means to secure it to the housing 2. The receiving means may take any suitable form but are preferably provided as hollow towers 13 formed on the inside of the housing 2, as can be seen in Figs. 6 or 7. A sub-assembly comprising the first compart- ment may thus be provided already at manufacture, whereas the second compartment is provided when the subassembly is subsequently mounted on the moist permeable surface with the sealing member 4 interposed between the gas pervious barrier 5 and the moist permeable surface. For this mounting the housing has been provided with a central passage 14 for receiving a screw or a bolt 15. As can be seen in Fig. 6 the passage 14 is adapted to extend all the way to the gas pervious barrier 5 and engage it, so as to avoid penetration of moist via the passage 14. Preferably, the gas pervious barrier 5 has a recess formed around the central hole 8 so that the end of the passage 14 is below the overall surface of the gas pervious barrier 5 before engaging it, thereby further reducing the risk of penetration of moist into the first compartment and the cavity.

As can further be seen from Fig. 6, in the second embodiment of the warning device 1, the recess 16 at the periphery of the gas pervious barrier 5 allows the sealing member to not only seal the cavity against the moist permeable surface, but also to seal the interface between the housing 2 and the gas pervious barrier 5, so that moist will only enter into the first compartment via perforations 6 in the gas pervious barrier 5.

Thus, when the warning device 1 according to the second embodiment is mounted on a moist pervious surface by means of the central screw or bolt 15, the cavity is also enclosed by gas impervious parts on all sides except the moist permeable surface. Accordingly, the moist which will enter into the cavity will enter via the moist permeable sur- face, except of course a negligible amount trapped in the subassembly and below the sealing member before and during mounting. Accordingly, also in the second embodiment the humidity measured by the electronics in the first compartment will originate from the moist permeable sur- face and the humidity within the cavity will be in equilibrium with the humidity of the material forming the moist permeable surface.

Returning now to Fig. 7 it can be seen that a number of indentations or recesses 17 are formed on the inside of the housing 2. In the illustrated embodiment the number of recesses is ten. Since, as can be seen in Figs. 4 and 5c the outside of the housing 2 is smooth, it will be understood that the material thickness of the wall of the housing 2 is reduced at these recesses. Though not visible in any other figures, it is to be understood that the housing 2 of the first embodiment and the third embodiment, which will be described below, may also have such re- cesses.

These recesses are located in such a manner that they register with a corresponding number of light sources, preferably LEDs 18, mounted on the printed circuit board 3. The LEDs 18 are configured to light up in predetermined patterns so at to provide an optical warning about the hum id ity of the surface on which the warning device 1 is mounted. One such pattern could be the number of lit LEDs 18 indicating the potential risk for mould or fungus, the more lit, the higher the risk. The LEDs 18 could also involve a color coding, such as green/amber/ red. The patterns and color combinations is a matter of preference and choice, as is the number of LEDs 18 used. Since the housing 2 is made of translucent material the LEDs 18 are readily visible through the housing 2 even without the recesses, but the recesses further increases the visibility, which, in turn, allows the power consumption to be kept down. Simply using reduced thickness of the wall is advantageous, as the inte- grity of the housing 2 is preserved, whereas the use of e.g. transparent inserts or having the LEDs penetrate the housing 2 would entail a risk of inducing undesired passages through which moist could penetrate.

Referring still to Fig. 7, it will be noted that the inside of the housing 2 is provided with small protrusions 19. The protrusions 19 have cylindrical portions 20. These cylindrical portions are adapted to engage corresponding holes 21 in the printed circuit board 3, so as to position and hold the printed circuit board 3. Though not shown, the cylindrical portions may be deformed after the printed circuit board 3 has been po- sitioned, e.g . by melting to form a rivet head which will further secure the printed circuit board 3 and seal the holes 21.

Turning now to Figs. 8 to 10, a third embodiment of the present invention is shown. Like the first and second embodiments the third embodiment provides a closed cavity allowing the secure detection of moist penetrating from a moist permeable surface. However, in addition to the closed cavity according to the invention, a further chamber which is open to the ambient air is provided, so as to also allow detection of air humidity. Due to the separate chamber and the cavity according to the invention, the warning device may not only securely warn against moist penetrating from the surface, by also against moist in the air. Unlike the prior art, it is however able to discriminate, and thus e.g. issue different warnings based on different conditions for the two detections.

Referring first to Fig. 8 it can be seen that like the first embodiment of Fig. 1 the warning device 1 according to the third embodiment comprises a housing 2, a printed circuit board 3, a gas barrier pervious barrier, and a sealing member. The holes 6 in the gas pervious barrier 4 are larger than those of the first and second embodiment. The size and number of the holes 6 is largely a matter of choice, and the different configurations shown in the three respective embodiments, are fully in- terchangeable between the embodiments. Moreover, the skilled person will understand that numerous other configurations are possible, including non-circular holes, e.g. slits.

Also, in the third embodiment, the holes 6 are located centrally. Thus, when the warning device 1 in the assembled state shown in Fig. 9a-9c is mounted on a moist permeable surface, e.g . by means of a screw or a bolt (not shown) through the central hole 8 in the gas pervious barrier 5, the gas pervious barrier 5 separates the warning device 1 into two compartments, i.e. a first compartment, in which the printed circuit board 3 is accommodated, and a second compartment, sealed against the moist permeable mounting surface by the o-ring 4. However, unlike the first embodiment and the second embodiment, the top part of the housing 2, has perforations 22 allowing moisture to penetrate. Since it is essential for the invention that the detection of moist penetrating through the moist permeable surface is not influenced by moist from the air the printed circuit 3 is used to subdivide the first compartment into a first compartment part forming part of the cavity, and a second compartment part open to the surroundings. To ensure that moisture does not penetrate from the second compartment part to the first compart- ment part second sealing member 23, such as a second o-ring, is provided, in order as to seal the printed circuit board 3 against the inner wall of the housing 2, as can be seen in Fig 10.

Thus, when, in the assembled state, the warning device 1 is mounted on a moist permeable surface, the gas pervious barrier 5 sepa- rates the warning device 1 into two compartments, i.e. a first compartment, in which the printed circuit board 3 is accommodated to form a sealed, and a second compartment, sealed against the moist permeable mounting surface by the o-ring 4. Thereby a subdivided, closed cavity is formed within said warning device 1, delimited by the moist permeable surface, the o-ring 4, the outer parts of the gas pervious barrier 5, the printed circuit board 3, the second sealing member 23, and the housing 2.

Turning now to figs. 11 to 13 a further preferred embodiment is shown. In this embodiment an operating button is 25 is provided in an aperture 24 in the housing 2. The operating button is connected to the electronics of the printed circuit board 3, and allows interaction with the warning device 1, such as suppressing or suspending an alarm.

Since, like in the third embodiment, the aperture 24 in top part of the housing 2, constitutes a perforations which at least potentially 22 allows moisture to penetrate, the printed circuit 3 is also here used to subdivide the first compartment. The arrangement corresponds to that of the third embodiment, i.e. subdividing the first compartment into a first compartment part forming part of the cavity, and a second compartment part potentially open to the surroundings. Thus, to ensure that moisture does not penetrate from the second compartment part to the first compartment part second sealing member 23, such as a second o- ring, is provided, in order as to seal the printed circuit board 3 against the inner wall of the housing 2, as can be seen in Fig 13.

Since the warning device 1 according to the invention comprises a closed cavity into which ambient air may not enter, except though the mounting surface, i.e. the wall on which the warning device is mounted, the humidity of the air trapped within the closed cavity reflects the humidity of the wall. The temperature inside the warning device 1 will also correspond to the temperature of the wall constituting the mounting surface. The electronics on the printed circuit board 3 is adapted to measure both the temperature and the humidity inside the warning device 1, and may thus also detect relative humidity of the air inside the closed cavity.

Growth of mould and fungus depend on a combination of relative humidity and temperature being favourable for growth, cf. e.g. Se- delbauer, K. "Prediction of mould fungus formation on the surface of and inside building components." [Online] Available from Internet: < URL: http://www.ibp.fraunhofer.de/content/dam/ibp/en/documents/ks _disser tation_etcml021-30729.pdf>.

The electronics on the printed circuit board 3 furthermore comprises electronics for predicting, based on measurements of temperature and humidity, the risk of growth of mould and fungus, and for issuing suitable warnings. The means for issuing warnings include the LEDs 18 but may also include an acoustic warning, e.g. for the highest level of warning. The actual electronics for predicting the risk of growth of mould and fungus is not considered important for the present invention, but preferably includes a suitably programmed microprocessor.

In fig. 14 four warning zones, A to D, are depicted in a diagram showing relative humidity vs. temperature. The skilled person will know that there could be other numbers of warning zones. In the warning zone A mould and fungus will rarely be a problem. In the warning zone B, mould and fungus would be expected to grow within 16 to 64 days. In the warning zone C mould and fungus would be expected to grow within 4 to 16 days. In warning zone D mould and fungus would be expected to grow within 1 to 4 days. As will be evident, urgency increases from warning zones A to D, and accordingly do the warning levels. In warning zone A there is no problem and no warning should be issued. Measure- ments of humidity and temperature could be made once or twice a day in order to keep power consumption down. If however the temperature of humidity changes to a combination falling inside the warning zone B, the frequency with which the measurements are made should be increased, e.g. to every 2 to 3 hours or so. If subsequent measurements remain inside the warning zone B, a warning should be given e.g . by switching on a first LED 18 (or at least a suitably low number of LEDs 18). Warnings should not be given off too early in order to avoid unnecessary alarming, and preferably the alarm corresponding to warning zone B is only given off if the subsequent measurements remain in the warning zone B for several days, e.g. four days. If subsequent measurements fall within warning zone A again the warning may be cancelled. If on the other hand the combination of relative humidity and temperature changes to the worse and fall into warning zone C, urgency increases and the measuring frequency is further increases, e.g. to mea- surements every half hour or so. If subsequent measurements show that the conditions persist increased a suitable number of further LEDs 18 are lit to indicate the increased urgency of the warning. Since the urgency is greater this is preferably done after a single day. If subsequent measurements show that the conditions are back to the warning zones A or B the alarm level and the measuring intervals could be reduced accordingly. If things get even worse and warning zone D is entered the measuring frequency will be increased even further, e.g. every 5 or 10 minutes or even more frequent, and an alarm be given off after 12 hours if the conditions persist. If not the alarm levels and measuring frequencies will be reduced accordingly.

The alarm, especially in the warning zone D preferably involves lighting all LEDs 18 and could include an acoustic warning. Acoustic warnings could be used at other warning levels too. However, since acoustic warnings are more penetrating they may quickly constitute a nuisance to a person once alerted to the problem. As an alternative to or in combination with the use of the number of LEDs 18 lit as an indication of urgency the LEDs could include different colours green/amber/ red as indicated above, e.g. by lighting first a few green LEDs for warning zone B, then (additional) amber LEDs, and finally (remaining) red LEDs.

Acoustic warnings for lower warning levels are thus generally not preferred. However, for the fourth embodiment of the invention, which including a push button, this is different because push button could be used to allow the alerted person to suspend the warning for a predetermined time.

In any case it is considered of less importance to the present invention how the alarm is presented to the persons to be alerted, and the skilled person will be able to devise numerous solutions to this.

Furthermore, he will understand that the above is merely an ex- ample of a preferred simple way to give off an alarm while at the same time keeping the number of false alarms low. The skilled person will readily be able to devise more sophisticated measurement and evaluation schemes, than those exemplified in order to further reduce the number of false alarms. Such evaluation schemes could involve statistical and temporal analysis of variations between measurements.

The skilled person will also know that mounting the warning device using screws or bolts is also merely an exemplary embodiment. Other means such as double adhesive tape, glue, adhesive putty, such as sticky tack or the like. In particular adhesive putty could be used where the warning device is to be mounted temporarily, e.g. in connection with sale of real estate.