MOISTURE MONITORING SYSTEM FOR BUILDINGS

• US 20090033507A1
• Filed: 08/03/2007
• Published: 02/05/2009
• Est. Priority Date: 08/03/2007
• Status: Active Grant

• Current Assignee: Detec Systems LLC
• Original Assignee: Detec Systems LLC
• Inventors: Vokey, David E.
• Granted Patent: US 7,768,412 B2
• Time in Patent Office: Days
• US Class Current: 340/604
• CPC Class Codes: G08B 21/20 responsive to moisture

Abstract

A method of monitoring moisture in a building is carried out using moisture detectors, which provide an output resistance value ranging from a dry value in the absence of moisture and different wet values in the presence of moisture depending on the quantity of moisture. Rather than emit an alarm based solely on a moisture threshold, a risk assessment of potential damage is calculated for at least a part of the building using the wet values from the moisture detectors for the sensor zones using as input data the wet values and as a first additional factor a value which is indicative of a total area of the moisture as provided by the number of sensor zones that are responding with a wet value and as a second additional value the number of consecutive time periods that the sensor zone has reported wet value. The calculation can use computer modeling to calculate a risk factor for growth of mold or a risk factor for growth of timber decay fungi

Claims

1. A method of monitoring moisture in a building comprising:

providing a plurality of moisture detectors, each having a detector parameter with a range of values ranging from a dry value in the absence of moisture and different wet values in the presence of moisture depending on the quantity of moisture;

dividing the building into a plurality of zones;

providing a plurality of sensor units each associated with a respective one of said zones;

locating the moisture detectors such that each zone contains at least one of the moisture detectors;

connecting each sensor unit to said at least one moisture detector in the respective zone;

providing a common monitoring unit for cooperation with a plurality of the sensor units;

causing the common monitoring unit to periodically poll each of the sensor units to obtain the value of the detector parameters of the at least one moisture unit connected thereto;

and performing a risk assessment calculation of potential damage for at least a part of the building using the wet values from the moisture detectors for the sensor zones in said at least a part;

wherein the risk assessment calculation is effected using the different wet values from a plurality of the moisture detectors in conjunction with at least one additional factor indicative of potential damage to the part of the building.

2. The method according to claim 1 wherein the building is divided into a plurality of separate parts to be included in a separate risk assessment calculation and wherein each part includes a plurality of zones each having a plurality of moisture detectors.

3. The method according to claim 1 wherein the risk assessment calculation includes as input data therein the wet values and as the additional factor a value which is indicative of a total area of the moisture as provided by the number of sensor zones that are responding with a wet value.

4. The method according to claim 1 wherein the risk assessment calculation includes as input data therein the wet values and as the additional factor the number of consecutive time periods that the sensor zone has reported wet values.

5. The method according to claim 1 wherein the risk assessment calculation includes as input data therein the wet values and as a first additional factor a value which is indicative of a total area of the moisture as provided by the number of sensor zones that are responding with a wet value and as a second additional value the number of consecutive time periods that the sensor zone has reported wet values.

6. The method according to claim 1 wherein the risk assessment calculation uses modeling to determine a risk factor for growth of mold.

7. The method according to claim 1 wherein the risk assessment calculation uses modeling to determine a risk factor for growth of timber decay fungi.

8. The method according to claim 1 wherein there is provided a temperature sensor and the moisture level calculation includes temperature compensation.

9. The method according to claim 1 wherein the moisture detectors comprise a tape having at least two parallel spaced conductors thereon and a plurality of probes inserted through the conductors at spaced positions therealong and wherein the moisture level calculation includes as input data the number of probes on the tape.

10. The method according to claim 9 wherein the moisture level calculation includes as input data moisture-resistance curves for a material on which the tape is applied.

11. The method according to claim 9 wherein the tape is located at the floor plate of a wall in the zone.

12. The method according to claim 9 wherein the tape is located under penetrations of a wall in the zone.

13. The method according to claim 12 wherein the penetration of a wall in the zone is defined by a window.

14. The method according to claim 1 wherein the risk assessment calculation is calculated using the following formula:

$\begin{array}{cc}R<br><br><br><br>E<br><br><br><br>L=\frac{1}{m<br><br><br><br>x<br><br><br><br>n}<br><br>\underset{k=1}{\overset{m}{\sum <br><br>}}<br><br>\underset{i=1}{\overset{n}{\sum <br><br>}}<br><br>L<br><br><br><br>R_k<br><br>\left(i\right)& \left(1\right)\end{array}$

where REL is the potential average accumulated over all zones in an elevation, m is the number days, n is the total number of zones in the evaluation, LR_k(i) derived from building science modeling for mold growth, is the potential the growth of mold on the i_th day as a function of the average moisture content and temperature during the day.

15. The method according to claim 1 wherein each sensor unit is operable when polled to respond to a coded signal having a characteristic uniquely representing the sensor unit.

16. The method according to claim 9 wherein the tape includes two conductors through which the probes are inserted.

17. The method according to claim 9 wherein the tape includes two conductors for surface moisture and two conductors through which the probes are inserted for material moisture.