EP3550085A1

EP3550085A1 - Apparatus for remotely inhibiting bacteria growth in a water supply

Info

Publication number: EP3550085A1
Application number: EP19167177.5A
Authority: EP
Inventors: Martyn SAVAGE
Original assignee: Campbell & Kennedy Maintenance Ltd
Current assignee: Campbell & Kennedy Maintenance Ltd
Priority date: 2018-04-04
Filing date: 2019-04-03
Publication date: 2019-10-09
Also published as: GB2572588A; GB201805533D0

Abstract

An apparatus for monitoring the temperature of water in a hot water system of a building, the apparatus comprising: flow means adapted to selectively prevent or allow hot water to flow from the hot water system to a drain; a temperature sensor adapted to measure the temperature of water flowing to the drain; and a controller connected to the flow means and connected to the temperature sensor for receiving measurement data of the temperature of water flowing to the drain.

Description

The present invention relates to methods and apparatus for inhibiting bacteria growth in a water supply and monitoring compliance in such methods and apparatus. In particular, but not exclusively, the present invention relates to methods and apparatus for inhibiting Legionella growth in a water supply.
All water systems can potentially cause hazard to health through the system becoming colonised and then the subsequent growth of water borne bacteria. The most common of these is Legionella. In the UK, under the Health and Safety At Work Act and the Control of Substances Hazardous to Health Regulations, employers and landlords have responsibility for risk assessing their water system and then putting measures in place to prevent and control the proliferation of bacteria. In the UK, the Health and Safety Executive (HSE) has produced the Approved Code of Practice L8 (ACoPL8) and corresponding technical guidance (HSG274 part 2).
Legionella requires a food source to feed on and grow. Therefore, all water systems should be routinely cleaned and inspected. The bacteria can only grow if the water that it is living in is stagnant and not moving. So, if the water regularly flows then the bacteria do not have a chance to grow. In water below 20 degrees C, the bacteria become dormant. Above 45 degrees C, the bacteria start to die and, from 72 degrees C, the bacteria die instantly. Consequently, one of the measures that is used to control and prevent the proliferation of Legionella is to ensure that the hot water in a hot water system of a building is, for at least some of the time, at a sufficiently high temperature to kill bacteria.
Therefore, a common approach for inhibiting bacteria growth is to ensure the hot water delivered to the outlet taps has a temperature of at least 50 degrees C within 60 seconds of opening the tap. Conventionally, this is performed manually and it is necessary for operatives to visit each test site, draw water from each outlet and record the temperature of the water after 60 seconds. Typically, this is done monthly.
Another approach that is recommended is for the stored water temperature (which is usually recommended to be stored at at least 60 degree C) to be regularly raised to 72 degrees C. The water is then circulated round the system and each outlet opened one at a time and the water drawn through each outlet for 60 seconds until all outlets have been opened. This is known as a pasteurisation cycle and it should be performed if a hot water system has been non-operational for a prolonged period. This should also be done annually. However, this process is potentially hazardous as there is a risk of scalding to users of the outlets in the building.
According to a first aspect of the present invention there is provided an apparatus for monitoring the temperature of water in a hot water system of a building, the apparatus comprising:

flow means adapted to selectively prevent or allow hot water to flow from the hot water system to a drain;
a temperature sensor adapted to measure the temperature of water flowing to the drain; and
a controller connected to the flow means and connected to the temperature sensor for receiving measurement data of the temperature of water flowing to the drain.

Optionally, the apparatus includes communication means for communicating the measurement data to a remote location. The remote location may be a control station.
Alternatively or in addition, the apparatus may include a memory for storing the measurement data.
Optionally, the communication means comprises a transmitter device for wirelessly transmitting the measurement data to the remote location.
Optionally, the controller is adapted to receive control instructions from a remote location via the communication means.
Optionally, the communication means comprises a receiver device for wirelessly receiving the control instructions.
Optionally, the communication means comprises a transceiver device.
According to a first embodiment of the invention, the apparatus may include a sampling conduit having an inlet which is connectable to the hot water system and an outlet which is connectable to the drain.
The flow means may comprise a valve provided along the conduit for selectively allowing or preventing the flow of hot water within the conduit to the drain.
Optionally, the controller is coupled to the valve for selectively opening the valve. Optionally, the controller is connected to a motor adapted to operate the valve.
Optionally, the controller is adapted to open the valve in response to an open valve control instruction being received.
Optionally, the controller is adapted to close the valve in response to a close valve control instruction being received.
Alternatively or in addition, the controller may include a timer and the controller may be adapted to open the valve at one or more pre-set times. Alternatively or in addition, the controller may be adapted to close the valve at one or more pre-set times or after the expiry of a pre-set time interval from when the valve was opened.
According to a second embodiment of the invention, the apparatus may be mountable to an existing tap of the hot water system.
Optionally, the apparatus includes a motor for operating the tap.
The apparatus may include clutch means such that the user may manually operate the tap. Alternatively or in addition, the apparatus may include a user control switch which causes the motor to turn the tap.
Optionally, the temperature sensor is in contact with the tap. Optionally, the temperature sensor is in contact with the stem of the tap.
According to a third embodiment of the invention, the apparatus may be adapted to replace an existing tap of the hot water system.
The apparatus may include a valve for selectively allowing or preventing the flow of hot water to the drain. The apparatus may include a motor adapted to operate the valve. The valve may be operable by the controller or by a user control.
Optionally, the controller is adapted to open the valve in response to the performing of a pasteurisation cycle. Optionally, the controller is adapted to sense when a pasteurisation cycle has been initiated.
The controller may be adapted to open the valve in response to the measured temperature being greater or equal to a predetermined value. The predetermined value may be greater than 60 degrees C. The predetermined value may be around 70 degrees C.
Alternatively or in addition, the controller may be connected to a boiler control unit which is adapted to control the boiler for performing a pasteurisation cycle. Optionally, the command from the boiler control unit to the boiler to perform the pasteurisation cycle is also received by the controller.
Optionally, an apparatus is provided at one or more hot water outlets or sentinel points of the building. Optionally, an apparatus is provided at each hot water outlet of the building.
According to a second aspect of the present invention there is provided a method of monitoring the temperature of water in a hot water system of a building, the method comprising the steps of:

using a controller, selectively preventing or allowing hot water to flow from the hot water system to a drain;
using a temperature sensor, measuring the temperature of water flowing to the drain; and
connecting the controller to the temperature sensor so that the controller can receive measurement data of the temperature of water flowing to the drain.

Optionally, the method includes communicating the measurement data to a remote location using the controller.
Alternatively or in addition, the method may include storing the measurement data using the controller.
Optionally, the controller includes a transmitter device for wirelessly transmitting the measurement data to the remote location.
Optionally, the method includes sending control instructions from the remote location to the controller.
According to a first embodiment of the invention, the method may include connecting the inlet of a sampling conduit to the hot water system and connecting an outlet of the sampling conduit to the drain.
The method may include locating a valve along the conduit for selectively allowing or preventing the flow of hot water within the conduit to the drain.
According to a second embodiment of the invention, the method may include mounting an apparatus comprising the controller to an existing tap of the hot water system. The apparatus includes a motor for operating the tap.
According to a third embodiment of the invention, the method may include replacing an existing tap of the hot water system with an apparatus comprising the controller.
The apparatus may include a valve for selectively allowing or preventing the flow of hot water to the drain. The apparatus may include a motor adapted to operate the valve. The valve may be operable by the controller or by a user control.
The method may include opening the valve in response to the performing of a pasteurisation cycle. Optionally, the controller is adapted to sense when a pasteurisation cycle has been initiated.
The invention will be described below, by way of example only, with reference to the accompanying drawing, in which:
Figure 1 is a schematic view of an apparatus in accordance with a first embodiment of the invention.
Figure 1 shows an apparatus 10 for monitoring the temperature of water in a hot water system of a building.
The hot water system comprises pipework 100 connected to a boiler 110 and associated pump 112 for circulating hot water around the building for heating and for supplying hot water to the taps 102 provided at various sink units 104 in the building. The apparatus 10 is provided at each sink unit 104.
The apparatus 10 comprises flow means which is adapted to selectively prevent or allow hot water to flow from the hot water system to a drain.
In the embodiment of Figure 1, a sampling conduit 20 has an inlet 22 which is connected to the pipework 100 leading to the sink 104 via a T piece 106 and an outlet 24 which is connected to a drainpipe 108 of the sink 104 via a second T piece 106. The flow means comprises a motorised valve 30 provided along the conduit 20.
A temperature sensor 40 is provided for measuring the temperature of water flowing to the drainpipe 108. This is a contact sensor which is in contact with the conduit 20.
A controller 50 is connected by extra low voltage wiring 52 to the motorised valve 30 and to the temperature sensor 40. The controller 50 receives the sensed temperature measurement data. The controller 50 includes a transceiver which wirelessly communicates the measurement data to a remote location (not shown). At this remote location is a control station for the personnel who are responsible for ensuring compliance that the hot water system is effectively inhibiting the growth of water-borne bacteria.
The controller 50 can also receive control instructions from the control station via the transceiver. The controller 50 can receive an open valve control instruction and, in response, open the valve 30 to allow water to flow in the conduit 20 to the drainpipe 108. Similarly, the controller 50 will close the valve 30 in response to a close valve control instruction being received.
In use, the control station can send an open valve control instruction to the controller 50 which will then open the valve 30. Hot water will flow in the sampling conduit 20 to the drainpipe 108. The temperature sensor 40 will sense the temperature of the flowing water. The temperature data is sent to the controller 50 which is then wirelessly transmitted to the control station.
This continues for at least 60 seconds, after which it is determined if the temperature has reached 50 degrees C. If it has then the system is in compliance. If not, remedial action can be undertaken. After the period of at least 60 seconds, the control station can sent an instruction to the controller 50 to close the valve 30. Alternatively, the controller 50 can include a timer and the controller 50 can close the valve 30 after the expiry of a pre-set time interval of at least 60 seconds.
The apparatus can also be used when remotely performing a pasteurisation cycle. The boiler 110 can be adapted such that it can be controlled from the control station. An advantage of remote operation (and utilising the invention) is that it is not necessary to arrange access to the building for operatives. Therefore, the pasteurisation cycle can be performed at a time of zero or low occupancy, such as during the night. Consequently, the risk of a person in the building being scalded when using the tap 102 is zero or low.
Also, as this is a time of zero or little water use by users, which could affect the results of the testing. It should also be noted that the hot water is flowing from the pipework 100 direct to drain, rather than out of the tap 102 and to the drain via the sink hole. This further reduces the risk of scalding.
In use, the control station may send a command to the boiler 110 to raise the water temperature to 72 degrees C. Once this has been achieved, the water is then circulated around the system by the pump 112. The control station now sends an instruction to the controller 50 to open the valve 30.
Alternatively, the controller 50 can be adapted to sense when a pasteurisation cycle has been initiated. For example, the controller 50 can be connected to a boiler control unit adapted to control the boiler 110 for performing a pasteurisation cycle. The command from the boiler control unit to the boiler 110 to perform the pasteurisation cycle can then be also received by the controller 50.
The temperature sensor 40 can be used to confirm that the water is at the correct temperature. After performing the pasteurisation cycle, the control station can control the boiler 110 to reduce the water temperature back to normal conditions. The control station also instructs the controller 50 to close the valve 30.
According to a second embodiment of the invention, the apparatus 10 can be mountable to an existing tap 102 of the hot water system. The apparatus can include a motor for operating the tap 102. Clutch means can be provided so that the user may manually operate the tap 102. Or there may be a user control switch which causes the motor to turn the tap 102. In this embodiment, the apparatus 10 can be a self-contained unit, incorporating the controller 50. However, the valve 30 may be omitted since the tap 102 provides this function. The temperature sensor 40 may be in contact with the stem of the tap.
According to a third embodiment of the invention, the apparatus 10 may replace the existing tap 102. The apparatus 10 would then include the valve 30 and motor for operating the valve 30. The valve 30 can be operable by the controller 50 or by a user control.
Various modifications and improvements can be made to the above without departing from the scope of the invention.

Claims

An apparatus for monitoring the temperature of water in a hot water system of a building, the apparatus comprising:
flow means adapted to selectively prevent or allow hot water to flow from the hot water system to a drain;

a temperature sensor adapted to measure the temperature of water flowing to the drain; and

a controller connected to the flow means and connected to the temperature sensor for receiving measurement data of the temperature of water flowing to the drain.
An apparatus as claimed in claim 1, wherein the apparatus includes communication means for communicating the measurement data to a remote location.
An apparatus as claimed in claim 2, wherein the communication means comprises a transmitter device for wirelessly transmitting the measurement data to the remote location.
An apparatus as claimed in claim 2 or 3, wherein the controller is adapted to receive control instructions from a remote location via the communication means.
An apparatus as claimed in claim 4, wherein the communication means comprises a receiver device for wirelessly receiving the control instructions.
An apparatus as claimed in any preceding claim, wherein the apparatus includes a sampling conduit having an inlet which is connectable to the hot water system and an outlet which is connectable to the drain.
An apparatus as claimed in claim 6, wherein the flow means comprises a valve provided along the conduit for selectively allowing or preventing the flow of hot water within the conduit to the drain, and wherein the controller is coupled to the valve for selectively opening the valve.
An apparatus as claimed in any preceding claim, wherein the apparatus is mountable to an existing tap of the hot water system.
An apparatus as claimed in claim 8, wherein the apparatus includes clutch means such that the user may manually operate the tap.
An apparatus as claimed in any preceding claim, wherein the apparatus is adapted to replace an existing tap of the hot water system.
An apparatus as claimed in claim 10, wherein the apparatus includes a valve for selectively allowing or preventing the flow of hot water to the drain.
An apparatus as claimed in any preceding claim, wherein the controller is adapted to open the flow means in response to the performing of a pasteurisation cycle.
An apparatus as claimed in claim 12, wherein the controller is adapted to sense when a pasteurisation cycle has been initiated.
An apparatus as claimed in any preceding claim, wherein an apparatus is provided at a plurality of hot water outlets of the building.
A method of monitoring the temperature of water in a hot water system of a building, the method comprising the steps of:
using a controller, selectively preventing or allowing hot water to flow from the hot water system to a drain;

using a temperature sensor, measuring the temperature of water flowing to the drain; and

connecting the controller to the temperature sensor so that the controller can receive measurement data of the temperature of water flowing to the drain.