EP4686882A1

EP4686882A1 - System to prevent frost damage to an outdoor heating appliance

Info

Publication number: EP4686882A1
Application number: EP24192148.5A
Authority: EP
Inventors: Guillaume Scheidt
Original assignee: BDR Thermea Group BV
Current assignee: BDR Thermea Group BV
Priority date: 2024-07-31
Filing date: 2024-07-31
Publication date: 2026-02-04

Abstract

A system to prevent frost damage in an outdoor heating appliance arrangement comprising piping, the heating appliance situated in a location potentially exposed to temperatures at or around 0°C and wherein the piping is arranged to hold a fluid capable of freezing at or around 0°C. Such locations can cause freezing and subsequent damage in exposed parts and piping when the temperature is on, around or below 0°C. The system detects loss of contact with the heating appliance whereupon, since loss of contact is a sign that the heating appliance has stopped operation, and unable to reestablish contact, it polls the internet for temperature and/or weather information local to the heating appliance. If the information gathered suggests the heating appliance is at risk of freezing the system signals to perform a draining of the fluid from the piping at the heating appliance.

Description

The invention relates to a system to prevent frost damage in an outdoor thermal appliance arrangement comprising piping.
Many thermal appliances are situated external to the buildings or properties to which they are attached or for which they provide heating, air conditioning or other thermal service.
In a known arrangement a thermal appliance such as a heat pump is sometimes installed in a building with both internal and external units, the internal unit situated for example on an internal wall of the property, and the external unit situated outside. The internal and external units are connected via piping, usually containing a working fluid, and other piping networks are provided to connect the internal unit with respective domestic piping networks.
In environments which are at risk of zero or sub-zero temperatures, that is temperatures either on, or around, or below 0°C, any parts of the thermal appliance and associated piping exposed to outdoor temperatures are at risk of freezing if operation of the device ceases for some reason and the fluid in the apparatus and/or piping is allowed to reach thermal equilibrium with the external temperature. During continued operation of the appliance this is not normally a risk. However, when for example a heat pump using water as a fluid is switched off, freezing occurs when the water temperature drops sufficiently due to a low outside temperature in winter. In this case there is a risk of freezing in the pipes most exposed to the cold external environment. If such freezing occurs, then the water naturally expands and can break the pipes and/or the heat exchanger. When the heat pump is working, such a risk does not occur because of two factors, the heat pump heats the fluid, and a pump is typically switched on to keep the water moving and avoid icing up.
Any pipe damage and breakage subsequent to freezing of working fluids can result in the risk of later fluid leakage when the thermal appliance, for example heat pump, defrosts and attempts to re-start normal working.
In an effort to reduce the risk of leakage manufacturers have provided different antifreeze solutions, which may depend on the external temperature or the temperature of the working fluid, for example water. These include provision of a water circulation pump to maintain flow, and provision of a heater to maintain temperature. However these only work when the device is connected to a power supply.
Cessation of operation therefore is a risk for freezing when ambient temperatures are around or below the freezing point of any working fluid, and in the case when such a fluid freezes this may cause serious damage to parts, for example the heat exchanger and piping, , causing rupture. This carries a further risk of leakage if an appliance restart is attempted before damage is noted.
Generally operation of any thermal device is controlled by the occupant of a property and therefore any cessation of operation will be swiftly noted and countermeasures, for example draining of the system to remove freezable fluids from the appliance, can be manually undertaken.
However in the event that the occupant is away, and operation ceases unnoticed, for example due to a power cut, the apparatus and piping is at risk of damage. In addition the homeowner or user may simply not be aware of the risk.
CA3106048A1 describes a cloud-controlled intelligent system which automatically captures and calls data of the highest weather forecast temperature of the equipment installation site within a subsequent 24 hour period and during a set time period of the system in order to improve equipment functioning in relation to expected weather conditions and maintain appliance integration. A direct connection with the device without the cloud is also provided.
WO2110093509A3 describes a method of allowing automatic adjustment of a heat pump water heater depending on environmental conditions and includes an interface for indicating a mode of operation, indicating at least one error condition, and to accept user input. The system as described is able to diagnose certain failure conditions and provide advice to a user regarding errors and environmental and other conditions.
Therefore it is an object of the invention to provide a system and method to mitigate the risk of damage due to severe external temperatures.
The object is solved by a system to prevent frost damage in an outdoor thermal appliance arrangement comprising piping, the thermal appliance situated in a location potentially exposed to temperatures at or around 0°C and wherein the piping is arranged to hold a fluid capable of freezing at or around 0°C. This system comprises a server remote from the thermal appliance and in communicative contact with the thermal appliance via a first communicative means. The server is arranged to detect loss of contact with the thermal appliance via the first communicative means, perform n attempts to re-establish contact over a time period T, wherein if after n attempts over the time period T there is still no contact with the thermal appliance the system is arranged to gather available information concerning an external temperature at the location, and further wherein if the information gathered indicates that the external temperature is less than m°C compared to 0°C the system is further arranged to send a signal via a second communicative means, the signal arranged to secure draining of the fluid from the outdoor heating appliance arrangement.
The system of the invention solves the problem by detecting loss of contact with the heating appliance, and acting on an assumption that this is a risk of loss of operation, polling the internet to find information indicative of the surrounding external, or ambient, atmospheric temperature or weather conditions in the locality of the apparatus, and if that information suggests a risk of freezing, then signalling to start drainage of any external pipes.
These actions mitigate the risk of later malfunction of the product due to breakage of pipes or of parts due to freezing.
The invention prevents, or mitigates, frost damage in the sense that it allows for a warning to be sent to a user, operator or installer of a thermal device when local conditions suggest that a loss of power to or in the device would carry a significant risk of frost damage. There may not be any actual loss of power within the thermal device, but the loss of connection, as detected at the remote server is sufficient to start the actions of attempting to re-establish contact, and if this does not work then to perform actions to identify local weather conditions at the site of the thermal device and if these are indicative of freezing conditions then to raise an alarm to start drainage of appropriate fluids.
Exterior local temperature is sometimes referred to as ambient temperature, however 'ambient' within the context of a heat pump product usually refers to temperature at an indoor unit which pumps heat inside, and at the heat pump position.
The outdoor thermal appliance arrangement includes any associated piping. In fact, the invention can apply to and be used to protect simply an arrangement of pipes if they are situated outside a building, and therefore exposed to outdoor temperatures, but are connected or otherwise coupled to a thermal device, for example a heat pump. Therefore an outdoor heating appliance arrangement comprising piping could include, but is not limited to, an externally situated heat pump, the outdoor portion of a heat pump which comprises both indoor and outdoor situated units, the externally situated piping for a heat pump, an externally situated boiler or the externally situated piping for a boiler, the source of heat of a heat pump and its connection for example in the case of a ground source heat pump. In all cases there is some extent of the appliance, either functional appliance parts or merely piping which is either situated externally or situated in such a way that it is exposed to ambient external temperatures.
The invention is particularly relevant for air/water monobloc outdoor units, because these forms of thermal appliance frequently comprise hydraulic piping between outdoor and indoor units, thereby risking exposure to freezing conditions when the weather temperature drops outside. In particular the invention also provides protection to the heat exchanger of such systems which typically include intricate arrangements of pipes and may be prone to breakage if their contents freeze.
The invention has the advantage that by providing a method of frost avoidance, glycol, which is currently relied upon by manufacturers, canbe replaced as a working fluid in the piping networks situated externally to the building. Even if not fully replaced the reliance on glycol can be reduced. For example, it can be at least partially replaced due to use of the invention. Alternatively the invention may be used alongside the use of glycol in which case it forms an additional safety precaution.
In an embodiment the system is arranged to gather available information concerning the ambient or external temperature from the internet via a third communicative means.
In an embodiment the first communicative means is a 4G or 5G wireless connection. It may also use Wi-Fi or Bluetooth to the installation site. Or any other protocol, for example IO Home Control. It can also be a wireless internet connection, for example via a thermal appliance control unit connected via Wi-Fi or wireless internet connection. It can for example be a wireless connection, in particular a Wi-Fi connection or Bluetooth connection, via a room-unit. A room-unit according to this application is a remote interface for communication and/or control of the thermal appliance. The wireless connection can be a direct internet/wireless connection or an indirect connection, wherein the data is also transmitted through Bluetooth, and/or DSL (Digital Subscriber Line, wherein digital data is transmitted over telephone lines utilizing the unused frequencies on the telephone line) and/or optical fiber and/or other wired connection through modules inside the installation site before reaching the internet, such as via the room-unit, wherein the room-unit is connected via Wi-Fi to e.g. a router or modem, wherein the router or modem is connected to the internet via a wired connection, such as optical fiber or DSL.
In many cases manufacturers use an internet connection for wireless monitoring heat pumps. The invention may therefore take advantage of this to perform these additional safety measure. The associated signaling of the invention can go through a server, but could also use a different means of communication without a server. For example, in some cases contact could be via a direct link between a user's phone, for example via an app or application for the thermal appliance, for example heat pump.
In an embodiment the second communicative means is a short message service. It could also be an alarm, or light signal, or mail, or app notification, etc. In fact any means can be used to alert the user, client, operator or installer that there is some form of disconnection that must be solved. The disconnection may be electric, for example a genuine power failure, and this can even be the result of adverse weather conditions, but could just be an internet failure.
The alarm to the user could also simply warn about possible loss of freezing protection mechanisms within the thermal appliance.
In an embodiment the server is also in communication with the heating appliance via the short message service and the short message is a message instructing the heating appliance to drain the fluid from the outdoor heating appliance arrangement.
In an embodiment the server is also in communication with an operator of the heating appliance via the short message service and the short message is a message instructing the operator to drain the fluid from the outdoor heating appliance arrangement. In this case the operator could be a customer or installer or manufacturer providing service for example. In an alternative embodiment the message may instruct the operator to solve the disconnection of power, or to take any required action to protect the device
In an embodiment T = 300 minutes, N = 1, and M = 2.
In an example N may be greater than 1. There may for example be a number of attempts made, say 5, to re-establish contact before remedial actions are taken. This may be useful for example in locations where there are frequent communication drop outs, for example mountainous areas or where communication infrastructure may be unreliable.
Alternative embodiments may focus on time than the number of iterations. For example, connection could be checked every 10 minutes and, if no signal is found after 6 hours, the alert is launched.
In an alternative embodiment T may be a range of between 10 and 7820 mins, or for example between 120 and 500 mins.
In an alternative embodiment instead of waiting for a failure of contact followed by checking the current temperature only, the system could work by integrating forecast temperature data. For example, if it's 1°C very early in the morning, and the forecast is for 5 to 10 degrees during the day, there's nothing to worry about. In this example should contact with the thermal appliance fail then the server already knows that there is limited frost risk, and that therefore no draining of refrigerant is required.
In an embodiment the server is arranged to detect loss of contact by monitoring for contact with the heating appliance.
In an embodiment the server is further arranged to monitor information concerning an external local temperature at the location, and wherein if the monitored information gathered indicates that the ambient temperature is less than p°C above 0°C the system is arranged to increase the rate of monitoring for contact with the heating appliance.
In an embodiment p = 4.
In another aspect of the invention, a method is provided to prevent frost damage in an outdoor heating appliance arrangement comprising piping, the heating appliance situated in a location potentially exposed to temperatures at or around 0°C and wherein the piping is arranged to hold a fluid capable of freezing at or around 0°C, wherein the method is performed in a server remote from the heating appliance and in communicative contact with the heating appliance via a first communicative means. The method comprises detecting loss of contact with the heating appliance via the first communicative means, performing n attempts to re-establish contact over a time period T, wherein if after n attempts over the time period T there is still no contact with the heating appliance the method further comprising, gathering available information concerning an ambient temperature at the location, wherein if the information gathered indicates that the ambient temperature is within m°C of 0°C the method further comprising sending a signal via a second communicative means, the signal arranged to secure draining of the fluid from the outdoor heating appliance arrangement.
In an additional aspect of the invention a frost-resistant heating complex is provided, comprising a heating appliance with outdoor arrangement comprising piping, wherein the piping is arranged to hold a fluid capable of freezing at or around 0°C, and wherein the heating appliance is situated in a location potentially exposed to temperatures at or around 0°C, and a system to prevent frost damage in an outdoor heating appliance arrangement comprising piping according to the invention, and wherein the heating appliance and the system are in communicative contact with each other via a first communicative means, and further where the system is in communicative contact with either the heating appliance or an operator of the heating appliance via a second communicative means, and wherein the heating appliance further comprises a residual tank arranged to receive drained fluid following application of the method of the invention.
In alternative embodiments the fluid can be water comprising an anti-icing adjuvant such as glycol. In these embodiments the temperature threshold value is adjusted to compensate for, or account for, the difference in freezing point of the fluid. For example, if primary 'water' includes water and glycol, the threshold value can be -5°C for example (threshold value depending on the concentration of glycol). The freezing point is 0°C if the fluid contains 0% glycol, decreasing to a freezing point of around -50°C if the fluid contains 60% glycol.
In an embodiment the heating apparatus is a heat pump.
In an embodiment the fluid is water. In particular primary water in a closed circuit.
In an embodiment the heating appliance comprises a communication card to mediate the communicative contact via the first communicative means.
In the figures, the subject-matter of the invention is schematically shown, wherein identical or similarly acting elements are usually provided with the same reference signs.

Figure 1: shows a diagrammatic overview of a heating appliance, system and complex according to the invention.
Figure 2: shows a diagrammatic overview of a method of working the invention including a heating appliance, system and overall complex.
Figure 3: shows the diagrammatic overview of a method of working the invention in operation and involving a heating appliance, system and overall complex.
Figure 4: shows a flow diagram of a method according to the invention.
Figure 5: shows a flow diagram of a method according to the invention.

Figure 1 shows a diagrammatic overview of a heating appliance, system and complex according to the invention. A heat pump comprises indoor unit 1 and outdoor unit 2, connected to indoor unit 1 via piping. Indoor unit 1 comprises an electronic control board connected via a bus 5 to a communication card 6 in communication with a remote server 7, via some communicative means. The communicative means may be a wireless connection.
Figure 2 shows a diagrammatic overview of a method of working the invention including a heating appliance, system and overall complex. Indoor unit 1 connects to server 7 via communication card 6 which in an embodiment is arranged to allow 4G communication. In this arrangement the indoor unit 1 is further connected to a room unit 8 which provides control, and to the wider electrical network 9. In addition the remote server 7 is connected via a connection, which may be wireless or may be a wired internet connection, to internet box 10. Through box 10 the server is able to provide commands to the heat pump 1, 2.
Figure 3 shows the diagrammatic overview of a method of working the invention in operation and involving a heating appliance, system and overall complex. Here some communication breakdown is shown, in which electrical network 9 has failed, and therefore room unit 8 has failed leading to failure of communication with server 7 via communication card 6. This failure of communication will be detected by server 7 which will then attempt to reestablish communication a certain number of times, which may be one, and upon failure will access, or poll, internet information regarding the local temperature at the site of units 1,2 and if the information suggests the local outdoor temperature is lower than a certain value, for example lower than 2°C, or within a certain range, for example between -50°C and 2°C, will send a signal intended to secure draining of any fluid exposed to outdoor temperatures. In this case the signal will be sent via box 10.
Figure 4 shows a flow diagram of a method according to the invention. In this embodiment the status of loss of connection is detected 20 by the remote server, which then takes the action 21 of checking the temperature in the locality of the appliance and if this complies with a certain relationship to a pre-determined threshold 22, in this case if it is above 2°C, no further action is taken, whereas if the temperature is not above, in this case, 2°C the server waits for a period of time 23, in this case 5 hours before checking again 24 to ascertain if communication has been reestablished. If it has 25 then the method ends. If it has not 26 then a signal, or message, is sent to an operator to check power shortage and possibly empty the hydraulic circuit.
Figure 5 shows a flow diagram of an alternative embodiment of the invention in which loss of connection is detected 30 and the server performs N attempts to reestablish connection 31. If connection can be re-established the process ends. If connection cannot be re-established the process proceeds to the action 32 of gathering, or polling, information from the internet about the likely external temperatures at the site of the appliance, and if a comparison 33 suggests that frost or freezing conditions are likely then a signal is sent, 35. If not then the process ends 34.

Reference Signs

1: indoor unit
2: outdoor unit
3: piping
4: electronic control board
5: bus
6: communication card
7: remote server
8: room unit
9: electrical network
10: internet box
20: status point
21: action step
22: comparison step
23: status step
24: decision step
25: end of process
26: action step
30: detection step
31: action step
21: action step
33: comparison step
34: end of process
35: action step

Claims

System to prevent frost damage in an outdoor thermal appliance arrangement comprising piping, the thermal appliance situated in a location potentially exposed to temperatures at or around 0°C and wherein the piping is arranged to hold a fluid capable of freezing at or around 0°C,
the system comprising:
- a server remote from the thermal appliance and in communicative contact with the thermal appliance via a first communicative means, wherein the server is arranged to:

- detect loss of contact with the thermal appliance via the first communicative means,

- perform N attempts to re-establish contact over a time period T, wherein if after N attempts over the time period T there is still no contact with the thermal appliance the system is arranged to

- gather available information concerning an exterior temperature at the location, wherein if the information gathered indicates that the external temperature is less than m°C compared to 0°C the system is further arranged to

- send a signal via a second communicative means, the signal arranged to secure draining of the fluid from the outdoor thermal appliance arrangement.
System to prevent frost damage to an outdoor thermal appliance arrangement according to claim 1, wherein the system is arranged to gather available information concerning the exterior temperature from the internet via a third communicative means.
System to prevent frost damage to an outdoor thermal appliance arrangement according to claims 1 or 2, wherein the first communicative means is a 4G or 5G wireless connection.
System to prevent frost damage to an outdoor thermal appliance arrangement according to claims 1, 2 or 3, wherein the second communicative means is a short message service.
System to prevent frost damage to an outdoor thermal appliance arrangement according to claim 4, wherein the server is also in communication with the heating appliance via the short message service and the short message is a message instructing the thermal appliance to drain the fluid from the outdoor heating appliance arrangement.
System to prevent frost damage to an outdoor thermal appliance arrangement according to claim 4, wherein the server is also in communication with an operator of the thermal appliance via the short message service and the short message is a message instructing the operator to drain the fluid from the outdoor thermal appliance arrangement.
System to prevent frost damage to an outdoor thermal appliance arrangement according to claim 1, wherein
T = 300 minutes,

N = 1, and

M = 2.
System to prevent frost damage to an outdoor thermal appliance arrangement according to claim 1, wherein the server is arranged to detect loss of contact by monitoring for contact with the thermal appliance.
System to prevent frost damage to an outdoor thermal appliance arrangement according to claim 8, wherein the server is further arranged to monitor information concerning an exterior temperature at the location, and wherein if the monitored information gathered indicates that the exterior temperature is less than p°C above 0°C the system is arranged to increase the rate of monitoring for contact with the thermal appliance.
System to prevent frost damage to an outdoor thermal appliance arrangement according to claim 9, wherein
p = 4.
A method to prevent frost damage in an outdoor thermal appliance arrangement comprising piping, the heating appliance situated in a location potentially exposed to temperatures at or around 0°C and wherein the piping is arranged to hold a fluid capable of freezing at or around 0°C, wherein the method is performed in a server remote from the thermal appliance and in communicative contact with the thermal appliance via a first communicative means,
the method comprising:
- detecting loss of contact with the thermal appliance via the first communicative means,

- performing n attempts to re-establish contact over a time period T, wherein if after n attempts over the time period T there is still no contact with the thermal appliance the method further comprising:

- gathering available information concerning an exterior local temperature at the location, wherein if the information gathered indicates that the exterior temperature is less than m°C compare to 0°C the method further comprising:

- sending a signal via a second communicative means, the signal arranged to secure draining of the fluid from the outdoor thermal appliance arrangement.
A frost-resistant thermal complex comprising:
- a thermal appliance with outdoor arrangement comprising piping, wherein the piping is arranged to hold a fluid capable of freezing at or around 0°C, and wherein the thermal appliance is situated in a location potentially exposed to temperatures at or around 0°C,

- a system to prevent frost damage in an outdoor thermal appliance arrangement comprising piping according to claim 1, and wherein

- the thermal appliance and the system are in communicative contact with each other via a first communicative means, and

- the system is in communicative contact with either the thermal appliance or an operator of the thermal appliance via a second communicative means, and

- wherein the thermal appliance further comprises a residual tank arranged to receive drained fluid following application of the method of claim 11.
A frost-resistant thermal complex according to claim 12, wherein the thermal apparatus is a heat pump.
A frost-resistant thermal complex according to claim 12, wherein the fluid is water.
A frost-resistant thermal complex according to claim 12 wherein the heating appliance comprises a communication card to mediate the communicative contact via the first communicative means.