Patent Application
20240410632
A heat pump is a machine that, with the use of technical work, receives thermal energy from a reservoir with a lower temperature and—together with the drive energy—transfers that energy as useful heat to a system to be heated having a higher temperature. This process is used for both heat generation and cooling. In the cooling process, the useful energy is the heat that is absorbed from the space to be cooled and, together with the drive energy, is dissipated to the environment as waste heat.
A refrigeration circuit of a heat pump may include an evaporator, a compressor, a condenser, and/or an expansion valve. The evaporator may be configured to change an aggregate state of a fluid in the refrigeration circuit from liquid to gaseous by adding thermal energy from a heat source or from a refrigeration circuit/primary circuit. The compressor may be configured to compress the gaseous fluid so that the pressure and a temperature of the gaseous fluid are increased. The condenser may be configured to change the physical state of the fluid from gaseous to liquid by releasing thermal energy to a secondary circuit, particularly a heating circuit, or heat sink. The expansion valve may be configured to cause expansion of the liquid fluid so that the pressure of the liquid fluid decreases. This allows a heat energy from a heat source or cooling circuit to be supplied to a heating circuit/secondary circuit or heat sink.
Since a heat pump operates independently of a fuel, user interaction with the heat pump is usually very low. As a result, monitoring of the heat pump's operation is usually neglected by the user and inefficient operation of the heat pump, i.e., with unnecessary energy consumption and/or high wear, is often not noticed. In addition, monitoring a heat pump with conventional methods is usually very complex, so that the expertise of a professional is required to monitor the heat pump.
For example, EP 3 608 603 B1 discloses a heating medium circulation system for this purpose. The heating medium circulation system comprises a heating means for heating a liquid heating medium, a pump configured to circulate the heating medium through a circulation circuit passing through an indoor heating terminal and the heating means; control means electrically connected to the heating means and the pump, the control means being configured to perform an indoor heating operation for supplying the heat medium heated by the heating means to the indoor heating terminal and a defrosting operation for causing frost adhering to the air heat exchanger to melt; and means for detecting a supply temperature that is a temperature of the heat medium supplied to the indoor heating terminal from the heating means.
The heating device comprises an air heat exchanger configured to exchange heat between a refrigerant and air; and a compressor configured to compress the refrigerant. The control means deactivates the compressor when the supply temperature exceeds a first deactivation temperature in the indoor heating operation after a predetermined period of time elapses from a switching time point from the defrosting operation to the indoor heating operation, and does not deactivate the compressor when the supply temperature exceeds the first deactivation temperature in the indoor heating operation in a post-defrosting period that is a period until the predetermined period of time elapses from the switching time point.
Based on the above, it is an object of the invention to provide a simple, efficient and cost-effective method, computer program product and system for monitoring a heat pump.
The invention is set out in the independent claims. The dependent patent claims relate to particular embodiments of the invention.
One aspect of the invention relates to a method for monitoring a heat pump. The method may comprise the steps of providing reference data, detecting a running time of the heat pump, comparing the running time of the heat pump with the reference data, and determining a monitoring result depending on the comparison result of the running time of the heat pump with the reference data. Providing reference data may include retrieving data from a reference heat pump, from a cloud storage, from a storage unit, or the like.
An error message may be output depending on the monitoring result. Alternatively, or in addition to outputting the error message, a control intervention in a control method of the heat pump may be performed depending on the monitoring result. Performing the control intervention may be suggested in particular in the error message and executed only after confirmation by a user or operator of the heat pump.
A control intervention includes changing or adapting a control method of the heat pump, for example by changing one or more control parameters. In particular, parameters of a heating curve may be adjusted. Further examples of a control intervention include increasing or decreasing a volume flow in a heating circuit of the heat pump. Furthermore, an output of the heat pump may be changed depending on the monitoring result. Furthermore, the control intervention may be performed by changing one or more set values, for example, a volume flow in the heating circuit and/or a temperature (e.g., supply temperature) and/or a power (e.g., heating power of the heat pump).
Detecting a running time of the heat pump may include detecting different modes of the heat pump depending on the time. Non-limiting examples of a mode include a power mode, a standby mode, a heat pump off mode, a heat generation mode, a cooling generation mode, a predetermined power mode, a predetermined power interval mode, a demand response mode, a normal mode, a heating mode, a water heating mode, or the like. In some embodiments, detecting a running time may include detecting an electrical energy consumption. The reference data may comprise running times of a reference operation, in particular from a simulation and/or from a reference heat pump. This has the advantage that the heat pump may be monitored with respect to efficiency in a particularly simple manner, since a data collection and an evaluation of the data with respect to efficiency is performed in a particularly simple and target-oriented manner.
In a particularly advantageous embodiment, providing reference data may comprise providing a minimum length of an operating interval, detecting the running time of the heat pump may comprise detecting a duration of an operating interval of the heat pump as an operating interval length, and comparing the running time of the heat pump with the reference data may comprise comparing the minimum length of the operating interval with the operating interval length. An operating interval of the heat pump may be a period of time by which the heat pump is operated with the purpose of generating heat and/or cooling. This has the advantage that short operating intervals, which are particularly inefficient, may be detected in a simple manner. Furthermore, this allows to detect errors in the operation of a heating system with a heat pump in a particularly simple way, so that the errors may be remedied and the wear of the heat pump may be reduced.
In a particularly advantageous embodiment, providing reference data may comprise providing a minimum length of an operation stoppage, detecting the running time of the heat pump may comprise detecting a duration of an operation stoppage of the heat pump as a stoppage interval length, and comparing the running time of the heat pump with the reference data may comprise comparing the minimum length of the operation stoppage with the stoppage interval length. An operation stoppage is an operation state of the heat pump in which the heat pump is not being operated to generate heat or to cool. Examples of corresponding operating states may be a standby mode and/or a switched-off heat pump. Thus, short stoppage intervals in the operation of the heat pump may be determined and, based on the determined short stoppage intervals, an error in the operation of the heat pump may be detected. Since switching from an operation stoppage of the heat pump to a load operation of the heat pump is particularly inefficient, operation stoppages of short duration are detected accordingly.
In a particularly advanced embodiment, providing reference data may comprise providing at least one of an upper threshold value and/or a lower threshold value of a ratio between the operating interval length and the stoppage interval length. Further, the method may comprise the step of determining a ratio between the operating interval length and the stoppage interval length as a running time ratio, wherein comparing the running time of the heat pump with the reference data comprises comparing the running time ratio to the upper threshold value and/or the lower threshold value.
Thus, errors in the operation of a heating system comprising the heat pump that have negative effects on the efficiency of the system may be detected. For example, it is possible to detect switch-on temperatures and switch-off temperatures of the heat pump that have been set incorrectly. Furthermore, inefficient set values of heating circuits may be detected in particular, which lead to short operating interval durations and long stoppage interval lengths. In addition, long operating intervals and short stoppage intervals may be caused by short-term overshoots of the supply temperature and/or return liquid temperature or fluctuations in the primary volume flow of the heat pump. Thus, the heat pump may be monitored particularly easily with regard to further sources of error.
In a particularly modified embodiment, the reference data may be provided depending on one or more, particularly on all, from among a group including: a device type of the heat pump, in particular air/water heat pump, ground source heat pump and water/water heat pump, or the like; a control method of the heat pump, in particular a power control of the heat pump or a constant power of the heat pump; a performance class to which the heat pump is assigned; an operating mode, in particular demand-response operation, normal operation, water heating operation, heating operation and cooling operation or the like; a climate zone in which the heat pump is installed; an age of the heat pump; an outdoor temperature; an air humidity; a time, in particular a season, a time of day, a day of the week; a wind force. Thus, the reference data may be particularly adjusted to influences affecting the operation of the heat pump and/or its running time, and the number of falsely detected errors or falsely non-detected errors may be reduced. In a particularly reliable embodiment, the reference data is provided depending on a plurality of operating data of heat pumps and/or depending on a simulation of a heat pump system. By using a plurality of operating data of heat pumps (or additional heat pumps), practical reference data about an efficient operation of a heat pump may be collected. By means of a simulation, the reference data may be adjusted to the heat pump system comprising the heat pump. Furthermore, by means of the simulation(s), reference data may be generated for heat pump systems for which no data are available from current practice.
In a particularly reliable embodiment, detecting a running time of the heat pump may comprise detecting the duration of a plurality of operating intervals. In addition, the method is comprising the step of determining an operating interval length depending on the duration of the plurality of operating intervals. Thus, the meaningfulness of the comparison may be improved, since short-term fluctuations in the operation in the plurality of operating intervals may be filtered out, so that the actual efficiency of the heat pump is distorted as little as possible by these fluctuations.
In another particularly reliable embodiment, detecting a running time of the heat pump may comprise detecting the duration of a plurality of operation stoppages. Furthermore, the method may comprise the step of determining a stoppage interval length depending on the duration of the plurality of operation stoppages. Therefore, the meaningfulness of the comparison may be improved, since short-term fluctuations in operation may be filtered out by the plurality of operation stoppages, so that the actual efficiency of the heat pump is distorted as little as possible by these fluctuations. This in turn may improve the result of the monitoring.
In a particularly accurate embodiment, detecting a running time of the heat pump may comprise detecting the duration of a plurality of operating intervals as a plurality of operating interval lengths, comparing the running time of the heat pump with the reference data may comprise comparing the minimum length of the operating interval with the plurality of operating interval lengths, and determining a monitoring result depending on the results of the comparisons of the minimum length of the operating interval with the plurality of operating interval lengths. Thus, it is possible to ensure that a duration of an operating interval of the heat pump, which may indicate a safety risk of the heat pump, for example, is used to determine the monitoring result.
In a particularly thorough embodiment, detecting a running time of the heat pump may comprise detecting the duration of a plurality of operation stoppages as the plurality of stoppage interval lengths, wherein comparing the running time of the heat pump with the reference data comprises comparing the minimum length of the operation stoppage to the plurality of stoppage interval lengths, and determining a monitoring result depending on the results of the comparisons of the minimum length of the operation stoppage with the plurality of stoppage interval lengths. Thus, it is possible to ensure that a duration of an operation stoppage of the heat pump, which may indicate a safety risk of the heat pump, for example, is used to determine the monitoring result.
In a particularly advanced embodiment, detecting a running time of the heat pump may comprise detecting a plurality of operating data each including a duration of an operating interval of the heat pump as an operating interval length and a duration of an operation stoppage of the heat pump as a stoppage interval length. Furthermore, the method may comprise the step of determining a ratio between the operating interval length and the stoppage interval length as a running time ratio for each of the plurality of operating data, wherein comparing the running time of the heat pump with the reference data comprises comparing the running time ratios to the upper threshold value and/or the lower threshold value. Advantageously, an operating interval temporally follows a stoppage interval or the stoppage interval temporally follows the operating interval, the duration/length of which is used to determine a corresponding running time ratio.
According to this embodiment, it is possible to ensure that a ratio between the operating interval length and the stoppage interval length of the heat pump, which may indicate a safety risk of the heat pump, for example, is used to determine the monitoring result.
A particularly more advanced embodiment may additionally comprise the steps of determining stochastic operating data from the plurality of operating interval lengths, from the plurality of stoppage interval lengths, and/or from the plurality of running time ratios; and determining stochastic reference data depending on the reference data when the reference data does not comprise stochastic reference data. Comparing the running time of the heat pump with the reference data may comprise comparing the stochastic operating data to the (corresponding) stochastic reference data. Therefore, a meaningful determination of the efficiency of the heat pump depending on a plurality, in particular a plurality, of recorded running times may be made in a simple manner. As a consequence, the heat pump may be monitored in a simple and target-oriented manner.
The determination of stochastic operating data and/or stochastic reference data may comprise, for example, a determination of one or more items selected from the group consisting of: a distribution function, a frequency distribution, a probability distribution, a mean value, a standard deviation, a variance.
A particularly more safety-aware embodiment may comprise the steps of providing one or more reference powers of the heat pump, in particular a maximum and/or minimum power of the heat pump; acquiring an electrical power during the duration of the operating interval of the heat pump; comparing the detected electrical power with the one or more reference powers of the heat pump. Determining the monitoring result may additionally be carried out depending on the comparison result of the detected electrical power with the one or more reference powers. Thus, wear and tear of the heat pump resulting in increased or decreased electrical power consumption may be detected and taken into account when monitoring the heat pump.
In a particularly modified embodiment, the one or more reference powers may be provided depending on one or more, particularly on all, from among a group including: a device type of the heat pump, in particular air/water heat pump, ground source heat pump and water/water heat pump, or the like; a control method of the heat pump, in particular a power control of the heat pump or a constant power of the heat pump; a performance class to which the heat pump is assigned; an operating mode, in particular demand-response operation, normal operation, water heating operation, heating operation and cooling operation or the like; a climate zone in which the heat pump is installed; an age of the heat pump; an outdoor temperature; an air humidity; a time, in particular a season, a time of day, a day of the week; a wind force or the like of the heat pump. In this way, the reference data may be particularly adjusted to influences affecting the operation of the heat pump and/or its running time, and the number of falsely detected errors or falsely non-detected errors may be reduced.
In a particularly reliable embodiment, the one or more reference powers may be provided depending on a plurality of heat pump operating data and/or depending on a simulation, in particular a plurality of simulations, of a heat pump system. By using a plurality of operating data of heat pumps (additional heat pumps), practice-oriented reference performances about an efficient operation of a heat pump may be collected. Simulation data may be provided by means of a simulation of a heat pump system. The one or more reference performances may be adjusted to the heat pump system comprising the heat pump depending on the simulation data. Furthermore, the simulation(s) may be used to generate reference powers for heat pump systems for which no data are available from the field.
A particularly advantageous method may comprise the step of outputting an error message depending on the monitoring result, and optionally depending on one or more comparison results. Thus, an error in the operation of the heat pump may be indicated in a particularly target-oriented manner. If the error message is output depending on one or more comparison results, an experienced person/user may also be given assistance in eliminating the error.
In a particularly maintenance-friendly method, outputting an error message may additionally be carried out depending on a result of one or more of the following comparisons: a predetermined return liquid temperature with a detected return liquid temperature of the heat pump; a predetermined supply temperature with a detected supply temperature of the heat pump; a first predetermined reference value with a difference between the detected return liquid temperature and the detected supply temperature; a second predetermined reference value with a detected primary volume flow; a third predetermined reference value with a detected pressure in the heat pump system; a fourth predetermined reference value with a detected primary temperature; a fifth predetermined reference value with a difference between the detected inlet and outlet temperature of the primary side. For example, a primary volume flow is a volume flow in the primary circuit of the heat pump. A heat pump may regularly include a primary circuit, a refrigeration circuit, and a secondary circuit. In some embodiments, a primary circuit and/or secondary circuit may be integrated into the refrigeration circuit. A primary circuit is used to absorb heat from the environment, for example, from the air, from water, from the ground, or the like. The secondary circuit serves to deliver heat, for example, to a heating circuit, to a hot water circuit, to a heat sink, or the like.
In some embodiments, the primary circuit and/or the secondary circuit may be connected to the refrigeration circuit via a heat exchanger.
The numbering of the reference values as first, second, third, fourth, fifth is not intended to represent any order or sequence of the reference values with respect to each other, but only serves to distinguish the individual reference values from each other.
The refrigeration circuit, for example, transfers a generated heat/cold to the secondary circuit, for example, by means of a heat exchanger/refrigeration exchanger. The secondary circuit may include a flow with high temperature (heating circuit) and a return. The primary circuit may comprise a low temperature supply (cooling circuit) and a return. In some embodiments, both a secondary circuit in the form of a heating circuit and a primary circuit in the form of a cooling circuit may be connected to the cooling circuit by a heat exchanger for heat/cold transfer. A primary temperature is a temperature measured in the primary circuit. A primary volume flow is a volume flow in the primary circuit. A detected pressure in the heat pump system may be a detected pressure in the primary circuit, a detected pressure in the secondary circuit, and/or a detected pressure in the refrigeration circuit.
Advantageously, a fault in the operation or in connection with the operation of the heat pump may be determined particularly easily and thus maintenance or error rectification may be carried out in a particularly efficient and target-oriented manner.
In some embodiments, running times and/or detected electrical powers of a first time interval may be compared with running times and/or detected electrical powers of a second time interval, in particular a plurality of second time intervals, for example by comparing operating interval lengths, stoppage interval lengths, running time ratios, detected powers, etc. This may have the advantage that a drop in efficiency may be detected particularly easily.
One aspect of the invention relates to a system for monitoring a heat pump. The system may comprise a reference data providing unit configured to provide reference data; a detection unit configured to detect a running time of the heat pump; a comparison unit configured to compare the running time of the heat pump with the reference data; and a monitoring result determination unit configured to determine a monitoring result depending on the comparison result of the running time of the heat pump with the reference data.
A running time may include data on an operation of the heat pump depending on time. In particular, the running time, may comprise data about a duration of an operating interval and/or a stoppage interval length, for example depending on time. The detection unit may comprise a memory unit in which corresponding data is stored. In some embodiments, the detection unit may comprise one/or more sensors. In some embodiments, the detection unit may comprise a communication unit for receiving and/or retrieving data, in particular a running time, for example from a sensor, a storage unit, a cloud storage, or the like.
In some embodiments, the reference data providing unit may comprise a memory in which reference data is stored. In some embodiments, the reference data providing unit may comprise a communication unit configured to receive and/or retrieve reference data, for example from a storage unit, a cloud storage, a simulation unit configured to perform a simulation depending on provided data, another heat pump, etc. In some embodiments, a communication unit and/or a storage unit may be equally used by the detection unit and the reference data providing unit.
In some embodiments, the reference data may comprise data relating to a reference running time, in particular a reference operating time, a reference interval length, or the like.
A particularly advanced system may comprise an output unit configured to output an error message depending on the monitoring result and optionally depending on one or more comparison results. For example, the output unit may be configured to output the error message acoustically, in particular by means of a loudspeaker, and/or visually, in particular by means of a display unit. In some embodiments, the output unit may be configured to send a message to an external device by means of a communication unit. An external device may be, for example, a PC, a cell phone, a server, or the like.
The output unit may be configured to output a signal for performing a control intervention in a control method of the heat pump depending on the monitoring result.
In some embodiments, the message may be an SMS, an email, a message in a markup language, etc. In some embodiments, a message may be sent, in particular depending on a monitoring result and/or one or more comparison results, to a professional (service installer), to a user, to a maintenance service, to a heat pump operator, and/or to a manufacturer, etc. In the following, this list is described by the terms “user or operator of the heat pump”. In this way, a heat pump may be operated in a particularly goal-oriented manner with respect to safety and efficiency. In some embodiments, a message may be sent to an external device depending on a monitoring result and/or one or more comparison results.
In particular, the message may comprise an error message. Further, the message may include a suggestion for performing the control intervention. A user or operator of the heat pump may initiate performing the proposed control intervention by inputting a confirmation.
Another aspect of the invention relates to a computer program product comprising instructions which when the program is executed by a computer, cause the computer to perform the steps of the method according to any one of claims 1 to 15. Therefore, existing systems may be easily equipped with the method according to the invention and the efficiency and safety of an already installed heat pump may be improved and error of the already installed heat pump may be avoided.
The method comprises step S11 detecting a running time of the heat pump. Detecting a running time may include detecting a duration of an operating interval of the heat pump as an operating interval length and/or detecting a duration of an operation stoppage of the heat pump as a stoppage interval length. An operating interval length reflects the duration of an operating interval of the heat pump in a load operation. A load operation is preferably an operation in which the heat pump is operated with the aim of generating heat or cooling. An operation stoppage may be, for example, in a standby mode or when the heat pump is switched off, or the like. In some embodiments, during an operation stoppage, the heat pump is not operated with the objective of generating heat and/or cooling.
In a step S12, the detected running time of the heat pump is compared with the reference data. The comparison may comprise, for example, a qualitative and/or quantitative comparison. In some embodiments, the result of the comparison may be an absolute result or a relative result.
In a step S13, a monitoring result is determined depending on the comparison result of the running time of the heat pump with the reference data.
In some embodiments, the method may comprise an optional step S14 outputting an error message depending on the monitoring result. In some embodiments, the error message may include an error code depending on the monitoring result. In some embodiments, the error message, in particular an error code, may additionally be output depending on one or more comparison results. In some embodiments, a unit for outputting the error message, in particular a display unit, a speaker unit, and/or a communication unit, may be selected depending on an error code and/or one or more comparison results.
In some embodiments, the method may comprise an optional step S15 determining a ratio between the operating interval length and the stoppage interval length as a running time ratio, in which case comparing the running time of the heat pump with the reference data comprises comparing the running time ratio with the upper threshold value and/or the lower threshold value.
In addition, the method may include a further optional step S22 determining stochastic reference data depending on the reference data in particular when the reference data does not comprise stochastic reference data or when stochastic reference data are available only for a part of the reference data. Thus, it is possible to ensure that the acquired running times may be compared with the reference data in an optimal manner. In some embodiments, especially if the reference data already reflect or comprise stochastic reference data, step S22 may be omitted.
In some embodiments, the method steps illustrated in
In some embodiments, a computer program product may comprise instructions that, when the program is executed by a computer, cause the computer to perform method steps of the methods illustrated in
The detection unit 42 is configured to acquire a running time of the heat pump. For this purpose, the detection unit 42 may be connected to a control unit of the heat pump and/or to one or more sensors. In some embodiments, the detection unit 42 may comprise a communication unit configured to receive or retrieve the running time of the heat pump from the heat pump and/or a cloud storage. In some embodiments, the unit 41 and the detection unit 42 may share a communication unit and/or a storage unit. The comparison unit 43 is configured to compare the running time of the heat pump with the reference data. For this purpose, the comparison unit 43 may comprise one or more analog and/or digital circuits, in particular a computing unit.
The monitoring result determination unit 44 is configured to determine a monitoring result depending on the comparison result of the running time of the heat pump with the reference data. In some embodiments, the monitoring result determination unit 44 may be configured to additionally determine the monitoring result depending on one or more further comparison results. The monitoring result determination unit 44 may comprise one or more analog and/or digital circuits, in particular a computing unit. In some embodiments, the units 43 and 44 may share a computing unit.
The output unit 45 is configured to output an error message depending on the monitoring result, and optionally depending on one or more comparison results. In some embodiments, the output unit 15 may be configured to output an error message visually, for example by means of a display, and/or acoustically, in particular by means of a loudspeaker, optionally depending on the monitoring result and/or one or more comparison results. In some embodiments, the output unit may comprise a communication unit configured to transmit an error message to an external unit, in particular depending on the monitoring result and/or one or more comparison results. An external unit may be, for example, a mobile device, a server, a maintenance device, or the like.
The output unit 45 may further be configured to output a signal that causes a control intervention. In particular, the control intervention may be performed after confirmation by a user or operator of the heat pump. For example, the control intervention may be proposed in the error message that is output.
According to an exemplary embodiment, a long running time of the heat pump with short operation stoppages may be detected. As a result, exceeding the maximum return liquid temperature may be detected. In an error message, the user or operator of the heat pump may receive an indication that the maximum return liquid temperature has been exceeded. A possible control intervention includes, for example, increasing the volume flow by appropriately controlling a circulation pump in the heating circuit and/or reducing the power of the heat pump. The control intervention proposed or performed may also depend, among other things, on whether the heat pump is operated in heating mode or for hot water production.
In some embodiments, the output unit may share a communication unit with the unit 41 and/or 42. In some embodiments, the output unit may be configured to output an error code depending on the monitoring result and, optionally, depending on one or more comparison results in the course of outputting the error message. An error code may be a code word representing a predetermined error/specified type of error. In some embodiments, an error code may also include a description of the error.
In some embodiments, units of the system 40 may be separated, combined, or the like without affecting the core of the invention. Further, in some embodiments, additional units may be added without affecting the core of the invention.
In some embodiments, the heat side 53 may form a secondary circuit 532 (heating circuit and/or hot water circuit). The liquefier/condenser 513 may act as a heat exchanger for transferring heat from the refrigeration circuit 515 to the heat side 53. For example, one or more heating circuits 533, 534 and/or hot water circuits 535 may be disposed on the heat side 53. In some embodiments, the heat side 53 may include a heat sink in addition to or instead of the heating circuits. In some embodiments, the heat side 53 may be integrated with the refrigeration circuit.
The heat pump system illustrated in
The color scheme represents a consumed electrical power in watts of the heat pump.
In the diagrams of
From the diagram of
In contrast, it follows from the diagram of
Since the wear of a heat pump is lower at a lower heating temperature and also the efficiency of the heat pump is higher at lower heating temperatures, the heat pump with the diagrams illustrated in
As evident in the diagram of
In some embodiments, a cumulative frequency for a predetermined range of a distribution function, in particular a frequency distribution/probability distribution, may be determined and compared to a reference value.
Thus, the operation illustrated in
In some embodiments, in particular in one of the embodiments illustrated in
In some embodiments, a heat pump that is of a “variable capacity-geothermal” type may be assumed to be an efficient heat pump at an average of between 0.05 and 0.2 switch-ons per hour of operation. In some embodiments, a heat pump that is of a “variable power-air” type may be considered to be an efficient heat pump at an average of between 0.2 and 0.6 switch-ons per hour of operation. In some embodiments, a heat pump that is of a “constant power-geothermal” type may be considered to be an efficient heat pump at an average of between 0.8 and 2.4 duty cycles per hour of operation.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 105 836.8 | Mar 2021 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/054987 | 2/28/2022 | WO |
