WO2024232755A1

WO2024232755A1 - Method and system for operating an hvac system.

Info

Publication number: WO2024232755A1
Application number: PCT/NL2024/050232
Authority: WO
Inventors: Cornelis Jozef VAN GRIEKEN; Sven Paul KRAAIJEVANGER; Wouter Matthijs KOK
Original assignee: Bgrid B.V.
Priority date: 2023-05-09
Filing date: 2024-05-06
Publication date: 2024-11-14
Also published as: NL2034788B1

Abstract

The disclosure relates to a method and system for operating an HVAC system. The HVAC system comprises an HVAC unit for conditioning an interior environment of a building and an HVAC controller for controlling the HVAC unit based on a sensor signal that is indicative of a measured state of the interior environment. The method comprises providing the HVAC controller with a spoofed sensor signal that is indicative of a spoofed state of the interior environment, and having the HVAC controller control the HVAC unit based on the spoofed state.

Description

Title: Method and system for operating an HVAC system.

FIELD

The invention generally relates to heating, ventilation and air conditioning (HVAC) systems, and more particularly to methods for operating HVAC systems.

BACKGROUND

Heating, ventilation, and/or air conditioning (HVAC) systems are used for controlling a level of comfort of an interior environment of a building. Some HVAC systems comprise an HVAC controller, sometimes referred to as a building management system (BMS), for controlling, e.g. activating and deactivating, one or more HVAC units to affect a environmental conditions of the interior environment. These environmental conditions for example include a temperature, humidity, ventilation, etc. The controlling is typically based sensor data, acquired from sensors that disposed in the interior environment, providing information to the HVAC controller of a state of the interior environment.

HVAC systems are typically setup to be controlled according to static setpoints that are predetermined for an envisioned use of the building. Building layouts and user-requirements may however change over time, posing challenges to have the HVAC system adapt accordingly. HVAC systems may however be complex, and difficult to adapt. Often times an entire redesign of the HVAC may be required. There is furthermore an increasing demand for allowing flexibility in the use of existing buildings, and for adaptable HVAC systems accordingly.

SUMMARY It is an aim to provide an improved system and method for operating an HVAC system. It is a particular aim to provide an improved system and method for operating an HVAC system that is effectively adaptable to the user-demands of and user-behavior in the building. Additionally or alternatively, it is an aim to provide a system and method for evaluating a performance of an HVAC system. In a more general sense, it is an object to overcome or ameliorate some of the disadvantages of the prior art, or at least provide alternative processes that are more effective than the prior art and which can be used relatively inexpensively. At any rate the present invention is at the very least aimed at offering a useful choice and contribution to the existing art.

According to an aspect, a method for operating an HVAC system is provided. The HVAC system comprises an HVAC unit for conditioning an interior environment of a building and an HVAC controller for controlling the HVAC unit based on a sensor signal that is indicative of a measured state of the interior environment. The method comprises providing the HVAC controller with a spoofed sensor signal that is indicative of a spoofed state of the interior environment, and having the HVAC controller control the HVAC unit based on the spoofed state. Hence, a behavior and performance of an existing HVAC system can be manipulated in accordance with a use-demand of the building, without having to adapt the existing HVAC system, particularly without having to adapt the HVAC controller. The spoofed sensor signal may imitate the sensor signal, and provide the HVAC controller with “false” state information in order to provoke a response of the HVAC system that is desirable over the response that would have been achieved based on the sensor signal. The spoofed sensor signal is accordingly a signal that pretends to be a sensor signal carrying true state information of the interior environment for the purpose of deceiving the HVAC controller, wherein the spoofed sensor signal furthermore carries state information that deliberately is not representative of the true state of the interior environment. The HVAC controller is accordingly deliberately deceived to control the HVAC unit based on intentionally falsified state information of the interior environment.

The sensor signal may be monitored while the HVAC controller is provided with the spoofed sensor signal for allowing validation and valuation of the response. The sensor signal may for example be collected and stored in a memory, e.g. in combination with the spoofed sensor signal. For example, if the HVAC system is undesirably setup to heat a room of the building to a preset setpoint temperature despite the room being currently empty or forecasted to remain empty for a period of time, the spoofed sensor signal may provide the HVAC controller with “false” state information indicating that the room temperature is at the preset setpoint temperature so as to provoke the HVAC controller to deactivate a heating unit for that room. The spoofed state may differ from the measured state, e.g. to provoke a control action by the HVAC controller, but it will be appreciated that the spoofed state may also correspond to the measured state, e.g. to prevent a control action by the HVAC controller. It will be appreciated that the state of the interior environment may include various parameters of the interior environment relevant for HVAC systems, e.g. including one or more of a temperature, humidity, ventilation, light condition, occupancy, air composition and quality, etc.

Optionally, the spoofed state is determined based on the measured state such that a desired response of the HVAC system to the controlling based on the spoofed state is obtained, particularly while not changing a presetting of the HVAC controller.

Optionally, the method comprises providing the HVAC controller with the spoofed sensor signal representative of a spoofed state of the interior environment that differs from the measured state of the interior environment in case a control action of the HVAC controller is required that would differ from a control action of the HVAC controller associated with the measured state.

Optionally, the method comprises providing the HVAC controller with the spoofed sensor signal representative of a spoofed state of the interior environment that corresponds to the measured state of the interior environment in case a control action of the HVAC controller is required that would correspond to a control action of the HVAC controller associated with the measured state.

Optionally, the method comprises adapting the spoofed state based on a difference between the measured state of the interior environment and a target state of the interior environment. The target state of the interior environment may differ from a setpoint state of the interior environment to which the controller is preset. The target state of the interior environment may for example be adjusted over time, e.g. dependent on current and/or future demands.

Optionally, the HVAC controller is arranged for controlling the HVAC unit so as to obtain a predetermined setpoint state of the interior environment, the method comprising providing the HVAC controller with the spoofed sensor signal representative of a spoofed state of the interior environment that differs from the setpoint state of the interior environment in case a control action of the HVAC controller is required and/or providing the HVAC controller with the spoofed sensor signal representative of a spoofed state of the interior environment that corresponds to the setpoint state of the interior environment in case no control action of the HVAC controller is required.

Optionally, the method comprises logging the spoofed state and/or the measured state and for example transmitting the logged spoofed state and/or the measured state to a repository, such as a remote repository.

Optionally, the method comprises monitoring the measured state of the interior environment and providing the HVAC controller with the spoofed sensor signal representative of a spoofed state that corresponds to the measured state in case the measured state exceeds a predetermined threshold. The predetermined threshold may hence be used for providing margins in which the HVAC system is to be operating, and to limit risks of instability of the HVAC system. The predetermined threshold may for example be a safety threshold, to prevent the HVAC system from exceeding safety limits.

Optionally, the spoofed sensor signal has an identifier for allowing the spoofed state to be distinguished from the measured state, for example by the HVAC unit and/or the HVAC controller and/or a person having access to the HVAC system and the data therein.

Optionally, the spoofed state includes a state value, and wherein the identifier includes a predetermined state value formatting, such as predetermined decimal digit of the state value.

Optionally, the method comprises determining an occupancy of the interior environment for a time in the future and adapting the spoofed state such that the measured state of the interior environment for said time in the future substantially corresponds a target state in accordance with the determined occupancy. Hence, energy consumption of the HVAC system can be reduced, while comfort in the environment can be improved.

Optionally, the occupancy of the interior environment for a time in the future is determined for a plurality of time-intervals, e.g. wherein each time-interval is 15 minutes, 30 minutes, 45 minutes or 60 minutes. An occupancy schedule can be determined, e.g. based on current and/or historic measured occupancy data.

Optionally, the building comprises a plurality of rooms each defining a respective interior sub-environment of the interior environment of the building, and wherein an occupancy is estimated for a time in the future for each of the plurality of rooms individually. Optionally, the method comprises providing the HVAC controller with the spoofed sensor signal representative of a spoofed state that corresponds to the measured state of the interior environment in case a presence of a human in the interior environment is detected.

Optionally, the method comprises determining a quality of a response of the HVAC system to the controlling based on the spoofed state. The providing of the spoofed state to the HVAC controller may trigger a response by the HVAC system, which can for example be compared to an expected or desired response, for determining the quality of the response. It may particularly be determined whether a spoofed state for a particular room of the building causes an expected response in the same room.

An aspect provides a method, particularly an at least partly computer-implemented method, for determining a quality of a response of an HVAC system. The HVAC system comprises an HVAC unit for conditioning an interior environment of a building and an HVAC controller for controlling the HVAC unit based on a sensor signal that is indicative of a measured state of the interior environment. The building comprises a plurality of rooms each defining a respective interior sub -environment of the interior environment of the building. The method comprises partitioning the plurality of rooms into a plurality of room groups, the plurality of room groups being less than the plurality of rooms, and for each room group separately in time, triggering a control action of the HVAC controller in the rooms of the room group, and observing a response in the plurality of rooms thereto for determining the quality of the response. Over time, building layouts may be changed, e.g. by subdividing rooms into multiple individual rooms and by merging rooms, whereas the HVAC system remains unchanged. It can hence be ascertained whether a triggered control action for a room causes a response in the same room, and whether the caused response is as desired or expected. A causal link between each room and the HVAC unit may hence be obtained. This is done for multiple rooms simultaneously, hence providing an efficient automatic determination of a quality of a response, and hence an efficient automatic validation of the HVAC system to proof end-to-end correct performance.

It will be appreciated that the control action may be triggered in various ways, such as by changing a setpoint state in the rooms of the room group.

Optionally, the control action of the HVAC controller for the rooms of the room group is triggered by providing the HVAC controller with the spoofed sensor signal.

Optionally, each room is provided with a sensor module arranged for measuring a state of the room and transmitting a spoofed sensor signal indicative of a spoofed state of the room to the HVAC controller for triggering the control action of the HVAC controller in said rooms of the room group. The sensor module can hence observe the response to the triggering of the control action in said rooms of the room group, for determining the quality of the response.

Optionally, the plurality of rooms are partitioned into the groups in such a way that a distance between the rooms of a room group is maximized for all room groups. Hence, cross-influence between rooms of a room group is minimized.

Optionally, the sensor signal is obtained by a sensor unit having a plurality of sensor modules that are dispersed in the interior environment of the building, and wherein the method comprises determining, for each room, which of the plurality of sensor modules are associated therewith, or vice versa. For example prior to the partitioning of the rooms in into the room groups, it may be automatically determined which sensor modules are associated with which rooms.

Optionally, each sensor module is arranged for detecting an artificial fighting state, and wherein the method comprises changing the artificial fighting state of a first room, and determining and/or validating that one or more first sensor modules of the plurality of sensor modules is associated with said first room in case said change is detected by the one or more first sensor modules. The artificial lighting state may for example indicate whether the artificial lighting is on or off and/or a current light intensity of the artificial lighting. A change in the artificial fighting state may for example include switching the lighting from its off- to its on-state, and/or vice versa, or while in the on-state actively increasing or decreasing a light intensity of the artificial fighting. The plurality of sensor modules can hence be arranged to detect if and when the lighting state of their associated room has changed, upon the forced lighting state change of the rooms. The artificial fighting of the plurality of rooms can be sequentially triggered to change it state. The detections of the plurality of sensor modules can be correlated to the timing of the trigger sequence to determine the association between the sensor modules and the rooms. It may for example be concluded that those sensor modules that detect the forced lighting state change in a certain room at a certain time are associated with the that room.

Optionally, the method comprise determining and/or validating that a one or more second sensor modules of the plurality of sensor modules, associated with a second room, is within a visibility range of the first room in case the one or more second sensor modules detect said change of the artificial fighting state of the first room. It can hence be determined how different rooms are arranged with respect to one another, such as if and how rooms are visible from other rooms. Lines of sight in a building can hence be determined. The first one or more sensor modules and the second one or more sensor module may be distinguished from each other based on their measured light intensities of the artificial lighting. It may for example be concluded that a sensor module is associated with the single room for which it measures a highest light intensity. It may also be concluded that a sensor module is not associated with a certain room in which the lighting state change is triggered, if a measured light intensity by the sensor module is below a predefined threshold, or in case, for the same triggering, a higher light intensity has been measured by another sensor module.

Optionally, the plurality of room groups includes a predetermined number of room groups.

Optionally, the number of room groups is predetermined based on an available time period for the determination of the quality of the response, the available time period being for example at least eight hours. It may for example be desired to have a time interval between each room group triggering, such as two hours. Based on the time interval and the available time period, the number of room groups can be determined.

Optionally, the plurality of room groups includes at least four room groups. By having at least four room groups, the rooms within a room group can be sufficiently distanced from each other. Particularly, it may be guaranteed that there are no adjacent rooms within a room group.

Optionally, if the building comprises a plurality of floors the plurality of rooms are partitioned into the plurality of room groups for each floor separately.

Optionally, a sequence in which the control actions for the room groups are triggered differs between adjacent floors, for example randomly, to limit cross-influencing between rooms at different floors.

Optionally, a time period between successive triggerings of control actions for the room groups is at least one hour, such as at least two hours.

Optionally, the partitioning comprises iteratively assigning each room of the plurality of rooms to one of the plurality of room groups, wherein each room is assigned to that room group having no adjacent rooms assigned thereto.

Optionally, in case more than one room group of the plurality of room groups has no adjacent rooms assigned thereto, the room is assigned to that room group of said more than one room group having the least number of rooms assigned thereto. Optionally, the rooms are iterated over randomly.

Optionally, the partitioning comprises assigning each room of the plurality of rooms to one of a number of clusters, the number of clusters being equal to or larger than the predetermined number of room groups, and iteratively reducing the number of clusters until the number of clusters corresponds to the predetermined number of room groups.

Optionally, the method comprises determining a distance between the clusters of the number of clusters, wherein the reducing comprises merging those clusters that define a largest determined distance therebetween.

Optionally, the method comprises determining a first partitioning of the plurality of rooms by iteratively assigning each room of the plurality of rooms to one of the plurality of room groups, wherein each room is assigned to that room group having no adjacent rooms assigned thereto, and determining a second partitioning of the plurality of rooms by assigning each room of the plurality of rooms to one of a number of clusters, the number of clusters being equal to or larger than the predetermined number of room groups, and iteratively reducing the number of clusters until the number of clusters corresponds to the predetermined number of room groups, and partitioning the plurality of rooms into the plurality of room groups according to either the first portioning or according to the second partitioning.

A further aspect provides a computer-readable medium provided with instructions thereon, which, when executed by a computer, cause the computer to carry out a method as described herein.

Another aspect provides a spoofed sensor signal for use in a method as described herein.

An aspect provides a sensor unit for an HVAC system having an HVAC unit for conditioning an interior environment of a building and an HVAC controller for controlling the HVAC unit, the sensor unit being configured for executing a method as described herein.

An aspect provides a sensor unit for an HVAC system having an HVAC unit for conditioning an interior environment of a building and an HVAC controller for controlling the HVAC unit, the sensor unit being configured for obtaining a sensor signal representative of a measured state of the interior environment, and communicating the obtained sensor signal to the HVAC controller for having the HVAC controller control the HVAC unit based on the obtained sensor signal, and wherein the sensor unit is further configured for communicating a spoofed sensor signal representative of a spoofed state, e.g. differing from the measure state, to the HVAC controller for having the HVAC controller control the HVAC unit based on the spoofed state.

Optionally, the sensor unit comprises a plurality of sensor modules arranged for being dispersed over the interior environment of the building, for example wherein each sensor module is associated with a respective room of the building.

Optionally, each sensor module of the plurality of sensor modules is arranged for detecting an artificial fighting state.

An aspect provides an HVAC system comprising an HVAC unit for conditioning an interior environment of a building, an HVAC controller for controlling the HVAC unit, and a sensor unit as described herein.

An aspect provides a building comprising an HVAC system as described herein.

The building optionally comprises a plurality of rooms, each defining a respective interior sub-environment of the interior environment of the building, wherein each room is associated with one or more of the plurality of sensor modules. It will be appreciated that any of the aspects, features and options described herein can be combined. It will also be appreciated that the methods described herein may include computer-implemented steps.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which:

Figures 1-3 show a schematic example of a floorplan of a building, including an HVAC system.

DETAILED DESCRIPTION

Figure 1 shows a schematic example a plan view of a floor of a building 100 that is, here, partitioned in a plurality of rooms 10a- 10k. An HVAC system 50, is provided comprising an HVAC unit for conditioning an interior environment of the building floor 100. The HVAC unit 40 can include various HVAC modules 40a-40k, e.g. with actuators, such as heaters, coolers, humidifiers, and ventilators. Here, each room 10a- 10k is associated with a respective HVAC module 40a-40k, but it will be appreciated that several rooms may alternatively share a common HVAC module, and/or that rooms can be associated with multiple HVAC modules. The HVAC unit 40 is operatively connected to an HVAC controller 30. The HVAC controller is configured for controlling the HVAC unit 40 based on a sensor signal that is indicative of a measured state of the interior environment. Here, the controller 30 is schematically shown as a centralized controller 30, configured for controlling HVAC modules 40a-40k of the floor of the building 100. Other control configurations are however also envisioned. For example, the controller 30 may include multiple control devices that are distributed over the floor, e.g. over the rooms 10a- 10k, each for controlling a part of the floor spaces, such as in a decentralized or distributed manner.

The HVAC system 50 is here provided with a sensor unit 60, which comprises a plurality of sensor modules 60a-60k. Here, each sensor module 60a-60k is provided in a respective room 10a- 10k of the building floor 100 for measuring a measured state of the room. The state of a room may for example be a temperature, humidity, ventilation, light condition, occupancy, air quality, etc.

The sensor unit 60 may be added to any existing HVAC system 50. The sensor modules 60a-60k can be installed in the rooms 10a- 10b of the building, and be communicatively connected to the HVAC controller 30, so as to have the HVAC controller 30 control the HVAC unit 40 based on the sensor signals provided by the sensor modules 60a-60k.

The sensor unit 60 is also configured for communicating a spoofed sensor signal to the HVAC controller 30 indicative of a spoofed state of the interior environment. Particularly, each sensor module 60a-60k is in this example configured for communicating a spoofed sensor signal to the HVAC controller 30 indicative of a spoofed state of the associated room 10a- 10k. The spoofed state may differ from the measured state or correspond to the measured state. By providing the spoofed sensor signal indicative of a spoofed state, the sensor unit 60 can be used for controlling the HVAC unit 50 without having to adapt the HVAC controller 30 and the HVAC unit. Furthermore, the sensor unit 60 can be used for validating the control configuration of the HVAC system.

To validate the control configuration of the HVAC system 50, e.g. whether the HVAC system 50 performs as expected and/or desired, a control action of the HVAC controller 30 is triggered for each room, and a response to the triggering is observed and evaluated. The triggering of the control action can be done, for example, using the sensor unit 60. Each sensor module 60a-60k can provide the HVAC controller 30 with spoofed state information, so as to provoke an control action by the HVAC controller 30 in the respective room. For example, a sensor module 60a-60k may measure a temperature in a room to be 20 degrees Celsius, while a setpoint state for the same room is also 20 degrees Celsius. The sensor module does not communicate the measured state information to the HVAC controller 30, but communicates spoofed state information to the HVAC controller 30 indicating that the current temperature in a room is 16 degrees Celsius, i.e. four degrees Celsius below the setpoint state. The HVAC controller 30 is accordingly expected to activate a heater in the room to elevate the temperature to from 16 degrees Celsius to 20 degrees Celsius. The sensor unit 60 may accordingly record a response in some or all the rooms 10a- 10k, particularly in the relevant room. Based on the observed response, it can be ascertained whether the heater in the room is indeed activated, and whether it activated appropriately. It may for example be observed that a heater in another, e.g. adjacent, room is activated instead, hence providing insight in the control configuration. Each room may be iteratively triggered, and the response may be observed. This can be rather time and resource consuming, as the time-constant of HVAC systems can be relative large. A more effective method is therefore proposed in which the rooms are divided in to a number of room groups, and wherein the rooms within a single room group are simultaneously triggered. The room groups are treated in consecutive order, with an appropriate time interval in between. The rooms are grouped in such a way that the distance between each room in a room group is maximized.

The partitioning into room groups can be done in various ways. Figures 2 and 3 shows the schematic plan view of the floor of the building 100, wherein the rooms 10a- 10k in the example of figure 2 are partitioned into groups in accordance with a graph coloring method, and wherein the rooms 10a- 10k in the example of figure 2 are partitioned into groups in accordance with a agglomerative hierarchical clustering method. In the example of figure 2, a graph is constructed of the building floor 100, wherein each room 10a- 10k is represented as a node. Adjacent rooms are represented by an edge between the respective nodes. The nodes are iterated over randomly, wherein each node is assigned to an available group which contains the least number of rooms at that instant. A group is an available groups if it contains no connected nodes, i.e. if the group contains no rooms that are adjacent to the room. The four color theorem guarantees that is feasible to construct such a partitioning for any graph, when there are at least four groups. Hence, a partition can be obtained in which rooms in a room group are not adjacent. Cross-influencing between rooms can hence be limited. In this example, the rooms 10a- 10k are partitioned into four different and evenly populated room groups.

In the example of figure 3, the rooms 10a- 10k are clustered. Each room 10a- 10k is assigned to one of a number of clusters, wherein the number of clusters are iteratively reduced until the number of clusters corresponds to the predetermined number of room groups. The clusters are particularly reduced by agglomerating those clusters that define a largest distance therebetween. This can be represented by the following heuristic f. If G and H are groups that contain rooms, then the heuristic /is the minimum of all distances between all area’s in group G and all areas in group H

/ = min(iistance(a, b) : a in G,b in H)

The distance between two rooms 10a- 10k can be defined by the distance of the room boundaries. This way, if two are adjacent each other, the distance will be zero. Each iteration of the clustering method two groups with the largest heuristic f are merged, i.e. which are furthest apart, until the number of groups is as large as the desired number of groups. Partitioning according to this method hence maximizes distances between rooms in the same group. Despite that it can theoretically not be guaranteed that adjacent rooms are assigned to the same group, it is found that this method performs well in practice. In the example of figure 3, with a relatively limited number of rooms, it can be observed that the resultant groups are unevenly populated. For larger room numbers however, the unevenness averages out. In this example, the rooms 10a- 10k are partitioned into four groups.

In a practical example, the graph coloring method and the clustering method can both be employed for partitioning rooms, wherein one of the two resultant partitions is selected, that is most appropriate for the situation. After the rooms 10a- 10k have been assigned to room groups, a control action is triggered for each room group sequentially, interspaced in time by an appropriate time interval, such as at least one hour. The rooms within the same room group are triggered simultaneously, wherein the partitioning takes account of the spatial variation of the rooms in the same room group, to limit any cross-influencing between the rooms of the same room group.

The examples pertain to a single floor of a building, but it will be appreciated that the method can be extended to multiple floors. In a particular example, each floor is partitioned separately, e.g. in accordance with a method described herein. A sequence in which the room groups are triggered on a single floor may be altered for the different floors, for example randomly, to limit cross-influencing through floors and ceilings.

It will be appreciated that the methods described herein may include computer-implemented steps. Some or all above mentioned steps can be computer implemented steps. Embodiments may comprise computer apparatus, wherein processes are performed in the computer apparatus. The invention also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into practice. The program may be in the form of source or object code or in any other form suitable for use in the implementation of the processes according to the invention. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a ROM, for example a semiconductor ROM or hard disk. Further, the carrier may be a transmissible carrier such as an electrical or optical signal which may be conveyed via electrical or optical cable or by radio or other means, e.g. via the internet or cloud.

Some embodiments may be implemented, for example, using a machine or tangible computer-readable medium or article which may store an instruction or a set of instructions that, if executed by a machine, may cause the machine to perform a method and/or operations in accordance with the embodiments.

Various embodiments may be implemented using hardware elements, software elements, or a combination of both. Examples of hardware elements may include processors, microprocessors, circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), logic gates, registers, semiconductor device, microchips, chip sets, et cetera. Examples of software may include software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, mobile apps, middleware, firmware, software modules, routines, subroutines, functions, computer implemented methods, procedures, software interfaces, application program interfaces (API), methods, instruction sets, computing code, computer code, et cetera.

Herein, the invention is described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein, without departing from the essence of the invention. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, alternative embodiments having combinations of all or some of the features described in these separate embodiments are also envisaged.

However, other modifications, variations, and alternatives are also possible. The specifications, drawings and examples are, accordingly, to be regarded in an illustrative sense rather than in a restrictive sense.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other features or steps than those listed in a claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to an advantage.

Claims

1. A method for operating an HVAC system, the HVAC system comprising an HVAC unit for conditioning an interior environment of a building and an HVAC controller for controlling the HVAC unit based on a sensor signal that is indicative of a measured state of the interior environment, the method comprising providing the HVAC controller with a spoofed sensor signal that is indicative of a spoofed state of the interior environment, and having the HVAC controller control the HVAC unit based on the spoofed state.

2. The method of claim 1, wherein the spoofed state is determined based on the measured state such that a desired response of the HVAC system to the controlling based on the spoofed state is obtained, particularly while not changing a presetting of the HVAC controller.

3. The method of claim 1 or 2, comprising providing the HVAC controller with the spoofed sensor signal representative of a spoofed state of the interior environment that differs from the measured state of the interior environment in case a control action of the HVAC controller is required that would differ from a control action of the HVAC controller associated with the measured state and/or providing the HVAC controller with the spoofed sensor signal representative of a spoofed state of the interior environment that corresponds to the measured state of the interior environment in case a control action of the HVAC controller is required that would correspond to a control action of the HVAC controller associated with the measured state.

4. The method of claim 3, comprising adapting the spoofed state based on a difference between the measured state of the interior environment and a target state of the interior environment.

5. The method of any preceding claim, wherein the HVAC controller is arranged for controlling the HVAC unit so as to obtain a predetermined setpoint state of the interior environment, the method comprising providing the HVAC controller with the spoofed sensor signal representative of a spoofed state of the interior environment that differs from the setpoint state of the interior environment in case a control action of the HVAC controller is required and/or providing the HVAC controller with the spoofed sensor signal representative of a spoofed state of the interior environment that corresponds to the setpoint state of the interior environment in case no control action of the HVAC controller is required.

6. The method of any preceding claim, comprising logging the spoofed state and/or the measured state and transmitting the logged spoofed state and/or the measured state to a repository.

7. The method of any preceding claim, comprising monitoring the measured state of the interior environment and providing the HVAC controller with the spoofed sensor signal representative of a spoofed state that corresponds to the measured state in case the measured state exceeds a predetermined threshold.

8. The method of any preceding claim, wherein the spoofed sensor signal has an identifier for allowing the spoofed state to be distinguished from the measured state, for example by the HVAC unit and/or the HVAC controller.

9. The method of claim 8, wherein the spoofed state includes a state value, and wherein the identifier includes a predetermined state value formatting, such as predetermined decimal digit of the state value.

10. The method of any preceding claim, comprising determining an occupancy of the interior environment for a time in the future and adapting the spoofed state such that the measured state of the interior environment for said time in the future substantially corresponds to a target state in accordance with the determined occupancy.

11. The method of claim 10, wherein the building comprises a plurality of rooms each defining a respective interior sub -environment of the interior environment of the building, and wherein an occupancy is estimated for a time in the future for each of the plurality of rooms individually.

12. The method of any preceding claim, comprising providing the HVAC controller with the spoofed sensor signal representative of a spoofed state that corresponds to the measured state of the interior environment in case a presence of a human in the interior environment is detected.

13. The method of any preceding claim, comprising determining a quality of a response of the HVAC system to the controlling based on the spoofed state.

14. A method for determining a quality of a response of an HVAC system having an HVAC unit for conditioning an interior environment of a building and an HVAC controller for controlling the HVAC unit based on a sensor signal that is indicative of a measured state of the interior environment, wherein the building comprises a plurality of rooms each defining a respective interior sub-environment of the interior environment of the building, the method comprising partitioning the plurality of rooms into a plurality of room groups, the plurality of room groups being less than the plurality of rooms, for each room group separately in time, triggering a control action of the HVAC controller in the rooms of the room group, and observing a response in the plurality of rooms thereto for determining the quality of the response.

15. The method of claim 14 when dependent on claim 13, wherein the control action of the HVAC controller for the rooms of the room group is triggered by providing the HVAC controller with the spoofed sensor signal.

16. The method of claim 8 or 9, wherein the plurality of rooms are partitioned into the groups in such a way that a distance between the rooms of a room group is maximized for all room groups.

17. The method of any of claims 14-16, wherein the sensor signal is obtained by a sensor unit having a plurality of sensor modules that are dispersed in the interior environment of the building, and wherein the method comprises determining, for each room, which of the plurality of sensor modules are associated therewith, or vice versa.

18. The method of claim 17, wherein each sensor module is arranged for detecting an artificial lighting state, and wherein the method comprises changing the artificial fighting state of a first room, and determining and/or validating that one or more first sensor modules of the plurality of sensor modules is associated with said first room in case said change is detected by the one or more first sensor modules.

19. The method of claim 18, comprising determining and/or vahdating that a one or more second sensor modules of the plurality of sensor modules, associated with a second room, is within a visibility range of the first room in case the one or more second sensor modules detect said change of the artificial fighting state of the first room.

20. The method of any of claims 14-19, wherein the plurality of room groups includes a predetermined number of room groups.

21. The method of claim 20, wherein the number of room groups is predetermined based on an available time period for the determination of the quality of the response, the available time period being for example at least eight hours.

22. The method of any of claims 14-21, wherein the plurality of room groups includes at least four room groups.

23. The method of any of claims 14-22, wherein if the building comprises a plurality of floors the plurality of rooms are partitioned into the plurality of room groups for each floor separately.

24. The method of claim 23, wherein a sequence in which the control actions for the room groups are triggered differs between adjacent floors.

25. The method of any of claims 14-24, a time period between successive triggerings of control actions for the room groups is at least one hour, such as at least two hours.

26. The method of any of claims 14-25, wherein the partitioning comprises iteratively assigning each room of the plurality of rooms to one of the plurality of room groups, wherein each room is assigned to that room group having no adjacent rooms assigned thereto.

27. The method of claim 26, wherein, in case more than one room group of the plurality of room groups has no adjacent rooms assigned thereto, the room is assigned to that room group of said more than one room group having the least number of rooms assigned thereto.

28. The method of claim 26 or 27, wherein the rooms are iterated over randomly.

29. The method of any of claims 14-28, wherein the partitioning comprises assigning each room of the plurality of rooms to one of a number of clusters, the number of clusters being equal to or larger than the predetermined number of room groups, and iteratively reducing the number of clusters until the number of clusters corresponds to the predetermined number of room groups.

30. The method of claim 29, comprising determining a distance between the clusters of the number of clusters, wherein the reducing comprises merging those clusters that define a largest determined distance therebetween.

31. The method of any of claims 14-30, comprising determining a first partitioning of the plurality of rooms according to a method of any of claims 19-21, and determining a second partitioning of the plurality of rooms according to a method of claim 22 or 23, and partitioning the plurality of rooms into the plurality of room groups according to the first portioning or according to the second partitioning.

32. A computer readable medium provided with instructions thereon, which, when executed by a computer, cause the computer to carry out the method according to any one of claims 1-31.

33. A spoofed sensor signal for use in a method of any of claims 1-31.

34. A sensor unit for an HVAC system having an HVAC unit for conditioning an interior environment of a building and an HVAC controller for controlling the HVAC unit, the sensor unit being configured for executing a method of any of claims 1-31.

35. A sensor unit for an HVAC system having an HVAC unit for conditioning an interior environment of a building and an HVAC controller for controlling the HVAC unit, such as in accordance with claim 34, the sensor unit being configured for obtaining a sensor signal representative of a measured state of the interior environment, and communicating the obtained sensor signal to the HVAC controller for having the HVAC controller control the HVAC unit based on the obtained sensor signal, and wherein the sensor unit is further configured for communicating a spoofed sensor signal representative of a spoofed state, e.g. differing from the measure state, to the HVAC controller for having the HVAC controller control the HVAC unit based on the spoofed state.

36. The sensor unit of claim 35 comprising a plurality of sensor modules arranged for being dispersed over the interior environment of the building.

37. The sensor unit of claim 36, wherein each sensor module of the plurality of sensor modules is arranged for detecting an artificial lighting state.

38. An HVAC system comprising an HVAC unit for conditioning an interior environment of a building, an HVAC controller for controlling the HVAC unit, and a sensor unit according to any of claims 34-37.

39. A building comprising an HVAC system of claim 38.

40. The building of claim 39, when dependent on claim 36 or 37, comprising a plurality of rooms, each defining a respective interior subenvironment of the interior environment of the building, wherein each room is associated with one or more of the plurality of sensor modules.