WO2018011621A1

WO2018011621A1 - Method for improving operational efficiency of a cooling system through retrofitting a building with a master controller

Info

Publication number: WO2018011621A1
Application number: PCT/IB2016/054222
Authority: WO
Inventors: Venu Kumar CHALLA
Original assignee: Barghest Building Performance Pte. Ltd.
Priority date: 2016-07-15
Filing date: 2016-07-15
Publication date: 2018-01-18
Also published as: TW201804115A

Abstract

The application provides a method of retrofitting a Heating, Ventilating, and Air Conditioning (HVAC) device with a Build ing Management System (BMS) for a building. The method in cludes a step of evaluating existing components of the HVAC device. After this, additional components, which are provided in parallel with the existing components, are provided. A plu rality of temperature sensors, a plurality of flow meters, an a plurality of power meters for the components are then in stalled. A plurality of Variable Speed Drives (VSDs) for the components is later installed. A controller is afterward in stalled.

Description

METHOD FOR IMPROVING OPERATIONAL EFFICIENCY OF A COOLING SYSTEM THROUGH RETROFITTING A BUILDING WITH A MASTER CONTROLLER

The application relates to a Heating, Ventilating, and Air Conditioning (HVAC) system for a building.

Many buildings have climate-controlled spaces. These con- trolled spaces can refer to a hotel room, to a shopping mall retail area, to an office, or to a freezer room.

Thermostats are often used to control the ambient temperature of these controlled spaces. A user, or more often an operator, selects a desired or preset temperature for a selected controlled space.

When the ambient temperature of the climate-controlled space is different from the preset temperature, a Heating, Ventilating, and Air Conditioning (HVAC) system then heats or cools the air of the controlled space until the preset temperature is reached.

In a case where the ambient temperature is higher than the desired temperature, the HVAC system transfers heat energy from the controlled space to a medium. Examples of the medium include water, air, and refrigerant. One or two mediums then goes through an evaporation and condensation cycle to transfer its heat energy to a second loop, which serves to transmit the heat energy to an outside space.

Due to high cost of energy, many HVAC systems and thermostats include features, which are designed to improve energy efficiency and thus reduce heating and cooling costs. For example, some thermostats provide set-point temperatures that vary over time. The variable set-point temperatures may be programmed to change when occupants of the climate-controlled spaces are ex- pected to be absent. These energy saving features are espe- cially important in large facilities , such as hotels .

It is an object of this application to improve energy efficiency of an existing heating, ventilating, and air conditioning (HVAC) system for a building.

It is believed that the HVAC system can be improved by lowering energy usage of its parts, such as pumps, fans, and compressors for supporting a desired cooling load. This cooling load can change over time and it relates to an amount of heat energy that is removed from a climate-controlled space in order to maintain the temperature of the climate-controlled space within an acceptable range. In short, the improved HVAC system supports the same cooling load with lower energy consumption. In this manner, the energy efficiency of the HVAC system is improved.

The application provides a method of retrofitting a Heating, Ventilating, and Air Conditioning (HVAC) device for a building. The HVAC device includes a Building Management System (BMS) .

The building has a physical structure with a roof and walls. Examples of the building include a house, a church, and a factory.

The HVAC device is used for adjusting the thermal comfort of climate-controlled spaces of the building. The climate- controlled spaces refer to rooms, passageways, or other areas of the building. The temperature and the humidity of a place can define the thermal comfort of the place. The BMS act to activate parts or components of the HVAC device such that the controlled spaces provide the desired thermal comfort. The HVAC device parts can refer to a water pump, to a chiller compressor, or to a cooling tower fan of the HVAC device. The BMS also act to adjust speed of these parts.

The method includes a step of evaluating existing components of the HVAC device. The evaluation may refer to judging predetermined values or predetermined conditions of the components .

After this, additional or back-up components are provided in parallel with the respective existing components. The additional component and the respective existing component perform the same functions. In one example, an additional water pump is provided in parallel to an existing water pump. The additional water pump, the existing water pump, or both can be activated to provide the function of forcing water to provide a flow of water.

A plurality of measurements sensors are then installed for the HVAC components. These measurements sensors include a plurality of temperature sensors, a plurality of flow meters, and a plurality of electrical power meters. The temperature sensors are used for the measuring the temperatures of fluids that pass through the respective HVAC components. Similarly, the flow meters are used for measuring the flow rates of the respective fluids. The electrical power meters are used for measuring electrical energy consumed by the respective HVAC components .

A plurality of Variable Speed Drives (VSDs) is later installed for the respective HVAC components. The VSDs can act to adjust speed of the HVAC components. In particular, the VSDs can serve to adjust speed of water pumps, of cooling tower fans, and of chiller compressors . The speed adjustment is often done by changing a pulse width of an electrical power supply of the respective HVAC component.

Thereafter, a master controller is installed in the HVAC vice. The master controller is connected to the installe measurement sensors and the installed VSDs .

The controller is configured for obtaining measurement data from the measurement sensors .

The controller is also configured for sending commands or instructions to the BMS for activating different combinations o the HVAC device components . The controller can activate the existing component, activate the corresponding additional com ponent, or activate both the existing component and the corre sponding additional component.

The controller also uses the VSDs to adjust corresponding speed parameters of the components. The component speed parameters are selected such that the component combination and the corresponding component speed parameters provide a predetermined thermal comfort for users of the building. In effect, the users of the building experience the same thermal comfort for the different component combinations with the respective component speed parameters .

From the different combinations, the controller later selects one combination of the components and the corresponding component speed parameters . This component combination with the corresponding component speed parameters allows the HVAC device to provide reduced energy consumption. The controller afterward sends to the BMS for activating th selected component combination and uses the VSDs to adjust corresponding component speed ; larameters .

The method has a benefit of reducing electrical energy consumption of the HVAC device. This is an especially important the building is large with many climate-controlled rooms . The energy consumption of the HVAC device is hence large.

The speed parameter data can refer to different types of data.

The speed parameter data can refer to water pump reduction speed data .

The speed parameter data can also refer to water flow rate reduction data.

The application also provides a further method of operating a Heating, Ventilating, and Air Conditioning (HVAC) device for a building .

The HVAC device includes a Building Management System (BMS) and a master controller, one or more water pump with a valve.

The water pump and the water valve are provided for a water pipe of a chilled water loop or a condenser water loop of the HVAC device. The water pump acts to force water through the pipe while the valve serves to control flow of water through the pipe. The BMS or the controller acts to activate a speed of the water pump. In other words, the BMS or the controller adjusts the flow rate of the water pump. The BMS or the controller acts to actuate positions of the valve. The method includes a step of actuating a valve of a water pump of a pipe of the HVAC device to a fully open position. In the fully open position, the valve does not constrict flow of water through the pipe. The water pump valve can include one or two valve elements for controlling flow of water through the pipe by opening or closing the valve elements . One valve element can be placed at a water supply side while the other valve element can be placed at a water return side of the water pump. flow rate of water is then measured. This flow rate corre onds to the fully open position of the water pump valve.

After this, a plurality of puise widths of a frequency of an electrical power supply of the water pump is determined ac- cording to said water flow rate measurement. The different frequency power widths are used for providing different corre- sponding water pump speeds . The water pump speeds relates to a flow rate of the water pump. A narrow pulse width would corre- spond to a low water pump speed while a wide pulse width would correspond to a high water pump speed .

The water pump is lat activated according to the plurality of pulse widths of th frequency the electrical power supply of the water pump for roviding the plurality of the water pump speeds .

At the same time, the valve is also actuated to corresponding positions. This is done such that each water pump speed and the corresponding water valve position provide the same predetermined water flow rate. The BMS or the controller can use formulae to determine the valve position. The BMS or the controller can also use trial and error methods to determine the valve position. In one implementation, the pulse width is narrowed to reduce the speed of the water pump for forcing less water. The reduced water pump speed and the corresponding position of the water valve provide the same desired rate of flow of water.

Electrical power consumption of the water pump is measured fo each water pump speed.

Thereafter, one water pump speed with the corresponding water valve position, which provides reduced electrical power consumption, is afterward selected for use.

This method has some advantages. It can be applied easily for several types of HVAC device. It can also be applied for different parts of the same HVAC device.

The application provides another method for operating a Heating, Ventilating, and Air Conditioning (HVAC) device for a building .

The HVAC device comprises a Building Management System (BMS), a controller, and a plurality of Variable Speed Drives (VSDs) The VSD is used for changing a pulse width of a frequency of an electrical power supply of a water pump. The controller or the BMS operates the VSD.

The method comprising a step o providing a first water pump which is adapted to operate at first predetermined electri cal power supply frequency pul width .

A corresponding water valve is also actuated to a first prede- termined water pump valve position. The first predetermined electrical power supply frequency pulse width and the first predetermined water pump valve position allows the water pump to provide a predetermined flow rate.

Electrical power consumption of the first water pump is then measured .

A second water pump is afterward provided in parallel with th first water pump. The first water pump and the second water pump are adapted to operate at a second predetermined electri cal power supply frequency pulse width.

The water valve is also actuated to a second predetermined water pump valve position such that the first water pump and the second water pump together provide the same predetermined flow rate, which is mentioned above.

The electrical power consumption of the first water and of the second water pump is later measured.

The first water pump, the second water pump, or both the first and the second water pumps are then selected for operating in order to reduce the electrical power consumption.

The method often includes a step of providing a plurality of operating boundary parameters for parts of the HVAC device.

The operating boundary parameters define practical limits of parameters of the HVAC device parts . The HVAC device parts may not work properly and can be damaged when it is operating outside of its practical limits. Put simply, the HVAC device parts

The water pump frequency pulse width is then compared with the corresponding operating boundary parameter. When the value of the water pump frequency pulse width exceeds the value of the corresponding operating boundary parameter, the value of the water pump frequency pulse width is changed to the value of the corresponding operating boundary parameter .

The water pump valve position is later compared with the corresponding operating boundary parameter.

When the value of the water pump valve position exceeds the value of the corresponding operating boundary parameter, the value of the water pump valve position is changed to the value of the corresponding operating boundary parameter.

The operating boundary parameter can be generated using statistical techniques. This is possible when the operating boundary parameter has a normal distribution. Computers can then be employed for calculating the operating boundary parameter while the operating boundary parameter can also serve as a quality control limit.

In one implementation, the water pump refers to a chilled water pump. The respective water valve refers to a chilled water valve .

In another implementation, the water pump refers to a condenser water pump. The respective water valve refers to a condenser water valve.

Fig. 1 illustrates an air cooling and circulating arrange- ment for a building that includes a Building Manage- ment System (BMS) and an energy control module, Fig. 2 illustrates parts of a chiller of the air cooling and circulating arrangement of Fig. 1,

Fig. 3 illustrates another air cooling and circulating arrangement with a further energy control module, which is a variant of the energy control module of Fig. 1,

Fig. 4 illustrates a further air cooling and circulating arrangement with an energy control module being connected to a cloud-based computer,

Fig. 5 illustrates a further air cooling and circulating arrangement, which is a variant of the air cooling and circulating arrangement of Fig. 1,

Fig. 6 illustrates an example of system curves of a water flow system with a throttling valve and an example of performance curves of a water pump for the air cooling and circulating arrangement of Figs . 1 and 5,

Fig. 7 illustrates a flow chart of a method of operating the air cooling and circulating arrangement of Fig. 5,

Fig. 8 illustrates a graph of a relationship between

chiller efficiency and condenser water temperature for the air cooling and circulating arrangement of Fig. 5, and

Fig. 9 illustrates graphs of a relationship between chiller efficiency and chiller speed for the air cooling and circulating arrangement of Fig. 5.

Is are

on . . It

at the

practiced without such details Some embodiments have similar parts. The similar parts may have the same names or similar part reference numerals with an alphabet or prime symbol. The description of one similar part also applies by reference to another similar part, where appropriate, thereby reducing repetition of text without limiting the disclosure.

Fig. 1 shows an air cooling and circulating arrangement 10 for a building, with a Building Management System (BMS) 13 and with an energy control module 16. The air cooling and circulating arrangement 10 is electrically connected to the energy control module 16 and to the BMS 13. The building is not shown in Fig. 1. The BMS 13 is also called a Building Automation System (BAS) .

The air cooling and circulating arrangement 10 includes a cooling tower 20 with a condenser water pump 22, an Air Handling Unit (AHU) 25 with a supply chilled water pump 27 and with a return chilled water pump 29, and a chiller 33. The cooling tower 20 comprises one or more fans 36.

The cooling tower 20 is fluidically connected to the condenser water pump 22 by a condenser water pipe, which is fluidically connected to the chiller 33 by another condenser water pipe. The chiller 33 is fluidically connected to the cooling tower 20 by a further condenser water pipe. The water pump 22 circulates condensed water between the chiller 33 and the cooling tower 20.

The AHU 25 is fluidically connected to the supply chilled wa- ter pump 27 by a chilled water pipe . The supply chilled water pump 27 is fluidically connected to the chiller 33 by another chilled water pipe. The chiller 33 is fluidically connected to the return chilled water pump 29 by a further chilled water pipe. The return chilled water pump 29 is fluidically connected to the AHU 25 by another chilled water pipe. The supply chilled water pump 27 and the return chilled water pump 29 circulate chilled water between the AHU 25 and the chiller 33.

As can be seen in Fig. 2, the chiller 33 includes a refrigerant gas compressor 40, an evaporator 43, a condenser 45, and an expansion valve 48.

The gas compressor 40, the evaporator 43, the condenser 45, and the expansion valve 48 are fluidically connected by a set of refrigerant pipes to form a refrigerant loop that allows a refrigerant to circulate in a thermodynamic cycle.

The gas compressor 40 is fluidically connected to the condenser 45, which is fluidically connected to the expansion valve 48. The expansion valve 48 is fluidically connected to the evaporator 43. The evaporator 43 is fluidically connected to the gas compressor 40. The gas compressor 40, the condenser 45, the expansion valve 48, and the evaporator 43 contain a refrigerant, which can be in a form or a gas and/or liquid.

As can be seen Figs. 1 and 2, the chiller condenser 45 is fluidically connected to the condenser water pipes such that the cooling tower 20, the condenser water pump 22, and the chiller condenser 45 form a condenser water loop that allows condenser water to circulate.

The chiller evaporator 43 is fluidically connected to the chilled water pipes such that the AHU 25, the supply chilled water pump 27 with the return chilled water pump 29, and the chiller evaporator 43 form a chilled water loop that allows chilled water to circulate . The supply chilled water pump 27 and the return chilled water pump 29 are adapted for circulating chilled water between the AHU 25 and the chiller evaporator 43.

Referring to the BMS 13, see seen in Fig. 1, it is adapted for activating electric motors of respective parts of the air cooling and circulating arrangement 10, such as pumps, fans, and compressors.

In detail, the BMS 13 is electrically connected to the chiller compressor 40, to the condenser water pump 22, to the cooling tower fan 36, to the supply chilled water pump 27, and to the return chilled water pump 29 for activating these parts. The connection lines are not shown in Fig. 1 for simplicity.

Referring to the energy control module 16, it includes a plurality of Variable Speed Drives (VSDs) 52, a parameter measuring module of the air cooling and circulating arrangement 10, and a master controller (MC) 73. The VSD is also called a Variable Frequency Drive (VFD) . Only one of the plurality of VSDs 52 is shown in Fig. 1.

The MC 73 is electrically connected to the VSDs 52.

In one implementation, the MC 73 is electrically connected to the VSDs 52 via an electrical switch for selectively connect- ing the VSD 52 to the MC 73.

The MC 73 is also electrically connected to the parameter measuring module, which is connected to respective sensors of parts of the air cooling and circulating arrangement 10 by wires. The connection lines between the MC 73 and the sensors are not shown Fig. 1 for simplicity. In a special implementation, the sensors are connected to the parameter measuring module by wireless data transmission means, instead of wired electrical connections.

The parameter measuring module comprises a plurality of temperature sensors 60, a plurality of pressure sensors 65, and a plurality of flow meters 70.

Regarding the flow rate, the MC 73 is electrically connected to one flow meter 70 that is adapted for measuring the flow rate of the supply chilled water pump 27 or the flow rate of the return chilled water pump 29. In effect, this flow meter 70 that is adapted for measuring the rate of flow of fluid in the chilled water loop.

Similarly, the MC 73 is electrically connected to one flow me- ter 70 that is adapted for measuring the flow rate of the con- denser water pump 22. In effect, this flow meter 70 is adapted for measuring the rate of flow of fluid in the condenser water loop .

Regarding the pressure, the MC 73 is electrically connected to one pressure sensor 65 that is adapted for measuring the pressure of the chilled water in the chilled water loop.

The MC 73 is also electrically connected to one pressure sen- sor 65 that is adapted for measuring the pressure of the chilled water being supplied to the AHU 25. This water pres- sure acts to force the chilled water through the AHU 25. In other words, a low-pressure reading from said sensor 65 indi- cates that inadequate amount of the chilled water is flowing through the AHU 25. In a special situation, the MC 73 is electrically connected to one pressure sensor 65 that is adapted for measuring the pressure of the condenser water in the condenser water loop.

Regarding the temperature, the MC 73 is also electrically connected to one temperature sensor 60 that is adapted for measuring the temperature of the condenser water being supplied to the chiller 33.

The MC 73 is also electrically connected to one temperature sensor 60 that is adapted for measuring the temperature of the condenser water being returned from the chiller 33. The condenser water is flowing out of the chiller 33.

The MC 73 is also electrically connected to one temperature sensor 60 that is adapted for measuring the temperature of the chilled water being supplied from the chiller 33.

The MC 73 is also electrically connected to one temperature sensor 60 that is adapted for measuring the temperature of the chilled water being return to the chiller 33.

With reference to the VSDs 52, they are adapted for adjusting frequency pulse width of corresponding electric motors of the respective parts of the air cooling and circulating arrangement 10. This in turn changes the electrical power consumption or energy consumption of the air cooling and circulating arrangement 10.

In a special implementation, the VSDs 52 are configured for changing voltage or frequency of the electric motor.

In detail, one VSD 52 is electrically connected to an electrical power supply of the chiller compressor 40 to adjust speed of the chiller compressor 40. One VSD 52 is electrically connected to an electrical power supply of the cooling tower fan 36 to adjust speed of the cooling tower fan 36. One VSD 52 is electrically connected to an electrical power supply of the condenser water pump 22 to adjust speed of the condenser water pump 22. One VSD 52 is electrically connected to an electrical power supply of the supply chilled water pump 27 to adjust speed of the supply chilled water pump 27. One VSD 52 is electrically connected to an electrical power supply of the return chilled water pump 29 to adjust speed of the return chilled water pump 29.

In another embodiment not shown here, the air cooling and circulating arrangement 10 includes all of its parts with the exception of the return chilled water pump 29.

In a general sense, the air cooling and circulating arrangement 10 can also include more than one supply chilled water pump 27, or more than one return chilled water pump 29, or more than one condenser water pump 22.

If more than one supply chilled water pump 27 is provided, the supply chilled water pumps 27 are connected in parallel, with electric valves for activating and deactivating each supply chilled water pump 27. The electric valves are electrically connected with the BMS 13 and/or the MC 73.

Similarly, if more than one return chilled water pump 29 is provided, the return chilled water pumps 29 are connected in parallel, with electric valves for activating and deactivating each return chilled water pump 29. The electric valves are electrically connected with the BMS 13 and/or the MC 73. If more than one condenser water pump 22 is provided, the condenser water pumps 22 are connected in parallel, with electric valves for activating and deactivating each condenser water pump 22. The electric valves are electrically connected with the BMS 13 and/or the MC 73. and cir

one coo

than o and cir

one chi

sor 40.

In a special embodiment, an electrical panel of activation switches replaces the BMS 13. The switches are used for activating respective parts of the air cooling and circulating arrangement 10.

In another embodiment, a heat exchanger is installed between the supply chilled water pump 27 and the return chilled water pump 29 for providing two water loops or circuits.

In detail, the heat exchanger is fluidically connected to the supply chilled water pump 27 and to the return chilled water pump 29, wherein the supply chilled water pump 27, the heat exchanger, the return chilled water pump 29, and the chiller 33 form a first water loop.

The heat exchanger is also fluidically connected to a secondary pump and to the AHU 25, wherein the heat exchanger, the secondary pump, and the AHU 25 form a second water loop. The secondary pump would drive this water loop. In use, the air cooling and circulating arrangement 10 is used for adjusting the temperature of climate controlled spaces of a building.

The BMS 13 manages or activates parts of the air cooling and circulating arrangement 10 in order that the controlled spaces has a user desired comfortable temperature.

The energy control module 16 changes frequency pulse width of electrical power supplies of the corresponding electric motors of the respective parts of the air cooling and circulating arrangement 10 for changing the energy consumption of the air cooling and circulating arrangement 10 while maintaining the user desired comfortable temperature of the controlled spaces .

The frequency pulse width corresponds to a speed of the elec- trie motor. Put differently, adjusting the frequency pulse width also changes the speed of the electric motor. The elec- trie motor is often used in water pumps, cooling tower fans, and compressors.

Regarding the chilled water loop, it absorbs heat energy from the AHU 25 and transfers this heat energy to the chiller 33.

In detail, the AHU 25 absorbs heat energy from the controlled spaces of the building and then transmits this heat energy to the chilled water flowing through the AHU 25.

The supply chilled water pump 27 and the return chilled water pump 29 circulate the chilled water between the AHU 25 and the evaporator 43 of the chiller 33.

Regarding the refrigerant loop, the chiller 33 act to transfer heat energy from the chilled water to the condenser water, wherein said chilled water and said condenser water flow through the chiller 33.

In detail, the evaporator 43 allows the refrigerant, which passes through the evaporator 43, to absorb heat energy from the chilled water, which passes through the evaporator 43. This causes the refrigerant changes from a liquid to a vapor.

The compressor 40 receives the refrigerant from the evaporator 43, wherein the compressor 40 causes the temperature and the pressure of the refrigerant to increase.

The condenser 45 receives the refrigerant from the compressor 40, wherein the refrigerant changes from a vapor to a liquid. During this phase change, the refrigerant transmits its heat energy to the condenser water, which flows through the condenser 45.

The expansion valve 48 provides a phase change of the refrigerant, thereby reducing the temperature of the refrigerant.

Regarding the condenser water loop, it transfers heat energy from the chiller 33 to the cooling tower 20.

In detail, the chiller condenser 45 transfers heat energy from the refrigerant, which flows through the chiller condenser 45, to the chilled water, which flows through the chiller condenser 45.

The condenser water pump 22 circulates the condenser water between the chiller 33 and the cooling tower 20. The cooling tower 20 with the fan 36 acts to expel the heat energy in the condenser water, which flows through the cooling tower 20, to an outside space.

Different methods of retrofitting the building with the air cooling and circulating arrangement 10 are described below.

With one method of retrofitting the building, the BMS 13 is already existing, as depicted in Fig. 1, the air cooling and circulating arrangement 10 does not yet have any VSDs . The BMS 13 is adapted to activate respective parts of the air cooling and circulating arrangement 10.

The method includes a step of adding an energy control module 16 to the air cooling and circulating arrangement 10.

The energy control module 16 includes VSDs 52 with an activation switch 75 and an MC 73. The switch 75 is adapted for selectively connecting the MC 73 to the VSDs 52. In other words, the selection of the switch 75 allows the MC 73 to send instructions or commands to the VSD 52.

The MC 73 is electrically connected to a parameter measuring module, which is connected to respective sensors of the air cooling and circulating arrangement 10.

The MC 73 is configured for receiving sensor measurement readings of the sensors of the air cooling and circulating arrangement 10 from the parameter measuring module. The MC 73 is also configured with an improved algorithm for controlling the VSDs 52 to reduce the energy consumption of parts of the air cooling and circulating arrangement 10 according to the sensor measurement readings while maintaining desired thermal or cooling comfort. A further method of retrofitting the building is described below, wherein a master controller is set up in relation to a BMS.

Fig. 3 shows an air cooling and circulating arrangement 10 with a BMS 13 and VSDs 52 that are already existing.

The BMS 13 is configured to control the VSDs 52 in order to adjust speed of respective parts the air cooling and circulating arrangement 10.

The method includes a step of providing an activation switch 77 between the BMS 13 and the VSDs 52. The switch 77 selectively connects the BMS 13 to tive VSDs 52.

The method further includes a step of providing a MC 73 and an activation switch 78 between he MC 73 and the VSDs 52. The switch 77 selectively connect the VSDs 52 to the MC 73.

The MC 73 is configured for receiving sensor measurement readings of the sensors of the air cooling and circulating arrangement 10 from a parameter measuring module. The MC 73 is also configured with an improved algorithm for controlling the VSDs 52 to reduce the energy consumption of parts of the air cooling and circulating arrangement 10 according to the sensor measurement readings while maintaining desired thermal or cooling comfort. Fig. 4 shows a further air cooling and circulating arrangement. The air cooling and circulating arrangement includes an energy control module that is communicatively connected to a cloud-based computer with a database. The database stores measurement data. The energy control module includes a Programmable Logic Controller (PLC) and/or Supervisory Control And Data Acquisition (SCADA) for treating or processing data from the cloud-based computer for additional evaluation.

In another implementation, the PLC or the SCADA sent data to the cloud-based computer for additional evaluation.

One method of operating the BMS 13 and the MC 73 of the air cooling and circulating unit 10 for a building is described below .

The BMS 13 and the MC 73 serve in a superimposition manner for reducing the energy consumption of the air cooling and circulating unit 10 while maintaining a desired thermal comfort.

The method includes a step of the BMS 13 obtaining parameter measurements from the parts of the air cooling and circulating unit 10.

The BMS 13 then sends the obtained parameter measurements to the MC 73.

After this, the MC 73 calculates an effective operational setting, such as number of operational equipment and speed of each operational pump and operational cooling tower, according to the parameter measurements.

The MC 73 then sends the calculated operational setting to the BMS 13. The BMS 13 afterward sends corresponding control signals, which are derived according to the calculated operational set ting, to VSDs, which are connected to pumps and cooling tower fans .

In another method of operating the BMS 13 and the MC 73, an operator of the air cooling and circulating unit 10 is provid ed with an activation switch for connecting parts of the air cooling and circulating unit 10 to the MC 73 or to the BMS 13 In other words, the operator selects either the MC 73 or the BMS 13 for providing controlling commands to the air cooling and circulating unit 10.

In another method of operating the BMS 13 and the MC 73, the MC 73 takes sensor measurement data from the air cooling and circulating unit 10 and sending controlling signals to the ai cooling and circulating unit 10 via the BMS 13.

In a special method of operating the BMS 13 and the MC 73, a combination of steps of the above methods are performed. Some sensor measurement data are taken from BMS 13 and control sig nals are sent through BMS 13, while other sensor measurement data are measured directly by the MC 73 with control signals being sent directly from the MC 73.

In a further method of operating the BMS 13 and the MC 73, no BMS 13 exists. Only the MC 73 exists for acquiring all sensor measurement data from the air cooling and circulating unit 10 and for sending all control signals to the air cooling and circulating unit 10.

One method of operating the air cooling and circulating arrangement 10 is described below. The BMS 13 selectively activates the chiller compressor 40, the condenser water pump 22, the cooling tower fan 36, the supply chilled water pump 27, and the return chilled water pump 29.

After this, the MC 73 receives parameter measurements from the sensors of the parameter measuring module 740 regarding sensor readings parameters of parts of the air cooling and circulating arrangement 10. In particular, the MC 73 receives parameter measurements from the temperature sensors 60, from the pressure sensors 65, from the flow meters 70, and from electrical power meters .

The MC 73 then generates control signals to the VSDs 52 according to said parameter measurements .

The MC 73 later sends to the generated control signals to the VSDs 52 for adjusting frequency pulse width of electrical power supplies of the corresponding electric motors of the respective parts of the air cooling and circulating arrangement 10 for reducing energy consumption of the air cooling and circulating arrangement 10 while allowing the controlled spaces to reach a user desired comfortable temperature.

Fig. 5 depicts an air cooling and circulating arrangement with additional chilled water pumps and additional condenser water pumps . These additional water pumps could be part of a chiller, which is currently not operating or running. These water pumps could also be installed as a backup, which are used when a normally operating water pump becomes faulty, or when the normally operating water pump is taken out for service or maintenance. Fig. 5 shows an air cooling and circulating arrangement 100 for a building, which includes a Building Management System (BMS) 130 and with an energy control module 160. The air cooling and circulating arrangement 100 is electrically connected to the energy control module 160 and to the BMS 130. The building is not shown in Fig. 5.

The air cooling and circulating arrangement 100 includes a cooling tower module 200 with a condenser water pump module 220, an Air Handling Unit (AHU) module 250 with a supply chilled water pump module 270 and with a return chilled water pump module 290, as well with as a chiller module 330.

The cooling tower module 200 and the condenser water pump mod- ule 220 are fluidically connected to the chiller module 330 by a set of condenser water pipes. The cooling tower module 200 is fluidically connected to the condenser water pump module 220, which is fluidically connected to the chiller module 330. The chiller module 330 is fluidically connected to the cooling tower module 200.

The AHU module 250, the supply chilled water pump module 270, and the return chilled water pump module 290 are fluidically connected to the chiller module 330 by a set of chilled water pipes. The AHU module 250 is fluidically connected to the supply chilled water pump module 270. The supply chilled water pump module 270 is fluidically connected to the chiller module 330, which is fluidically connected to the return chilled water pump module 290. The return chilled water pump module 290 is fluidically connected to the AHU module 250.

In detail, the cooling tower module 200 includes a cooling tower 20 with water valves 20A and 20B and a cooling tower with water valves 2 OA' and 20B' . The water valves 2 OA, 20B, 20A' , and 20B' are also called isolation valves, or - in short - valves.

The valve 20A is fluidically connected to a water inlet of the cooling tower 20 while the valve 20B is fluidically connected to a water outlet of the cooling tower 20.

Similarly, the valve 20A' is fluidically connected to a water inlet of the cooling tower 20' while the valve 20B' is fluidically connected to a water outlet of the cooling tower 20' . The valve 20A is also fluidically connected to the valve 20A' while the valve 20B is fluidically connected to the valve 20B' .

The cooling tower 20 includes a fan 36 while the cooling tower module 20' includes a fan 36' .

Referring to the condenser water pump module 220, it includes a condenser water pump 22 with water valves 22A and 22B as well as a condenser water pump 22' with water valves 22A' and 22B' .

The valve 22A is fluidically connected to a water inlet of the condenser water pump 22 while the valve 22B is fluidically connected to a water outlet of the condenser water pump 22.

Similarly, the valve 22A' is fluidically connected to a water inlet of the condenser water pump 22' while the valve 22B' is fluidically connected to a water outlet of the condenser water pump 22' . The valve 22A is also fluidically connected to the valve 22A' while the valve 22B is fluidically connected to the valve 22B' . Referring to the AHU module 250, it includes a AHU 25 with water valves 25A and 25B and a AHU 25' with water valves 25A' and 25B' . The valve 25A is fluidically connected to a water inlet of the AHU 25 while the valve 25B is fluidically connected to a water outlet of the AHU 25.

Likewise, the valve 25A' is fluidically connected to a water inlet of the AHU 25' while the valve 25B' is fluidically connected to a water outlet of the AHU 25' . The valve 25A is also fluidically connected to the valve 25A' while the valve 25B is fluidically connected to the valve 25B' . Referring to the supply chilled water pump module 270, it includes a supply chilled water pump 27 with water valves 27A and 27B as well as a supply chilled water pump 27' with water valves 27A' and 27B' . The valve 27A is fluidically connected to a water inlet of the supply chilled water pump 27 while the valve 27B is fluidically connected to a water outlet of the supply chilled water pump 27. In the similar manner, the valve 27A' is fluidically connected to a water inlet of the supply chilled water pump 27' while the valve 27B' is fluidically connected to a water outlet of the supply chilled water pump 27' . The valve 27A is also fluidically connected to the valve 27A' while the valve 27B is fluidically connected to the valve 27B' .

Referring to the return chilled water pump module 290, it includes a return chilled water pump 29 with water valves 29A and 29B and a return chilled water pump 29' with water valves 29A' and 29B' .

The valve 29A is fluidically connected to a water inlet of the return chilled water pump 29 while the valve 29B is fluidically connected to a water outlet of the return chilled water pump 29.

Likewise, the valve 29A' is fluidically connected to a water inlet of the return chilled water pump 29' while the valve

29B' is fluidically connected to a water outlet of the return chilled water pump 29' . The valve 29A is fluidically connected to the valve 29A' while the valve 29B is also fluidically connected to the valve 29B' .

Referring to the chiller module 330, it includes a chiller 33 with water valves 33A1, 33A2, 33B1, and 33B2 as well as a chiller 33' with water valves 33A1' , 33A2' , 33B1' , and 33B2'. The valve 33A1 is fluidically connected to a condenser water inlet of the chiller 33 while the valve 33B1 is fluidically connected to a condenser water outlet of the chiller 33. The valve 33A2 is fluidically connected to a chiller water inlet of the chiller 33 while the valve 33B2 is fluidically connect- ed to a chiller water outlet of the chiller 33.

Similarly, the valve 33A1' is fluidically connected to a condenser water inlet of the chiller 33' while the valve 33B1' is fluidically connected to a condenser water outlet of the chiller 33' . The valve 33A2' is fluidically connected to a chiller water inlet of the chiller 33' while the valve 33B2' is fluidically connected to a chiller water outlet of the chiller 33' . The valve 33A1 is fluidically connected to the valve 33A1' and the valve 33B1 is also fluidically connected to the valve 33B1' . The valve 33A2 is fluidically connected to the valve 33B2' while the valve 33B2 is fluidically connected to the valve 33B2' .

Referring to the BMS 130, it is adapted for activating electric motors of respective parts of the air cooling and circulating arrangement 100, such as pumps, fans, and compressors. The activation relates to provision of electrical energy to the electric motors. The BMS 130 is electrically connected to these electric motors by cables for selectively connecting these electric motors to corresponding electrical power supplies for providing electrical energy to these electric motors .

The BMS 130 is also adapted for actuating the water valves 20A, 20B, 22A, 22B, 25A, 25B, 27A, 27B, 29A, 29B, 29A, and 29B. The BMS 130 is also adapted for actuating the water valves 20A' , 20B' , 22A' , 22B' , 25A' , 25B' , 27A, 27B' , 29A', 29B' , 29A' , and 29B' .

The actuation of a water valve refers to changing the position or the state of the water valve, for example from a closed state to a partially open state. The water valve is mechanically connected to an actuator, which electrically connected to the BMS 130 with an electrical cable. In use, the BMS 130 sends a valve actuation electrical signal to the actuator such that the actuator changes or moves the position of the water value .

In detail, the BMS 130 is adapted for actuating the water valves 20A and 20B of the cooling tower 20 and the water valves 20A' and 20B' of the cooling tower 20' . The BMS 130 is also adapted for actuating the water valves 22A and 22B of the condenser water pump 22 and the water valves 22A' and 22B' of the condenser water pump 22' .

The BMS 130 is also adapted for actuating the water valves 25A and 25B of the AHU 25 and the water valves 25A' and 25B' of the AHU 25' . The BMS 130 is also adapted for actuating the water valves 27A and 27B of the supply chilled water pump 27 and the water valves 27A' and 27B' of the supply chilled water pump 27' .

The BMS 130 is also adapted for actuating the water valves 29A and 29B of the return chilled water pump 29 and the water valves 29A' and 29B' of the return chilled water pump 29' .

The BMS 130 is also adapted for actuating the water valves 33A1, 33A2, 33B1, and 33B2 of the chiller 33 and the water valves 33A1' , 33A2' , 33B1' , and 33B2' of the chiller 33' .

These water valves act to isolate parts of the air cooling and circulating arrangement 100. Fully closing of a pair of corresponding water valves, which are respectively connected to a water inlet and to a water outlet of a part of the air cooling and circulating arrangement 100, in effect, acts to remove the part from the air cooling and circulating arrangement 100.

Similarly, opening of the water valves, in effect, acts to include the part in the air cooling and circulating arrangement 100. As an example, closing of the water valves 20A and 20B acts to remove the cooling tower 20 from the air cooling and circulating arrangement 100. Opening of the water valves 20A and 20B acts to include the cooling tower 20 in the air cooling and circulating arrangement 100.

As a result, by way of selectively actuating the cooling tower 20 or 20' by the BMS 130, the air cooling and circulating ar- rangement 100 can run with both or with only one selected cooling tower 20.

Referring to the energy control module 160, it includes a plurality of Variable Speed Drives (VSDs) 520, a measuring module 740 for measuring parameters of the air cooling and circulating arrangement 100, and a master controller (MC) 730. Only one VSD 520 is shown in Fig. 5 for the sake of simplicity. The VSDs 520, the measuring module 740, and the MC 730 cooperate with each other.

The MC 730 is electrically connected to the VSDs 520, which are connected to parts of the air cooling and circulating arrangement 100.

The MC 730 is also electrically connected to the measuring module 740, which is electrically connected to sensors of the air cooling and circulating arrangement 100. The sensors include temperature sensors, pressure sensors, and flow meters. These sensors are connected to the parts of the air cooling and circulating arrangement 100 for measuring parameters of these parts.

As a result, the MC 730 can obtain parameter measurements of parts of the air cooling and circulating arrangement 100 from the measurement module 740. The MC 730 can then use the VSDS 520 to adjust frequency pulse widths of electrical motors of the air cooling and circulating arrangement 100 according to these parameter measurements .

Different manners of installing the flow meters are possible.

In one implementation, the flow meters are installed at respective common headers of the chillers 33 and 33' to measure accurately a rate of flow of water from corresponding parts of both of the chillers 33 and 33' . The header refers to a water chamber where water pipes from these corresponding parts of both chillers 33 and 33' are fluidically connected. As an example, the common header can be fluidically connected to water outlets of both water pumps 27 and 27' . The common header is labelled "H" in Fig. 5 for easier reference.

In another implementation, the flow meters are installed at respective parts of each chillers 33 and 33' to measure accurately the water flow rates of these parts of the chillers 33 and 33' .

The pressure sensors are often placed farthest away from the respective water pump 22, 22', 27, 27', 29, and 29', such as the AHU 25 and 25', where the pressure of the water is lowest.

The MC 370 is adapted for actuating the water valves 20A, 20B, 22A, 22B, 25A, 25B, 27A, 27B, 29A, 29B, 29A, and 29B. The MC 370 is also adapted for actuating the water valves 20A' , 20B' , 22A' , 22B' , 25A' , 25B' , 27A, 27B' , 29A', 29B', 29A', and 29B' .

As a result, the MC 370 can selectively add or remove parts of the air cooling and circulating arrangement 100, which are as- sociated with these water valves . In a general sense, in principle, the considerations of the configurations of the energy control module 16 of Figs. 1, 3, and 4 can be applied to the energy control module 160 of Fig. 5.

Several methods of operating the air cooling and circulating arrangement 100 are shown below. Steps of one method can also be combined with steps of another method, where appropriate for providing different ways of operating the air cooling and circulating arrangement 100.

A method for operating the air cooling and circulating arrangement 10 or 100 of Figs 1, 3, 4, and 5 for a building for supporting a desired cooling load is described below.

The method includes a step of providing a set of interlinked decision-making matrixes that is derived for the air cooling and circulating arrangement 10 or 100.

The energy control module 16 or 160 then obtains parameter measurement information from the respective parameter measuring module . uses the rixes to oling and culating arrangement 10 or 100

The adjustments enable the ai cooling and circulating ar- rangement to operate in high fficiency to provide required thermal comfort for occupants of the building without affect- ing operational safety. The adjustments of operating parameters can be done by providing instructions a system administration staff for changing these operating parameters . The staff then performs said change of parameters .

In another implementation, the energy control module 16 or 160 automatically changes the parameters without any manual intervention .

A method of operating the air cooling and circulating arrange ment 100 of Fig. 5, using boundary parameter data to support pre-determined cooling load is described below.

The operating boundary parameter data define limits within which the parts can operate properly. For example, operating chiller below a minimum flow 1imit can cause the chiller to trip or malfunction.

The boundary parameter data includes

data of minimum operational motor speed of the water pumps 22, 22' 27, 27', 29, and 29',

data of minimum pressure produced by the water pumps 27 and 27' in order to transfer the chilled water from the

AHUs 25 and 25' to the chillers 33 and 33',

data of minimum pressure produced by the water pumps 29 and 29' in order to transfer the chilled water from the chillers 33 and 33' to the AHUs 25 and 25' ,

data of allowable rate of change of flow of the chilled water during adding or removing of the respective water pump 27, 27', 29, and 29', and

data of allowable rate of change of flow of the condenser water during adding or removing of the water pump 22, and The operating boundary parameter data can be obtained from manufacturers of the equipment. The data can also be obtained during a testing and commissioning stage of the MCT 730. The operating boundary parameter data can also be produced using statistical techniques in accordance with measurements of the respective equipment.

The method comprises a step of equipping the MC 730 with operating boundary parameter data of equipment or parts of the air cooling and circulating arrangement 100, such as water pumps 22, 22' 27, 27' , 29, and 29' .

After this, the MC 730 receives a new operating parameter data of a part of the air cooling and circulating arrangement 100. As an example, the new operating parameter data can relate to a frequency pulse width of the water pumps 22, 27, 29, 22', 27' , and 29' .

The MC 730 then compares the new operating parameter data with the respective operating boundary parameter data.

If the new operating parameter data is within a limit, which is defined by the operating boundary parameter data, the MC 730 then changes the respective operating parameter of the air cooling and circulating arrangement 100 according to the new operating parameter data.

If the new operating parameter data is outside the limit, which is defined by the operating boundary parameter data, the MC 730 later changes the new operating parameter data to the respective operating boundary parameter data. After this, the MC 730 changes the respective operating parameter of the air cooling and circulating arrangement 100 according to the new operating parameter data. This method has a benefit of preventing the air cooling and circulating arrangement 100 from operating outside its operating boundary limits, which can cause damage to its parts.

The flow rate, the pressure, and the electrical power consumption of the corresponding water pumps 22, 22', 27, 27', 29, and 29' can be described by affinity laws, which are shown below .

These parameters can also be described with graphs.

Fig. 6 shows different system curves of a water flow system with a throttling valve and d fferent performance curves of water pumps of the water flow system for the air cooling and circulating arrangement 10 or 100 of Figs. 1, 3, 4, and 5.

The following disclosure is a generic teaching that applies in principle to all water pumps of Figs 1, 3, 4, and 5. Many pumps are provided with a water valve that is provided as a throttling valve. The throttling valve acts to constrict or adjust the flow of water through the throttling valve.

The performance curves comprise graphs 400 and 400a. The graph 400 shows a relationship between the pressure and the flow rate of water from the water pump, wherein the water pump is operating at a predetermined full speed. The graph 400a shows a relationship between the pressure and the flow rate of water from the water pump, wherein the water pump is operating at a predetermined reduced speed.

The system curves include graphs 410a and 410b. The graph 410a shows a relationship between the pressure and the flow rate of water of the water flow system, wherein the throttling valve is fully open. The graph 410b shows a relationship between the pressure and the flow rate of water of the water flow system, wherein the throttling valve is only partially open.

In one implementation, the water pump is operating at the predetermined full speed and the water valve is placed in a partially open position. The water from the water pump later has a respective resistance or pressure of about 150 pounds per square inch (psi) and a respective flow rate of about 45 gallons per minute (GPM) , which corresponds to an intersection point A between the water pump performance curve graph 400 and the system curve graph 410b.

If the throttling valve is placed in a fully open position, the water from the water pump then has a respective resistance of about 100 pounds per square inch (psi) and a respective flow rate of about 100 gallons per minute (GPM) , which corresponds to an intersection point B between the water pump performance curve graph 400 and the system curve graph 410a.

If the speed of the water pump is reduced, the water from the water pump has a respective resistance of about 20 pounds per square inch (psi) and a respective flow rate of about 45 gallons per minute (GPM) , which corresponds to an intersection point C between the water pump performance curve graph 400a and the system curve graph 410a.

Comparing the point A and the point B, they correspond to the same flow rate but to different resistances with different pump speeds, and to different states or positions of the throttling valve. The point B, which corresponds to the lower resistance and to the lower pump speed, in due course, also corresponds to a lower energy consumption of the water pump.

In other words, the water pump consumes the smallest power when it runs with a fully open water valve at a low speed, which is represented by the point C.

In many air conditioning systems, actual water flow resistance and resulting water flow rate is only known after installation and commissioning of an air conditioning system or an air cooling and circulating arrangement .

As such, throttling valves are installed across the air conditioning system to allow for adjustment of the water flow rate of the air conditioning system. However, as seen in the description of Fig. 6 above, a reduction of flow by closing a throttling valve would lead to an increased pressure in the water pump, which translates or leads to an increased energy consumption, according to the equations below:

Pump Power (kW) = [Flow rate (m3/s) x Pressure (N/m2)]/

(1000 x pump efficiency)

Hence, the power consumption of the pump can be reduced if the same flow rate is achieved with lower pressure, in order to support the same cooling load. In short words, the embodiments described here apply this by switching between one or more water pumps, according to the required flow rate, and by adjusting the speed of the pump motor accordingly, in order to improve the energy consumption of the pumps, and the corresponding air cooling and circulating arrangement, in order to support the same cooling load.

Similar considerations apply to the cooling towers and their respective fans, as well as to the chillers and the AHUs . In other words, for a given cooling load and a given conditions, it can be more efficient to use one chiller with its compressor running at full speed than using two or more chillers with their compressors running at halve speed.

It can be more efficient to use one cooling tower with its fan running at full speed than using two or more cooling towers with their fan running at halve speed, in order to support the same cooling load.

The above principle is applied in a strategy for reducing the chilled/condenser water flow rate and increasing the opening of the throttling valve for providing the same

chilled/condenser water flow rate and thereby the same cooling load, but with lower power consumption.

A method of operating the air cooling and circulating arrangement 100 for overcoming resistance or pressure to provide a water flow rate is described below. The resistance refers to the pressure of water at an outlet of a water pump at a given water flow rate, and it can be referred to as friction. Sometimes this resistance is also called "pressure loss". This applies to all elements in the water flow. The water flow enables an air cooling and circulating arrangement to support a pre-determined cooling load for providing a desired thermal comfort. The cooling load refers to amount of heat removed from a climate-controlled space. The thermal com- fort relates to the temperature and to the humidity of climate-controlled spaces of a building.

Fig. 7 shows a flow chart 500 of the above-mentioned method, by illustrating the operation of the air cooling and circulat- ing arrangement 100 of Fig. 5.

The flow chart 500 includes a step 515 of the BMS 370 actuating the water valves 22A, 22B, 27A, 27B, 29A, 29B, 22A' , 22B' , 27A' , 27B' , 29A', and 29B' of the respective water pumps 22, 27, 29, 22', 27', and 29' to a fully open state. The fully open water valves 22A, 22B, 27A, 27B, 29A, 29B, 22A' , 22B' , 27A' , 27B' , 29A', and 29B' do not block or restrict the flow of water through these water valves 22A, 22B, 27A, 27B, 29A, 29B, 22A' , 22B' , 27A' , 27B' , 29A' , and 29B'. In effect, they act like being removed from the air cooling and circulating arrangement 100.

The flow meters of the chillers 33 and 33' then performs a step 520 of measuring respective water flow of the chillers 33 and 33' . Thereafter, the flow meters send the respective water flow information of the chillers 33 and 33' to the MC 730.

After this, the MC 730 performs a step 530 of determining frequency pulse width of corresponding electrical power supplies of the corresponding water pumps 22, 27, 29, 22', 27' and 29' and also determines corresponding valve positions of the corresponding water pumps 22, 27, 29, 22', 27', and 29' according to the received flow meter water flow information. The fre- quency pulse width corresponds to a motor speed of the corresponding water pumps 22, 27, 29, 22', 27', and 29'.

The frequency pulse width and the corresponding valve position are determined such that they correspond a desired water flow rate of the air cooling and circulating arrangement 100 for supporting the desired cooling load.

The MC 730 later performs a step 540 of transmitting control signals to the VSDs 520 for changing pulse width of the water pumps 22, 27, 29, 2 2' , 27' , and 29' according to the deter- mined puise widths and for changing the corresponding valve positions according to the determined valve positions.

The respective water flow rate of the water pumps 22, 27, 29, 22', 27' and 29' are then measured to verify the desired water flow rate is achieved.

The respective electrical power consumption of the water pumps 22, 27, 29, 22', 27' and 29' are also measured.

After this, the above steps are performed for different frequency pulse widths and the corresponding valve positions for providing the desired water flow rate.

One frequency pulse width with its corresponding valve position is later selected for use in order to provide a reduced electrical power consumption of the water pump.

This method provides a benefit of providing the same flow rate with lower power consumption. In effect, the water pumps 22, 27, 29, 22', 27', and 29' operate at lower speeds while allowing the AHUs 25 and 25' to provide the desired thermal comfort . In a variant of the above method, the throttling valves are kept fully open at all times while the flow is adjusted only with VFDs.

The above methods are also applicable for condenser water pumps, and other water pumps.

In other words, the structure of the air cooling and circulating arrangement 100 is automatically adapted such that the energy consumption for a given cooling load is improved, within the operating boundary parameter data of its components.

The same considerations apply for cooling towers, fans, chillers, and AHUs, as it will become apparent in the following description of the embodiments .

A further method of operating the air cooling and circulating arrangement 100 of Fig. 5 for overcoming resistance to provide a specific water flow rate to support a pre-determined cooling load for providing a desired thermal comfort is described below .

By way of example, the method is explained with the water pumps 27 and 27' .

The MC 730 activates the water pump 27 for the air cooling and circulating arrangement 100, wherein the water pump 27 operates at a first pre-selected speed for providing a desired water flow rate.

The MC 730 then determines the energy consumption of the water pump 27. The energy consumption of the water pump can be de- termined by measuring a first energy consumption of the water pump 27.

After this, the MC 730 activates the additional corresponding water pump 27' , wherein both the water pump 27 and the corresponding water pump 27' operate at a second pre-selected spee for providing the same predetermined water flow rate. The sec ond pre-selected speed is slower than the first pre-selected speed. In effect, the activation of the corresponding water pump 27' serves to add the water pump 27' to the air cooling and circulating arrangement 100.

Thereafter, the MC 730 determines a second energy consumption of both the water pump 27 and the corresponding water pump 27' .

The MC 730 later compares the first energy consumption with the second energy consumption.

The MC 370 then selects either a first configuration compris- ing the water pump 27 alone or a second configuration compris ing the water pump 27 with the corresponding water pump 27' for use, wherein the selected configuration provides a reduce consumption of energy. In other words, the MC 370 switches be tween the two pump configurations .

In a general sense, the number of operating water pumps can be increased from one to two, or to more than two, wherein these water pumps act together to provide a desired water flow rate. The number of operating water pumps can be decreased from two to one, wherein one water pump acts to provide a desired water flow rate. In a further example, the air cooling and circulating arrangement 100 is operating in a "one pump" configuration, wherein the chiller 33, the supply chilled water pump 27 with the return chilled water pump 29, the AHUs 25 and 25' , the condenser water pump 22, and the cooling tower 20 are activated while the supply chilled water pump 27' with the return chilled water pump 29', the chiller 33', and the cooling tower 20' are not activated. In another example, the air cooling and circulating arrangement 100 is operating in a "two pump" configuration, wherein the chiller 33, the supply chilled water pump 27 with the return chilled water pump 29, the supply chilled water pump 27' with the return chilled water pump 29' , the AHUs 25 and 25' , the condenser water pump 22, and the cooling tower 20 are activated while the chiller 33' and the cooling tower 20' are not activated.

In a further embodiment, the activation of the water pump can be accomplished by the MC 370 sending an activation signal to the BMS 130. After this, the BMS 130 sends a visual text message and/or an email to an operator for manually activating said water pump. This method has a benefit of reducing the total energy consumption for achieving a required cooling load.

A method of operating of the air cooling and circulating arrangement 100 for supporting a cooling load is described be- low. The cooling load refers to amount of heat removed from a climate-controlled space.

The method includes a step of the MC 730 receiving temperature measurement data of the chilled water flowing through the Air Handling Unit (AHU) . The AHU supplies air to the climate- controlled spaces of building.

The MC 730 also receives electrical power consumption measurement data of a chiller compressor, which is operating a predetermined speed and receives electrical power consumption measurement data of a corresponding chilled water pump, which is operating at predetermined speed.

After this, the MC 730 reduces the speed of the chilled water pump. This, in turn, reduces the water flow rate of the chilled water flowing through the AHU. The reduced water flow rate serves to increase the return temperature of the chilled water to the AHU.

The MC 730 then increases speed of the compressor of the chiller for reducing the supply temperature of the chilled wa ter to the AHU. The reduced supply temperature serves to decrease the return temperature of the chilled water. This also acts to increase a delta T of the chilled water, wherein the delta T refers to a temperature difference between the chille water supplying to and the chilled water returning from the AHU.

The above-mentioned speed of the chiller compressor is increased such that the overall return temperature for the chilled water remains constant. The constant chilled water return temperature allows the AHU to support the same cooling load. In other words, the reduced speed of the chilled water pump and the increased speed of the chiller compressor act to support the same cooling load.

The MC 730 then receives electrical power consumption measurement data of the chiller compressor, which is operating at an increased speed. The MC 730 also receives electrical power consumption measurement data of the corresponding chilled water pump, which is operating at a reduced speed.

The above steps are repeated for different chilled water pump speed with different corresponding chiller compressor speed.

After this, the MC 730 selects one chilled water pump speed with one corresponding chiller compressor speed for use, wherein the total electrical power consumed by both the chilled water pump and the chiller compressor is reduced.

This method provides a way of reducing the electrical power consumption of the air cooling and circulating arrangement 100 while supporting the same cooling load.

In summary, the delta T is increased by reducing the speed of chilled water pump, thereby allowing the temperature of chilled water returning to the chiller to rise while maintaining the temperature of the water supplied from the chiller. The MC 730 ensures that any increase of the energy consumption by the AHU and compressor to meet required cooling comfort is compensated by reduced energy consumption of the chilled water pump .

A method of operating the air cooling and circulating arrangement 100 to support a cooling load to provide a desired thermal comfort is described below.

The thermal comfort perceived by occupants of the climate controlled space is a function of flow rate and temperature of the supply air from the AHU. The method comprises a step of the MC 730 obtaining electrical power consumption measurement data of the supply chilled water pump 27 and of the return chilled water pump 29, which circulate the chilled water to the AHU. The MC 730 also receives power consumption measurement data of the AHU fan.

The MC 730 also obtains temperature measurement data of the supply air from the AHU. The MC 730 also obtains flow rate data of the supply air from the AHU fan.

The MC 730 changing the valve positions of the water valves 25A and 25B of the AHU in order to adjust the flow rate of the chilled water flowing through the AHU. The change of the flow rate of the chilled water acts to change the temperature of the supply air from the AHU to the climate controlled space.

The MC 730 afterward changes the speed of the VFD, which is linked to the AHU fan, thereby altering the flow rate of the supply air from the AHU.

The MC 730 also obtains temperature measurement data of the supply air from the AHU and obtains flow rate data of the supply air from the AHU fan. The speed the fan is changed such that the flow rate and the temperature of the AHU supply air provides the same thermal comfort for users of the climate controlled space.

The MC 730 then obtains power consumption measurement data of the supply chilled water pump 27 and of the return chilled water pump 29, which corresponds to the changed valve positions. The change of the chilled water flow rate also changes the power consumed by the supply chilled water pump 27 and by the return chilled water pump 29. The MC 730 also receives power consumption measurement data of the AHU fan, which corresponds to the changed fan speed.

The MC 730 afterward computes the total power consumed by both the supply chilled water pump 27 with the return chilled water pump 29 and the corresponding AHU fan according to the chilled water pump power consumption measurement data and to the AHU fan power consumption data.

After this, the MC 730 repeats the above steps for different valve positions with the different corresponding AHU fan speed while providing the same thermal comfort.

The MC 730 then selects one valve position with one corresponding AHU fan speed that provides a reduced total power consumed by both the supply chilled water pump 27 with the return chilled water pump 29 and the corresponding AHU fan.

The method has an advantage of providing a means to reduce power consumption while providing the same thermal comfort.

A method of operating the air cooling and circulating arrangement 100 by changing the flow rate and the temperature of the condenser water is described below. Fig. 8 shows a graph of a relationship between chiller efficiency and condenser water temperature. The graph depicts a case, wherein an increase of the compressor efficiency corresponds with improved cooling of a compressor, which occurs in many cases . The MC 730 obtains temperature measurement data of the supply condenser water and temperature measurement data of the return condenser water.

The MC 730 also obtains power consumption data of the condenser water pump. The MC 730 also obtains power consumption data of the cooling tower fan.

The MC 730 then adjusts the speed of the condenser water pump for changing the flow rate of the condenser water.

After this, the MC 730 changes the number of operating cooling towers and/or also changes speed of each cooling tower fan for changing temperature of the supply condenser water.

The above-mentioned adjustment of operating cooling towers and/or changes of speed of cooling tower fan are done such that the temperature of the return condenser water remains the same .

The MC 730 later obtains power consumption data of the cooling tower fan.

The MC 730 also obtains power consumption data of the conden- ser water pump with the adjusted pump speed. The MC 730 also obtains power consumption data of the cooling tower fan with the changed fan speed.

The MC 730 then computes total power consumption of both the condenser water pump and the cooling tower fan.

After this, the MC 730 repeats the above steps for different condenser water pump speeds with different corresponding num- bers of operating cooling tower and with different corresponding cooling tower fan speeds for providing the same return condenser water temperature.

The MC 730 then selects one condenser water pump speed with one corresponding number of operating cooling tower and/or one corresponding cooling tower fan speed, wherein the total power consumption of the condenser water pump and the corresponding cooling tower fan is reduced.

The method has an advantage of providing a means to reduce the power consumption while providing the same thermal comfort.

A method of operating the air cooling and circulating arrangement 100 by selecting equipment to support a pre-determined cooling load is described below.

This method includes a step of the energy control module 16 accessing equipment of the air cooling and circulating arrangement 100.

The energy control module 16 later selects equipment, which are more energy efficient, for operating.

The energy control module 16 also automatically adds the selected equipment for operating.

The equipment can also be added automatically in an event of equipment failure. The equipment failure can lead to system level shutdown, which requires an energy intensive and operationally complex restart process.

This method acts to improve energy efficiency of the air cool- ing and circulating arrangement 100. The method also acts to increase operational flexibility and decrease system level failure rate of the air cooling and circulating arrangement 100.

A method of operating the air cooling and circulating arrangement 100 with improved equipment reliability to support a predetermined cooling load is described below.

This method includes a step of reducing system level failure. This is performed by adding additional Central Processing Unit (CPU) to allow communication of commands from a Programmable Logic Controller (PLC) . Even if one Central Processing Unit (CPU) is failing, a second CPU can take over the operation.

Hardware interlocks are also introduced in a design of the energy control module 16 to ensure that operation of equipment is not disrupted in the unlikely case of both the CPUs of the PLC are malfunctioning. Hardware interlocks ensure that the last sent command remains in place even with both CPUs of the PLC failing. This is different from other systems, whereby failure of CPU will lead to a faulty "off" command being sent to equipment in an Air Cooling and Circulation unit, causing system level shut down.

Such system level disruption would lead to major operational disruption and very energy intensive restart of the air cooling and circulating arrangement 100.

This energy control module 16 is different from a simple on- and-off scheduling logic, which is used by many central chiller plants. These plants operate with no or little consideration impact of its operation on energy efficiency. This method has a benefit of improving reliability of the air cooling and circulating arrangement 100.

The embodiments also provide a method of operating the air cooling and circulating arrangement for improving reliability using statistical techniques.

A method of operating the air cooling and circulating arrangement is described below.

The method includes a step of optimizing the cooling load of each compressor by selecting the number of operating chillers and the number of operating compressors within each chiller for the given cooling load. Each compressor type has peak efficiency normally in the range of 70-80% load. The MC then measures the required cooling load and chooses the number of chillers to best match the optimal loading at compressors.

In a variant of the method, the MC has the ability to start or stop individual compressors in each chiller to further optimise the load of all compressors.

In yet another variant of the method, the MC sends signals to the VSDs connected to each compressor to spread the load with yet greater accuracy across the compressors.

Fig. 9 shows graphs of a relationship between chiller efficiency and chiller speed. The graphs depict benefits of above methods .

A method operating the air cooling and circulating arrangement 100 is provided below. In a multi-compressor chiller, the chiller compressor can be operated at better than design efficiency by momentarily expanding heat exchanger area to compressor ratio. This is done by operating one compressor while allowing heat exchanger areas of all compressors to be made available. The flow of condenser water and the flow of chilled water are then also adjusted accordingly.

A method operating the air cooling and circulating arrangement 100 by removing or servicing of equipment according to measurement data while supporting a pre-determined cooling load is described below.

The method includes a step of the energy control module 16 accessing to a database of equipment operating parameter data of the air cooling and circulating arrangement 100.

In detail, the equipment operating parameter data includes the supply temperature and the return temperature of a medium that is cooling the climate controlled space. In a case of a chilled water system, this refers to chilled water supply temperature and to chilled water return temperature. In a case of a Direct Expansion System, this refers to supply air temperature and to return air temperature. In a case of a Direct Refrigerant Cooling System, this refers to refrigerant supply temperature and to refrigerant return temperature.

The equipment operating parameter data also refer to rate of flow of the medium cooling the climate controlled space. In a case of a chilled water system, this refers to the chilled water flow rate. In a case of a Direct Expansion System, this refers to the supply air flow rate. The equipment operating parameter data also comprises pressure of the medium cooling the space, such pressure of chilled water, and chilled water delta pressure, which is a difference between leaving water pressure and entering water pressure.

The equipment operating parameter data also includes the supply temperature and the return temperature of the medium cooling the refrigerant. In a case of a water cooled system, this refers to condenser water supply temperature and to condenser water return temperature. In a case of an air cooled chiller system, this refers to the supply condenser air temperature and to the return condenser air temperature.

The equipment operating parameter data also relate to rate of flow of the medium cooling the refrigerant. In a case of a water cooled system, this refers to condenser water flow.

The equipment operating parameter data also includes equipment level power consumption data.

After this, the energy control module 16 checks the equipment operating parameter data using statistical techniques.

In particular, the energy control module 16 determines a parameter operating range for each operating parameter according to a standard deviation and a statistical mean of the respective operating parameter data over a sufficiently long period time. The determined parameter operating range acts to define normal operating behavior of the equipment .

The energy control module 16 then checks new operating parameter data against the respective determined parameter operating range . The energy control module 16 initiates steps for removing equipment from operation or for servicing the equipment to keep it working properly, when the parameter data of the equipment deviates from its determined parameter operating range .

The method advantageously allows detecting of equipment that is close to the point of failing. Even new equipment can deteriorate over time. Maintenance staff can then address the equipment by removing the equipment from operation or by repairing the equipment such that the equipment does not fail or malfunction during operation. A piece of equipment that malfunctions during operation can cause other equipment to fail, which requires a long time to rectify.

In effect, the energy control module 16 acts to improve energy efficiency by dynamically changing equipment to support a pre- determined cooling load while providing desired thermal com- fort .

The embodiments can also be described with the following lists of features or elements being organized into an item list. The respective combinations of features, which are disclosed in the item list, are regarded as independent subject matter, respectively, that can also be combined with other features of the application.

A method of retrofitting a Heating, Ventilating, and Air Conditioning (HVAC) device for a building, the HVAC device comprises a Building Management System (BMS), the method comprising

evaluating existing components of the HVAC device, providing additional components, which are provided in parallel with the existing components, installing a plurality of measurements sensors for the components, the plurality of measurements sensors comprises a plurality of temperature sensors, a plurality of flow meters, and a plurality of power meters,

installing a plurality of Variable Speed Drives (VSDs) for adjusting speed parameters of the components, installing a controller, which is adapted for

obtaining measurement data from plurality of measurements sensors,

sending commands to the BMS for activating different combinations of the components and using the VSDs to adjust corresponding speed parameters of the components such that each component combination and the corresponding component speed parameters provide a predetermined thermal comfort for users of the building, select one combination of the components with the corresponding component speed parameters, wherein the HVAC device provides a reduced energy consumption, and

sending commands to the BMS for activating the selected combination of the components and using the VSDs to adjust corresponding speed parameters of the components.

The method according to item 1, wherein

the speed parameter data refers to water pump reduction speed data.

The method according to item 1 or 2 , wherein

the speed parameter data refers to water flow rate reduction data. A method of operating a Heating, Ventilating, and Air Conditioning (HVAC) device for a building, the HVAC device comprises a Building Management System (BMS), a controller, at least one water pump with a valve, the method comprising

actuating a valve of a water pump to a fully open position,

measuring a flow rate of water, which corresponds to the water pump valve being provided in the fully open position,

determining a plurality of pulse widths of a frequency an electrical power supply of the water pump for providing a plurality of water pump speeds according to the water flow rate measurement,

activating the water pump according to the plurality of pulse widths of the frequency of the electrical power supply of the water pump for providing the plurality of the water pump speeds,

actuating the valve to corresponding positions, wherein each water pump speed and the corresponding water valve position provide a predetermined water flow rate, measuring electrical power consumption of the water pump for each water pump speed, and

selecting one water pump speed with the corresponding water valve position, which provides a reduced electrical power consumption, for use.

A method of operating a Heating, Ventilating, and Air Conditioning (HVAC) device for a building, the HVAC device comprises a Building Management System (BMS), a con troller, and a plurality of Variable Speed Drives (VSDs) the method comprising

providing a first water pump, which is adapted to operate at a first predetermined electrical power supply frequency pulse width and actuating a corresponding water valve to a first predetermined water pump valve position for providing a predetermined flow rate,

measuring electrical power consumption of the first water pump,

providing a second water pump in parallel with the first water pump, wherein the first water pump and the second water pump are adapted to operate at a second pre- determined electrical power supply frequency pulse width and actuating the water valve to a second predetermined water pump valve position such that the first water pump and the second water pump together provide said predeter- mined flow rate,

measurement the electrical power consumption of the first water and the second water pump, and

selecting at least one of the first water pump and the second water pump for operating in order to reduce electrical power consumption.

The method according to item 4 or 5 further comprising providing a plurality of operating boundary parameters for parts of the HVAC device,

comparing the water pump frequency pulse width with the corresponding operating boundary parameter,

when the value of the water pump frequency pulse width exceeds the value of the corresponding operating boundary parameter, changing the value of the water pump frequency pulse width to the value of the corresponding operating boundary parameter,

comparing the water pump valve position with the corresponding operating boundary parameter, and

when the value of the water pump valve position exceeds the value of the corresponding operating boundary parameter, changing the value of the water pump valve po sition to the value of the corresponding operating boundary parameter.

7. The method according item 6 further comprising

generating the operating boundary parameter using statistical techniques .

The method according to item 6 or 7 , wherein

the water pump refers to a chilled water pump.

9. The method according to item 8, wherein

the water valve refer to a chilled water valve.

The method according to item 6 or 7 , wherein

the water pump refers to a condenser water pump

11. The method according to item 10, wherein

the water valve refer to a condenser water valve

Although the above description contains much specificity, this should not be construed as limiting the scope of the embodiments but merely providing illustration of the foreseeable embodiments. The above stated advantages of the embodiments should not be construed especially as limiting the scope of the embodiments but merely to explain possible achievements if the described embodiments are put into practice. Thus, the scope of the embodiments should be determined by the claims and their equivalents, rather than by the examples given. REFERENCE NUMBERS

10 air cooling and circulating arrangement

13 Building Management System (BMS)

16 energy control module

20 cooling tower

22 condenser water pump

25 Air Handling Unit (AHU)

27 supply chilled water pump

29 return chilled water pump

33 chiller

36 fan

40 compressor

43 evaporator

45 condenser

48 expansion valve

52 Variable Speed Drive (VSD)

60 temperature sensor

65 pressure sensor

70 flow meter

73 master controller (MC)

75 switch

77 switch

78 switch

80 cloud based computer

100 air cooling and circulating arrangement

130 Building Management System (BMS)

160 energy control module

200 cooling tower module

220 condenser water pump module

250 Air Handling Unit (AHU) module

270 supply chilled water pump module

290 return chilled water pump module

330 chiller module 370 master controller (MC)

400 graph

410 graph

500 flow chart

510 step

515 step

520 step

530 step

540 step

550 step

560 step

730 master controller

740 measuring module 2 OA water valves

20B water valves

22Ά water valves

22B water valves

25A water valves

25B water valves

27A water valves

27B water valves

33A1 water valves

33A' water valves

33B1 water valves

33B2 water valves

20' cooling tower 20'

22' condenser water pump 25' AHU

27' supply chilled water pump

29' return chilled water pump

33' chiller

36' fan 2 OA' water valves

20B' water valves

22A' water valves

22B' water valves

25A' water valves

25B' water valves

27A' water valves

27B' water valves

29A' water valves

29B' water valves

33A1' water valves

33A2' water valves

33B1' water valves

33B2' water valves

400a graph

400b graph

Claims

1. A method of retrofitting a Heating, Ventilating, and Air Conditioning (HVAC) device for a building, the HVAC device comprises a Building Management System (BMS), the method comprising

evaluating existing components of the HVAC device, providing additional components, which are provided in parallel with the existing components,

installing a plurality of measurements sensors for the components, the plurality of measurements sensors comprises a plurality of temperature sensors, a plurality of flow meters, and a plurality of power meters,

obtaining measurement data from plurality of measurements sensors,

sending commands to the BMS for activating different combinations of the components and using the VSDs to adjust corresponding speed parameters of the components such that each component combination and the corresponding component speed parameters provide a predetermined thermal comfort for users of the building,

select one combination of the components with the corresponding component speed parameters, wherein the HVAC device provides a reduced energy consumption, and

The method according to claim 1, wherein the speed parameter data refers to water pump reduction speed data.

The method according to claim 1, wherein

the speed parameter data refers to water flow rate reduction data.

A method of operating a Heating, Ventilating, and Air Conditioning (HVAC) device for a building, the HVAC device comprises a Building Management System (BMS), a controller, at least one water pump with a valve, the method comprising

actuating a valve of a water pump to a fully open position,

The method according to claim 4 further comprising providing a plurality of operating boundary parameters for parts of the HVAC device,

when the value of the water pump valve position exceeds the value of the corresponding operating boundary parameter, changing the value of the water pump valve po sition to the value of the corresponding operating bound ary parameter.

The method according claim 5 further comprising

generating the operating boundary parameter using statis tical techniques .

The method according to claim 5, wherein

the water pump refers to a chilled water pump.

The method according to claim 7, wherein

the water valve refer to a chilled water valve.

The method according to claim 5, wherein

the water pump refers to a condenser water pump.

The method according to claim 9, wherein

the water valve refer to a condenser water valve.

A method of operating a Heating, Ventilating, and Air Conditioning (HVAC) device for a building, the HVAC device comprises a Building Management System (BMS), a controller, and a plurality of Variable Speed Drives (VSDs), the method comprising

measuring electrical power consumption of the first water pump,

providing a second water pump in parallel with the first water pump, wherein the first water pump and the second water pump are adapted to operate at a second predetermined electrical power supply frequency pulse width and actuating the water valve to a second predetermined water pump valve position such that the first water pump and the second water pump together provide said predetermined flow rate,

The method according to claim 11 further comprising

providing a plurality of operating boundary parameters for parts of the HVAC device,

when the value of the water pump valve position exceeds the value of the corresponding operating boundary parameter, changing the value of the water pump valve position to the value of the corresponding operating boundary parameter.

13. The method according claim 12 further comprising

generating the operating boundary parameter using statistical techniques .

The method according to claim 12, wherein

the water pump refers to a chilled water pump

15. The method according to claim 14, wherein

the water valve refer to a chilled water valve.

The method according to claim 12, wherein

the water pump refers to a condenser water pump

17. The method according to claim 16, wherein

the water valve refer to a condenser water valve