WO2012099464A1

WO2012099464A1 - Cooling system for cooling air in a room and data centre comprising such cooling system

Info

Publication number: WO2012099464A1
Application number: PCT/NL2012/050023
Authority: WO
Inventors: Cornelis Albert Zwinkels
Original assignee: Dataxenter Ip B.V; Kgg Dataxenter Holding B.V.
Priority date: 2011-01-18
Filing date: 2012-01-16
Publication date: 2012-07-26
Also published as: WO2012099465A1; NL2007293C2

Abstract

The invention and embodiments thereof relate to a cooling system for cooling a data room, the system comprising two ducts in parallel. A first duct takes in air from the data room and from the outside. Both airflows are mixed and provided to the data room. As the outside temperature rises, more and more outside air is taken in for cooling. If the outside temperature is too high, it is also led through a second duct with an active cooling element, preferably by means of adiabatic evaporative cooling. Air flows and ratios of various air flows are controlled directly at inlets by fan units. The fan units are controlled by a controlling unit that is coupled to various temperature sensors to enable proper control of cooling. The cooling system is particularly suited for compartmentalised data centres.

Description

Cooling system for cooling air in a room and data centre comprising such cooling system

FIELD OF THE INVENTION

The invention relates to cooling systems for rooms and data rooms in particular.

BACKGROUND OF THE INVENTION

United States patent application US 2009/0210096 discloses a data centre comprising a computer room air conditioner and an air economiser. An air economiser or outside air economiser is a system that cools a building using air from outside the building. This system is most effective when the outside air is cooler than the air inside. The air exhausted by the air economiser flows along chilled water valves and compressors of computer room air conditioners, whether the computer room air conditioners are used to the data centre or not.

OBJECT AND SUMMARY OF THE INVENTION

It is preferred to have air that does not need to be cooled not flowing along a cooling unit. The invention provides in a first aspect a cooling system for cooling air in a room comprising a mixing duct comprising: a first mixing inlet provided with a first flow regulation element for taking in air from the room; a second mixing inlet provided with a second flow regulation element for taking in air from a source other than the room; and a mixed air outlet for providing a mix of air from the room and air from the source other than the room from the mixing duct to the room; the mixing duct being arranged for mixing air from the first mixing inlet and the second inlet and for providing the mixed air to the mixed air outlet; the cooling system further comprising a cooling duct comprising: a cooling inlet provided with an a third flow regulation element for taking in air; a cooling unit for cooling air taken in; a cooling outlet for providing cooled air from the cooling duct to the room; the mixing duct and the cooling duct being arranged to operate in parallel.

By enabling the mixing duct and the cooling duct to operate in parallel rather than in series, air that does not require additional cooling by the cooling unit does not flow through or along the cooling unit. A first advantage is that this results in less wear of the cooling unit, e.g. due to pollution. A second advantage is that less power is required to generate an air flow, as air flowing through the cooling system that does not need to be cooled is not obstructed by the cooling unit. In an embodiment of the cooling system according to the invention, the mixed air outlet and the cooling outlet are arranged to be connected to a mixing plenum that is arranged to mix air from the mixed air outlet and air from the cooling outlet and to provide the mix of the mixed air and the cooled air to the room.

An even flow of output air of the cooling system to the room is important for efficient and effective cooling. Connecting a mixing plenum to the mixed air outlet and the cooling outlet of the cooling system enables air provided by the mixed air outlet and the cooling outlet to be properly mixed to an even flow of air.

A further embodiment of the cooling system according to the invention comprises a control unit arranged for controlling a first airflow through the first mixing inlet, a second airflow through the second mixing inlet and/or a third airflow flowing through the cooling inlet by controlling the operation of the first flow regulation element, the second flow regulation element and the third flow regulation element.

By controlling the various flow regulation elements, air taken in by the various air inlets can be controlled. Air taken in from the room usually has a temperature different from air taken from the other source, which will have a temperature different from that of other air sources. By controlling the amounts of air taken in, the temperature as well as the total amount of air provided by the cooling system can be controlled.

In another cooling system according to the invention, the control unit is connected to: a first temperature sensor for sensing an outside temperature; a second temperature sensor for sensing a temperature of air exhausted by the cooling system; a third temperature sensor for sensing a temperature of air taken in by the first mixing inlet; and a fourth temperature sensor for sensing a temperature of air in the room; and the control unit is arranged to control the first flow regulation element, the second flow regulation element and the third flow regulation element based on at least one of the following criteria: the actual outside temperature; the actual temperature in the room where air flowing out of the cooling system is provided to; a desired temperature or temperature range in the room where air flowing out of the cooling system is provided to; the actual temperature of air taken in by the first mixing inlet; the actual temperature of air taken in by the second mixing inlet; the actual temperature of air taken in by the cooling inlet; the actual temperature of mixed air; a desired temperature or temperature range of the mixed air; the actual temperature of cooled air; and/or a desired temperature or temperature range of the cooled air; the actual temperature of a mix of the mixed air and the cooled air; and/or a desired temperature of a mix of the mixed air and the cooled air. By closely monitoring input and output parameters and controlling the air flow and/or cooling process, the appropriate and/or desired temperature can be achieved in the room.

In yet a further embodiment of the cooling system according to the invention, the control unit is arranged to control the first flow regulation element, the second flow regulation element and the third flow regulation element in at least one of the following ways: controlling the magnitude of the first airflow, the second airflow and/or the third airflow; controlling the ratio of the first airflow and the second airflow; and/or controlling the ratio of a mix of the first airflow and the second airflow on one hand and the third airflow on the other hand.

By controlling the ratios of air flows, the temperature of air exhausted by the cooling system can be controlled. By controlling the magnitude of various air flows, the magnitude of the total flow of air towards the room can be controlled. The total cooling of the room can thus be controlled by controlling the magnitude of the airflows and the ratios of the airflows, providing several degrees of freedom for cooling the room.

In yet another cooling system according to the invention, the control unit operates the first flow regulation element, the second flow regulation element and the third flow regulation element based on the actual outside temperature such that: If the outside temperature is below a first temperature value, only the first flow regulation element and/or the second flow regulation element are operated; if the outside temperature is between the first temperature value and a second temperature value being higher than the first temperature value, the first flow regulation element and/or the second flow regulation element are operated and the third flow regulation element is operated; and if the outside temperature is above the second outside temperature value, only the third flow regulation element is operated.

By closely monitoring input and output parameters, the operation of the cooling system can be well controlled. In again a further embodiment of the cooling system according to the invention, the first flow regulation element, the second flow regulation element and the third flow regulation element comprise fans. Currently available cooling systems with one or more inlets use air dampers for controlling the inlet. A fan is provided at an outlet to which multiple inlets are coupled. The inflow of air is controlled by opening or closing a vent. The actual amount of air taken in by one specific inlet depends on a lot of other parameters, like the opening ratios of air dampers of other inlets, any obstructions in the paths between inlets and outlet(s) and the speed of the fan. By providing fans at the inlets of the various ducts, the amounts of air taken in and the ratios of the various air flows can be controlled more directly than with air dampers at the inlet and a single fan at the output.

Again another embodiment of the cooling system according to the invention comprises an evaporative cooling element.

An advantage of an evaporative cooling is that it requires less energy than evaporative cooling. Only a supply of a liquid to be evaporated is required - usually water - and no compression or further transport of a cooling fluid is required.

In yet a further embodiment of the cooling system according to the invention, air cooled by the evaporative cooling element is fed along a cooling element of a direct expansion cooling unit and a condenser element of the direct expansion cooling unit is placed in the cooling duct such that process air of the evaporative cooling element, which process air comprises vapour evaporated from the evaporative cooling element, flows at least partially along the condenser element.

In humid environments and in particular in tropical areas, air is usually almost fully saturated with water vapour and can therefore not take up much more water. In such environments, evaporative cooling is not very efficient as cooling in such systems is effectuated by evaporation of water in air. Therefore, evaporative cooling is followed by cooling via direct expansion cooling. Having cooling by direct expansion followed by cooling through an evaporative cooling element would not be very effective. By cooling humid air by means of direct expansion cooling would result in further saturation of the air with water vapour as cool air can hold less water vapour than warm air. As the cooled air is further saturated, it can take up far less or even no water vapour while flowing through the evaporative cooling unit which may in certain cases render the evaporative cooling unit even useless.

By placing the condenser element of the direct expansion cooling in the process air flow, very humid air passes along the condenser element. This allows the direct expansion cooling to work very effectively as the humid air has a large heat capacity and is able to take up a lot of heat from the condenser.

The invention provides in a second aspect a data centre comprising a serving housing module as the room for housing data cabinets arranged for housing data servers and the cooling system according to claim 1 for providing mixed air and/or cooled air to the serving housing module for cooling the data servers.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and embodiments thereof will now be further elucidated in conjunction with figures. In the figures,

Figure 1 : shows an embodiment of the data centre according to the invention;

Figure 2: shows an embodiment of the cooling system according to the invention; shows a cross-section of a mixing duct of an embodiment of the cooling system according to the invention; shows a cross-section of a cooling duct of an embodiment of the cooling system according to the invention; shows a cross-section of a cooling duct of another embodiment of the cooling system according to the invention; shows a detail of a cooling duct of an embodiment of the cooling system according to the invention; Figure 6 A shows another embodiment of the data centre according to the invention; Figure 6 B shows a further embodiment of the data centre according to the invention; and

Figure 7 shows yet a further embodiment of the data centre according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 shows a data centre 100 comprising a server housing module 1 10 and a cooling housing module 120. The server housing module 1 10 is compartmentalised in two side corridors 1 12 and a middle corridor 1 14. Between the middle corridor 1 14 and the two side corridors data cabinets 1 16 for housing servers are provided on either side of the middle corridor 1 14.

The cooling housing module 120 comprises a cooling unit 200 for cooling air. The cooling unit 200 takes in air from the server housing module 1 10 via a data room intake duct 132. The cooling unit 200 also takes in air from a source other than the server housing module 1 10, in this embodiment in particular from outside, via an outside intake duct 122. The cooling unit 200 exhausts air to the server housing module 1 10 and in particular the right side corridor 1 12 via a data room exhaust duct 134. The cooling unit 200 is also arranged to exhaust air to the outside via an outside exhaust duct 124. The data room exhaust duct 134 is coupled to a data room diffuser plenum 136 comprising a diffuser medium 138. The operation of the cooling unit 200 is controlled by a controlling unit 140 coupled to the cooling unit 200. The controlling unit 140 is coupled to an outside temperature sensor 142, an exhaust temperature sensor 146, an intake temperature sensor 148 and a data room temperature sensor 144.

In operation, the cooling unit 200 exhausts cool air in the right side corridor 1 12 through the data room diffuser plenum 136. The exhausted air flows through the servers in the data cabinets 1 16; this flow is indicated by a first arrow 162. It is noted that this flow is at least aided by fan units available in servers housed in the data cabinets 1 16. The air is heated by heat dissipated by the servers. The cooling unit 200 takes in air from the middle corridor 1 14 via the data room intake duct 132, establishing an air flow through the servers as indicated by the second arrow 164. In this way, a circular air flow is established from the cooling unit 200, through the right side corridor 1 12, the right data cabinet 1 16, the middle corridor 1 14, back to the cooling unit 200. As air cooled by the cooling unit 200 is exhausted in the right side corridor 1 12, the temperature in the right side corridor is relatively cool. Analogously, the air flowing into the middle corridor 1 14 is relatively high as it is heated up by the server in the data cabinet 1 16. This means that the airflow from the data room diffuser plenum 136 via the data cabinets 1 16 towards the data room intake duct 132 is at least partially provided by means of convection. Cool air exhausted via the data room diffuser plenum 136 drops in the right side corridor 1 12 and air heated by the servers in the data cabinets 1 16 rises in the middle corridor 1 14 towards the data room intake duct 132. Because of this convection, the server housing module 1 10 does not necessarily have to be compartmentalised to enable cooling and airflow. However, compartmentalisation is preferred to prevent cool air exhausted by the cooling unit 200 via the data room diffuser plenum 136 being taken in without having flown through the servers in the data cabinets 1 16, as this would lead to less efficient cooling operation in the server housing module 1 10.

Analogous to cooled air being provided to the right side corridor 1 12, also cool air is provided to the left side corridor 1 12 for cooling servers in the left data cabinets 1 16. For reasons of clarity, details on cooling of the left data cabinets 1 16 have been omitted in Figure 1 .

Figure 2 shows the cooling unit 200 in further detail. The cooling unit 200 comprises a cooling housing 201 that is divided in a mixing duct 210 and a cooling duct 250 by a dividing wall 203. At the front of the cooling unit 200, located at the bottom of Figure 2, a door 202 is provided. The door 202 comprises a first intake grating 204 for providing air to the mixing duct 210 and a second intake grating 206 for providing air to the cooling duct 250.

The mixing duct 210 comprises a first mixing inlet 212, provided with a first mixing fan unit 220 comprising a first mixing fan blade section 222 and a first mixing fan motor section 224. In the cooling duct 210, a mixing diffuser 216 is provided. The working of the mixing diffuser 216 will be discussed hereafter. The mixing duct 210 comprises a mixed air outlet 214 for providing mixed air to the data room diffuser plenum 136 via the data room exhaust duct 134. The cooling duct comprises a cooling cassette 270 comprising a cooling inlet 252, provided with a cooling fan unit 260 comprising a cooling fan blade section 266 and a cooling fan motor system 264. In the cooling cassette 270, a cooling block 272 is provided. The cooling block is preferably an adiabatic evaporative cooling block as marketed by the company Statiqcooling B.V.. The cooling duct 250 comprises a cooled air outlet 254 for providing cooled air to the data room diffuser plenum 136 via the data room exhaust duct 134. The cooling cassette 270 is preferably releasably mounted in the cooling duct 250, to facilitate replacement of the cooling cassette 270 in case another type of cooling is required or for repair purposes. In another embodiment of the cooling unit, no cooling cassette 270 is provided and instead, the cooling block 272 is provided directly in the cooling duct 250, with the cooling fan unit 260 and the cooling inlet 252 provided at the front side of the cooling duct 250.

To enable efficient operation, it is preferred to ensure that substantially all air taken by the first intake grating 204 and the second intake grating 206 flows through the mixing duct 210 and the cooling cassette 270. For that purpose, various seals have been provided in the cooling unit 200, indicated by various thickened lines in Figure 2.

Figure 3 shows a cross-section of the mixing duct at the line A-A' drawn in Figure 2. Figure 3 discloses the first mixing fan unit 220 provided in twofold. Both first mixing fan units 220 operate to take in outside air via the outside intake duct 122 (Figure 1 ). In addition to elements already shown by Figure 2, Figure 3 also shows a second mixing fan unit 230 comprising a second mixing fan blade section 232 and a second mixing fan motor section 234 for taking in air via a second mixing inlet 218 and a second mixing inlet opening 208 at the bottom of the cooling unit 200. The second mixing inlet 218 and the second mixing inlet opening 208 are separated by an inlet separator 236. The second mixing inlet opening 208 is connected to the data room intake duct 132.

The operation of the first mixing fan units 220 and the second mixing fan unit 230 is controlled by the controlling unit 140. The controlling unit 140 is provided with input from the outside temperature sensor 142, the exhaust temperature sensor 146, the intake temperature sensor 148 and the data room temperature sensor 144. An objective of the controlling unit 140 is to keep or to set the temperature in the right side corridor 1 12 at a pre-determined level or within a pre-determined temperature range. In this embodiment, the preferred temperature is 22°C. Alternatively, the preferred temperature is between 20°C and 23°C. In another alternative, the controlling unit 140 sets the temperature to be achieved the temperature of air provided through the data room diffuser plenum 136.

To achieve this temperature or temperature range, the controlling unit 140 operates the first mixing fan motor sections 224 and the second mixing fan motor section 234 to take in outside air and air from the middle corridor 1 14 - inside air - of the server housing module 1 10 in such quantities that a mix of the air flows taken in has a temperature that is fit to achieve the desired temperature or temperature ranges in the right side corridor 1 12. To improve mixing of the air taken in the mixing duct 210, the air taken in is led through the mixing diffuser 216. The mixing diffuser 216 is preferably provided as a web of a textile material or another porous medium to ensure good mixing, without creating large turbulence in the air flow or at least reducing turbulence.

The first mixing fan motor sections 224 and the second mixing fan motor section 234 are controlled by controlling the ratio of outside air and inside air and the total amount of air taken in. This is controlled by controlling the speeds of the motor sections, taking into account characteristics of the fan blade sections.

If the temperature of the outside air is relatively low, in the order of 5°C, the ratio of air taken from the middle corridor 1 14, which is in this example about 45°C, on one hand and air taken in from outside will be relatively low to achieve a desired temperature of 22°C in the right side corridor 1 12. On the other hand, if the temperature of the outside air is in the order of 20°C, almost only air from outside is taken in to the mixing duct 210 and provided to the right side corridor 1 12. A person skilled in the art will appreciate that this will result in pressure building up in the middle corridor 1 14 if air is not removed or cannot escape other than through the data room intake duct 132. Therefore, overpressure vents have been provided in the middle corridor 1 14 to let air out, for example to outside. Alternatively or additionally, such overpressure vents are provided a the top of the mixing duct 210, opposite to the mixed air outlet 214. Such vent is preferably coupled to the outside exhaust duct 124.

As discussed, apart from controlling ratios of airflows taken in, also the total amount of air taken in can be controlled by the controlling unit 140. If the servers in the data cabinets 1 16 operate at full load level and the temperature of the air in the right side corridor 1 12 is kept at a constant level, more air will have to be provided for cooling the servers than in a case where the servers would operate at a load level of 20%.

The air taken in from either the middle corridor 1 14 or the outside or a mix of both is fed to the right side corridor 1 12 via the mixed air outlet 214, the data room exhaust duct 134 and the data room diffuser plenum 136 comprising the diffuser medium 138. In this way, an even flow of air at a desired temperature is provided to the right side corridor 1 12 for cooling serves in the data cabinets 1 16. A person skilled in the art will appreciate that if the outside temperature rises above the desired temperature for the right side corridor 1 12, other ways of cooling the air are required. As already discussed, the data centre cooling unit 200 comprises a cooling duct 250 provided in parallel to the mixing duct 210. Figure 4 A shows a cross-section of the cooling duct at the line B-B' drawn in Figure 2. Figure 4 A discloses the cooling fan unit 260 provided in twofold. In addition to elements already shown by Figure 2, Figure 4 A also shows a process air outlet 256 at the top of the cooling duct 250. The process air outlet 256 is connected to outside exhaust duct 124.

The cooling block 272 is preferably an evaporative cooling unit as disclosed by international patent application WO 2005/106343 or as disclosed by international patent application WO 2007/136265. These patent applications disclose enthalpy exchangers in which air is led through small horizontal ducts in vertically oriented plates. The vertically oriented plated are spaced apart and clad with a hygroscopic cloth that is humidified.

Through the spaces between the vertically oriented plates an air flow is provided. As this air flow passes along the humidified hygroscopic cloth, water or another liquid is evaporated, resulting in a temperature of the liquid. Water is preferred as such liquid; therefore the rest of the description will refer to water, though alternatives can be envisaged as well. This drop of temperature results in a temperature drop of air flowing through the small horizontal ducts in vertically oriented plates by virtue of heat exchange. This latter flow will be referred to as cooled air; the air flow with water evaporated from the humidified hygroscopic cloth will be referred to as process air.

In this embodiment, air in which water is evaporate to cool of the air is taken in directly at the front of the cooling block 272 rather than fed back from the rear of the cooling block 272. The front of the cooling block 272 is the side of the cooling block 272 facing the cooling fan unit 260. Cooled air is provided through the cooled air outlet 254 and process air, indicated by the small arrows at the top, is exhausted through the process air outlet 256.

Figure 4 B shows another embodiment of the cooling duct 250. The cooling duct 250 shown by Figure 4 B comprises the elements of the cooling duct 250 shown by Figure 4 A. In addition, the cooling duct 250 comprises a direct expansion cooling module 280 comprising a compressor 282 and an expansion valve 284. The compressor 282 and the expansion valve 284 are connected to an evaporator coil 286 and a condenser coil 288. The total of the coils and the direct expansion cooling module 280 operate as a standard refrigeration system or air conditioning system. In Figure 4 B, the direct expansion module 280 is located outside the cooling duct 250. In another embodiment, the direct expansion module 280 is located inside the cooling duct 250 and preferably inside or attached to the cooling cassette 270.

A working fluid is compressed by the compressor 282, resulting in a temperature rise of the working fluid. In the condenser coil 288, the working fluid condenses, preferably in an air flow provided around the condenser coil 288. In this particular embodiment, the condenser coil 288 is provided in a flow with process air from the cooling block 272. As the process air comprises relatively large amounts of evaporated water, it has a high heath capacity. This means that the process air is capable of effectively cooling the condenser coil 288, resulting in condensing of the working fluid.

The condensed working fluid is subsequently fed through the expansion valve 284, where the working fluid expands and evaporates in the evaporator coil 286. This results in a temperature drop of the working fluid in the evaporator coil 286. Air cooled by the cooling unit 272 is further cooled as it passes along the evaporator coil 286 and exchanges heat with the working fluid in the evaporator coil 286. The working fluid, having exchanged heat with the cooled air and having thus risen in temperature, is fed to the compressor 282 where the refrigeration cycle recommences. The process air that has passed along the condenser coil 288 is exhausted through the process air outlet 256. Further cooled air is provided through the cooled air outlet 254.

In another embodiment, the cooling cassette 270 only comprises the direct expansion cooling module 280. By providing multiple types of the cooling cassette 270 that can be inserted in the cooling duct 250, an operator of the cooling unit 200 is provided with enhanced flexibility in operating the cooling unit 200. In case a different type of cooling is required for the server housing module 1 10, for example due to change of weather or re-deployment of the data centre 100 to a location with a different climate, only the cooling cassette 270 can be replaced instead of replacement of the entire cooling unit 200. Figure 5 shows a detail of the cooling duct 250. In addition to the elements disclosed by Figure 4 A and Figure 4 B, Figure 5 shows roller bearings 292 connected to a bearing holding rail 290. The bearing holding rail 290 is connected to the cooling duct 250. The cooling cassette 270 is insertable in the cooling duct 250 via the door 202. The roller bearings 292 enable smooth insertion and removal of the cooling cassette 270 in and from the cooling duct 250. Figure 5 also shows a first sealing 296 for sealing off an airflow pathway from the second intake grating 206 towards the cooling cassette 270. The first sealing 296 is provided around the front side of the cooling cassette 270 to prevent or at least reduce leakage of air taken in via the second intake grating 206 along the sides of the cooling cassette to improve efficiency of the cooling cassette 270. Around the cooling block 272, a second sealing 298 is provided to prevent leakage of air taken in along the sides of the cooling block 272 and to guide the air taken in towards an intake of the cooling block 272.

The cooling duct 250 and in particular the cooling fan units 260 are operated when the outside temperature, measured by the outside temperature sensor 142 (Figure 1 ), is substantially above a first threshold temperature which is desired for the right side corridor 1 12. If the temperature of the outside air rises substantially above that level and stays above that level for a certain time period like 5 minutes, 30 minutes or two hours, the cooling fan units 260 are operated in parallel to the first mixing fan units 220 and/or the second mixing fan unit 230. The first threshold temperature is preferably at 24°C. If the outside temperature drops below the first threshold temperature, either significantly and/or for a substantial period of time, the operation of the cooling fan units is discontinued. With fan units being operated in both the mixing duct 210 and the cooling duct 250, air is provided to the data room exhaust duct 134 and the data room diffuser plenum 136 by the mixed air outlet 214 as well as the cooled air outlet 254. To ensure an even distribution and mix of the mixed air and the cooled air in the right side corridor 1 12, the diffuser medium 138 is provided in the data room diffuser plenum 136. The diffuser medium 138 may be provided with materials that are the same as or similar to those of the mixing diffuser 216. This allows mixed air provided by the mixing duct and cooled air provided by the cooling duct to be provided to the right side corridor 1 12 in an evenly distributed way, with no or little turbulence. If the temperature of the outside air rises above a second threshold temperature, in a significant way and/or for a significant period of time, the first mixing fan units 220 and the second mixing fan unit 230 are shut down. This means that the right side corridor 1 12 is provided with cooled air only. The second threshold temperature is preferably 30°C. If the temperature of the outside air drops below the second threshold temperature, significantly and/or for a substantial period, the first mixing fan units 220 and/or the second mixing fan unit 230 are operated again.

Due to the modular structure of the data centre 100, the data centre 100 can also be provided with an additional cooling housing module 120. This is particularly advantageous in case a larger cooling capacity is required for the electrical equipment housed in the server housing module 1 10. This is shown by Figure 6 A. For reason of clarity, the controlling unit 140 and the temperature sensors have been omitted in the Figure.

Figure 6 A shows the data centre 100 comprising a lower cooling housing module 120 and an upper cooling housing module 120'. The lower cooling housing module 120 comprises a lower cooling unit 200 and the upper cooling housing module comprises an upper cooling unit 200'. To couple the second mixing inlet opening of the upper cooling unit 200' to the hot middle corridor 1 14, an upper data room intake duct 602 is provided, which is coupled to the data room intake duct 132. The first mixing inlet of the upper cooling unit 200' takes in outside air via an outside intake branch 608 that is coupled to the outside intake duct 122. The first mixing inlet of the lower cooling unit is coupled to the outside intake duct 122.

Cool air provided by the upper cooling unit 200' is provided to the data room exhaust duct 134 via an intermediate data room exhaust duct 604. In this way, the data room exhaust duct 134 exhausts cool air to the right side corridor 1 12 that is provided by both the upper cooling unit 200' and the lower cooling unit 200. The lower cooling unit 200 is coupled to the outside exhaust duct 124 via an intermediate outside exhaust duct 606. In this way, the outside exhaust duct 124 exhausts excess air that is provided by both the upper cooling unit 200' and the lower cooling unit 200.

Figure 6 B shows the data centre 100 with another embodiment of a double cooling configuration. The data centre 100 that is shown by Figure 6 B comprises a single cooling module 120 placed on top of the server housing module. The cooling module 120 comprises a lower cooling unit 200 and an upper cooling unit 200'. Both second mixing inlets of the lower cooling unit 200 and the upper cooling unit 200' are coupled to the data room intake duct 132. The first mixing inlet of the upper cooling unit 200' takes in outside air via an outside intake branch 608 that is coupled to the outside intake duct 122. The first mixing inlet of the lower cooling unit is coupled to the outside intake duct 122.

Cool air provided by the upper cooling unit 200' is provided to the data room exhaust duct 134 directly via the lower cooling unit 200. Referring to Figure 3, an opening is provided in the cooling housing 201 at the op of the mixing duct 210 of the lower cooling unit 200. Via this opening, the lower cooling unit 200 receives mixed air from the upper cooling unit 200' that the upper cooling unit 200' exhausts via the mixed air outlet 214 of the upper cooling unit 200'. The mixed air of the upper cooling unit 200' and the mixed air of the lower cooling unit 200 is subsequently provided to the data room exhaust duct 134. Any outlets of the lower cooling module 200 are coupled to the outside exhaust duct 124 through the upper cooling module 200' in an analogous way.

Though the various components of the data centre 100 have been thus far discussed in a modular fashion and in particular to be housing in modules, this is merely to disclose preferred embodiments of various aspects of the invention. It is stipulated that the invention is not limited to modular and/or housed implementations. For example, the cooling unit 200 or stacked multiples thereof do not necessarily have to be provided in the cooling module 120 but can also be directly placed on the server housing module 1 10. This is particularly convenient if the server housing module 1 10 is placed in a building, where no protection or cover for the cooling module 120 is required. In such scenario, the outside intake duct 122 and the outside exhaust duct 124 are extended to the roof of the building or otherwise to the environment outside the building. Figure 7 shows a server housing module 1 10 compartmentalised in two side corridors

1 12 and a middle corridor 1 14. Between the middle corridor 1 14 and the two side corridors data cabinets 1 16 for housing servers are provided on either side of the middle corridor 1 14. Figure 7 further discloses a left cooling unit 200' and a right cooling unit 200. In this embodiment, the left cooling unit 200' and the right cooling unit 200 have substantially the same configuration as the cooling unit 200 as shown by Figure 2.

Furthermore, the left cooling unit 200' and the right cooling unit 200 are placed at the same level as the server housing module 1 10 rather than stacked on top of the server housing module 1 10. This configuration is particularly advantageous in upgrading already existing data centres with a new cooling unit like the cooling unit 200 as shown by and discussed in conjunction with Figure 2. The second mixing inlets 218 (Figure 2) of the left cooling unit 200' and of the right cooling unit 200 are connected to the middle corridor 1 14 for taking in air from the server housing module 1 10. The second mixing inlets 218 (Figure 2) of the left cooling unit 200' and of the right cooling unit 200 are connected to the middle corridor 1 14 via a left horizontal intake duct 704 and a right horizontal intake duct 704', respectively.

The outlets of the left cooling unit 200' and of the right cooling unit 200 are connected to the left and right side corridors 1 12 via a left outlet duct 702' and a right outlet duct 702. In particular, the left outlet duct 702' is connected to a left data room diffuser 136' and the right outlet duct 702 is connected to a right data room diffuser 136.

As in this embodiment the left cooling unit 200' and of the right cooling unit 200 are located at substantially the same level as the server housing module 1 10, the cooling units have a slightly different configuration as discussed above. In particular, the mixed air outlet 214 (Figure 3) and the cooled air outlet 254 (Figure 4 A and Figure 4 B) are provided at the rear side of the cooling modules 200 rather than at the bottom as disclosed by Figure 3, Figure 4 A and Figure 4 B.

The other inlets and outlets of the cooling modules are in this embodiment substantially similarly constructed as shown by and discussed in conjunction with Figure 1 and other relevant Figures. However, they may be embodied differently, in accordance with constructions and modifications available for use with either new data centres or data centres to be upgraded. Outlets and inlets may also be connected to outside air or other locations via a sidewall of a building.

In summary, the invention and embodiments thereof relate to a cooling system for cooling a data room, the system comprising two ducts in parallel. A first duct takes in air from the data room and from the outside. Both airflows are mixed and provided to the data room. As the outside temperature rises, more and more outside air is taken in for cooling. If the outside temperature is too high, it is also led through a second duct with an active cooling element, preferably by means of adiabatic evaporative cooling. Air flows and ratios of various air flows are controlled directly at inlets by fan units. The fan units are controlled by a controlling unit that is coupled to various temperature sensors to enable proper control of cooling. The cooling system is particularly suited for compartmentalised data centres. Expressions such as "comprise", "include", "incorporate", "contain", "is" and "have" are to be construed in a non-exclusive manner when interpreting the description and its associated claims, namely construed to allow for other items or components which are not explicitly defined also to be present. Reference to the singular is also to be construed in be a reference to the plural and vice versa. When data is being referred to as audiovisual data, it can represent audio only, video only or still pictures only or a combination thereof, unless specifically indicated otherwise in the description of the embodiments. In the description above, it will be understood that when an element such as layer, region or substrate is referred to as being "on", "onto" or "connected to" another element, the element is either directly on or connected to the other element, or intervening elements may also be present. Furthermore, the invention may also be embodied with less components than provided in the embodiments described here, wherein one component carries out multiple functions. Just as well may the invention be embodied using more elements than depicted in Figure 2 and other figures, wherein functions carried out by one component in the embodiment provided are distributed over multiple components.

A person skilled in the art will readily appreciate that various parameters disclosed in the description may be modified and that various embodiments disclosed and/or claimed may be combined without departing from the scope of the invention. It is stipulated that the reference signs in the claims do not limit the scope of the claims, but are merely inserted to enhance the legibility of the claims.

Claims

1. Cooling system for cooling air in a room comprising:

a) a mixing duct comprising:

5 i) a first mixing inlet provided with a first flow regulation element for taking in air from the room;

ii) a second mixing inlet provided with a second flow regulation element for taking in air from a source other than the room; and

o iii) a mixed air outlet for providing a mix of air from the room and air from the source other than the room from the mixing duct to the room;

the mixing duct being arranged for mixing air from the first mixing inlet and the second inlet and for providing the mixed air to the mixed air outlet;

5 b) a cooling duct comprising:

i) a cooling inlet provided with an a third flow regulation element for taking in air;

ii) a cooling unit for cooling air taken in;

iii) a cooling outlet for providing cooled air from the o cooling duct to the room;

The mixing duct and the cooling duct being arranged to operate in parallel.

2. Cooling system according to claim 1 , wherein the mixed air outlet and the cooling outlet are arranged to be connected to a mixing plenum that is arranged to mix 5 air from the mixed air outlet and air from the cooling outlet and to provide the mix of the mixed air and the cooled air to the room.

3. Cooling system according to claim 1 , further comprising a control unit arranged for controlling a first airflow through the first mixing inlet, a second airflow 0 through the second mixing inlet and/or a third airflow flowing through the cooling inlet by controlling the operation of the first flow regulation element, the second flow regulation element and the third flow regulation element.

4. Cooling system according to claim 3, wherein the control unit is connected 5 to:

a) a first temperature sensor for sensing an outside temperature; b) a second temperature sensor for sensing a temperature of air exhausted by the cooling system;

c) a third temperature sensor for sensing a temperature of air taken in by the first mixing inlet; and/or

d) a fourth temperature sensor for sensing a temperature of air in the room;

and the control unit is arranged to control the first flow regulation element, the second flow regulation element and/or the third flow regulation element based on at least one of the following criteria:

e) the actual outside temperature;

f) the actual temperature in the room where air flowing out of the cooling system is provided to;

g) a desired temperature or temperature range in the room where air flowing out of the cooling system is provided to;

h) the actual temperature of air taken in by the first mixing inlet; i) the actual temperature of air taken in by the second mixing inlet;

j) the actual temperature of air taken in by the cooling inlet;

k) the actual temperature of mixed air;

I) a desired temperature or temperature range of the mixed air; m) the actual temperature of cooled air;

n) a desired temperature or temperature range of the cooled air; o) the actual temperature of a mix of the mixed air and the cooled air; and/or

p) a desired temperature of a mix of the mixed air and the cooled air.

5. Cooling system according to claim 3, wherein the control unit is arranged to control the first flow regulation element, the second flow regulation element and/or the third flow regulation element in at least one of the following ways:

a) controlling the magnitude of the first airflow, the second airflow and/or the third airflow;

b) controlling the ratio of the first airflow and the second airflow; and/or

c) controlling the ratio of a mix of the first airflow and the second airflow on one hand and the third airflow on the other hand.

6. Cooling system according to claim 4, wherein the control unit operates the first flow regulation element, the second flow regulation element and the third flow regulation element based on the actual outside temperature such that:

a) If the outside temperature is below a first temperature value, only the first flow regulation element and/or the second flow regulation element are operated;

b) If the outside temperature is between the first temperature value and a second temperature value being higher than the first temperature value, the first flow regulation element and/or the second flow regulation element are operated and the third flow regulation element is operated; and

c) If the outside temperature is above the second outside temperature value, only the third flow regulation element is operated.

7. Cooling system according to claim 1 , wherein the first flow regulation element, the second flow regulation element and the third flow regulation element comprise fans.

8. Cooling system according to claim 1 , wherein the cooling unit is releasably comprised by the cooling duct.

9. Cooling system according to claim 1 , wherein the cooling unit comprises an evaporative cooling element.

10. Cooling unit according to claim 9, wherein air cooled by the evaporative cooling element is fed along a cooling element of a direct expansion cooling unit.

1 1 . Cooling unit according to claim 10, wherein a condenser element of the direct expansion cooling unit is placed in the cooling duct such that process air of the evaporative cooling element, which process air comprises vapour evaporated from the evaporative cooling element, flows at least partially along the condenser element.

12. Cooling unit according to claim 1 , wherein air from a source other than the room is taken from outside and/or air taken in by the cooling inlet is taken from outside.

13. Data centre comprising a serving housing module as a room for housing data cabinets arranged for housing data servers and further comprising the cooling system according to claim 1 for providing mixed air and/or cooled air to the serving housing module for cooling the data servers.

14. Data centre according to claim 13, wherein the server housing module is

5 compartmentalised in at least a first space and a second space, wherein the data cabinets face the first space at a first side and the second space at a second side, the data cabinets being arranged for housing data servers such that air can flow from the first space to the second space through the data servers, and wherein the mixed air and/or cooled air is provided to the first space and the first inlet is coupled to the second l o space for taking in air from the second space.