Thermostatic Assembly, in Particular for Laboratory Chambers, Climate Chambers, Cold Chambers or Environment Simulation Chambers

Abstract

A thermostatic assembly with a cooling circuit with a coolant is provided. The cooling circuit comprises a cold source, a consumer heat exchanger in the return of the cold source, and a circulation pump. Between the return of the cold source and the forerun of the consumer heat exchanger is disposed a first three-way junction and between the return of the consumer heat exchanger and a forerun of the cold source a second three-way junction is disposed. The first three-way junction and the second three-way junction are connected with a bypass line and the circulation pump is disposed either between the first three-way junction and the forerun of the consumer heat exchanger or between the return of the consumer heat exchanger and the second three-way junction as well as to a laboratory chamber, climate chamber, cold chamber or environment simulation chamber with a sample compartment and such thermostatic assembly.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application No. DE 10 2023 133 725.4, filed Dec. 1, 2023, which is incorporated by reference in its entirety.

FIELD OF APPLICATION

The application relates to a thermostatic assembly, in particular for laboratory chambers, climate chambers, cold chambers or environment simulation chambers.

BACKGROUND

Use of a thermostatic assembly for the temperature control of a sample compartment of laboratory chambers, climate chambers, cold chambers or environment simulation chambers in order to regulate or fine tune the temperature in the sample compartment in the desired manner is known.

DE 10 2004 040 737 A1 discloses an assembly for the control or regulation of a constant forerun or feedline temperature at fluid cooling and in heat pumps, wherein a buffer circuit, comprising a buffer fluid for the energy transport, is provided which is connected with a heating/cooling circuit and a consumer each, wherein into the storage circuit a storage reservoir is integrated, and wherein in the storage circuit into the connection to the cooling/heating circuit a buffer storage, through which a storage fluid can flow in one direction, and the consumer are connected in series and parallel to the buffer storage a connection is provided, whose throughflow is controllable or adjustable, between an inlet line and an outlet line of the buffer storage. Such assembly enables maintaining and regulating the forerun at a constant temperature, if desired, regulating the heating and cooling capacity can be limited at the consumer. The buffer storage acts herein as energy storage and energy is extracted and stored as required. The off-time of a compressor can be bridged without the forerun temperature increasing or decreasing. However, this assembly has the disadvantage that the entire storage fluid present in the storage circuit is continuously circulated.

SUMMARY

The application addresses the problem of providing a thermostatic assembly with which a more effective temperature control is enabled.

The problem is resolved according to the application through a thermostatic assembly as disclosed herein.

Advantageous embodiments and further developments of the application are disclosed herein in some embodiments.

In the thermostatic assembly according to the application with a cooling circuit with a coolant, wherein the cooling circuit comprises a cold source, a consumer heat exchanger in the return of the cold source, and a circulation pump there is disposed between the return of the cold source and the forerun of the consumer heat exchanger a first three-way junction, and between the return of the consumer heat exchanger and the forerun of the cold source is disposed a second three-way junction, wherein the first three-way junction and the second three-way junction are connected with a bypass line, and the circulation pump is disposed either between the first three-way junction and the forerun of the consumer heat exchanger or between the return of the consumer heat exchanger and the second three-way junction.

In the following a three-way junction is to be understood as a convergence of at least three inflows and/or outflows. A three-way junction can be realized, for example, by a T fitting.

By means of the bypass line a subcircuit can be formed from the first three-way junction, via the consumer heat exchanger to the second three-way junction, and via the bypass line back to the first three-way junction. This enables to compensate for the energy difference supplied to the consumer heat exchanger or extracted from it across the first three-way junction and, by doing so, circulating a smaller quantity of coolant, essentially the coolant in the subcircuit, and maintaining it at the desired temperature.

The first three-way junction and/or the second three-way junction are advantageously developed as three-way valves. The inflows and outflows through the three-way junction can thereby be regulated accordingly.

It should be noted that within the meaning of the present application by three-way valve any valve is to be understood that comprises at least three paths. For example, the application can also be realized by a correspondingly connected four-way valve.

According to an especially preferred embodiment of the application the first three-way junction is developed as a three-way valve, wherein the circulation pump is disposed between the return of the consumer heat exchanger and the second three-way junction, wherein the first inlet of the three-way valve is in connection with the return of the cold source, an outlet of the three-way valve is in connection with the forerun of the consumer heat exchanger and a second inlet of the three-way valve is in connection across the second three-way junction with the return of the circulation pump and the forerun of the cold source.

Such an assembly can, for example, be operated in the following manner: the cold source makes available a cold coolant which, with the aid of the circulation pump, is supplied through the first inlet of the three-way valve and the outlet of the three-way valve to the consumer heat exchanger. Across the consumer heat exchanger a sample compartment can be cooled, wherein to the coolant in the consumer heat exchanger energy is supplied. As a rule, the cooling circuit is laid out of such size that the temperature of the coolant through the consumer does not change significantly. In the return of the circulation pump a temperature sensor can be disposed, with the aid of which the supplied energy difference can be determined. The temperature sensor can herein also be part of a sensor combination. At the first inlet of the three-way valve subsequently such quantity of cold coolant can be supplied that at the outlet of the three-way valve the coolant is available at the desired temperature. Only a quantity of warmer coolant flowing back from the consumer heat exchanger that corresponds to the quantity of supplied cold coolant is carried by the circulation pump directly to the cold source in order to be able to be cooled here anew.

An especially advantageous further development of the application provides for a heating unit to be disposed between the first three-way junction and the consumer heat exchanger. Such heating unit enables the temperature control over a wider temperature range, in particular the temperature control at temperatures that lie above the temperature of the coolant provided by the cold source.

According to an advantageous embodiment the cold source comprises a cold-water reservoir, which can include, for example, process water. By using a cold water reservoir of this type, already existing cold water can be put to further use.

An alternative preferred embodiment of the application provides that the cold source is part of a second heat exchanger, across which an external refrigerant circuit is coupled to the cooling circuit. The external refrigerant circuit can include a refrigeration unit and be operated with a coolant such that temperatures markedly below the freezing point of water are enabled. Separating the cooling circuit and external refrigerant circuit in this way, moreover, makes it possible when installing the external refrigerant circuit in a laboratory chamber, climate chamber, cold chamber or environmental simulation chamber placing it in such a way that the external refrigerant circuit is disposed in a machine compartment separate from the sample compartment. Furthermore, such a separation can also enable the disposition of one or several laboratory chambers, climatic chambers, cold chambers or environmental simulation chambers at an energy-efficient, central cold source.

The second heat exchanger is preferably developed as a plate heat exchanger or a coaxial tube heat exchanger. Such heat exchangers can be of compact construction and enable good heat transfer.

According to a preferred embodiment of the application a buffer storage is disposed between the second heat exchanger and the bypass line. In such a buffer storage a relatively large quantity of cold coolant can be held available whereby switching off the refrigeration unit of the external refrigerant circuit intermittently, in particular even for longer periods, is enabled.

The return of the second heat exchanger advantageously terminates into a buffer storage and a discharge of the buffer storage is connected with the first three-way junction, in particular with the first inlet of the three-way valve, wherein preferably a further intake of the buffer storage is connected with the second three-way junction and a further discharge of the buffer storage is connected with the forerun of the second heat exchanger. Such configuration enables the second heat exchanger having to compensate for the energy difference extracted and not having to circulate the entire quantity of coolant of the refrigerant circuit.

An especially preferred embodiment of the application provides disposing the second heat exchanger within the buffer storage. In such a configuration the buffer storage can be utilized for storing cold coolant and can also be regulated when the three-way valve has not set any throughflow through the three-way valve. The heat exchanger disposed within the buffer storage furthermore enables the pre-temperature control of the buffer storage. Moreover, a pump can be omitted which is required in the case of a heat exchanger disposed outside of the buffer storage for the energy transfer between cold source and buffer storage.

The return of the second heat exchanger is in particular preferably connectable across a three-way switchover valve, on the one hand, with the buffer storage and, on the other hand, by means of a line directly with the first inlet of the three-way valve.

A laboratory chamber, climate chamber, cold chamber or environment simulation chamber with a sample compartment comprises a thermostatic assembly as described above wherein the consumer heat exchanger is disposed such that it maintains temperature control of the sample compartment. The advantages of such laboratory chamber, climate chamber, cold chamber or environment simulation chamber conform to the advantages described in conjunction with the thermostatic assembly.

A preferred laboratory chamber, climate chamber, cold chamber or environment simulation chamber according to the application with a sample compartment comprises a thermostatic assembly as described above in which the cold source is part of a second heat exchanger across which an external refrigerant circuit is coupled to the cooling circuit, wherein the consumer heat exchanger is disposed such that it maintains temperature control of the sample compartment, and wherein the external refrigerant circuit, preferably including the second heat exchanger, is disposed in a machine compartment, separated from the sample compartment, which in particular comprises ventilation apertures. Such separation between external refrigerant circuit and cooling circuit enables the use of a combustible coolant in the external refrigerant circuit since the external refrigerant circuit is disposed in a machine compartment separated from the sample compartment, which machine compartment can be well ventilated such that here the safety requirements made of refrigerant circuits with combustible coolants can be met which is not possible in a closed sample compartment. The energy input into the sample compartment can take place by means of the cooling circuit wherein the second heat exchanger is disposed outside of the sample compartment in the machine compartment.

The external refrigerant circuit especially preferably comprises a hydrocarbon, in particular propane or isobutane, as the coolant. Such coolants represent a climate-friendly alternative to halogenated coolants since they do not contribute significantly to the greenhouse effect, wherein, however, stringent safety requirements are made of the use of such coolants due to their combustibility. These stringent safety requirements can be met by using a thermostatic assembly with a separation between external refrigerant circuit and cooling circuit, wherein the external refrigerant circuit is disposed in a machine compartment separated from the sample compartment, and the energy input into the sample compartment takes place across the cooling circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the application will be explained in detail in conjunction with embodiment examples. Therein depict:

FIG. 1a a schematic representation of a first embodiment example of a thermostatic assembly according to the application with a cold source, a consumer heat exchanger and a circulation pump,

FIG. 1b a schematic representation of a second embodiment example of a thermostatic assembly according to the application which corresponds to the thermostatic assembly depicted in FIG. 1a and additionally comprising a heating unit,

FIG. 2a a schematic representation of a third embodiment example of a thermostatic assembly according to the application with a cold source, a consumer heat exchanger, a circulation pump, a buffer storage and a second heat exchanger for the system separation as well as a pump for the energy transfer between the cold source and the buffer storage,

FIG. 2b a schematic representation of a fourth embodiment example of a thermostatic assembly according to the application corresponding to the thermostatic assembly depicted in FIG. 2a and additionally comprising a heating unit,

FIG. 3a a schematic representation of a fifth embodiment example of a thermostatic assembly according to the application with a cold source, a consumer heat exchanger, a circulation pump, a buffer storage, a second heat exchanger and an external refrigerant circuit with a refrigeration unit as well as a pump for the energy transfer between the cold source and the buffer storage,

FIG. 3b a schematic representation of a sixth embodiment example of a thermostatic assembly according to the application corresponding to the thermostatic assembly depicted in FIG. 3a and additionally comprising a heating unit,

FIG. 4a a schematic representation of a seventh embodiment example of a thermostatic assembly according to the application with a cold source, a consumer heat exchanger, a circulation pump, a buffer storage, a second heat exchanger, and an external refrigerant circuit with refrigeration unit, wherein the second heat exchanger is disposed within the buffer storage,

FIG. 4b a schematic representation of an eighth embodiment example according to the application corresponding to the thermostatic assembly depicted in FIG. 4a and additionally comprising a heating unit,

FIG. 5 a schematic representation of the buffer storage with the second heat exchanger according to FIGS. 4a and 4b disposed therein, and

FIG. 6 a schematic representation of a laboratory chamber, climate chamber, cold chamber or environment simulation chamber with a thermostatic assembly according to FIG. 4a.

DETAILED DESCRIPTION

FIGS. 1a to 5 show various embodiment examples of thermostatic assemblies 10-1 to 10-8, FIG. 6 illustrates the installation of such thermostatic assemblies. Like reference numbers denote like or functionally like components, wherein for greater clarity not all reference numbers are given in all Figures. FIG. 1a shows a schematic representation of a first embodiment example of a thermostatic assembly 10-1 with a cooling circuit 20 with a coolant. The cooling circuit 20 comprises a cold source 22 with a forerun 22a and a return 22b, a consumer heat exchanger 24 with a forerun 24a and a return 24b which is disposed in the return 22a of the cold source 22, and a circulation pump 26 in the return 24b of the consumer heat exchanger 24 and in the forerun 22a of the cold source 22. The circulation pump 26 can alternatively also be disposed in the forerun 24a of the consumer heat exchanger 24. The cold source 22 can comprise, for example, a cold-water reservoir, in particular a process-water reservoir such that water can be utilized as the coolant of the cooling circuit 20.

Between the return 22b of the cold source 22 and the forerun 24a of the consumer heat exchanger 24 is disposed a first three-way junction 41 and between the return 24b of the consumer heat exchanger 24 and the forerun 22a of the cold source 22 a second three-way junction 42 is disposed, wherein the first three-way junction 41 and the second three-way junction 42 are connected with a bypass line 45. The circulation pump 26 is herein disposed either between the first three-way junction 41 and the forerun 24a of the consumer heat exchanger 24 or, as depicted in FIG. 1a, between the return 24b of the consumer heat exchanger 24 and the second three-way junction 42.

The first three-way junction 41 and/or the second three-way junction 42 can be developed as three-way valves 30. In some embodiments, the first three-way junction 41 is developed as a three-way valve 30, wherein the first inlet 31 of the three-way valve 30 is in connection with the return 22b of the cold source 22, an outlet 33 of the three-way valve 30 is in connection with the forerun 24a of the consumer heat exchanger 24, and a second inlet 32 of the three-way valve 30 is in connection across the second three-way junction 42 with the return 26b of the circulation pump 26 and the forerun 22a of the cold source 22.

The thermostat assembly 10-1 can be operated, for example, in the following manner: the cold source 22 makes available a cold coolant, for example process water, which is supplied to the consumer heat exchanger 24 with the aid of the circulation pump 26 through the first inlet 31 of the three-way valve 30 and the outlet 33 of the three-way valve 30. Across the consumer heat exchanger 24 a sample compartment 110 can be cooled, wherein energy is supplied to the coolant in the consumer heat exchanger 24. The sample compartment 110 is in particular part of a laboratory chamber, climate chamber, cold chamber or environment simulation chamber 100 as depicted in FIG. 6. As a rule, the cooling circuit 20 herein is laid out of such size that the temperature of the coolant through the consumer, in the present case the sample compartment 110 of the laboratory chamber, climate chamber, cold chamber or environment simulation chamber 100, does not change significantly. In the return 26b of the circulation pump 26 a temperature sensor 28 can be disposed with the aid of which the supplied energy difference can be determined. At the first inlet 31 of the three-way valve 30 subsequently such quantity of cold coolant can be supplied that at the outlet of the three-way valve 33 coolant is available at the desired temperature. Only a quantity, corresponding to the quantity of supplied cold coolant, of warmer coolant returning from consumer heat exchanger 24 is carried from the circulation pump 26 directly to the cold source 22 in order to be cooled here anew.

A second embodiment example of a thermostatic assembly 10-2 according to the application depicted schematically in FIG. 1b differs from the thermostatic assembly 10-1 depicted in FIG. 1a in that the thermostatic assembly 10-2 comprises additionally a heating unit 40 which is disposed between the first three-way junction 41 and the consumer heat exchanger 24, in particular between the three-way valve 30 and the consumer heat exchanger 24. The coolant supplied through the outlet 33 of the three-way valve 30 to the consumer heat exchanger 24 can be heated through the heating unit 40 to the desired temperature in order to make feasible the temperature control within a wider temperature range.

A third embodiment example of a thermostatic assembly 10-3 according to the application depicted schematically in FIG. 2a differs from the thermostatic assembly 10-1 depicted in FIG. 1a thereby that the cold source 22 is part of a second heat exchanger 50 across which an external refrigerant circuit 60 is coupled to the cooling circuit 20. The second heat exchanger 50 comprises a forerun 50a and a return 50b. The second heat exchanger 50 can be developed, for example, as a plate heat exchanger or as a coaxial tube heat exchanger.

Between the second heat exchanger 50 and the bypass line 45 a buffer storage 70 can be disposed. The buffer storage 70 can be disposed in particular such that return 50b of the second heat exchanger 50 terminates into the buffer storage 70 is, in particular connected with an intake 71 of the buffer storage 70, and a discharge 72 of the buffer storage 70 is connected with the first three-way junction 41, in particular with the first inlet 31 of the three-way valve 30. Furthermore, a further intake 73 of buffer storage 70 can be connected with the second three-way junction 42 and a further discharge 74 of the buffer storage 70 with the forerun 50a of the second heat exchanger 50. For the energy transfer between the cold source 22 and the buffer storage 70 is disposed a pump 55, for example in the forerun 50a of the second heat exchanger 50.

A fourth embodiment example of a thermostatic assembly 10-4 according to the application differs from the thermostatic assembly 10-3 depicted in FIG. 2a in that the thermostatic assembly 10-4 comprises additionally a heating unit 40 which is disposed between the first three-way junction 41 and the consumer heat exchanger 24, in particular between the three-way valve 30 and the consumer exchanger 24.

To the external refrigerant circuit 60 of the thermostatic assemblies 10-3, 10-4 can be connected a cold-water reservoir for example of process water. A fifth embodiment of a thermostatic assembly 10-5 according to the application depicted schematically in FIG. 3a differs from the thermostatic assembly 10-3 schematically depicted in FIG. 2a thereby that the external refrigerant circuit 60 comprises a refrigeration unit 62. As the coolant of the external refrigerant circuit 60 a combustible coolant, for example a hydrocarbon, in particular propane or isobutane, can be utilized.

A sixth embodiment example of a thermostatic assembly 10-6 according to the application schematically depicted in FIG. 3b differs from the thermostatic assembly 10-5 depicted in FIG. 3a in that the thermostatic assembly 10-6 comprises additionally a heating unit 40 which is disposed between the first three-way junction 41 and the consumer heat exchanger 24, in particular between the three-way valve 30 and the consumer heat exchanger 24.

FIG. 4a shows a schematic representation of a seventh embodiment example of a thermostatic assembly 10-7 according to the application which differs from the thermostatic assembly 10-5 depicted in FIG. 3a thereby that the second heat exchanger 50 is disposed within the buffer storage 70. An enlarged representation of buffer storage 70 is shown in FIG. 5. The return 50b of the second heat exchanger 50 terminates into the buffer storage 70, forms here in particular the intake 71 of buffer storage 70, wherein intake 71 of the buffer storage 70 is preferably disposed in the proximity of the floor of buffer storage 70. The intake 71 can be disposed in particular between the floor of the buffer storage 70 and a perforated sheet 75 whereby the uniform distribution of the inflowing coolant can be supported. The discharge 72 of the buffer storage 70 can be connected with the first inlet 31 of three-way valve 30. In addition, a line 80 can be provided which connects the return 50b of the second heat exchanger 50 directly with the first inlet 31 of three-way valve 30 through which the cold coolant can be supplied directly to the consumer heat exchanger 24 without having to pass through the buffer storage 70. A three-way switchover valve (not depicted) can be provided by means of which can be controlled whether to the inlet 31 of the three-way valve 30 coolant is supplied from the buffer storage 70 across the discharge 72 or coolant is supplied directly from the return 50b of the second heat exchanger 50.

An eighth embodiment example depicted schematically in FIG. 4b of a thermostatic assembly 10-8 differs from the thermostatic assembly 10-7 depicted in FIG. 4a in that the thermostatic assembly 10-8 comprises additionally a heating unit 40 which is disposed between the first three-way junction 41 and the consumer heat exchanger 24, in particular between the three-way valve 30 and the consumer heat exchanger 24.

FIG. 6 shows a laboratory chamber, climate chamber, cold chamber or environment simulation chamber 100 with a sample compartment 110 and a thermostatic assembly 10-1 to 10-8 as described in conjunction with FIGS. 1a to 4, wherein the consumer heat exchanger 24 is disposed such that it maintains temperature control of the sample compartment 110. The installation of all of thermostatic assemblies 10-1 to 10-8 as described in conjunction with FIGS. 1a to 4 into the laboratory chamber, climate chamber, cold chamber or environment simulation chamber 100 is fundamentally conceivable. FIG. 6 illustrates an embodiment example utilizing the thermostatic assembly 10-8 depicted in FIG. 4b. The laboratory chamber, climate chamber, cold chamber or environment simulation chamber 100 comprises a machine compartment 120 separated from the sample compartment 110, wherein the external refrigerant circuit 60, preferably including the second heat exchanger 50, as depicted in FIG. 6 inclusive of the buffer storage 70, in which the second heat exchanger 50 is disposed, is disposed in the machine compartment 120. The machine compartment 120 comprises in particular ventilation apertures 122 and can thereby fulfill the safety requirements made of the use of combustible coolants, in particular hydrocarbons such as propane or isobutane. Advantageously only the consumer heat exchanger 24 of the thermostatic assembly 10-8 is disposed in or at the sample compartment 110 while the further elements of the thermostatic assembly 10-8 are disposed spatially separated in the machine compartment 120.

LIST OF REFERENCE NUMBERS

• • 10-1 to 10-8 Thermostatic assembly
  • 20 Cooling circuit
  • 22 Cold source
  • 22 a Forerun
  • 22 b Return
  • 24 Consumer heat exchanger
  • 24 a Forerun
  • 24 b Return
  • 26 Circulation pump
  • 26 a Forerun
  • 26 b Return
  • 28 Temperature sensor
  • 30 Three-way valve
  • 31 First inlet
  • 32 Second inlet
  • 33 Outlet
  • 40 Heating unit
  • 41 First three-way junction
  • 42 Second three-way junction
  • 45 Bypass line
  • 50 Second heat exchanger
  • 50 a Forerun
  • 50 b Return
  • 55 Pump
  • 60 External refrigerant circuit
  • 62 Refrigeration unit
  • 70 Buffer storage
  • 71 Intake
  • 72 Discharge
  • 73 Intake
  • 74 Discharge
  • 75 Perforated sheet
  • 80 Line
  • 100 Laboratory chamber, climate chamber, cold chamber or environment simulation chamber
  • 110 Sample compartment
  • 120 Machine compartment
  • 122 Ventilation opening

Claims

1. A thermostatic assembly comprising: a cooling circuit having a coolant, wherein the cooling circuit further comprises: a cold source,a consumer heat exchanger in a return of the cold source, anda circulation pump,wherein between the return of the cold source and a forerun of the consumer heat exchanger is disposed a first three-way junction and between a return of the consumer heat exchanger and a forerun of the cold source a second three-way junction is disposed,wherein the first three-way junction and the second three-way junction are connected with a bypass line and the circulation pump is disposed either between the first three-way junction and the forerun of the consumer heat exchanger or between the return of the consumer heat exchanger and the second three-way junction.

2. The thermostatic assembly of claim 1, wherein the first three-way junction and/or the second three-way junction are developed as three-way valves.

3. The thermostatic assembly of claim 1, wherein the first three-way junction is developed as a three-way valve, that the circulation pump is disposed between the return of the consumer heat exchanger and the second three-way junction, wherein the first inlet of the three-way valve is in connection with the return of the cold source, an outlet of the three-way valve is in connection with the forerun of the consumer heat exchanger, and a second inlet of the three-way valve is in connection across the second three-way junction with the return of the circulation pump and the forerun of the cold source.

4. The thermostatic assembly of claim 1, wherein between the first three-way junction and the consumer heat exchanger a heating unit is disposed.

5. The thermostatic assembly of claim 1, wherein the cold source comprises a cold-water reservoir.

6. The thermostatic assembly of claim 1, wherein the cold source is part of a second heat exchanger across which an external refrigerant circuit is coupled to the cooling circuit.

7. The thermostatic assembly of claim 6, wherein the second heat exchanger is developed as a plate heat exchanger or as a coaxial tube heat exchanger.

8. The thermostatic assembly of claim 6, wherein between the second heat exchanger and the bypass line a buffer storage is disposed.

9. The thermostatic assembly of claim 6, wherein a return of the second heat exchanger terminates into the buffer storage and a discharge of the buffer storage is connected with the first three-way junction, in particular with the first inlet of the three-way valve and that preferably a further intake of the buffer storage is connected with a second three-way junction and a further discharge of the buffer storage is connected with a forerun of the second heat exchanger.

10. The thermostatic assembly of claim 6, wherein the second heat exchanger is disposed within the buffer storage.

11. The thermostatic assembly of claim 10, wherein the return of the second heat exchanger is connectable, particularly by a three-way switchover valve, on the one hand with the buffer storage and, on the other hand, by a line directly with the first inlet of the three-way valve.

12. A chamber comprising: a sample compartment; anda thermostatic assembly comprising: a cooling circuit having a coolant, wherein the cooling circuit further comprises: a cold source,a heat exchanger in a return of the cold source, anda circulation pump,wherein between the return of the cold source and a forerun of the heat exchanger is disposed a first three-way junction and between a return of the heat exchanger and a forerun of the cold source a second three-way junction is disposed,wherein the first three-way junction and the second three-way junction are connected with a bypass line and the circulation pump is disposed either between the first three-way junction and the forerun of the heat exchanger or between the return of the heat exchanger and the second three-way junction,wherein the heat exchanger is disposed such that it maintains temperature control of the sample compartment.

13. A chamber of claim 12, wherein the cold source is part of a second heat exchanger across which an external refrigerant circuit is coupled to the cooling circuit, wherein the heat exchanger is disposed such that it maintains temperature control of the sample compartment and wherein the external refrigerant circuit, preferably including the second heat exchanger, is disposed in a machine compartment separated from the sample compartment, which machine compartment in particular comprises ventilation apertures.

14. A chamber of claim 13, wherein the external refrigerant circuit comprises a hydrocarbon, in particular propane or isobutane, as the coolant.