Top IPC subclasses
1
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F25B
|
4
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refrigeration machines, plants, or systemscombined heating and refrigeration systemsheat pump system
|
2
|
F28F
|
1
|
details of heat-exchange or heat-transfer apparatus, of general application
|
3
|
F28D
|
1
|
heat-exchange apparatus, not provided for in another subclass, in which the heat-exchange media do n
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