A temperature equalisation system constituted by a heat equaliser disposed in a natural thermo-carrier having a comparatively large and reliable heat-carrying capacity, and an installation, whose internal temperature is to be maintained at a substantially constant temperature, the system being such that heat exchange fluid passes through the installation via a fluid transmission duct to the heat equalizer, and flows back to the installation via the fluid transmission duct to regulate for temperature equalisation of the installation, the heat equaliser providing good heat conduction with the natural thermo-carrier to provide temperature equalisation regulation of the backflow of fluid to the installation, the system further comprising: a pump connected in series with the fluid transmission duct; an auxiliary temperature regulation device, to heat or cool the fluid; a first and a second bypass duct disposed in parallel in the installation, both of the bypass ducts being in fluid communication with the fluid transmission duct; a first and a second bypass control valve disposed in the first and the second bypass ducts respectively; a control unit, for controlling the flow rate of the fluid between the heat equaliser and the installation, and for controlling the operation of the first and second bypass control valves to control the flow rate of the fluid passing through them, the system being characterized in that it further comprises a bypass auxiliary pump disposed in one of the bypass ducts for pumping the fluid therethrough; and in that the control unit is also adapted to control the pumping operation of the bypass auxiliary pump. a heat equaliser disposed in a natural thermo-carrier having a comparatively large and reliable heat-carrying capacity, and an installation, whose internal temperature is to be maintained at a substantially constant temperature, the system being such that heat exchange fluid passes through the installation via a fluid transmission duct to the heat equalizer, and flows back to the installation via the fluid transmission duct to regulate for temperature equalisation of the installation, the heat equaliser providing good heat conduction with the natural thermo-carrier to provide temperature equalisation regulation of the backflow of fluid to the installation, the system further comprising: a pump connected in series with the fluid transmission duct; an auxiliary temperature regulation device, to heat or cool the fluid; a first and a second bypass duct disposed in parallel in the installation, both of the bypass ducts being in fluid communication with the fluid transmission duct; a first and a second bypass control valve disposed in the first and the second bypass ducts respectively; a control unit, for controlling the flow rate of the fluid between the heat equaliser and the installation, and for controlling the operation of the first and second bypass control valves to control the flow rate of the fluid passing through them, the system being characterized in that it further comprises a bypass auxiliary pump disposed in one of the bypass ducts for pumping the fluid therethrough; and in that the control unit is also adapted to control the pumping operation of the bypass auxiliary pump. a pump connected in series with the fluid transmission duct; an auxiliary temperature regulation device, to heat or cool the fluid; a first and a second bypass duct disposed in parallel in the installation, both of the bypass ducts being in fluid communication with the fluid transmission duct; a first and a second bypass control valve disposed in the first and the second bypass ducts respectively; a control unit, for controlling the flow rate of the fluid between the heat equaliser and the installation, and for controlling the operation of the first and second bypass control valves to control the flow rate of the fluid passing through them, the system being characterized in that it further comprises a bypass auxiliary pump disposed in one of the bypass ducts for pumping the fluid therethrough; and in that the control unit is also adapted to control the pumping operation of the bypass auxiliary pump.