What are the differences between the air-cooled and the liquid cooled electrolyser?

The air-cooled and liquid-cooled electrolyser are nearly identical devices. The only difference is in the heat exchanger subassembly, which has the primary function to maintain a stable electrolyte temperature for the electrolyser operation. Air-cooled The air-cooled electrolysers use a fan

February 19, 2022

The air-cooled and liquid-cooled electrolyser are nearly identical devices. The only difference is in the heat exchanger subassembly, which has the primary function to maintain a stable electrolyte temperature for the electrolyser operation.

Air-cooled

The air-cooled electrolysers use a fan to blow ambient air to keep the electrolyte at the nominal operating temperature of 55°C. Air with a maximum allowed temperature of 45 °C is taken in at the front of the device and blown out hotter at the back. The operator must ensure distances at the front and the back of the device to allow sufficient air flow.

Pros: uses ambient air, therefore easy and fast to set up

Cons: higher requirements on HVAC and installation space in small rooms or containers

Liquid-cooled

The liquid-cooled electrolysers have a liquid-liquid heat exchanger and use a valve to allow/interrupt the cooling liquid flow. The liquid-cooled version of the electrolyser has minimal air flow requirements for safety purposes and to cool the electronics. Therefore the installation space for the air flow can be reduced depending on the room temperature. It has an additional cooling liquid inlet and outlet on the front panel. The operator must supply pressurized cooling liquid at the inlet, and the device will release the cooling liquid at a higher temperature from the outlet. The temperature increase depends on the supplied pressure and flow rate. The waste heat amount can be found in the datasheet.

Pros: more compact setup as air flow requirements is reduced

Pros: reduced requirements on the HVAC system for indoor installations

Cons: requires the installation of a cooling liquid circuit

Using waste heat

In both the air-cooled and liquid-cooled cases, the total waste heat energy from the electrolysis process is the same. This waste heat, while of relatively “low quality”, could potentially be used by integrators in some specific applications to increase overall efficiency of their energy systems. In most cases however, it is just released to the environment.