R12 Guentner Cooler Replacement

Hi Guys

I have cooled store equipped with Guentner cooler, unfortunately the unit capacity is not mentioned, the only data i have are:

Cooler type: GHDE 63 B/38
3 axial fans 1030 RPM 0.9 KW power cons. per each
Power supply 380V, 3 Ph, 60 Hz.

I need to the capacity of this unit because the client want just to replace it because of R12 headage, i don’t to recalculate the load since this was satisfying the load.

Pleassssse help