and yes, both hashfast and cointerra are using high end pc cooling technology, but even then, I'm sure they're using the extra strength version of it.. not the standard common or garden models. cointerras radiators look custom (and big!)... they're not similar to anything I've seen in a store.. though hashfast's radiators do look similar to high end pc ones like the Corsair Hydro series (probably H80).
These aren't high end water cooling, they are about as cheap as water cooling gets. Note this shouldn't be taken as a hit against either company high end water cooling is expensive, maintenance prone, and complex to install. It really isn't suited for mass production. These are the OEM (unbranded) version of popular sealed (self contained rad, pump, res, waterblock, & fluid) water cooling systems.
Kudos to both companies for ingeniously using off the shelf parts but I think you overstated the cooling challenges. Cooling something 24/7 isn't any harder than cooling it for an hour. You are going to reach equilibrium (especially with water) within minutes and if you don't have sufficient cooling the system isn't going to last an hour. If it does lat an hour it isn't going to get harder to cool over time, baring a fan or pump failure the temp after an hour, day, week, year will be roughly the same.