The air-conditioning of a Hamburg data centre with a surface area of 800 m² and a heat load of 1 MW costs only € 34,000.- a year with Direct Free Cooling, as opposed to € 296,000.- a year with compressor cooling only. This corresponds to savings of € 262,000.- a year.

Source:
STULZ comparison of system costs, basis for calculation 13 ct/kWh