In areas where water is not in particularly short supply, you can cool by evaporating water into the exhaust pre-heat-exchanger of an MVHR system. This then ven

In areas where water is not in particularly short supply, you can cool by evaporating water into the exhaust pre-heat-exchanger of an MVHR system. This then vents the warmer humid air into the outside and cools incoming air. The enthalpy diagram suggest it's quite helpful and there's a product on the market that uses exactly this approach. It's basically half of a closed cycle heat pump, in which the hot side is an externality.