You could do that, but you'd need to build a heavily insulated place to have the A-coil/evap head, as it stands right now the efficiency loss would be too much.

You could do that, but you'd need to build a heavily insulated place to have the A-coil/evap head, as it stands right now the efficiency loss would be too much. Additionally, the current HVAC model also acts as a rudimentary de-humidification system for buildings which helps reduce the "felt" temperature and maintain humidity levels beyond just cooling.