The central air conditioning sanitation standard in hospital is higher than other industry. Temperature and humidity requirements various from each consulting room or ward. The design of the central air conditioner in hospital follows the principles of energy saving, anti bacteria and anti cross infection. The equipment that can be selected includes: water source / ground source heat pump system, water cooling unit, air cooling heat pump heat recovery unit: multifunctional heat pump, multifunctional water heater, medical air conditioning unit (water coil and direct expansion).