The CoilPro CC-400HF from Goodway provides a solution to cleaning thick evaporator and condenser coils. According to the company, there is either too much pressure that damages coils and fins or too little water volume to get through the thick coils.
The Windows-based Refrigerant Piping Design program determines the minimum pipe size required to deliver refrigerant between the compressor, condenser, and evaporator within specified pressure loss limits.
Leaning on experience and data from various K-12 cities and projects, the author pursues some less conventional design approaches. They may revolve around radiant heating and/or cooling, but depending on school size and other factors, the smart use of heat recovery, DOAS, and improved central plants could also put a project on the HVAC honor roll.