The main difference between the three systems is the structural integrity, design and the size of the system. Typically the more fans you have the larger pump size you need to properly pressurize the number of nozzles per fan. Also a big determining factor is the fan head diameter (size), fan speed and durability to elements of outdoor exposure. For instance our residential and commercial fans are built with more design and ambiance in mind where our Extreme Fans (Industrial Series) are built with more ruggedness and power. There are trade-offs for each. In most cases smaller fans and pumps are quieter thus more suited for patios and restaurants where larger more powerful fans are generally used for cooling large outdoor venues, steel mills, warehouses, and factories where noise is not an issue.