The equipment was just started up on this commercial job in Luverne MN and it all works flawlessly. The main source of heating and cooling comes from 2 geothermal closed loop pressurized systems. There is one 17.5 ton unit that services the shop and one 3 ton unit that services the offices. Both units have inline duct heaters installed to work as a 3rd stage of heat/emergency heat if the compressors or pumps would happen to fail on the geo’s. There is an economizer on the bigger unit to take advantage of free cooling during the cooler spring and fall days. There are two variable frequency drive controllers that run the pumps and a customized controller that executes the order of operations for all of the equipment. The state required a temperature controlled eye wash station due to the harmful products dealt with in the shop. The shop area has two 1725 cfm exhaust fans and an intake louver that work simultaneously to deliver fresh air to the shop. Fun project that turned out great!