industrial and commercial units and systems for cooling, heating, and treating water, air and other process fluids, comprising one or more of the following; water chillers, sand and gravel water filters, water cooling towers, compressed air dryers, blown film, coolers, ion exchange water softeners, chemical feeders for corrosion inhibition in water supply systems, bleed-off controllers for reduction of solids concentration in water supply systems, acid feeders for control of PH in water supply systems, combination heater and temperature control units for process liquids, heat pumps, heat recovery units, closed circuit water coolers, expansion tanks, air separators, centrifugal separators, and pump/reservoir units; dehumidifying dryers; dehumidifying drying enclosures; hot air dryers; plenum drying hoppers; negative pressure water circulating units; filter chambers; and blown film cooling units and parts therefore