I love Helmer products. Used to be you called up and spoke with one of the Helmers . . . that said. Had an iseries in NH. After the first year it would crash, for a number of small reasons, every 10-12 months . . . a gasket deteriorates, the inside unit attached to the fan craps out, nothing major but it forces you to move product, increase documentation. At my current facility iseries: fan motor dies, compressor dies, - I think there might be exterior pressures on those parts which I have resolved but still . . . I just put in a capital request for one of the Panasonics. Hopeuflly it will perform more efficiently.
Have had no problems with Helmer Refs except to add coolant sporadically. Have that built into maintenance schedule where I am now (I think so anyway)