and the desiccant must be regenerated this dilute desiccant is collected in a drain pan 24 disposed at the bottom of desiccant absorber 12 the drain pan 24 includes an intermediate support plate 26 defining at least one drain hole 28 which enables the dilute desiccant to flow into a bottom chamber defined between support plate 26 and a bottom wall 30 of drain pan 24 a drain tube 32 including a one way or check valve 33 extends from the bottom chamber to direct the dilute desiccant out of absorber 12 the absorber components are disposed within a frame 35 as shown in fig1 which can be fabricated from materials including but not limited to polypropylene polyethylene polytetrafluoroethyline referred to herein under the trademark teflon polyvinylidene fluoride polycarbonate pvc or polystyrene the frame 35 includes a plurality of shelves 37a 37b and 37c for supporting the respective components of the unit described below the dilute liquid desiccant is regenerated into concentrated desiccant by boiling the liquid desiccant in a boiler 34 at a temperature in the range of from approximately 260 u00b0 f to 320 u00b0 f an improvement over prior art systems resides in the use of steam from desiccant regeneration to sensibly preheat the dilute liquid desiccant the dilute liquid desiccant is passed through a condenser and preheated using the latent heat of condensation of the steam produced by boiling the liquid desiccant preferably a series of interchange heat exchangers are employed to further preheat the dilute liquid desiccant entering the boiler 34 by recovering heat from the concentrated liquid desiccant delivered to absorber 12 from boiler 34 to further increase operating efficiency these.