A parametric analysis on the regeneration performance of silica gel in a proposed comfort provision strategy for a typical office space in Harare, Zimbabwe

• Silica gel applied for enhancing humidity control in an office.
• Solar dried (regenerated) silica gel bed utilized for air drying that will be applied to internal surfaces regeneration.
• Performance depends on both design as well as environmental parameters.
• Simulation is necessary to verify performance for a given site.
• The passive strategy show feasibility for simulated site, Harare, Zimbabwe.

This paper reports the influence, design and climate parameters have on the regeneration performance of a proposed strategy for passive comfort provision for an office space. Solar regeneration of an external silica gel bed is later followed by regeneration of internal surfaces laden with silica gel. The internal surfaces regeneration is effected utilizing air dried by the external bed. External bed regenerating air conditions are evaluated based on simple energy balance and buoyancy models. Thermal efficiency is formulated based on its fundamental definition. Silica gel drying models are obtained from literature. MS Excel Spreadsheet program is applied in the present simulations. Internal surfaces regeneration depends largely on; ventilation rate, initial dryness and mass of external silica gel bed. There is an optimum ventilation rate for a given mass of silica gel in the external bed for particular initial moisture content. Channel depth is quite critical to the regeneration effect on the external silica gel bed, with an average influence coefficient of 200%. The specific humidity of the regenerating air has the least coefficient of influence of 82%. Considering the foregoing, the design of the proposed system calls for simulation to estimate performance.