Modern industries utilize solar thermal energy in heat pump applications due to its enhanced performance and improved plant efficiency. The investigation presents the effective utilization of solar thermal energy in heat pump applications using different fluid pairs like zeolite/water, silica gel/water and alumina nanofluid/water. The effect of fluid pairs on heat transfer rate, thermal adsorption and mass loss of heat pump is monitored by STA Netzsch 409 differential thermogravimetric apparatus with a temperature range of 15–200 °C. The heat transformation of a heat pump is estimated by various water absorbed amounts of 0/1, 0/15, 0/20, 0/25, 0/30, 0/35 and 0/4 g/g under 0.005, 0.01, 0.05, 0.1, 1, 10 and 100% relative humidity. The result revealed that the alumina nanofluid-operated heat pump found higher thermal adsorption behaviour of 41.28 W/m °C. The heat transfer rate of the alumina/water fluid pair was 117 kJ/mol. Different adsorption temperature points predict the saturation point of alumina at 0–200 min. © 2023 Elsevier B.V., All rights reserved.