Development and evaluation of a multistage thermoelectric air cooling and dehumidification system

Air cooling and dehumidification have numerous industrial applications. This study presents the development and evaluation of a thermoelectric air cooling and dehumidification (TECD) system, using a combined modeling–experimental approach. A mathematical model based on thermoelectric relations and heat-balance equations is developed to predict the outlet air temperature, cooling load, and coefficient of performance of the thermoelectric module (COP_TEC), vapor condensation rate, and dehumidification effectiveness. The model is validated using a laboratory single-stage unit then it is used to predict the performance of a multistage TECD system (10 stages) under different design configurations (parallel and series stage connections) and operating conditions. Results show that for the single-stage system, there are two operating scenarios: a high COP_TEC (3 to 9) at low-input power below 20 W and an optimal cooling capacity region near input power of 200 W, where total cooling and condensate (water) production peak at a low COP_TEC of 0.4. For the multistage TECD (10-stages) system, model results showed that series airflow arrangement outperforms the parallel airflow arrangement, delivering lower outlet temperature, higher condensate rate and condensation efficiency, reduced input power, and higher COP_TEC. With a low-power input of 43.5 W, 10 CFM airflow, and 10 LPM cooling water, the 10-stage system provided 13.5 °C outlet air (89.3 W sensible cooling), 171 g/h condensate (123.5 W latent), 49% condensation effectiveness, and a high COP_TEC of 4.89. When maximum cooling capacity is demanded, operation at input power of 1600–1700 W achieves an air outlet temperature of −12.5 °C (228 W sensible cooling), 328 g/h condensate (275 W latent), 93% condensation effectiveness, and low COP_TEC of 0.31.