Session: 02-05 Innovations for Sustainably Built Environments

Paper Number: 116809

116809 - Performance of a Solid-State Thermoelectric Thermoregulation System Under Different Climate Zones in the Us 

A solution for an on-site all-electric and refrigerant-free thermoregulation is to implement commercially available thermoelectric (TE) systems that provides both heating and cooling, and full modulation of the thermal output. Currently, the literature for the thermoelectric-based cooling systems reports low coefficients of performance (COPs) between 0.38 and 1.77, with the media (solid-air or air-air) temperature difference staying between 5K and 60K. There is scarcity of literature reports on the heating operation of TE systems. This work discusses theoretical modeling and analysis of a solid-state thermoelectric thermoregulation system (SSTTS) and compares its performance with two systems for heating and cooling in residential settings, such as an all-electric heat pump [Packaged Terminal Air Conditioner (PTAC)] and an air-conditioner with fossil-fuel heating source [Variable Refrigerant Flow (VRF)]. A south-facing apartment unit, derived from the Department of Energy building prototype, is simulated using EnergyPlus™ to determine the heating and cooling loads, and the power consumed by the two alternative solutions, on hourly basis across all the IECC climate zones in the US. Using the hourly thermal loads, the room-ambient air temperature differences and the additional air-to-TE pellet junction temperature differences, an analytical solution is obtained for the steady state optimum current, the number of TE modules required and input power to obtain the maximum COP for SSTTS operation.

When using the commercially available TEC1-19940 TE modules (from Thermonamic) with ZT 0.77, preliminary results suggested that the SSTTS performed better in the zones with colder climates under well-controlled parasitic losses. Compared to the PTAC system, the SSTTS performed better on average by 37.9% in 12 and worse on average by 18.4% in 4 of the 16 simulated climate zones on an annual basis. Compared to the equivalent VRF system, it performed better on average by 13.7% in 3 and worse on average by 29.4% in 13 of the 16 simulated climate zones. This study indicates that optimized solid-state based solutions for thermal regulation in buildings may provide better COPs than state-of-the-art heating, ventilation and air-conditioning (HVAC) systems in multiple climate zones. While the preliminary study used the material properties from a commercially available TE module, this work aims to use the properties of an improved TE material with literature reported effective ZT greater than 1.0. The TE device with better material properties would have the same footprint as that of the commercially available one and its performance would be analyzed across all the climate zones.

Presenting Author: Amogh Wasti Rensselaer Polytechnic Institute

Presenting Author Biography: Ph.D. student with research focused on novel and energy efficient thermoregulation systems for buildings