The Laboratory for Thermal Transport and Storage (LET+S) seeks to better understand fundamental fluid dynamic and heat transfer processes, and use this insight to make more efficient thermal energy systems. Our lab uses a combination of experimental and modeling techniques to make these advances, which feed into a variety of applications including nuclear power production and building energy systems. Our lab is part of a collaborative research group at University of Wisconsin – Madison called the Solar Energy Laboratory.
At the LET+S, we lead and contribute to projects that:
- Enable us to shift and shave building electrical loads with thermal energy storage, allowing for a more renewable and sustainable electricity grid.
- Increase the efficiency of thermal equipment to reduce the energy required for a variety of processes, from industrial manufacturing to home heating and cooling.
- Facilitate the transition to electrified buildings by developing heat pump systems that can work in a wide range of climates
- Improve reactor safety in nuclear power production
Our overall goal is to develop safe and effective thermal systems that provide a benefit to society while helping our world transition to a low-carbon energy future.

Lab News
Presented two-phase flow work at GRC
Dr. Mahvi and Joe Farrell presented some of our work on annular two-phase flow at the Micro and Nanoscale Phase Change Gordon Research Conference in January.
February 3, 2025Mahvi awarded funds to advance cold-climate heat pumps
Mechanical Engineering Assistant Professor Allison Mahvi was recently selected for a $2M award from the Department of Energy to develop a more sustainable heat pump that can replace existing, less efficient boilers in older buildings. …
October 5, 2024Naleah Boys awarded research fellowship
Naleah was awarded the Faustin Prinz Undergraduate Research Fellowship. The fellowship supports undergraduate Mechanical Engineering and Engineering Mechanics students who want to develop a research project with ME or EM faculty, get access to cutting-edge …
July 1, 2024Welcomed Jack to the group!
We are excited to welcome our newest member, Jack Prout, to the group! Jack is a Masters student in Mechanical Engineering. He received her BS in Mechanical Engineering from University of Wisconsin in 2024. His …
July 1, 2024- More Posts