Project Objective
Design, build, and test a prototype for an innovative approach to passively cool up to 25W in a smart home device.
Team
The project team is:
Customer/Market Requirements
The sponsor requested a device to cool an Amazon Echo gen 1 that has been upgraded with a higher power SOC for increased local compute capability. The cooling device must be silent, cannot significantly change the Echo in size or functionality, and must keep all surfaces and air that users may come in contact with at comfortable temperatures.
Design Challenges
Design Challenges
The design team is focused providing a design that would allow the sponsor to develop a device that supports up to 25W platform power. The most difficult part of achieving this goal was keeping the volume and external temperatures within limits.
Outcomes
The team has developed a design that utilizes natural convection to force airflow through chimneys over a custom-fit heat sink. To keep exterior surface temperatures low, the design had an air gap between the chimneys and the exterior surface as well as thin exterior insulation. This had the additional effect of keeping the chimney walls heated which helped encourage flow over the heat sinks which, in turn, increased heat transfer. This helped address the second major challenge of meeting the volume limitation.
The following plot shows heater temperature over time with different heights of fin inside a chimney.
