Radon is the second leading cause of lung cancer after active smoking and the second leading cause among non-smokers. The United States Environmental Protection Agency (EPA) recommends that steps should be taken to remove Radon in homes with levels that are higher than 4 picocuries per liter. This is becoming more common as houses become more airtight to conserve energy. Existing Radon fans consist of low-efficiency vertical fans with primitive diffusers. These fans operate 24 hours per day and are not particularly efficient. The United States Department of Energy (DOE) awarded Mechanical Solutions, Inc. (MSI) a Phase 1 and 2 Small Business Innovation Research Grant to develop a new fan that would fit into the envelope of an existing Radon fan to provide a more efficient design to reduce the cost of operating the fan. The design process started with the establishment of a manufacturing partner. Fantech and MSI entered a collaborative agreement to develop the new fan. Fantech selected a standard model to act as the source of the optimization. After that, a comprehensive CFD analysis was performed on this model to identify areas of improvement. Attention focused on the impeller and stationary diffuser. An alternate impeller geometry and two candidate diffusers were developed and optimized using a commercial turbomachinery design tool (CFturbo) and a commercial CFD code (STAR-CCM+). MSI manufactured the fan components using additive manufacturing and constructed a test rig to test the new designs and contrast these designs with the original Fantech design. The test results conclude that both MSI prototypes outperform the original Fantech design. MSI was required to use the original electric motor for this effort. To determine its performance, a motor test rig was built, and the motor torque and efficiency were measured. This facilitated the ability to isolate the fan aerodynamic performance. It establishes the improvement of the aerodynamics of the MSI-designed fans.