One of our medical device clients, a manufacturer of oxygen concentrators needed to create a lightweight, compact machine with an outstanding battery life that was competitively priced.
One of the biggest challenges their engineers faced in achieving these objectives was keeping the machine’s compressor cool enough to operate at peak performance, using a minimal amount of power. In our initial discussions with our clients engineering team we learned that they had planned on using multiple fans or blowers placed at various locations within the device; a fan to draw in cool air through a filter, a fan to cool the compressor and control PCB and, one to blow hot air out of the system. While this approach dissipated heat sufficiently it drew far too much power to achieve the desired battery life. The obvious solution was to reduce the number of cooling devices. They looked at axial cooling fans that were good at producing high airflow (CFM) however due to the resistance to airflow caused by the machine’s components being tightly packed together in a small enclosure they also needed a great deal of static air pressure. Off-the-shelf fans could provide enough CFM and off-the-shelf blowers could provide the required static pressure; however, they could not find an off-the self-solution that could do both.
Fortunately, we manufacture custom fans and blowers that far outperform off-the-shelf solutions. Using a computer simulation of their system we produced an axial cooling fan that provided more than 17 CFM at nearly an inch of static pressure while drawing less than two watts of power. We quickly produced prototypes for them, and they were delighted with the test results. Based on the power and space savings that our fan provided they were able to easily meet all their objectives. They were also impressed that our fan was able to deliver these levels of performance while operating in near silence.
Having decided to use our fan was not the end of the story. Since an oxygen concentrator is a Class II medical device their engineers needed to ensure that each component used met an extremely high standard of safety and reliability. We were able to provide built-in safety functions such as locked rotor protection which prevented the fan from overheating or burning out if the fan’s blades became jammed. We also provided custom Pulse with Modulation (PWM) Control which allowed their device to finely regulate the fans speed from zero it’s maximum RPM, further reducing power consumption and noise. We also, provided options for IP rated versions of the fan that would allow the fan to be reliably operated in environments where dust, water, or harsh chemicals were present. These features and our ability to provide the UL, CUL, and TUV test results allowed their engineering team to easily create the documentation needed for FDA compliance of their device.