Company C, a housing equipment manufacturer, was working on a new heat exchange ventilation system. Ms. H, of Company C's product development department, discussed her challenges.
"The market is rapidly moving toward smaller and cheaper heat exchange ventilation systems, and we had begun to develop a new product to meet this trend. Our current systems used separate fans for intake and exhaust. The intake fan draws in outside air through a filter to supply fresh air, and the exhaust fan expels the dirty air from the room. In our new heat exchange ventilation system, we looked into making the system smaller by using only one fan that could switch airflow direction."
Ms. H consulted fan manufacturers right away, and started to evaluate samples.
"We tried switching airflow direction with one fan, but found that the difference in airflow between forward and reverse rotation was more than expected. Since the heat exchange ventilation system uses an internal heat storage element to maintain the temperature, the temperature retention efficiency decreases when the volume of intake and exhaust differs. For this reason, we needed to finely control the forward and reverse rotational speed so as not to break the intake and exhaust balance, but controlling this was difficult," complained Ms. H.
Stuck in development, Ms. H sought a solution to the problem.
Seeking to solve her problem, Ms. H stopped by SANYO DENKI's booth at an industrial technology event and discussed her problems with a sales representative.
The SANYO DENKI representative listened carefully to her problems, and proposed a Reversible Flow Fan equipped with the PWM control function. Ms. H was strongly attracted to this proposal.
"The impeller and frame shape of the proposed fan were optimized to have almost the same airflow and static pressure in both forward and reverse rotation. This made control easier because there was no need to change speed settings for forward and reverse rotations," enthused Ms. H.
Ms. H immediately carried out in-house testing of the proposed fan and confirmed that it could maintain the intake and exhaust volume balance. The results of the in-house testing were so positive that Company C quickly adopted the Reversible Flow Fan and successfully developed their new heat exchange ventilation system. "By going from two fans to one, we could make our heat exchange ventilation system smaller and still satisfy our customers. In addition, during in-house testing the SANYO DENKI representative proposed we use a box-type PWM controller. Using it in the prototype helped us smoothly complete the airflow evaluation. I really feel that I got the best fan this time. I will continue to consult SANYO DENKI in the future," said Ms. H.
