Editor’s note: This is the second in a series of guest blogs by Jeff Nilles from Texas Instruments. Jeff will be giving us his observations of APEC 2014 as he tours the conference this week.
When I entered college I supported the ecology movement. Not that I was much of a hippie, being an engineering student, but I did take a field biology class which strongly influenced me. Somehow, I became an ecologist of sorts due to this class. I saw the movement as a way to save the planet by using fewer resources. As the years went on, I connected the idea of saving resources to the save the world with improving efficiencies in power supplies and equipment so the world could use less electric power.
In Monday’s opening plenary session at APEC, Dave Freeman, CTO of power for TI, reminded us about resource savings again with a great example — something that kept us on the hook waiting for the real answer. His speech, “Transforming Energy Management,” covered the vast territory of power in automotive to powering the cloud.
Dave started the case study with a customer needing an ultra-low-power sensor for a room. This sensor needed to figure out if there were four people in a room, and it also needed to be ultra-low-power so it could harvest enough energy to run. From there, the sensor needed to send the information it gathered to the master system via WiFi. As I was listening, I speculated that this was some sort of security system sensor, or something to predict the need for more air conditioning due to these four people heating up the room.
Then the customer tells him they really need it to be a CO2 sensor. Is that really how they will figure out if there are four people in the room? Unless one person can hold his or her breath for a long time, this might work. Or is it for a security or heating/cooling (HVAC) system?
As it turns out, the goal was to make sure there is not too much CO2 in the room due to the occupants' breathing. In order to keep these four people alert, and keep them from making mistakes due to a high level of CO2 , the system would increase the level of outside air coming in from the HVAC system. It seems so simple now. If the room is empty, then there is no reason to bring cold or hot air in from outside or to expend the energy it takes to move or cool the air.
This ultra-low-power sensor would allow the system to adjust the blower speed and outside air mix as people moved into the room, allowing the CO2 to maintain a safe level. Since HVAC systems are a major electrical grid load, this simple device could be a major resource saver, making those who use it ecologists. As a side benefit, no one will fall asleep in conference rooms anymore. I’ll talk with you again soon.