Taking Digital Signage Outside the Usual Cooling Schemes to Save Costs
Compressor-less cooling can increase energy efficiency as well as saving upfront hardware costs.
When EECatalog spoke with Mike Bruno, vice president and general manager, Electronics Cooling at Phononic, Bruno described how the company is applying thermoelectric technology to thermal challenges in a number of fields, including digital signage.
EECatalog: We’re about to talk about how Phononic technology can apply to digital signage applications, but could you first give us an overview of Phononic?
Mike Bruno, Phononic: Sure. We’re a material science company focused on thermoelectric technology. Our CEO [Dr. Tony Atti, Ph.D.] started the company after doing an investment thesis on the thermoelectric industry. Through his research and investigation he found that there really hasn’t been much innovation in the field of thermoelectric materials and he wanted to change that.
So Phononic began designing, manufacturing, and developing our own devices. We do not manufacture standard products. Our devices are designed to be application-specific to support the unique challenges our customers are facing. Our core device technology is derived from our own material science and manufacturing capabilities.
My business unit is Electronic Cooling, which supports the thermal challenges of electronic systems, and that goes for everything from CPUs to speciality electronics to digital signage. You will find our devices embedded into fiber-optic systems. We’re helping manage the thermal loads associated with Gigabit Ethernet, and we’re supporting the Internet of Things [IoT] by enabling faster networks.
EECatalog: How would you characterize the thermal challenges embedded designers are facing and Phononic’s role in addressing them?
Bruno, Phononic: As we as consumers push the envelope with an insatiable desire for information and data, we’ve become our own worst enemies as it pertains to thermal challenges. Hardware is not always limited by the performance of the silicon or how the semiconductor manufacturers are shrinking the the feature size, and/or how many transistors they are putting on a chip. The thermal challenges of these devices is starting to become one of the performance limiting factors.
And now the question is: As devices get hotter and hotter, how are we going to be able to effectively cool these without necessarily putting an extra large heatsink on the end product—because doing that takes away the advantage of shrinking the electronics.
We’re not necessarily replacing what is used today in the cooling of electronics, but augmenting them to higher performance levels. This might include, for example, lasers or fiber-optics going to higher data rates, whether it’s CPUs operating at higher frequencies (rather than continuing to add more cores, if you have creative ways of cooling them, you can continue to increase the clock speeds) to cooling RF radio chips that otherwise may be a high point of thermal load for a board—we are applying our technology in all those areas.
EECatalog: How does thermoelectric technology play a role when an outdoor digital signage application uses Phononic technology?
Bruno, Phononic: One of the biggest knocks on using thermoelectrics in the past was: they were always on, and they consumed a lot of power. Through device technology and design capabilities that we have, we can design solutions that are not always on and not always consuming power.
We have developed ways of doing active/passive cooling, and that is using the active portion when it is needed and only when it is needed, [while at the same time] we leverage the strength of passive cooling.
You can think about it from a CPU perspective. When you are just surfing the Web or running Excel, your CPU is not utilizing its full capacity. But when you start running CAD models, rendering videos, or doing other heavy computing, and that CPU starts to crank, that is when we apply the power of our technology. We’ve structured this in an innovative way to mininimze the overhead asociated with having an active cooling element, while providing the highest level performance possible that extends beyond what you can do with a passive fan and heatsink solution.
On the question of how this innovation addresses the needs of outdoor digital signage, the cooling for this application has up to now been done with very expensive, very loud refrigeration-like compressor systems. Toxic chemicals such as Freon or [HFC] 134a would also be needed in this type of configuration.
Instead, we do the cooling with our solid-state technology and nontoxic refrigerant. And a big component of what we have at Phononic is a full electrical engineering team that designs the control systems for these solutions as well. For the outdoor digital signage application, we have done entire cooling system designs, including the power supply, the control hardware, and, the thermal sub-system.
By doing the cooling with our solid-state technology rather than with a compressor, it’s more cost-effective—not just in upfront hardware costs, but in terms of operational efficiency as well. We can directly control the energy efficiency of our solid-state solution through electronic control systems and software algorithms. This control allows us to apply only the amount of cooling power that is necessary to maintain the desired temperature. The technique of duty cycling our cooling engine in terms of power level and frequency allows us to be much more efficient than an on/off compressor solution.
EECatalog: What’s on the horizon for Phononic?
Bruno, Phononic: In the coming months, we are introducing the HEX 2.0, a small form factor CPU cooler that outperforms any fan/heatsink CPU cooler that we have seen on the market, including units that are almost 2x the size of our unit. Our performance allows us to effectively compete with much larger water-based CPU cooling solutions. Our solution does pretty darn well in the total power dissipation (TDP) with a very small unit. It is a testament to what is possible with the right combination of thermoelectrics that are designed and leveraged specifically for an application.