“Some building systems are born smart, some achieve smartness and some have smartness thrust upon them,” Shakespeare might have said if he were a 21st century mechanical engineer or facility manager working in Chicago. Taking center-stage in the ambitious Midwest city is a smart building retrofit worthy of applause.
Completed in 1990, 311 South Wacker Drive is an iconic post-modern 65-story skyscraper. At 961 feet tall, it is the seventh tallest building in Chicago and the 21st tallest in the US. Its heating, ventilation and air-conditioning systems (HVAC), however, were less impressive until the building’s owners, Zeller Realty Group, found an innovative way to drag the outdated building into the smart world.
Like many buildings of its generation, 311 South Wacker’s HVAC system is made up of mechanically operated pneumatic thermostats. This pre-digital system utilizes an old-fashioned pressure release, provides no centralized control function and creates absolutely no data at all.
“The problem with the existing pneumatic thermostats in 311 S. Wacker and other buildings like it, is that they rely entirely on mechanical compressed air action to operate,” says Harry Sim, CEO of California-based Cypress Envirosystems, who worked with Zeller on the retrofit.
“All the things we take for granted in modern, smart buildings – fault detection, optimization, the smart grid, sensor networks – none of that is possible with these pneumatic thermostats because they’re all mechanical compressed air,” added Sim, who estimates that roughly 70% to 80% of buildings in downtown Chicago have the same kind of pneumatic HVAC controls.
Seeking the benefits of smartness, most similar projects would have begun the costly, disruptive and arduous process of ripping out the obsolete equipment before installing a state-of-the-art HVAC system. Zeller and Cypress, however, had other ideas.
Embarking on what it calls the “smartest energy efficiency retrofit in Chicago,” Zeller decided to update the archaic yet reliable analog equipment already present. Instead of a complete overhaul, they substituted the mechanical pneumatic thermostats for smarter versions - essentially still a traditional pneumatic thermostat but with the addition of a pressure sensor, a temperature sensor and an antenna. Begging the question, if you put lipstick on a pig, isn’t it still just a pig?
Instead of creating a truly intelligent system Zeller was basically applying a layer of smart on what was, for all intents and purposes, a “dumb” system – a virtual thumb for pressing a button remotely.
Nevertheless, in doing so, Zeller was able to achieve energy savings of 30% from the HVAC efficiency alone. The whole retrofit cost less than $900,000 dollars, a small fraction of a full overhaul, and $400,000 of that was provided by the Smart Ideas energy-efficiency program of local utility ComEd. Considering the rebate, the project covered its costs in less than two years.
Furthermore, the wireless pneumatic thermostats can fundamentally still function on the physics of mechanical compressed air, the basis of the original design. Meaning the system would be able to retain basic temperature-regulating functionality even if the batteries and electronics were to fail completely.
“Are we happy? Absolutely,” says Consolato Gattuso, senior vice president of technical operations at Zeller. “[The reduction] does a lot in real estate. It makes you more competitive. You have happier tenants. What’s important is that the 30 percent savings was without any tenant complaint. We didn’t freeze them out – or make it so hot that they were uncomfortable – to make that savings happen.”
The 30% energy savings is just the start, the system now produces masses of data that feeds back into IntelliCommand, a smart-building monitoring system developed by Chicago-based real-estate services firm JLL. This not only means data can be analyzed to generate greater efficiency for 311 S. Wacker, but that they now have an unprecedented information stream to help them further develop smart retrofits for these common and highly-inefficient building systems.
Some of the credit should also go to the smart city of Chicago. In 2013, city legislators passed an ordinance that requires commercial, institutional, and residential buildings larger than 50,000 square feet to track and report all energy use. The green pressure such public exposure generates forces large buildings to invest in efficiency, or in this case, it helped inspire an innovative low-cost solution. The policy and the technology should provide encouragement to other cities and large buildings around the world.
So will this inspire a counter-revolution of smart devices that incorporate the accuracy of modern digital devices with the rugged reliability of our legacy systems?
Well, no, probably not, but it does encourage us to think outside the box and proves that in some cases smartness can be effectively thrust upon a dumb system. Maybe the value of putting lipstick on a pig depends on the quality of the lipstick, and the size of the pig.
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