affordable solutions. We need to use global expertise to meet local needs. Applications When it comes to technology, we need to keep the Our control systems are too comusers in mind. We need to keep it simple. Do we replicated. I remember 30 years ago when I became involved with a wonderful project. I was so proud ally need those latest technologies in all cases? Do of it—a triple cascade system that took water from 45°F to 200°F. It we need complicated buildings? had three different machines with different refrigerants. Wonderful, but the controls were so complicated that only two people in the world—I happened to be one of them—could start the machines. It was that people have installed that are running at a constant speed great technology, but it was too difficult to operate, and I had a on compressors and fans. Why wouldn’t you have them control lot of air miles before it was over. Those are exactly the types the speed to match the demand? It’s that simple. If you’re going of solutions that we do not need. to install a VFD, make sure you design the system to match the Kirk Mescher, an incoming ASHRAE director-at-large, demand and train the operators to maintain the design. It seems tells me there are geothermal units over-pumping with too fundamental, but it does not happen often enough. much water flow. Why is that? Because the controls are too We have complicated thermostats. How many of you need to complicated and the operators don’t understand the impact of program thermostats for relatives or friends? It is important that the settings they use. We have variable frequency drives (VFDs) we develop interfaces for controls that can be used by a typical Need caption. www.info.hotims.com/41642-21 www.info.hotims.com/41642-43 18 ASHRAE Journal August 2012