Nathan Rothman is a serial entrepreneur. Before founding Seattle-based Optimum Energy in 2006, he launched a number of widely disparate companies, including a bar and restaurant in New York, Valiant Yachts Corp. in Texas, and a manufacturing company that built plants around the world for Nike and Reebok. “I just have this quirky interest in how things work,” says Rothman, 63.

He lives on an island 15 minutes from Optimum Energy’s downtown Seattle headquarters. The company has opened another office in San Diego and boasts a growing labor force of 23. The entrepreneur, however, spends most of his time traveling the U.S., selling the wares of his latest company, Optimum Energy Loop technology. The software application is installed with HVAC systems to achieve estimated annual electricity savings of 30% to 50%. NREI recently spoke with Rothman about his new product.

NREI: Can you describe Optimum Energy Loop technology and how it works with buildings systems?

ROTHMAN: Optimum Energy Loop is a software application that resides in an appliance, called a controller. The controller hooks up by Ethernet to the building’s automation system. Our controller is brand agnostic so we can talk to any building automation system, be it Siemens or Johnson Controls or Honeywell or Alterton. That’s important because some of these building owners think that because they’re Siemens, no other equipment can come in there but Siemens, and the owner is generally not thrilled with that prospect of being captive to one supplier.

NREI: Why is Optimum Energy Loop technology effective?

ROTHMAN: The technology is for heating and air and ventilation plants, which are powered by large electric motors. A 30-story building, for example, will have approximately 1,000 horsepower of electric motors operating the HVAC equipment — that’s the chillers, the pumps and the fans. In summary, what we do is we vary the speed of all of those motors and we look at the plant holistically. We network everything together and then it comes into the building automation system and back to our software program, which adjusts the speed of all of the motors in the plant to run more efficiently. There’s a law in physics called the affinity law that says, if you reduce the speed of an electric motor, you reduce its consumption by a factor of three. The key to our technology is knowing how to operate the plant — all of the components together — at varying speeds. We have patents on that methodology and technology.

NREI: Is the technology suited for new chiller plants or is it primarily used for upgrades?

ROTHMAN: We can design a new plant that would have this technology as it’s built. Usually we save some money when a developer uses this technology because we can downsize and use standard equipment. If you’re building a new plant, we can help you build at an approximately 20% lower cost than a standard plant, but it’s going to operate through its entire lifecycle probably 30% to 50% better. On retrofits, 98% of what we see is just very inefficient. At a minimum, we’ll save 30%, and there are some plants where we can save as much as 60%.

NREI: What is the cost to install your system? And can you cite an example of project savings?

ROTHMAN: Symphony Towers in San Diego is a 500,000 sq. ft., high-rise office tower owned by The Irvine Co. The installation cost was approximately $350,000 to do everything. That includes our controller, the software, plus electronic speed-controlled devices for the motors. The savings with the technology is $165,000 annually on electricity bills. This technology also traditionally saves between 8% and 13% on water consumption because less water is running through the cooling tower and the use of the water is more controlled. The Irvine Co. enjoyed a two-year payback on the installation, which was our first project in 2005.

NREI: With the slower motors, does the temperature in the building remain the same?

ROTHMAN: The temperature remains as cool as the customer wants it. There is no degradation or change in temperature or comfort that the client wants.

NREI: Does the installation cost rise with the size of the building?

ROTHMAN: It depends on what equipment the building has and how big its plant is, so it is a variable and it will go up. We are currently doing some plants for the University of Texas. They have four, 20,000-ton plants and the cost of implementation there is closer to $800,000. It’s also a two-and-a-half-year payback.

NREI: How many buildings have been installed with Optimum Energy Loop technology and where are they?

ROTHMAN: Optimum Energy Loop technology is currently installed in 45 buildings, including office buildings, a hotel, a military installation, city and county facilities, life sciences buildings, data centers and others. The properties are primarily located on the West Coast, however, we’re negotiating a number of projects in New York and the Mid Atlantic.

NREI: Have any prominent structures had the technology installed?

ROTHMAN: We’re doing the California State Capital for Arnold Schwarzenegger, which is still under construction. It’s a two-year project. They have a campus of six buildings and they’re building a new central plant to cool all of these buildings. It’s an approximately $200 million project and our portion of that will be about $200,000. We’ve also completed one building for Morgan Stanley’s Glenborough Realty REIT, and they’ve asked us to assess five other buildings.

NREI: How long does installation take, and how are tenants affected during the process?

ROTHMAN: It takes two weeks to a month to install, depending on how together the contractor is. The equipment continues to run through the installation so there is no interruption of service to the occupants of the building.