Enron Building’s Efficiency Earns an Energy Star
The first surprise might be that this state-of-the-art scenario begins with lighting. A team of young engineers with a definite gleam in their eyes saw problems and heard complaints about lighting in several areas. This lead to an in-depth look at hvac systems.
Incidentally, Enron was the first building here to do a complete Green Light upgrade, says Stephen B. Woods, director of facilities operation, Enron Energy Services. “In a building this size, we anticipated significant savings.”
Also leading the team were Stephen B. Wurzel, vice president, project management, and Harry W. Grubbs, facilities coordinator, both of Enron Energy Services.
It Started with LightingThe initial project included converting from T-12 bulbs with magnetic ballasts to T-8 bulbs with electronic ballasts. Where possible, incandescents and other spots were replaced with compact fluorescents. Other options weren’t available then.
Woods comments that “In 1992, we became the first corporate facility in Houston to be recognized as a Green Lights partner.”
The next step in plans for this built-on-spec building: a total energy-efficiency upgrade.
However, this was accomplished in smaller increments, as plans were made and then put on the back burner.
There were concerns about buying chilled water from another plant. Says Woods, “We were running as efficiently as we could within limits imposed by their operation.
“To get control of pressures in our building, we added two variable-speed drives on two pumps at half speed. Running two pumps at half speed is also more efficient than running one at full speed.
“That gave us flexibility to control the differential across our building. This was essential to our next project: cold deck reset.”
Although savings can result from reducing pump speed, combining that change with complete system integration is more effective.
Originally, the team looked at putting variable-speed drives on each of 110 air handlers. Fan motors were 7.5 to 15 hp. However, the team didn’t look forward to offering management variable-speed drive paybacks in a nine- to 10-year range. The decision went against making the change at that time.
“There was a big difference between our winter and summer loads, also our day and evening loads,” Woods says. In summer, one pump and sometimes a second ran at full speed. Since the system was set up for a mean average, it was pretty inefficient. “We also did not do our next big project, the cold deck temperature reset.”
Focus On BasWhat grabbed the team’s attention was the building automation system (bas); it was hard to program and didn’t allow needed flexibility.
After research, the team opted for a building automation system produced by Computrols, New Orleans, LA. Ease of installation and programming, the way the system looks and feels, and streamlined training time were features that worked here.
“You needn’t go to school for 80 hours to use Computrols,” Woods says. After 15 minutes of training, someone can be programming. Keeping automation system technicians on-site had cost $100,000 annually, so ease of use was critical.
The team encountered few problems with the project. Delivery for some components was delayed as long as a month. Says Grubbs, “Even that was acceptable, because we got panels that were flexible and programmable.”
Says Woods, “We understood the product was being upgraded, and the manufacturer wanted us to have the latest components available.” Enron’s results could be something of a showcase for Computrols.
“We installed the system ourselves and immediately started getting control of our cold deck reset. We could realize the most savings by reducing pump speeds and varying cold deck setpoints from 55Â° to 65Â°F.”
Says Woods, “We vary the reset based on optimum start, outside air temperature, or something else. It’s not rocket science.
“With Computrols and cold deck resets in place, we could see what was going on in our system and further reduce differential pressure, which we had been measuring, but not at the optimum location.
“Closing off two-way valves at the air handlers would create severe pressure problems unless we could make the variable-speed drives and cold deck resets work together.
“We moved pressure sampling to the upper part of the loop. At the bottom of the loop, we could vary pump speed by 30% to 40% without changing differential pressure more than a pound or two.
“At the top of the loop, varying the speed 30% to 40% would change the pressure, sometimes as much as 10 to 15 lb. Also, we could monitor more closely what we were doing and what we needed to do to satisfy our chilled water requirements.
“Doing so, you realize that even a slight change in one piece affects the operation of another piece. With this automation system and its speed, we can tweak the system. We can literally change logic six times a day until we get it exactly where we want it.”
Comfort and PaybackSays Grubbs, “Even with these energy-saving measures, tenant comfort has not been compromised. In fact, with most of the components in place, hot and cold temperature calls dropped by at least 80%.” (You understand that some people will never be fully comfortable.)
Says Woods, “In part the drop in calls occurred because in the past we accepted a 4Â° swing in building temperature. Today our standard is plus or minus 1Â°. We’ve come very close to that.
“Payback on the system was less than a year,” he continues. “In fact, we realized the majority of that saving in the first six months.” After only nine months, the utility savings totaled $100,000.
Efficiency Certified Through AwardsIn 1998, after the building automation system was installed, BOMA (Building Owners and Managers Association) awarded Enron the International Office Building of the Year Corporate Facility Award, based, in part, on efficiency of operation.
Says Woods, “Through our Green Lights partnership, we found out about the Energy Star label. We didn’t look at it seriously until we became more energy efficient.”
To qualify, the re-energized building would have to meet EPA’s criteria and provide one year of actual billing data. In both cases the building performed well.
Anyone can buy and install components. However, says Woods, “We believe in a truly integrated solution to increasing energy efficiency. We can change differential pressure by tenths of a point and get the operation exactly where we need it.
“With most other systems, this opportunity just doesn’t exist. That’s what sets us apart; that’s what works for us.”
As a result, Enron received the EPA’s Energy Star Label, a mark of excellence conferred on top-performing buildings either designed or renovated to increase energy efficiency and reduce harmful air emissions.
Enron is one of some 100 buildings nationwide which have reduced energy use by 30% on average.
Sidebar: News You Can Use From the EPAThe EPA’s Energy Star Label is an opportunity that’s already happened to some of your peers, and with a little effort it could lead to a burgeoning bottom line for you.
Here’s news your fiercest competitors won’t share.
Fortunately, the EPA will share it. And the agency tries to simplify things by posting information on the Internet about the label and buildings which have qualified, as well as the official benchmarking tool.
Mechanical contractors and others in the hvac industry can find information by keying in to a special component of the EPA website, designed for energy product and service providers.
From www.EPA.gov/buildings, tap into ASAP (allied services and products). Kate Lewis, EPA’s director of communications for the Energy Star Program, says, “We’ve created this special module to help members of the hvac industry. And they do get answers!”
The benchmarking tool evaluates building energy performance on a 0 to 100 scale, using detailed data on physical attributes, operating characteristics, and monthly energy consumption. To qualify, the building must score 75 or higher.
Also available at this website is a directory of qualified industry members. To qualify, use the website and provide information as requested about your organization. A list of qualified buildings is included, enabling the contractor in Cleveland, OH, to check out recognized buildings in his service area and target others whose management may be receptive to long-term energy savings.
If interested, use e-mail to submit additional questions (those not answered on the website) and receive a response. Just get your questions together and contact email@example.com.
Finally, if necessary, you may call Energy Star at 888-782-7937. What could be easier? “The EPA began its foray into energy efficiency with the Green Lights Program,” says Lewis. “Green Lights is now a part of Energy Star, part of a whole-building upgrade. But lighting upgrades are still a good place to start.
“We want owners to decrease energy use to the greatest extent possible, as long as it does not compromise the quality of their interiors.” Some owners are still slow to approve.
“What I think is actually helping surmount that challenge is the industry itself. In some cases, providers are flexible with financing arrangements. So we’re starting to see some movement there.
“Small buildings are not labeled as Energy Star, but receive support tailored specifically toward them, obviously with an eye toward cost control. With improvement, they gain efficiency and cost control,” says Lewis.
In an industry where the building is the product, such as a motel or bed and breakfast, the recognition attracts a growing number of customers sensitive to environmental problems.
Sidebar: Psst, Residential New Construction ContractorsWant a piece of the action?
With competition from many directions trying to muscle in on your business and the shortage of trained technicians rearing its head on the other side of the fence, you’re probably ready for some good news.
The Energy Star homes program allows hvac contractors, along with builders and suppliers, to have a piece of the action. Only new homes are potentially eligible for this award.
Builders and contractors, as partners in the program, would agree to construct new homes that use at least 30% less energy for home cooling and water heating than homes based on the Model Energy Code.
Consumers who buy these homes gain comfort, save on their utility bills, and foster good feelings about their contribution to a healthy environment. Energy savings typically exceed the small monthly mortgage cost of the extra energy features.