A New School of SystEMS Controls
To upgrade all the university's hvac systems at one time, however, would be extremely expensive. So a decision was made in the late 1990s to phase in new equipment and systems through performance contracting and as capital funds became available.
Slowly but surely, change is taking place at the university. A new central steam plant, submetering system, and EMS are now in place, as well as all-new lighting and plumbing fixtures. The effect of these new systems on the utility bills has been tremendous, but a bigger bonus may be that it is now possible to have much more control over most of the hvac systems on campus.
Lights and Meters FirstLike many universities with older buildings, CUA has always done what it could at the moment to keep its systems operating as well as possible. When Robert Burhenn came aboard 10 years ago as director of energy and utilities management, he saw that a comprehensive plan was needed to bring the systems up to date.
"We started looking around at different ways we could do things, and we looked at performance contracting. We talked with different groups, and we met Custom Energy (a national energy services company whose corporate headquarters is in Overland Park, KS). They presented a phased-in approach to performance contracting, so we didn't have to bite the whole thing off in one chunk, which a lot of companies want to do," says Burhenn.
Phase 1, which was finished in 1999, consisted of an energy-efficient lighting retrofit throughout 42 buildings on campus, representing over 2 million sq ft of building area. The lighting portion alone is estimated to save CUA over $140,000 annually. "We didn't do the one-for-one changeouts like a lot of people do. We changed some fixtures at the same time. It hurts payback when you do that because it's running up your initial costs," notes Burhenn.
A utility submetering system was also installed during Phase 1. Each building now has its own meter in order to measure actual electricity and steam usage. This will help Burhenn and his staff determine savings opportunities for future phases and to establish a load profile for individual buildings.
Burhenn is very excited about this particular part of the project, because before Phase 1, he only had one meter for the whole campus. He had no idea what was happening in each individual building. Now he can use that information to identify energy-hungry buildings and start looking for ways to save energy in the future.
Next Up, BoilersPhase 2 started shortly after Phase 1 ended, and it originally consisted of mechanical upgrades to five buildings as well as replacing the central steam plant, which provided heat to over 50 buildings on campus. The steam plant contained four 750-hp vertical watertube boilers that were approximately 50 years old.
However, it was determined that the whole project was too expensive, so something had to go. "This is where the phased-in approach was nice. Instead, I went through the shopping list of the proposal and started cutting things out. What we ended up with was just the central boiler plant, which was a $1.2 million project," says Burhenn.
What really helped CUA with this project was its insurance provider, of all things. The insurance company inspected CUA's boilers and refused to insure them for the upcoming season unless they were completely overhauled. It would have cost approximately $400,000 to rebuild two of the boilers, then in four years the other two boilers would have to be rebuilt.
That helped clinch the deal, and Phase 2 was underway. Before the new boilers could be installed, it was first necessary to remove the asbestos, demolish the old boilers, and take off part of the roof of the boiler room. Having the roof gone made it much easier to install the new boilers, as a crane was used to place the boilers rather than trying to squeeze them through little doors.
Only two of the old boilers had to be removed, as the four new, Kewanee three-pass, wetback, firetube boilers were so much smaller, they took up a lot less space. The other two old boilers were simply abandoned in place.
Because of higher efficiencies, the new boilers are only 500 hp each, and right now CUA only needs to run two of the four boilers. A new student union building is currently being built, and Burhenn estimates that the third boiler may then be needed on really cold days.
"All the piping in the boiler plant was changed completely," says Pete Ewart, business development manager, Custom Energy (Columbia, MD). "CUA had gone through a distribution system piping replacement program over the last several years where they had replaced problematic sections of piping through capital dollars."
Once the new boilers were in place, a boiler control automation system was installed, and renovations were made to the plant electrical systems. In addition, boiler plant operations offices were constructed and there were upgrades made to the boiler support systems. According to Burhenn, the project went almost without a hitch.
"We have a Title 5 Clean Air permit, so we had to go through the permitting process during the same time. Here we were doing acceptance tests after we were up online heating the campus, running data collection for the permit. But we had no trouble passing," says Burhenn. Indeed, emission levels for CO and NOx have been significantly reduced for the plant in accordance with District of Columbia regulations.
The project started in April 1999, and the system was up and ready to go by that October. It is estimated that this phase of the project is reaping $127,000/year in energy savings and a total of $220,000 in capital cost avoidance.
Analyze ThisPhase 3 involved a study in which Custom Energy went completely through the campus and looked for other improvements that could be made. Those suggested improvements included water conservation, steam trap replacements, electric peak shaving capabilities, and EMS upgrades.
"I did not have a centralized energy management system for the campus. I had about 11 buildings online and the others belonged in the Smithsonian," jokes Burhenn. "Things were running 24 hours a day. You'd turn on a chiller in the spring and turn it off in the fall and other than that it would run continuously. You'd put the heat on in the fall and turn it off in the summer. Outside air temperature didn't matter. Very inefficient operations."
This study also involved looking at the big picture; basically determining how buildings could be grouped together either by commonality of use or diversity of use and proximity. This was done primarily for the cooling systems. The campus has no central chilled water plant and uses a variety of different types of cooling systems. (As Burhenn notes, they have everything from thermal storage to window units to just opening the window a little wider.)
Burhenn would ideally like to see a number of buildings tied together with self-contained cooling systems. An example of this involves using excess cooling capacity from a chiller in an administration building for the Hartke Theater building that's right next door. Given that administration personnel go home at 5:00 p.m. and the theater really doesn't get going until then, it makes sense to interconnect the buildings so it's not necessary to have full capacity in either building.
Creating a science complex was another idea that came out of the study. "Right now we have wet labs in four different buildings that are all sort of connected. Let's take one of those buildings, make it all high-tech labs and share lab people, then there's one building out of four that I have to run 365/24 instead of four buildings that we're running 365/24," notes Burhenn.
All these possibilities are 5 to 10 years off, notes Burhenn, but the main goal of the study was to include the utility infrastructure analysis in CUA's 10-year master plan, which was presented to the District of Columbia.
Save The WaterPhase 4 began during summer 2000 and involved some of the items uncovered during the Phase 3 analysis, including water conservation, steam trap replacement, some mechanical upgrades to buildings, and a new EMS.
The water efficiency work basically involved the bathrooms, as they are the primary source of water use in buildings. "When you have old buildings like Catholic does, you'll have old plumbing fixtures like toilets and urinals that use a lot of water. New equipment is available that consumes significantly less water per flush, so it's straight math," says Ewart.
CUA has fairly high water and sewer rates, so it was deemed necessary to replace toilets, rebuild urinal flush valves, replace aerators on sinks, and replace shower heads. An added benefit, notes Ewart, is that the university's students are particularly sensitive to environmental issues such as water conservation. In a sense, it's a good marketing tool for CUA to show that it's interested in conserving resources.
A complete steam trap replacement was next on the list. "Most data from manufacturers suggest that traps typically fail after about 7 years in operation," says Ewart. "When a trap fails, it's not possible to recover condensate effectively, so you lose energy efficiency and interrupt the proper flow of steam, which causes heating problems."
Custom Energy used fixed orifice traps, which don't rely on moving mechanical components the way conventional traps do, so they don't require maintenance and they have a longer life cycle. Due to the tremendous job of the subcontractor, notes Ewart, the steam trap replacement project went very smoothly.
The mechanical system enhancements of Phase 4 largely involved three buildings. In one building, electric reheat coils were replaced with hot water coils on several air handlers and vfd's were placed on secondary loop pumps.
In the second building - Ward Hall, the music building - the steam heating system was replaced with a new heat exchanger and hot water baseboard heaters. Even though this improved comfort, it technically was not an energy improvement. The system was changed because the steam radiators would ping and bang, often during a student's graduate recital. That was very distracting to the students and resulted in a lot of complaints.
The third building, which contained laboratories and classrooms, had a very large built-up air handler - two supply fans, two outside air makeup fans, two return fans, all of which ranged between 40 and 75 hp - with inlet vanes that were pneumatically controlled. The pneumatic controls had failed, so these needed to be repaired or replaced, and vfd's were installed.
The EMS EmergesThe EMS is really the pièce de résistance of the project. Ewart notes that how the EMS was installed depended on the energy savings that were available at that particular building. "In a few buildings we did complete energy management, where we were doing temperature control as well as starting and stopping major equipment. In a number of the buildings we're doing some basic monitoring and just starting and stopping the equipment," says Ewart.
All that information is sent to an operator workstation at the power plant where Burhenn and his staff work. It is connected to their campus-wide wide area network, so everything operates in real time as a single system as opposed to the old way of dial-up.
By diving head first into the EMS, Burhenn has found out some very interesting information. For example, by attending one of the programming classes, he discovered that if he installs flowmeters in the hot water and chilled water of some of his buildings, he can get direct calculations in Btuh.
"That gives me a true cooling or heating load of that building, which means then I can look at things like the envelope. And when I have true numbers of what it actually costs to heat or cool that building in Btuh, I can start looking at payback on those things, which is usually very hard to do," says Burhenn.
The EMS is also going to allow him to look into peak shaving, which he hopes to have up and running this summer. "Through my energy management system, we're going to start looking at the peak electric load and working through different scenarios to try and actively shave the peak when it starts getting close to one that I've set. Whether it's running an emergency generator, transferring a building load onto it, or rotating some of the window air conditioners around in 10 or 15 minute intervals. It's going to be interesting," notes Burhenn.
Burhenn chose to continue with the Invensys EMS, as he had used it in some of the other buildings on campus. "It's very user friendly, and it wasn't completely new. That helped us, because I'd already set up standards with them, like how I want the graphics to look or how I want the addressable reset schedules. They know our standards, and that's all addressable without having to get into real programming," says Burhenn.
Installing the EMS sometimes proved to be interesting, because it was necessary to try and automate equipment that had been run manually for a number of years. "The guys knew exactly where the valve had to be set and it worked. All of a sudden we automate it, and you find all these little secrets of, well, this damper hasn't worked in 10 years, and that valve has been locked in this position since I don't know when, and that diaphragm has been blowing out for 5 years," says Burhenn.
It took a little more time to work out those glitches than he originally anticipated, but Burhenn says it was all worthwhile. "We're doing exceptionally well. Right now, I am looking at giving back to the budget about $530,000. We're up to about $460,000 on the principal and interest, so we're looking at a $900,000 savings this year in utilities." (The total performance contract with Custom Energy was worth over $2.6 million and will provide CUA with a simple payback of 6.6 years.)
While Phase 5 has not yet been planned, it is almost certain that with Burhenn at the helm, it will probably occur sooner rather than later. ES