Pictures of the Future      Spring 2008

Buildings with Brains

High energy consumption in buildings is not only wasteful, but relatively easy to overcome. A growing focus on automation is helping to achieve substantial savings in new office high-rises, swimming pools, and schools.

^{Austria’s Feldkirch hospital—as well as a clinic in Aalst, Belgium (inset) keep their CO₂ emissions to a minimum thanks to a package of energy-saving measures}

Just about everyone’s heard of bosses who turn down the heat and turn off lights. These days, however, energy conservation is more than just a question of pinching pennies; in view of climate change, it’s become an urgent necessity. What’s more, it also pays significant financial dividends. For the past 30 years or so, most big buildings have been equipped with automation systems for monitoring and regulating a variety of complex equipment, ranging from heating to fire alarms and elevators.

The potential for savings here is enormous, as buildings account for around 40 % of total energy consumption and 21 % of greenhouse gas emissions worldwide (see Pictures of the Future, Spring 2007, Facts and Forecasts – Environment). So it’s not surprising that the European Union has issued a directive governing overall energy efficiency in buildings (see box). The energy conservation wave has also hit the U.S., where Siemens Building Technologies (BT) is a member of the Clinton Climate Initiative (CCI). The initiative’s Energy Efficiency Building Retrofit Program is designed to make private and public building owners more aware of the need to modernize their building systems. "With its global presence, broad range of environmentally friendly building systems technology, and extensive expertise, Siemens is ideally suited to support the CCI," says Bob Dixon, vice president of BT in the U.S., who is responsible for BT’s worldwide energy and environment activities.

Minor Improvements, Major Savings. In recent years BT has modernized automation systems in approximately 1,500 buildings in the U.S. For example, in Cleveland, Ohio, Siemens has renovated more than 200 apartments and buildings belonging to the Cuyahoga Metropolitan Housing Authority (CMHA). Replacing windows, plumbing fittings and lighting systems, and making use of building automation systems will save the CMHA around $50 million over the next 12 years. Associated energy savings will add up to almost 8,400 t of CO₂ and more than 250,000 barrels of crude oil.

Although regulatory requirements often set the stage for energy conservation, rising energy prices are the most fundamental trigger. Building managers today are truly amazed by how little it takes to reduce energy and operating costs by as much as 20 %.

"Operators of big buildings generally don’t realize how much energy they’re wasting," says Thomas Baum, head of Energy Optimization Services at BT. "In order to understand, they need comparative data." Siemens develops this information with the help of a site visit and the public data on similar buildings. A Web-based energy management program is used to process the data from different locations and years to make it comparable. "This tool can, for example, reveal that a department store’s outlet in Cologne uses much more energy than its counterpart in Munich. Then, with support from Siemens’ energy experts, an analysis can identify the causes of the discrepancy," Baum explains.

Regardless of their age, many buildings are operated with systems that are not optimally set up and not matched to one another at all. "That’s not surprising," says Wolfgang Hass, who is responsible for Development and Innovation at BT, "since the manner in which individual rooms are used after construction of a building has been completed often deviates from what was originally planned. Heating, ventilation, and air conditioning systems have not been adapted accordingly."

Climate-Friendly Clinic. According to Hass, until recently, little attention was paid to the optimal adjustment of systems after a building was handed over to the operator. "Building operators usually didn’t budget for that type of work." Today, Hass says, a "second commissioning" of a building can generate major savings. Siemens offers such second commissioning worldwide in the form of its Energy Optimization Services (EOS) package.

Energy expert Frederiek Demeyer of BT in Belgium explains how this works in an ideal case, using as an example a clinic at a general hospital that was opened in the city of Aalst, Belgium in 2000. "The clinic building and its windows were well insulated, and the heating system appeared to have the proper settings," says Demeyer, describing his first impression. Nevertheless, the clinic’s technical director said employees and patients often complained that it was too warm or too cold, and the hospital’s administration felt operating costs were too high.

Demeyer analyzed one north-facing and one south-facing room on each of the clinic’s three floors and in the basement—during the day and at night, and in all four seasons. His measurements revealed that the heat was turned up high on spring and fall mornings, but many of the rooms were already being cooled down again by midday. Demeyer also measured the effect medical equipment had on room temperature, and then wrote algorithms for the climate control system to ensure it would adjust climate in accordance with a given room’s use and the direction it faced. "You can’t do that with a standard program, of course; you have to tailor it to the building and setup in question," says Demeyer, who also teaches Energy Management and Automation at the University College of West Flanders. Demeyer also recalibrated the air conditioning unit’s control system, which previously operated using a predefined water temperature setting with no regard to the external temperature. That system is now linked to outside temperature sensors. The water used by the air conditioning system for cooling purposes had previously always had a temperature of 6 °C. But that was unnecessary in bad weather. Now the temperature of the cooling water is automatically set to 10 °C on cold days, for example. "We save 3 % on energy costs for every degree," says Demeyer.

The "human factor" also played a big role in the Aalst project, as all users used to be able to manually raise or lower the temperature in any room by 3 °C. "The temperature setting then stayed the same until it was changed by someone else," explains Demeyer, who cut the alteration range in half to 1.5 °C, but without changing the scale information on the controllers. He also programmed all controllers to reset themselves to the average temperature at midnight. The result was that everyone felt more comfortable, and there were fewer complaints than before. In the end, all these measures reduced energy consumption by more than 30 %—and CO₂ emissions by more than 920 t per year. In addition, the costs of the energy analysis and customized system programming were amortized in less than a year without need for any new equipment.

Investments that Pay for Themselves. A second commissioning isn’t enough for older buildings, however. That’s because the equipment in such buildings isn’t efficient enough to operate economically. Replacing the equipment requires a high level of initial investment—but this finances itself through energy-performance contracting, in which the costs are more than covered by the savings achieved. Take, for example, a customer with annual energy costs of €200,000. Siemens guarantees a 25-percent saving, i.e. €50,000 per year. Over the term of a ten-year contract, that makes €500,000 available for optimization measures and accompanying energy services—without the customer having to pay a cent. Siemens has already implemented nearly 2,000 such contracts in more than 6,500 buildings around the world, and has won several awards for its work. The European Energy Service Initiative, for example, named the modernization project for the Brigittenau indoor swimming pool in Vienna, Austria, the Best European Energy Service Project in 2007.

Built in 1983, Brigittenau now benefits from annual savings of more than €200,000 on heating and water costs, and approximately 600 t less CO₂ emissions per year—savings of 45 and 60 % respectively. All of this required replacing equipment, including the water treatment unit, the ventilation systems, the fixtures, and the lighting systems. Siemens also installed a new building management system that monitors and regulates all the facilities and equipment.

"We’ve substantially reduced heat losses and cut water use by almost half," says Oskar Böck of BT in Vienna. The facility’s building management system monitors all processes, ensuring that waste is avoided. "The pool attendant used to filter the water according to his or her own feeling, then check to see if it was clean enough," Böck explains. "Now there are sensors that measure water purity, and filtering—and associated data management—are performed automatically." The water and air temperatures, as well as the ventilation process, are continually monitored and controlled. In addition, a new solar power unit can be used to heat pool or shower water as needed. "As with all swimming pools in Vienna, the base temperature is achieved using district heating," says Böck. The result is heat savings of 66 % and a 45-percent reduction in water consumption.

Surplus Savings. Brigittenau’s energy performance contracting will run for ten years, and the associated investment of €1.4 million will be paid off through the guaranteed annual savings of €200,000. "Our savings actually exceed the guaranteed figure, and we’re currently talking to the technical director of the Vienna public swimming pools about how to invest the extra money in additional energy-saving equipment and systems," says Böck. "So energy-performance contracting is a way to enable urgently needed investment, especially in the public sector." To date, Siemens has modernized 24 swimming pools throughout Europe within the framework of such contracts (see Financing).

"Buildings are a key factor in production today," says Hass. "And like any other production factor, they also need to deliver maximum productivity." With this in mind, Hass is confident that additional investment in building technology and energy services will soon become the norm for all large public and private buildings.
                                                                                                            Katrin Nikolaus