Energy Efficiency Features of The ECE Building
The Electrical and Computer Engineering Building on the University of Illinois at Urbana-Champaign campus is designed to be net-zero energy, or to produce as much energy as it consumes annually. It opened in the fall of 2014, and is targeting LEED Platinum certification.
The ECE Building is meant to be a living laboratory, allowing students and faculty members to research its sustainable features. It’s also meant to be a model for net-zero energy design in the Midwest, proving you don’t have to live in a tropical climate to produce more energy than you consume within a building.
Allow Professor Phil Krein and architect Coty Sandberg from SmithGroupJJR to show you around the ECE Building with our audio tour. You’ll get an inside look at the array of features that makes the ECE Building the largest target net-zero building of its kind.
Before construction, architecture firm SmithGroupJJR considered the building’s orientation and its position on the Engineering Quad, in order to maximize energy efficiency. The architects also created custom energy-use models based on a list of must-have features in the facility. The ECE Building is designed to consume about half the energy of an average new building of the same size and type, and comes in at less than 50 percent of the national minimum energy standards.
Minimizing waste was important during the construction on the ECE Building, so contractors first built a small-scale mockup on the building site, making sure complex systems like windows, terra cotta tiles, and other features could be installed correctly, with minimal extra material. The building's contractor recycled 75 percent of the waste generated during construction.
The ECE Building was built with recycled and regionally-made materials. Regional materials are those manufactured within 500 miles. Some examples include granite from Minnesota, glass from Wisconsin, and bricks and steel from Indiana. The building's curtain walls were fabricated in in East Moline, Ill. Recycled materials included counter tops made from resin and recycled wood fiber, and metal lab cabinets made from recycled materials. The building also features steel reinforcement, structural steel, and steel decking with a high percentage of recycled materials.
About 70 percent of the building is covered in distinctive terra cotta, which is a part of a rain screen system that has a high insulating quality, to keep the building well-insulated. This reduces temperature fluctuations inside the building, and therefore, the amount of energy used for heating and cooling. The building has 16,348 terra cotta wall panels.
The ECE Building has a reflective white roof, which provides an R-30 thermal value. This feature helps prevent the heat island effect, which happens when urban areas are significantly warmer than nearby rural areas. This reflective roof material repels solar radiation on the surface, keeping the roof surface cooler, which also reduces the need to cool the building in hot summer months.
Displacement ventilation in the ECE Building’s lobby and Grainger Auditorium supplies fresh low-velocity cool air at the floor level, and recovers hot air at the ceiling. This is more efficient than traditional ventilation methods.
Chilled beams are used throughout the ECE Building as the primary way to cool it. This efficient cooling strategy pumps cold water rather than cold air through occupied spaces. It takes advantage of natural convection and the building’s fresh air ventilation system, and represents about 10 percent of the building’s energy savings.
Heat recovery chillers provide water to heat and reheat the building, and produce chilled water as a byproduct. This heat-pump system provides about 23 percent energy savings in the ECE Building, and extra chilled water is fed back into the campus’ chilled water network for storage or for use in other buildings.
The building also features heat recovery wheels, which transfer heat between incoming fresh air and outgoing air during ventilation. This saves on heating and cooling costs and results in about a 10 percent energy savings.
The ECE Building features premium, high-efficiency motors that circulate air, allow for heating and cooling, transport water and steam, and power elevators. Most of these motors use variable-speed power electronic drives that adjust them to run only as fast as necessary. A motor running at half-speed can drop its energy use by more than 80 percent. Both features save energy.
Optical equipment such as lasers, and electronic equipment in labs throughout the building generate heat as they operate. The ECE Building has a water cooling loop to support this equipment and move heat more efficiently to the outdoors, reducing loads on air conditioning systems.
Windows cover the south side of the ECE Building in order to maximize daylighting. This reduces the need to turn on lights, and allows in warmth from the sun in the winter. The windows are especially energy efficient and feature a low-E coated glazing. Windows account for 3 percent of the ECE Building’s energy savings.
The louvered metal canopy above the south hallway is designed to block hot sunlight in the summer but allow it inside during the winter. Terra cotta baguettes, located on sun shades in front of many of the ECE Building’s windows, share this purpose and offer a 5 percent energy savings. The building sports 2,500 of these baguettes. These features shade about 80 percent of the building’s windows.
The building also features efficient LED and fluorescent lights. The florescent tubes use solid-state electronics for ballasts, which operate silently and are more efficient than magnetic ballasts. The LED lights, ultimately deriving from inventions by Professor Emeritus Nick Holonyak Jr., have electronic controls to adjust to daylight conditions.
The building’s design also includes windows to interior rooms. Clerestories, which are windows along the tops of many rooms, as well as frosted glass walls and glass doors, allow diffused natural light to stream inside the building.
Occupancy sensors can be found throughout the building, and they turn off lights and reduce ventilation in spaces that aren’t being used or aren’t full. This prevents lighting rooms that are full of sunlight, and heating and cooling spaces that aren’t occupied.
Solar panels generate electricity when sunlight hits their surface. The sun’s photons give electrons enough energy to move from one type of “doped” material (n-type semiconductor) to another (p-type semiconductor). This unidirectional movement of electrons can be directed through wires, creating direct-current (DC) electricity.
The ECE Building is designed to use high-reliability integrated inverters for solar power. An inverter enables energy from solar panels to be used in the building, or by the electrical grid. It converts the panel direct current (dc) power to alternating current (ac) power. Inverters are up to 97 percent efficient.
The photovoltaic arrays, or solar panels, coming soon to the ECE Building’s roof, face south to capture the maximum amount of sunlight. They’ll generate about 11 percent of the energy the ECE Building requires, and will pair with solar panels on the nearby parking garage to make the facility net-zero energy.
The landscaping around the ECE Building features native plants, which will easily be able to survive without an irrigation system. They’re also lower-maintenance than grass or sod. It also features permeable pavers and a drainage design to control storm water around the building and store excess water underground. This reduces runoff from rainstorms and melting snow.
The ECE Building has ample bike parking on its north and south sides. Two showers in the building’s basement support employees who bike or run to work. The Illinois campus is emphasizing bicycle commuting and unveiled its campus bike plan in March 2015. A nearby bus stop encourages use of mass transportation, as well.
Many indoor features make the building energy-efficient and environmentally friendly, as well, including the Distance Learning Classroom. It’s equipped with cameras, microphones, and other special features to make it especially useful for telecommuting to conferences, meetings, or offering distance-learning classes. This will help reduce the carbon footprint of those who would otherwise travel.