Buildings: A LIVING LABORATORY
If any building should be designed to be energy efficient, it's the headquarters of the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) in Atlanta.
If any building should be designed to be energy efficient, it’s the headquarters of the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) in Atlanta.
The society’s 52,000 members are directly involved in designing the mechanical and electrical systems that go into buildings. The contribution of buildings to the whole problem of greenhouse gas emissions and hence to climate change is a large one. At the opening of ASHRAE’s newly renovated headquarters in October, the association’s president Bill Harrison pointed out that the building sector consumes 40% of the energy generated in North America, and 70% of the electricity. In fact buildings use more energy than industry (32%), and transportation (28%).
ASHRAE originated more than a century ago in 1895, merged with refrigeration engineers in 1959, and moved from New York to its present building in Atlanta, Georgia in 1981. While the majority of ASHRAE members are still in the U. S., the organization has chapters in 24 countries. There are roughly 4,500 members in Canada, many from academia and manufacturing, as well as consultants.
For decades ASHRAE has been educating people in the HVAC industry, doing research and providing building performance standards. It has an astonishing 2,500 people actively involved in various technical committees.
While energy efficiency has always been ASHRAE’s concern, it is only in the past few years as the environmental movement has gained momentum that the organization has taken on a role in promoting holistic green design.
Now ASHRAE is busy producing advanced energy design guides to show how to exceed its own 90.1-2004 standard for energy efficiency, and it is developing a green commercial building standard with the U. S. Green Building Council and IESNA.
Ultimately ASHRAE’s goal is to have all buildings operating at “net zero energy” by 2015. There are various definitions about what constitutes net zero energy buildings, but one of the simplest describes them as buildings where the energy being fed into the building is equal to the energy generated on the site.
Revamping a 1960s Building
Since 2004, ASHRAE has been working on rehabilitating its own headquarters in northeast Atlanta to become a green building showpiece. They have gutted the interior of the existing two-storey 1965 structure, but saved 90% of the original building envelope. On the side they added a 4,500-sq. ft. learning centre, making the building 31,000 sq. ft. in total. They also turned the building back-to-front. A former parking lot that faced onto busy Highway 85 is now a bioswale for soaking up stormwater run-off
The most exciting feature of the revamped headquarters is that it will be a “living laboratory.” As several speakers noted at the opening, there is a great need for real-time monitoring of building operations. Kent Peterson, past ASHRAE president and a consulting engineer with PSE Engineering of Long Beach, California, for example, said: “The biggest thing we fail in is how to benchmark the operations.” Operations are extremely important to ongoing energy efficiency, he suggested, because no matter how good the design and energy modelling are, there is no guarantee the building will be operated as intended. “As an engineer,” said Peterson, “I will say you can design as elegant a solution as you want, but the building will operate how the building operator wants it to.”
Tracking the Systems
The Atlanta building will help redress the lack of information. With metering and submetering equipment to record and display details of its interacting systems and equipment, the building provides a real-time window on a working building’s operations. There is even a weather station on the roof to relate the building’s performance to conditions outside.
Monitoring on this scale and with this detail is unprecedented for commercial buildings. The data is to be available on-line for members and ASHRAE is hoping that this rich mine of information will be used by its technical committees and other researchers.
The monitors track all the building functions: HVAC energy and electrical power, and the various systems’ on/off status, pressures and flows. Also monitored are the general interior conditions such as temperature, humidity, air flows, air quality (carbon monoxide and VOC detection), lighting levels, ambient noise, and water consumption, which is expected to be 43% less than the standard. The anticipated energy performance is 30% below ASHRAE 90.1-2004.
The building’s two levels each have different heating/cooling systems, which will make for an interesting comparison of performance.
Two Levels/Two Systems
Level 1 has a variable refrigerant volume (VRV) heat pump system, with ducted fan coil units. These VRV systems are commonly used in Europe but relatively rare in North America. They allow for modular zone-by-zone heating and cooling, with the controls shifting the load from one zone to another, making for efficiencies.
Level 2 is served by a ground-source heat pump system. It uses 27-EER two-stage variable speed pumps, with closed loop piping connecting to twelve 400-ft. deep wells below the parking lot.
The ventilation in the building is 30% above the minimum rate set by ASHRAE Standard 62. Outdoor air is pumped inside by a roof-mounted DOAS (dedicated outdoor air system), with air-to-air heat recovery, desiccant heat wheels, and MERV 13 air filters.
A 20-kW photovoltaic array on the roof generates 10% of the building’s electricity usage. All systems are integrated and controlled using direct digital controls and ASHRAE’s BACNet protocol.
Multiple other green design strategies were used on the project. Daylighting, for example, is a huge part of the lighting energy savings.
The total renovation cost $7.6 million and there were donations by many manufacturers and others. The architect was Richard Wittschiebe Hand, mechanical engineer was Johnson, Spellman, and electrical engineer was Jeffers Engineering.