Part I of this series discussed the first two trends impacting the way research buildings are designed. Those trends are the ratio of lab to lab support space and the adaptability of lab design and construction. Part II features information about the third trend, sustainable design, and the drivers fueling this movement.

Sustainable design is raising the industry’s consciousness about opportunities to reduce energy costs while enhancing the long-term viability and flexibility of facilities. Skyrocketing energy prices and the subsequent concern about mitigating the risks associated with rising costs and enhancing life cycle value are primary drivers. Sustainable design of lab facilities also improves quality of life, reflects corporate values of good environmental stewardship, and meets government and industry mandates requiring LEED certification.

“The number of projects where LEED certification is being pursued is increasing every day,” says Sandy Mendler, senior vice president and design principal of the Science and Technology Group for Hellmuth, Obata + Kassabaum Inc. (HOK) in San Francisco. “Obtaining LEED certification is especially valuable for laboratory buildings because they have such high utility bills and high construction costs related to mechanical systems.”

The Labs21 “Environmental Performance Criteria (EPC),” a rating system designed specifically to help identify sustainable design opportunities in laboratory facilities, is a valuable resource. The EPC builds upon the LEED Green Building Rating Systems and is the foundation for the new LEED Application Guide for Labs, which is currently under development.

Sustainable Design Strategies

Right Sizing

“Right sizing begins with the program to determine the distribution of space in the lab and non-lab zones of the building. Ultimately right sizing is applied to each of the systems within the building as well. This needs to be done at the outset of a project because that is when the largest gains can be made,” says Mendler.

By carefully defining the lab zone to be only as large as necessary, large savings can be gained in first cost as well as operating costs, while creating a safer building for occupants.

Right sizing goals need to be carefully balanced with the needs for flexibility over time. A concept referred to as “long life–loose fit” makes sense when considering both space requirements and mechanical systems right sizing. What is the reasonable range of expected requirements and how can additional requirements be accommodated within the same envelope? Flexible zones that are designed to accept the ebb and flow of program requirements, such as office space vs. lab space and support space vs. assigned lab space, can be helpful. Distribution systems, such as ductwork, can be designed larger to accommodate possible future growth, while equipment can be phased in as needed.

Right sizing mechanical systems is the low hanging fruit of sustainable lab design. It is important to consider diversity and power levels because not everyone works at the same time and not all of the equipment is running simultaneously. Many studies have demonstrated that equipment loads are typically overestimated and data from operating buildings confirms this. Misunderstanding peak load within the facility can compound inefficiencies because equipment operates at greatly reduced loading. If possible, existing conditions should be metered to provide a baseline for electrical energy use.

Managing Energy Costs

Controlling the energy use in a building offers the largest opportunity for sustainable lab design. An energy monitoring and control system should be developed to provide detailed information for optimal control of the heating, cooling, and mechanical systems. Where possible, high-energy producing equipment, such as freezers and coolers, should be stored in spaces where it can be efficiently cooled.

The design should also include systems that allow equipment to be shut down when not in use and energy-efficient lighting, such as direct/indirect lighting, task/ambient lighting, and the use of daylight dimming sensors. According to an occupant satisfaction survey conducted by the Center for the Built Environment (CBE), task lighting is an important component of lighting in the lab since it enables occupant control. Labs without task lighting generate more complaints from users about insufficient lighting.

Substantial savings can be realized by using separate mechanical systems to service the lab and non-lab zones. Optimizing the distribution of mechanical equipment will minimize transport loss. An analysis conducted by HOK for the University of California, Davis, shows that savings of 40 percent could be achieved simply by designing its new lab building with separate variable air volume systems in the lab and office zones of the building, versus a single constant-volume HVAC system.

“Split systems for lab and office sides of a building provide cost savings, greater operational flexibility, and better efficiency,” notes Mendler. “Office space only needs to be conditioned and ventilated when occupied, whereas lab space typically runs ventilation systems 24/7. Office mechanical systems also accept re-circulated air and have looser control requirements. This means that a building with separate systems for the lab and office side can accommodate operable windows and mixed-mode ventilation on the office side without compromising lab requirements.”

Optimizing HVAC Systems

Energy analysis can begin as soon as preliminary planning decisions have been made.

“We develop energy analysis that enables us to review energy and cost savings for a range of potential strategies,” says Mendler. “It allows the designer to see what the potential savings are and what type of investment is necessary to achieve those savings.”

Ventilation and air conditioning are the primary components of energy consumption, while internal heat loads from equipment and lighting are the top drivers of building thermal loads. The best solutions start with an analysis of ventilation requirements separate from the heating and cooling requirements. This can lead to a tremendous savings over conventional systems that provide cooling based on the spaces requiring the most cooling, while conditioning all other spaces with re-heat.

Cascading ventilation systems, radiant cooling, and heat recovery are becoming more prevalent in research facilities designed with an eye toward long-term sustainability. Cascading air systems reuse exhaust air from non-lab areas, such as offices and classrooms, as makeup air for exhaust devices in the labs.

Many lab facilities have consistent ventilation requirements and highly variable cooling requirements due to equipment loads within the labs and/or building envelope. Localized cooling using radiant panels, chilled beams, or distributed fan coil units is an effective way to respond to variations in internal loads without increasing ventilation requirements. Heat recovery systems can be used to reduce cooling, heating, humidification, and dehumidification requirements.

“Radiant cooling, which uses water as the heat transfer system, is fundamentally more efficient than air-based systems for space conditioning,” explains Mendler. ”In the case of laboratory design, radiant systems have the added benefit of decoupling space conditioning and ventilation. This enables the two requirements to be addressed separately.”

Minimum air flow requirements, typically defined by health and safety personnel, can be set and remain constant even when equipment loads demand additional cooling. The cooling can be adjusted on a zone by zone basis, thereby reducing the need to reheat, which is an inherently wasteful process. Instead, the air is cooled and then “re-cooled” as needed.

Practical Integration of Strategies

HOK recently completed the design phase for the Vet Med 3B facility to be constructed at the University of California, Davis. The 120,000-sf biomedical research facility, slated for completion in 2011, will support the School of Veterinary Medicine. HOK began working with the University during the programming phase in 2004.

Organization of the building is driven by the internal requirements to promote cross-disciplinary research and collaboration. The lab design is based on flexible, generic, open labs that locate fixed elements in the lab support zone rather than inside the open lab. A large lab support zone in the center of the building is a flexible zone that can be converted into lab space, bench space, or whatever the research dictates at any given time. Fume hoods are situated in alcoves in the support zone to allow for enhanced flexibility in the labs.

The building office zones are organized as suites that are directly adjacent to the lab. This is a new concept on a campus where all of the laboratory buildings are currently double loaded corridor environments that limit awareness of other people and their activities in the building. The office zones will facilitate collaboration while also assisting the distribution of daylight in interior office areas.

Solar orientation places laboratories on the north side of the building, which is illuminated with indirect lighting. Glazing on the south side accommodates sun control for individuals working in offices. Daylighting is provided in the open office zones and glare conditions are prevented through the integration of light shelves, clerestories, and use of translucent glazing.

A radiant cooling system has been designed for the Vet Med 3B facility. The labs at the Vet Med 3B facility require six air changes per hour. Using a radiant system means having 50 percent less duct work, one penthouse instead of two, and one 50,000 cubic feet per minute (CFM) air handling unit rather than two. The cost of the radiant panels is offset by the reduction in equipment and the elimination of a penthouse.

The ventilation system will be supplemented with active chilled beams in the open lab and lab support zones, which facilitates a better response to the heat load from these areas. Using radiant panels in the perimeter offices minimizes air supply rates on the office side so that operable windows can be provided without the need for interlocks since the air is less pressurized.

Mendler says the design of the Vet Med 3B represents a successful approach to sustainability by using an integrated collaborative team effort, an increased amount of analysis, and examining the life cycle costing of alternatives.

HOK is also working with the NOAA Pacific Regional Center in Hawaii to conduct an adaptive reuse of World War II airplane hangars. Two hangars will be linked with a new building, while another hangar is being renovated for use as marine mammal science support and warehouse space. A value study was conducted during the programming phase to determine which energy-reduction strategies would result in the most savings. A 50-percent energy-reduction strategy was developed using solar hot water, efficient lab equipment, improved glazing, radiant cooling, and natural ventilation systems, to save almost $500,000 per year in energy costs.

The design provides daylighting and views to all occupants of this deep floorplate building, while reducing energy use by more than 50 percent. In addition to using radiant cooling in the labs, passive ventilation systems are used on the office side of the building.  Wind scoops on the roof pull in fresh air, which goes across cooling coils to provide cooling and dehumidification. The air is then distributed through an under-floor plenum, and is then released up through the atrium. The combination of the wind and convective stack moves air through the office side of the building without fans. On the lab side, fans will be used, but less air flow will be required due to the radiant cooling.

Innovative design solutions require careful development however they can produce both cost savings and qualitative improvements.

“Working upfront with the architects and engineers will help you find real savings,” says Mendler. “It used to be less expensive to develop simple buildings that just use more energy, but now it is no longer less expensive and we are seeing a shift in priorities. People may call it environmental thinking, but it’s actually logical economic thinking.”

By Tracy Carbasho

We welcome your Questions and Comments

Copyright 2008 Tradeline Inc.
All Rights Reserved
ISSN: 1096-4894