How does a research facility or biotech company with older laboratories update existing facilities to current energy conservation standards?

When building a new facility, incorporating green strategies is fairly straightforward, but the goal for most institutions is to update existing structures. Essentially, how can an older laboratory be improved to meet better energy consumption and green building standards?

Why older laboratories consume so much energy

Laboratories and other science facilities are among the most energy consuming of building types. In particular, these facilities are large consumers of heating and cooling energy, mainly because air that is heated or cooled cannot be recycled, due to the potentially hazardous nature of some of the materials used. The typical older research laboratory that uses chemicals or biological materials is designed to provide generally between 10 and 20 air changes per hour, compared to about three changes per hour for a typical office space. Heating and cooling this amount of fresh air can be wasteful and costly. There are significant savings to be gained if you can find ways to reduce this waste.

Balancing safety and energy usage

Creating green labs means selecting a method that achieves the desired balance between safety and reduced energy usage. Building codes and good practice mandate that the heating, ventilation, and air-conditioning (HVAC) unit provides 100 percent of makeup air (new air) to ensure safe conditions for occupants. The most efficient means of energy conservation entails reducing the amount of air used and recovering heating and cooling energy while maintaining indoor air quality.

Most efficient green methods

Retrofitting labs and science facilities to be more energy efficient involves a number of strategies to reduce energy consumption. The most effective incorporate reduction of unnecessarily high air change rates (ventilation), airflow reduction strategies for hoods, updating mechanical systems with better controls, and heat recovery for the supply and exhaust air systems.

Reduce airflow rate

One source of major energy draw in laboratories is the various types of air hoods, which are devices critical to protecting the health and safety of lab workers while they work with chemicals and/or biological materials. Hoods create a sufficient airflow and a contained pathway to protect the personnel working within them. It requires a substantial amount of air to dilute the hazardous materials enough to create safe working conditions. Unfortunately, reconditioning this air can add thousands of dollars per hood to an institution’s yearly energy bill.

Reducing air requirements involves several methods, but the most effective is through hood sash management air reduction. Others include replacing outdated fume hoods with either low-flow hoods or variable air volume (VAV) hood controls. Each of these reduces the amount of air exhausted from fume hoods. Sash management techniques include installing fume hood sash restrictors and occupancy and proximity sensors. The VAV control reduces airflow in relation to the fume hood’s open sash area. Existing auxiliary fume hoods can also be retrofitted with controls that limit the airflow while still protecting the hood workers.

Mechanical systems for older laboratories and other science facilities have outdoor air changes of up to 10 to 20 times per hour. From a safety perspective, there are many cases in which the mechanical systems and ventilation rates are overdesigned. Check current codes and update master specifications that may be outdated. Often the amount of ventilation can be reduced, resulting in energy savings.

Energy recovery systems

Heating and cooling the large amount of air utilized through frequent air changes consumes enormous amounts of energy. Installing energy recovery systems can substantially reduce the cost and use of energy in laboratories. These systems recycle thermal energy from exhaust air by recovering heat and cooling from the hood and general exhaust and transferring it back into the air intake system for redistribution into the building. Thus a portion of the exhaust heat and cooling is recovered and used again in the building, consequently saving significant energy and money.

There are many types of heat recovery systems that can be utilized in building retrofits. A heat recovery system is essentially a heat exchanger. It obtains ambient heat or cooling from the exhaust before it is discharged. This heat is then transferred to the intake or makeup air side of the building’s HVAC system. As a result, the amount of energy needed to preheat or cool the air is reduced considerably.

Popular heat air-to-air recovery systems include the rotary enthalpy wheel, fixed plate, heat pipe, and run around loop. With the right application, these systems can be cost-effective. The systems described below can both preheat ventilation air in the winter and pre-cool ventilation air in the summer.

Choosing the right system depends on a variety of factors, including the building’s existing mechanical system, location of fresh air and exhaust, and climate. For laboratories with a significant amount of exhaust that is separated from the actual hood exhaust, the enthalpy wheel may be an option on the general exhaust side. Today, however, more and more owners are using enthalpy exhaust recovery on hood systems as well. Enthalpy wheels transfer energy between the exhaust air and the incoming outside air. The supply and exhaust streams must be located next to each other. The installation cost is reasonably low. In colder climates, the enthalpy wheel is the most efficient heat recovery method, but it can be the most difficult to retrofit into an existing lab building, because it is a large component that requires space (height) and proximity to the fresh air supply and the exhaust air.

For laboratories with fume hood and biosafety cabinet exhaust, the heat pipe and run around loop are good systems to consider. The heat pipe energy recovery system is an efficient and safe method for fume hood exhausts. This system, similar to the enthalpy wheel, requires proximity to the fresh and exhaust air streams and can be challenging in some existing facilities. While not requiring quite the space of an enthalpy wheel for energy recovery, the heat pipe does add some sizable components to a likely already crowded existing mechanical space.

A very popular energy recovery system for many existing lab buildings is the run around loop. Run around loops circulate a fluid between two streams of air, and retrofits involve additional coils and pumps. Although it is less efficient than some of the other measures, doing this still saves significant energy. This is the most likely system for fume hood exhaust–intensive buildings that have exhaust systems and makeup air systems at opposite ends of the building or side by side. The run around loop requires that a coil be added to the air handling supply side and another coil be added to the exhaust manifold. Selecting the appropriate heat recovery system, designing the system correctly, meeting the applicable codes, and commissioning are all essential to a successful retrofit.

Recommissioning

If replacing an existing mechanical system in a laboratory facility is not feasible, then recommissioning the mechanical system will save energy. As the laboratory building ages, the mechanical systems degrade in operation. Recommissioning focuses on optimizing the HVAC system operation and control for the existing building conditions. Studies have shown that the average measured utility savings are about 20 percent, with simple paybacks often occurring in less than two years. Monitoring of energy consumption and optimizing system operation improves system reliability and building comfort as well as energy savings.

Indoor air quality

Retrofitted mechanical systems need to provide a high standard of safety, good indoor air quality, and low noise levels, as well as energy savings. Maintaining consistent indoor air quality is essential for “green” laboratories and can be challenging due to the varying lab types and usage. Design strategies include VAV fume hoods, carbon dioxide sensors for larger occupancies, and usage of materials with low pollutant emissions (low VOC).

Insulation

The building envelope is a major contributor to the heating and cooling load. Heat moves through the windows and walls, into the building in the summer and out of it in the winter. Better insulation reduces the flow of heat through the building envelope. This is true of any building type, including labs and science facilities. Upgrading the exterior insulation and/or windows in retrofits is an effective way to lower energy consumption.

Lighting controls

Retrofits for laboratories should include “smart lighting” systems that incorporate daylight-responsive and occupancy-sensor lighting. These lighting systems save on energy because less lighting is used and the air-conditioning loads are reduced. Payback in energy savings for installing new lighting controls can be as quick as one year, especially when reinforced by utility incentives. The most basic and cost-effective measure for reducing lighting energy costs is to simply use high-efficiency fixtures, lighting schedule control, and occupancy sensors. Lighting reduction is also a strategy. If the amount of light needed can be reduced, removing unnecessary fixtures can achieve electrical energy savings.

Equipment

In comparison to other institutional and commercial buildings, laboratories have unusually high plug loads, which is the energy required to run equipment such as servers, centrifuges, or other unusual devices. Unplugging equipment that is not in use and utilizing the energy savings settings can go a long way in reducing energy demand.

In comparison to other institutional and commercial buildings, laboratories have unusually high plug loads, which is the energy required to run equipment such as servers, centrifuges, or other unusual devices. Unplugging equipment that is not in use and utilizing the energy savings settings can go a long way in reducing energy demand.

Water use reduction

When renovating laboratory facilities, auxiliary spaces should also be designed for energy conservation. Water use reduction can be obtained by installing low-flow plumbing fixtures and other means such as occupancy sensors and controls.

Cost and payback considerations

Obviously replacing an entire HVAC system for a laboratory facility is a significant investment, and building owners and managers would want significant energy savings and concomitant cost savings as a result of their investment. For installing a new highly efficient HVAC system, paybacks of five to seven years are not unfeasible. If the systems are already in need of repair or replacement to begin with, paybacks on energy measures become even more attractive.

Retrofits to fume hoods to reduce airflow can cost up to several thousand dollars per fume hood. This is approximately 10 to 20 percent of the price of buying new energy-efficient fume hoods, resulting in paybacks of only a few years.

Installing heat recovery systems will provide significant energy savings and environmental benefits. The enthalpy wheel can save around 50 percent of gas used, with even higher savings in colder climates. Heat pipes and run around loops can achieve between 35 and 40 percent of gas savings, which translates into considerable monetary savings, estimated to be $1 to $1.50/CFM annually, again depending on climate and utility rates.

Some green building initiatives for laboratories can be implemented for minimal cost and produce an almost immediate payback. Utility companies are anxious to support such energy savings initiatives with significant rebate incentives.

For instance, in Massachusetts, institutions that upgrade to energy-efficient technologies such as water heaters, lighting, lighting controls/sensors, chillers, furnaces, boilers, heat pumps, central air conditioners, and energy management systems/building controls can obtain a variety of rebates through their local utility providers. Rebates are much greater than those offered even five years ago and can approach significant mid-sixfigure sums for aggressive energy reduction.

Design for daylight

Along with the evaluation of the mechanical systems it can involve, greening the older lab can incorporate rethinking the organization of spaces to bring in daylight and allow for flexibility. Integrating daylight into lab spaces is an important goal for reducing energy requirements (both electrical and heating) as well as improving aesthetics and ambience. Daylight has also been shown to improve employee performance and productivity.

Bringing daylight into laboratories can be challenging when retrofitting existing facilities, but there are design methods to achieve this goal. The design trend toward open laboratories facilitates better ‘day-lit’ spaces. For major retrofits, an organized layout should locate laboratories along the building exterior to provide natural light and views. Research support spaces and offices can be located along a central corridor, with windows providing visual access into the laboratory space. For interior laboratories that cannot be reconfigured, or for enclosed laboratories, existing walls can be retrofitted with glass openings wherever possible to bring in light.

Space utilization

There has been a change in teaching and research methods over the past few decades to an increasingly team-oriented and interdisciplinary approach. Reconfiguring individual labs to combined larger rooms with multiple modules can be incorporated in design retrofits to reduce the amount of space required.

Often wet lab areas can be decreased, classroom space in academic facilities concentrated, laboratories combined, and new types of workstations designed to allow for ancillary spaces such as break rooms, conference rooms, or informal gathering areas where people can interact outside their labs. This flexible use of space and sharing of resources contributes to energy efficiency.

Design for flexibility

Now that they are prevalent, multipurpose laboratories and those used for different types of research require systems that can adapt to changing requirements.

The lab and desk furniture systems should be able to accommodate simple and cost-effective changes in services throughout the life cycle of the laboratory. Some strategies are to use the mobile components a furniture system offers, such as under-bench units and modular benches and desk units, fume cupboards, and sinks.

Flexible engineering services allow less expensive changes. There are many types of services frequently provided for in laboratories; these include gas, water, electricity, supply and exhaust air, data and electronic systems, etc.

Labs can have easy connects/disconnects to allow for fast, affordable hookups of equipment and still maintain safety. Current lab design separates services from the benches to overhead service carriers, thus allowing easier changes.

Materials

Green your laboratory with materials that contain recycled content, as well as materials that are recyclable when they are no longer needed. Sustainable materials could include FSC-certified wood doors and casework, carpet with recycled content, concrete with reclaimed fly ash, rubber tiles, and epoxy counters. Also, to maintain high indoor air quality, specify materials that have low pollutant emissions.

Conclusion

Laboratory facilities are among the most energy consuming of building types, and older facilities are particularly wasteful of energy. There are several strategies building owners or facility managers can employ to reduce energy consumption; they range from small to major retrofits.

While major mechanical retrofits that reduce heating and cooling energy consumption are costly, they have a payback of typically between five and seven years, and as energy costs go up, the payback period will be shorter. Recommissioning to optimize the function of existing HVAC systems can often save a considerable percentage of energy consumption. There are a number of less costly methods to reduce energy consumption, such as installing exterior insulation, retrofitting fume hoods to reduce airflow, installing new lighting, educating tenants and users about energy conservation practices, and taking advantage of rebates offered by utility companies to support such energy savings.

Mitchell Goldman and Lisa Reindorf are principals in Goldman Reindorf Architects, Inc. (www.GRarchitects.com) The firm has designed hundreds of laboratories and science facilities over the past 25 years for universities such as Massachusetts Institute of Technology, Tufts University, and University of Massachusetts Amherst and biotech companies including Immunogen, Inc., and Biogen, Inc.

Mitchell Goldman received his MA from Washington University. He is a renowned laboratory designer, recognized for his technical expertise and project management skills. Lisa Reindorf is a graduate of UPenn and Columbia University. She is an instructor of Architecture at RISD and known for her ability to create designs that entail reasonable construction costs.