Instrumentation was limited. Scientists relied on many all-purpose tools that had been proven over decades, if not centuries. The limited instrumentation meant that labs did not have to adapt repeatedly to new equipment. Building layouts stayed the same for decades, so fixed utilities carried no penalty. Utilities could be inefficient, since water and energy cost so little. The science buildings of the day were designed for that world. That world is gone. Today, science is multidisciplinary; the boundary between the physical sciences and life sciences, between biochemistry and molecular biology has faded away. Problem-focused research crosses all disciplines, from biology to engineering. Further, research priorities change constantly in response to scientific developments and funding sources.
New instrumentation appears almost daily, requiring flexibility in space planning to accommodate the advances. Computer simulations and electronics play an increasing role, so that many lab buildings have fewer wet labs, with major implications for the utilities needed. Sensitivity to energy and water use is almost as intense as sensitivity to funding resources.
All of these changes in how science is done have changed the character of the facilities that are needed. Those high performance facilities need to be adaptable and sustainable. Unfortunately, fixed, building-wide utilities that have traditionally served science have become an impediment to the advancement of science. For our buildings to support our scientific purposes, they need to adapt economically to the changing demands we place on them.
Modular utilities can help put those goals within reach. Three examples of modular options for building utilities will illustrate the adaptability and technical performance that modular utilities can contribute to lab buildings while offering, in many installations, capital and operating cost savings as well. Representative systems include point-of-use pure water, local vacuum networks, and ductless fume hoods.
Point-of-Use Water Systems
Scientific work often requires pure water to ensure that results are not compromised either by impurities in the water or natural properties of the water that can be removed with processes like reverse osmosis. The design of the appropriate system requires an analysis of the incoming feed water, determination of the required quality for the scientific operation, and assessment of the quantities needed. The quantities needed depend on the average usage per lab, derived from the equipment being used, the number of labs that need water of the prescribed quality, and the regularity of use.
The traditional option for buildings in which such pure water supply was needed would be a central purification system with building-wide piping that delivers pure water to every lab. Modular, point-of-use (POU) systems now offer an alternative that permits installation of point-of-use purification systems in each lab that needs pure water. The analysis of the two options involves determination of the need in each lab and comparative feed and waste water costs of central vs. distributed approaches, as well as the electrical demands to run each system, maintenance costs, availability (uptime) and flexibility as needs change.
In a typical case, the POU system has lower installed costs and lower energy costs with better flexibility and up-time, though a distributed system may use somewhat more water and have higher maintenance costs. On the other hand, if pure water is not needed in every lab – often the case in multidisciplinary buildings – unanticipated demands for pure water can be met with a POU system where needed. It may be that right-sizing of the pure water installation with the modular POU technology can reduce the total installation and operating costs such that there is little premium for the flexibility afforded by POU installations.
Bench & Fume Hood Vacuum
Our second modular utility option is the vacuum used to supply to bench turrets, fume hoods and biosafety cabinets in labs. Service vacuum in most labs supports two main uses: suction applications, like liquid aspiration and filtration; and evaporative applications, like drying, concentration or distillation. These uses require very different vacuum support. Suction applications take pretty modest vacuum, and demand tends to be intermittent – on for a minute, off for a while. These are the predominant applications in biology labs. In contrast, when vacuum is used for evaporation applications, the vacuum needed is usually deeper, more stable and more prolonged. Chemists, typically, are trying to maintain specific experimental conditions.
In contrast to the biologists and chemists, when physicists need vacuum, they usually need very deep vacuum that no central system can supply; this requires specialized pumps. The dry labs used by computational scientists don’t need vacuum at all. They just need electricity for the computers. The first challenge with central vacuum supply is that it delivers only the modest vacuum needed for suction operations, so the chemists will usually need dedicated pumps to supplement the central supply. In addition, since a central pump or pumps supply vacuum for all users, the system must operate 24/7 in order to ensure vacuum is available for any scientist who might be working late or on weekends.
Finally, central vacuum is very inflexible; it is nearly impossible to upgrade a central system during a lab renovation or to support expanded demand, so new buildings with central vacuum supply typically install excess capacity to ensure adequate future supply. This adds to capital and operating costs for the life of the building. Modular local vacuum networks are put only in the labs where the need is known. Small, quiet, oil-free pumps are located under the bench or fume hood and plumbed with chemical-resistant fluoropolymer tubing to workstations within the lab. Vacuum is produced on demand and can be tailored to the needs of the scientists in that lab.
The risk of inter-lab cross-contamination or competition for vacuum resources is eliminated. If you have labs that don’t need vacuum at all, such as computer labs, or where specialized vacuum requiring different pumping technology is needed, you don’t install vacuum networks. If the programming changes at a later date, a local vacuum network can be installed where needed. Local vacuum networks offer economies from right sizing of the installation, as well as the labor and material savings afforded by in-lab installation vs. building-wide piping runs. Production of vacuum on-demand by small local pumps reduces energy consumption compared with large central pumps operating 24/7, and significantly extends maintenance intervals. All of these savings complement the adaptability provided by modular vacuum supply.
Filtered Fume Hoods
Fume hoods are used in labs to protect the scientists working there. Exhaust fans move air through the hoods away from the scientists to ensure that hazardous chemical vapors leave the lab without exposing the lab occupants. Traditional practice was to operate the exhaust ducts 24/7 at speeds necessary to exhaust any emissions that might occur, even from an unplanned release, such as a chemical spill.
Unfortunately, the air that is exhausted with the hazardous vapors has already been cooled or heated for building comfort. This makes fume hoods one of the biggest energy wasters in lab buildings, and so technology has advanced to ensure safety while also reducing the total amount of conditioned air that is exhausted. This reduces the load on boilers, chillers, exhaust fans and supply and exhaust ducting. These technological improvements include variable air volume (VAV) hoods, which can reduce the volumes of exhaust air when the hood is not in use. Control technologies are also available that detect activity in the lab and either close hood sashes to reduce air flow, or even detect instances (e.g., spills) in which higher exhaust speeds are needed, while maintaining safe conditions with lower flows during normal operations.
The modular alternative is the filtered fume hood. These hoods rely on filter systems to collect contaminants from lab activities rather than exhausting them to the outside atmosphere through a network of exhaust ducts. Built-in detection systems alert users when the filters are saturated, and back-up filters are part of the design to ensure continued safety while awaiting filter replacement.
In addition to the environmental benefits of avoiding these chemical vapor releases, ductless, filtered fume hoods dramatically reduce the energy costs of exhausting and replacing all of that conditioned air. Without duct connections, filtered fume hoods can be installed in labs where needed, even during renovations or when programming changes. Filtered fume hoods cost considerably more per unit than traditional ducted fume hoods, but the savings on ducting, fans and installation costs, normally mean that the installed costs of filtered fume hoods is actually less than the installed costs of traditional fume hoods with their associated infrastructure. There are on-going maintenance costs of filter replacement, but these are normally offset by energy savings in the interim. Given the added flexibility of this modular approach, and the adaptability to change with building needs, filtered fume hoods are another modular lab utility that warrant your investigation.
Summary
Each of these modular utilities for labs may not be the right solution for every science building, but they should be considered when planning new lab building construction or renovations. The adaptability of these approaches permits right-sizing of installations without risk of building obsolescence, while the energy savings, maintenance savings and space savings contribute to the long-term economy of building operations. Most importantly, modular utilities offer these benefits while providing scientists with the support they need for their scientific work, even as those needs change.
