Since its inception in 2010, our firm has had the opportunity to work with several major research laboratories, which has given us first-hand insight into the unique characteristics and challenges of labs as a building type. Labs frequently use three to four times as much energy as comparably sized commercial office buildings, with HVAC accounting for a larger portion of total energy consumption: as much as 80 percent, according to information shared at the I2SL Annual Conference (formerly the Labs21 Annual Conference), vs. around 67 percent, according to recent data from the U.S. Energy Information Administration. Plug loads often are 15 percent in chemistry labs and as much as 25 percent or more in biology labs.
In addition to being extremely large energy consumers, labs are large water consumers. Recently, we completed our second Florida Water Star (FWS) certification project for a major research laboratory in South Florida. (FWS is a statewide water-conservation certification program for both new and existing properties, with performance-based water-efficiency standards and guidelines for indoor fixtures and appliances, landscape design, and irrigation systems.) Because labs use more 100-percent outside air than typical office buildings do and, because of their specialized equipment, generally have higher plug loads, their comfort-cooling loads are high. Most stand-alone labs utilize water-cooled chillers for primary cooling, so cooling towers represent a major opportunity for water savings. In the case of our most recent lab project, the facility had approximately 1,000 tons of cooling-tower capacity and, prior to our involvement, was running its water treatment at approximately 3.5 cycles of concentration (COC). At the conclusion of the project, the COC had been increased to 5.0, resulting in a reduction of approximately 270 gal. of water per hour.
We were fortunate the client’s facilities staff was very knowledgeable, and the relatively new building was designed and constructed to LEED standards. The staff already was recovering condensate, and all of the interior plumbing fixtures and appliances were low-flow. The staff was irrigating the facility’s substantial landscaping with reclaimed water, although it had to reduce irrigation-cycle times to meet FWS annual water-budget requirements.
Today’s cooling towers and associated water-treatment technologies are designed to be more water- and energy-efficient than ever (features such as drift eliminators and variable-frequency drives on cooling-tower fan motors are all but standard now, and near-zero-bleed water-treatment technologies—both chemical and non-chemical—are regularly coming to market). However, the thermodynamics of heat removal doesn’t change, so cooling towers will continue to be major water consumers in all types of buildings, not just labs. As HVAC professionals, we should view cooling towers as a good opportunity to help our clients save money and reduce their environmental impact. In other words, it’s another chance to do good and to do well.