As organisations look to reduce their carbon footprint the pressure is on to save energy – even to become carbon neutral. But university and commercial labs are expensive to build and to run. Susan Birks looks at energy issues and strategies raised at the Effective Lab conference in Liverpool
The need to save energy and reduce budgets is a pressing issue for all facility and lab managers. In most labs, the quality of the environment is critical for people, lab animals and the experiments being carried out. Because of this, energy efficiency has been low on the priority list and there has been a conservative tendency on the part of designers to re-use proven designs regardless of their efficiency.
Many labs are old, have outdated equipment and are regarded as difficult to refit. In addition, considering that labs are frequently only partially occupied, they are often ‘over-designed’ (over-powered for their size) and utilities usage is rarely measured in a meaningful way.
These and more issues were addressed at the Effective Laboratory conference, organised by the not-for-profit organisation Safe-Lab and held at the University of Liverpool, UK, in June. The speakers revealed how, rather than stick with the status quo, good facility managers are addressing energy consumption and there are many quick wins to be had from low capital expenditure.
HVAC is the most important element of energy consumption and focusing the effort here gets the fastest and most impressive results. Air change rates (ACRs) in particular have a massive effect on energy consumption, and their relationship follows a non-linear curve – i.e. doubling the amount of air pushed through the system actually cubes the amount of energy consumed.
Frequent air changes are used to ensure safe air quality, remove contaminants and to adjust temperature and humidity. Many engineers in the industry believe the current ACRs are set too high and can be reduced. Quality control and safety managers, however, are hard to convince, as they have to face the regulators, who are sensitive to change.
Fintan Lyons, MD of Cube Clean Tech, says the situation is exacerbated because the regulatory bodies define best practice and set the guidelines but then institutional guidelines are often set significantly higher.
‘Often 15 air changes per hour (ACH) are set, yet we come across guidelines at over 20 ACH,’ he said. He believes that high ACRs have been linked to safer environments as a ‘belt and braces policy’ and there is plenty of confusion in how to apply the standards. ‘People just accept figures they are given,’ he stated, but he would challenge whether more air means a healthier, safer environment.
High ACRs have been linked to safer environments as a ‘belt and braces policy’ and there is plenty of confusion in how to apply the standards
The complexity of managing several room parameters, such as temperature and humidity, makes the situation more difficult. Set too low, these parameters can affect lab animal health; set too high and energy is wasted. There is also an ongoing fight for many facilities to maintain the required pressure zoning.
But Lyons is one of many engineers to have run tests to demonstrate the feasibility of reducing ACRs. He presented a study on a biomed facility that was carrying out animal experiments. Having first agreed the protocol and safety needs with the company, the engineers set about measuring the key parameters in a room that was holding individually ventilated cages (IVCs) and then reducing stepwise the overall ACRs. The parameters that can affect human and animal welfare are: temperature, humidity, noise, CO2, ammonia and LAA (lab animal allergy levels). They reduced the ACR from the existing 20 ACH, down to 17, 15 and finally to 12 (the IVCs remained at 60–70 ACH).
Lyons emphasised the need for a good team of HVAC engineers to do this. For accurate measuring they used Dräger gas detector tubes and labelled samples were sent to health and safety labs for independent analysis.
Lyons said the results showed little or no difference in temperature (within the 2°F tolerance rate); there was a slight widening of humidity levels, but not to significant levels; there was no rise in CO2 or ammonia; there were a couple of spikes in allergen levels but again, well within acceptable levels.
‘The results did not show that the use of more air meant a better environment,’ said Lyons and he added that they had had similar results in open caged rooms.
The reduction in ACR meant a significant reduction in energy requirement. He suggested facilities operating at 12 ACH could be running IVCs for ‘20% of the cost expected to run caged rooms. He did warn, however, that facilities vary considerably and each has to be reviewed individually to ensure that the health of people or animals is not compromised in any way.
The big question for lab managers is whether the regulators would accept it. In answer to this issue, Lyons said it was best to talk to the inspectors beforehand, then to run a trial to demonstrate that there is no impact on health or safety and to get the process independently tested.
Another major issue for labs is the fact that they are frequently left unoccupied for large periods. This issue was discussed by Otto Van Geet, Principal Engineer at the National Renewable Energy Laboratory (NREL). He suggested there should be two states for containment: occupied and unoccupied. This would involve ‘setback’ – running ACRs at a lower rate for the latter. Van Geet has been involved in the joint EPA/DOE Lab 21 programme, which aims to provide technical assistance on how to make labs more efficient.
While setback can work for labs that have regular hours of non-occupancy, it may be less useful in areas where occupancy is more irregular
But setback doesn’t suit everybody. While it can work for labs that have regular hours of non-occupancy, it may be less useful in areas where occupancy is more irregular. For example, many organisations found that they have to flush the room prior to entering, which meant putting the ACR up for an hour.
On this topic, Gordon Sharp, Chairman of Aircuity, a US company that provides energy savings through its intelligent measurement solutions, suggested setback’s scope is being limited. He quoted the New 2011 ASHRAE Handbook (Lab chapter 16: Occ/Unocc Control), which says: ‘There should be no entry into the laboratory during unoccupied setback times...’ and ‘…Occupied ventilation rates should be engaged possibly one hour or more in advance of occupancy to properly dilute any contaminants.’
Other quick savings could be made on fume hoods. Van Geet suggested that by reducing their size or by making the fume hood sash opening smaller the ventilation rates can be reduced. In addition, reducing the number of fume hoods and sharing them where possible is also beneficial. Using variable air volume – so that as the sash moves, the air change rate changes with it – is also important.
Van Geet ran a campaign for a US University, training students on how to use the fume hood sash; this produced a dramatic reduction, although it did need repeating when application rates dropped.
Other suggestions by Aircuity’s Sharp included reducing fan amplitude and the pressure drop where possible by using bigger air ducts. ‘Going from a 20in to a 24in duct means you can go from a three-quarter horsepower fan to a quarter horsepower,’ he said.
Matthew Gudorf, Campus Energy Manager at the University of California (UC), Irvine, looked at the ‘Smart Labs’ initiative in the US and how it was contributing to UC’s aim to become climate neutral by 2015. ‘Smart Labs’ are newly constructed or retrofitted labs that reduce building system energy consumption by 50% or more, augment established safety protocols and designs, and provide a data stream for more effective running of the building.
Gudorf said for labs currently using 6–10 ACH, the university had been introducing demand-controlled ventilation to achieve a target of 4 ACH during occupancy and 2 ACH during unoccupied hours. He said the prerequisites for this were a move from constant air volume to variable air volume; from pneumatic to digital metering; and individual exhausts being changed to a manifold of exhausts – bringing them all into a common plenum.
Demand-controlled ventilation requires effective metering using sensors to measure CO2, particulates, VOCs, humidity and temperature. The readings are then used to put more air into the room system when needed.
For example, Aircuity’s OptiNet system takes samples of air remotely throughout a facility (from specific rooms or from air supply ducts) and routes them to a centralised suite of sensors. By measuring critical parameters, the system can provide input to building ventilation systems for energy efficiency. Use of a single set of high quality sensors increases the accuracy and lowers maintenance and calibration costs.
The Aircuity system is used to inform building ventilation controls to optimize ventilation rates based on what is actually going on in the environment. Gudorf added that this system can also alert staff to contaminates in the air, so that the source can be pinpointed and investigated.
He said that while they wouldn’t change airflow in BL3 Classification labs, more than 80% of the labs in the 15 university buildings looked at, could be reduced to the 4 and 2 ACH system.
Holistic strategies to energy savings
Source: Gordon Sharp, Aircuity
Exhausting air is another area where savings can be made. Gudorf illustrated how UC’s original facility design used bypass fans, placed just prior to the exhaust point, to blow additional air from outside into the exhaust. This was designed to ensure the air would achieve the required exhausting height. However, they have since carried out modelling in wind tunnels to see what additional stack height would be needed to avoid any additional air injection. The results showed the stack heights had to be raised only slightly, and that by doing this they could reduce fan energy consumption by 78%. It also meant less fan noise.
Sharp also suggested that exhaust air velocity should be varied if possible, i.e. reduced when it is clean.
The issue of ‘over-sizing’ or ‘over-designing’ was also a common theme in presentations. Van Geet noted that plug loads (the heat emitted by plug-in electrical equipment) were often grossly overestimated. He suggested plug load should be based on estimates from measurements made in similar labs rather than simply being guessed at. A modular design for labs would also enable the power to be scaled up if needed.
Sharp noted the importance of a holistic approach to energy reduction, as any one action could have an impact on other parameters. For example, if inefficient freezers are replaced with more efficient ones, ‘reheat’ may be required to replace the heat that the old freezers were producing, that kept the room from being overcooled. However, if the airflow rate can also be reduced, then reheat is reduced and energy is saved.
Van Geet was also adamant that a lot of money is wasted on cooling and reheating, and companies should, whenever possible, say no to reheat.
It is important to optimise thermal environments. For example, in relatively temperate regions such as the UK, it is possible to locate freezer rooms in warehouses where outdoor air can be used for cooling. In addition, speakers suggested the use of more dedicated cooling for those labs that need it.
The use of energy recovery can be useful in some regions with relative temperature extremes but is less beneficial in temperate climates such as the UK.
Although potential savings on lighting are not as large as those possible with HVAC, simple changes can provide a quick win. Gudorf suggested the use of perforated window blinds for maximising daylight without the glare, and the use of light shelves outside the windows to reflect light onto the ceilings internally. At UC, they replaced 32W T8 linear fluorescent tubes with 25W T8 lamps. This meant fewer lumens on benches but most people don’t even notice, he claimed. Magnetically-mounted LED lights can be added over benches where additional lighting is needed.
He also suggested rewiring circuits for sequence lighting so that light is controlled per lab, and circuits are zoned by bay. This creates a bigger initial outlay but gives the flexibility to drive down costs overall, he said.
UC has installed lights that automatically come on to 50% of their brightness when people walk in the room, but the occupier then has to the flick switch to get 100% of the brightness. Most of the time people don’t flick the switch, he said.
Several of the speakers touched on the importance of metering and calibration. For example, Lyons noted that lamentably few Building Management Systems or monitoring devices are actually calibrated in the years following installation.
Lab technicians are not HVAC engineers yet they often have to use instrumentation that they are not trained to use
‘Lab technicians are not HVAC engineers yet they often have to use instrumentation that they are not trained to use,’ he said, adding ‘you rarely see a certificate of calibration’. Considering they are measuring quite small differences in pressure or humidity, he believes this situation needs to be addressed.
At the other end of the scale, UC takes monitoring to the limit. It uses a smart lab information dashboard giving data trends for each zone to make people aware of the energy performance. Gurdorf says it enables emails to be sent to any lab manager when fume hood usage is poor.
He admits that with such systems the maintenance costs may go up initially but once any anomalous equipment has been fixed, the situation stabilises and it becomes a preventative programme of maintenance.
There were many more excellent presentations and suggestions that cannot be covered here, but the general message was clear: for labs to be more economical in future, the ACRs, lighting and heating all need to be more dynamic and responsive to occupancy. Right-sizing is important and better monitoring and calibration is something all companies need to work at.
|S-Lab 2013 Awards – recognising laboratory excellence|
|University of California, Irvine||Smart Labs’ Initiative to achieve a 50% improvement in lab energy efficiency||Laboratory Operations category|
|University of Edinburgh: School of Chemistry Environmental, Financial and Science||Benefits from chemical lifecycle management||Environmental Improvement category|
|University of Edinburgh: Scottish Centre for Regenerative Medicine||Integrating basic and clinical research with licensed clinical production in a translational science facility||New Laboratory category|
|University College London||An online resource exchange enables sharing and donation of laboratory equipment and supplies to reduce carbon, costs and waste||Laboratory Effectiveness category|
|London South Bank University: Centre for efficient and renewable energy in buildings||An inspirational teaching, research and demonstration lab whose renewable and low carbon energy technologies are a teaching tool||Laboratory-Based Teaching and Learning category|
|University of Manchester, Paterson Institute for Cancer Research||IT at the heart of a truly integrated and efficient drug discovery laboratory||Laboratory Information Technology category|
|New Zealand Forestry Institute (Scion), Rotorua||Combining and refurbishing two lab buildings triples utilisation, fosters cross-disciplinary interaction and improves safety and sustainability||International New Buildings category|
|Peter Reid, Senior Technician, Faculty of Life Sciences, University of Manchester||Eliminating ethidium bromide and UV radiation hazards from molecular biology experimentation||Making a Difference category|
|Stephen Baker, Cardiff University||Technician of the Year Award|
|University of Cambridge: Gurdon Institute||Changing behaviour cuts energy use by 19% in research laboratories||Laboratory Effectiveness category|
|Newcastle University, Department of Chemistry||An innovative cyclotron design to allow the integrated production of pre-clinical and clinical radiopharmaceuticals||Laboratory Environmental Improvement category|
|University of Stirling, Nutrition Analytical Service||A new fingerprick test enables faster, cleaner and less intrusive analysis of human blood fatty acid compositions||Laboratory Effectiveness category|
|Victoria University of Wellington, Alan MacDiarmid Building||An award-winning laboratory integrates biological, chemical and physical sciences||International New Buildings category|
|University of Edinburgh, School of Biomedical Sciences||Reducing costs and environmental impacts through laboratory improvement||Laboratory Effectiveness category|
|University of Manchester||A planned preventative maintenance approach to maximising operational efficiency, energy saving and storage system reliability in –80°C freezers||Laboratory Effectiveness category|