Cut energy use in the lab

8-Aug-2011

Energy consumption in laboratories, particularly from moving, heating or cooling air, makes it difficult to meet carbon targets. The S-Lab programme has designed an audit guide to assist in reducing energy use by addressing the design specification of ventilation systems and fume cupboards and instituting a monitoring strategy

Laboratories are energy guzzlers and prime targets for efficiency measures to cut costs and carbon footprints. S-Lab, working with energy consultants on some ground-breaking audits, has found out where most lab energy is spent.

Laboratories consume large quantities of energy – often three to four times more than offices per square metre. In research-focused universities, for example, they can therefore account for up to 60% of non-residential energy consumption, making it impossible for the universities to meet carbon targets without taking major action.

To improve our understanding of where energy is used and to identify opportunities for improvement, S-Lab, together with consultants Energy & Carbon Reduction Solutions and KJ Tait, have undertaken detailed pilot audits at five university labs: Biosciences Building (Liverpool); Edinburgh Cancer Research Centre (ECRC); Department of Biology (York); Department of Chemistry (Cambridge); and Department of Chemistry (Manchester).

Table 1 shows that main energy use is moving, heating or cooling air through laboratory spaces (especially in Chemistry), and that equipment use is high in Life Science. Audits also highlighted IT’s importance in many labs, such as Cambridge Chemistry, where server rooms mean that IT energy use accounts for 17% of total energy consumption.

Table 1: Energy consumption in labs
Indicative consumption split Chemistry Life Science
Ventilation-related
60%
45%
Space heating
20%
20%
Equipment and small power
15%*
25%
Lighting
5%
10%
*Excluding server room energy (17% at Cambridge)

A detailed analysis of equipment at two labs identified the main energy using types based on the formula:

number x rated power x hours of usage

For chemistry labs these were, in order of total use: heaters/stirrers (particularly in teaching labs); mass spectrometers; gas chromatographers; rotary evaporators; NMR; ovens; fridges; pumps (diaphragm and pumps); and water baths.

In life science they were: freezers (-20 and -80s); environmental growth chambers; water baths; incubators; ovens; ice makers; hybridisers; incubator-shakers; and thermal cyclers.

A rule of thumb is anything that is heating or cooling, is on 24/7, or has a 3-phase power supply is likely to be a significant energy consumer.

Energy saving actions identified by the audits were:

  • Optimising supply fan power consumption by delivering the actual pressure required, and not a theoretical design value
  • Switching off individual fan coil units when the rooms they serve do not require special ventilation for prolonged periods
  • Experimentally increasing cooling control range within fridge/freezer or cold room
  • Regularly checking filter conditions and replacing filters proactively (as clogged filters have a higher energy consumption)
  • Reviewing HVAC sensors to ensure they are optimally positioned
  • Turning off or powering down (selected) equipment when not in use, together with related devices e.g. AC/DC converters
  • Turning off lights when rooms/chambers are not in use
  • Examining equipment consolidation/ sharing opportunities
  • Switching off (overnight or permanently) those fume cupboards that are little used
  • Allowing reduced temperature out of hours – aligned to switching off
  • Encouraging closure of VAV fume cupboard sashes.
  • Applying whole life costing to purchases of actually or potentially “always on” equipment, such as computers and freezers.

All actions should be subject to a safety assessment before implementation.

An S-Lab audit guide based on the pilot audit experiences stresses the need to begin the exercise by establishing ownership (with senior management backing from both Estates and principal investigators being vital).

It recommends starting with a quick first stage with the aims of building relationships; understanding the lab building and its operation; creating a broad picture of energy consumption; identifying improvement opportunities; recording key lab features; and building momentum for change.

Professor Peter James of the University of Bradford, director of the S-Lab (Safe, Successful and Sustainable Laboratories) programme, said: “A key question is whether the design specifications of the ventilation system and fume cupboards are being achieved in practice – this is often not the case and unravelling the reasons why can be extremely revealing.”

A second stage can then prioritise immediate opportunities for improvement; scope medium-long term plans; and develop a monitoring strategy (e.g. new sub-meters, fume cupboard control data) to provide more target areas.

Further information, including the full lab audit report, process guide and guidance on sustainable equipment procurement can be found at www.goodcampus.org.

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