Energy audit of the school science labs and design technology workshops
30Investigating energy usageKS3
Most schools use electrical equipment in science laboratories, and design technology studios. The energy used by these items of apparatus can be significant when added together.
The easiest way to conserve energy is to use equipment in a way that minimises energy
consumption. Usually, equipment is prepared by a technician at the start of the lesson and left on until the session ends. In busy science labs and design technology studios, there is a danger that equipment will be left on all day – and maybe even overnight. It is good practice to assign clear responsibility for switching off equipment after the lesson and encourage staff and students to minimise energy use during lessons. It may be impractical to turn off some measurement equipment for which the accuracy is affected by insufficient ‘warm-up’ time.
Fume cupboards are a significant consumer of energy. Not only do fume cupboards use electrical energy to drive the fan, they also remove warm air from the lab, increasing the need for space heating. A single fume cupboard can cost around £750 a year to run due to the additional heating required to heat incoming replacement air. Simply switching fume cupboards off out of hours can reduce this to under £200 a year.
A few simple procedures can reduce energy use associated with fume cupboards:
• Use the right sash height – a high sash height can increase energy use as well as putting users at risk from the ineffective extraction of fumes
• Do not use the fume cupboard as bench space – use the cupboard for stages of the experiment that present a hazard rather than the entire experiment
• Switch cupboards off when they are empty or not in use and avoid using them to store chemicals. Instead, store chemicals in a dedicated storage cupboard.
Aim of the investigation
During the energy audit, you will look for opportunities to reduce the amount of energy used in the school science labs and design technology workshops. When you have completed your audit you should be able to identify priorities for improvement in these areas of the school, which you can present to the relevant department and school management teams.
Design a spreadsheet or handwritten results table to record lab and workshop equipment, their location, energy consumption, and usage patterns.
Use the Energy Sparks charts to check whether your school has separate meters for electricity for the school science labs or design technology workshops? Can you use the charts to find out how much electricity these areas of the school use each day in term time? Can you find out how much energy these areas of the school use over the weekend and in the school holidays from appliances left running constantly, such as fume cupboards, extractor fans, equipment left on standby etc?
Go around the school labs and design workshops recording the number of different types of electrical appliances and equipment. Keep things simple and only record appliances and equipment running on mains electricity. Don't include battery operated equipment on this occasion. Try to find out how much energy each appliance or item of equipment uses when in use. Most appliances will have a label on them telling you their energy consumption in watts (W) or kilowatts (kW). Record their energy use in your results table.
Interview science and technology department staff to understand how often each item of equipment is used.
Data Analysis and Presentation
Can you identify the top 5 items of electrical equipment for energy consumption in each lab, workshop or studio?
Can you identify where you think energy is being wasted in the school science labs and design technology workshops?
How would you recommend that staff and pupils change their behaviour to save more energy?
Can you devise a way to share your top energy saving recommendations with the science and technology departments and your fellow pupils?
From your audit of the science laboratories and technology workshops, can you identify how energy efficient you think these departments are? Give your evidence for your conclusion. How can you use the information you have learnt to create an action plan to save energy in these departments?
Next Steps to save energy
Check the door seals on any fridges and freezers (used for storing chemicals and biological specimens) are intact so cold air is not escaping.
Set fridge thermostats at the right level for the contents.
Always close the door to the fridge or freezer immediately after use.
Defrost freezers regularly.
Turn off fridges and freezers during holiday periods, where appropriate. If it is not possible to switch off all appliances, consolidate the contents so that some can be turned off.
Ventilation units and fume cupboard/extractor hood filters should be cleaned at regular intervals. Regular cleaning of ventilation systems can increase efficiency by as much as 50% compared with systems that are not maintained.
Switch on equipment only when necessary, and ensure it is switched off fully overnight.
Switch off fume cupboards and extraction fans when they are not being used.
Evaluate how you carried out the audit and what could be improved.