Autoclaves in the School of Life Sciences at Warwick Janine Kimpton – Technical Services Centre Manager Dave Hibberd – Workshop & Infrastructure Manager

Distribution  15 autoclaves in 8 locations across 3 sites  3 prep room  1 media prep  4 containment  1 BSU (Total of 9 at Gibbet Hill)  2 Phytobiology  4 Wellesbourne (plus numerous bench tops)

Gibbet Hill

Makes/Models  Boxer – 400/700L, 400/500L 400/300L, 400/150L  Priorclave – PS/RSC/SH350D, PS/RSC/SH700, PS/RSC/SH350

Maintenance  Annual service – in house (Workshop & Infrastructure Team) or Autoclave Services ( )  Annual validation – priority given to containment machines (schedule in downtime) and those handling licensed material  Significant commitment - c£20K/annum

Remote Monitoring  ABB 4 channel recorder  Web based, remote access  Early warning of problems

Purchasing History  : Rodwell → Drayton Castle → Boxer → Priorclave → Boxer  Historically largely dependent on contacts and word of mouth  What would we buy if we bought a new one now? – market has changed

Power Options  Gas steam generation  Electric self-generation  Dual gas-electric integration

Gas Steam Generation  Installation and maintenance costs high  Generator consistently running at full pressure  Steam can be turned off overnight when not in use, but must then reheat next morning  Only cost effective & energy efficient if running multiple large autoclaves for many hours a day

Electric Self-Generation  Low pressure  heat from cold (via elements)  only use significant energy during the heating phase of the run  can be slow to reach temperature  High pressure  self contained boiler – keep on - quicker  higher energy consumption  recommend fitting a timer

The Reality in Life Sciences  School consists of several buildings of varying ages  Recent rationalisation from 2 prep rooms to 1  Concentration of high throughput machines now in one building  1 steam plant shut down

Current situation – dual gas-electric  2 gas powered steam generators (run on alternative weeks)  Steam at 10Bar/11 hours a day  6 autoclaves running off steam (electric used less frequently)  Total electrical power requirement would be around 400Ah – would require a huge upgrade to the existing substation.

Other Considerations  Location and air handling  Single machine can take ambient temp up to o C  Produce radiated as well as convected heat  Water rather than air cooling the chamber rather can help - air cooling can dramatically increase the ambient temperature.

Other Considerations  Local Exhaust Ventilation - required  Plumbing & Electrics – can be extensive ‘New’ locations can be costly

Other Considerations  Metal boxes - improve the thermal conductivity of the steam, ensuring that the load has achieved sterilizing temperature as quickly as possible.  Rationalisation – but not good practice to share use between waste and media prep