Assessing Energy Savings in Cooperation With Novel Containment Evaluation

Paul Leitch, University of Toronto

The University of Toronto is a research intensive university with over 1600 fume hoods (FH), most of which are constant air volume (CAV). A recent survey shows that a majority of FH have an average face velocity over 110 fpm which equates to approximately 660 cfm (at 4 ft x 18") of conditioned outside air. Reducing the excessive exhaust rates of the CAV FHs is one of the many energy saving initiatives the University is assessing. As this energy saving concept may impact the performance of the FH's, the Facilities & Services Sustainability Office and the Environmental Health and Safety Office initiated a FH energy performance evaluation program in parallel with FH efficiency of containment following ASHRAE 110 test protocols and smoke pattern visualization. These tests were completed at different sash heights using a multi-grid airflow arrangement under "as-used" conditions. Different exhaust rates using VAV FH's were tested to see the effect on containment. Based on the smoke pattern visualization and cross draft measurement, FH containment was graded at a range of face velocities into four different levels: (A) full containment, will pass "as used"; (B) small leaks observed, safe, but requires further investigation and testing; (C) containment testing required, may require increased exhaust; (F) smoke escape from FH, failed certification, remedial action required. The energy savings when the FH passed at lower than "as-used" face velocities was calculated. This was then used to estimate the potential for FH's across the campus portfolio assuming they could be safely operated at lower face velocities as shown in the tests.

This paper will present the methodology and how containment testing results can be used to optimize and quantify energy savings without compromising laboratory safety.

Learning Objectives

  • Verify the safe operation of the hood and optimize the exhaust rate for energy savings and learning the energy metrics and effect of exhaust rates.
  • Cooperation with the EH&S team for optimizing fume hood operations
  • Assessing the energy savings potential using existing EH&S performance data and optimized performance opportunities.
  • Showing that the optimum operation can be achieved without sacrificing EH&S standards.


Paul is a registered mechanical engineer involved with energy conservation and clean technology systems for many years. His current role is as director of sustainability at the University of Toronto where he develops and assesses energy conservation projects in the facilities. He has recently been collaborating with the EH&S team to develop energy saving concepts while maintaining or improving the safety of the labs. In particular how to maintain containment with appropriate fume hood exhaust


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