The iCAP recommends removal of 25 percent of CFHs on campus over the first five years resulting in a total removal of 432 CFHs for a theoretical annual savings $1.62 million dollars and reduction in CFH-produced carbon emissions by 25 percent annually. The quantity of removals is based on the assumption that many rooms have multiple CFHs that do not require simultaneous use and many CFHs are being improperly used for chemical storage.  Currently, there are 95 CFHs that have been mothballed or have had a negligible exhaust flow for at least two years.  Many other CFHs are being used improperly due to a lack of the proper laboratory equipment to support the work being conducted in the CFHs.  Removing CFHs without providing the proper laboratory equipment in its place will result in a decline in laboratory safety.  It is recommended that before any action to remove or alter large quantities of CFHs, a detailed survey of each CFH on campus be conducted to determine what, if any alterations can be made and calculate the associated cost and energy savings associated with it.    

Introduction

In May 2010, the University of Illinois (U of I) published iCAP A Climate Action Plan for the University of Illinois at Urbana-Champaign in an effort to fulfill its obligation to the 2008 American College & University President’s Climate Commitment.  The goal of the iCAP is to make U of I carbon neutral by 2050.

Several strategies were presented in the iCAP to reduce greenhouse gas (GHG) emissions.  One strategy presented for GHG reduction is to reduce the number of chemical fume hoods (CFHs) on campus by five percent per year for the next five years.

Background

A CFH is a laboratory exhaust system specially designed to contain and remove hazardous chemicals being used inside of it.  A CFH operates by taking in conditioned air from the lab room through an opening at its face and exhausting it through ducting.  U of I standards require that CFHs operate with an average face velocity of 100 linear feet per minute (lfpm) through an 18 inch-high opening.  At this face velocity and opening height, a six foot wide CFH exhausts at a flow rate of 900 cubic feet per minute (cfm).

There are 1,673 CFHs that are considered active, with an additional 56 that are mothballed.  Physical removal of five percent of the total CFHs for five years would result in a total of 432 (86 the first 3 years and 87 the last two years).  A total of 1,241 CFHs would remain.

The iCAP estimates that the average annual cost to operate a CFH is $3,750.  Theoretically, the average annual energy savings from removal of 25 percent of the hoods would total $1.62 million.  In actuality the savings would be less because inactive hoods would be the first to be removed.  CFHs that are most likely to be removed are those that are currently mothballed (electrically or mechanically disconnected) and those that have had inadequate flow for an extended period of time – that is, 95 of the 432 CFHs that would be targeted for removal.  Removal of these CFHs would have a negligible impact in reducing energy consumption and GHG emissions, so a more reasonable estimated annual cost savings is about $1.26 million.

Analysis

Removing 25 percent of the CFHs on campus is not a viable option because:  1.) there is potential for high-use CFHs to be removed and researchers will perform hazardous experiments on benchtops rather than seek out an available CFH.  This can create a hazardous environment for the researchers performing the experiments and other building occupants, as well as increasing liability for the University.  2.)  CFH use is largely driven by research.  If CFHs are removed and ceilings are placed on the number of CFHs on campus our ability to expand our research capabilities is limited.  The cost to install new CFHs to replace those that have been removed averages about $30,000 per CFH.  3.)  CFHs are department-owned equipment that are installed and maintained at the department’s expense to meet their teaching and research needs.  If departments were forced to remove CFHs it could have significant negative impact on their ability to meet their missions.

An alternative to removing 25 percent of the CFHs, would be to apply a multi-solution approach.  Such an approach would maintain safe laboratory practices and lower exhaust flow through CFHs while providing more flexibility to the using departments.  F&S would work with departments, the Division of Research Safety, and others groups to:

• remove CFHs that are not needed;
• mothball CFHs that are not currently being used, but allowing for re-activation if needed in the future;
• convert CFHs that are being used for storage into true chemical storage cabinets by removing the sashes, installing doors, and reducing exhaust flow; and
• identify CFHs that are being used for non-chemical exhaust, install appropriate exhaust equipment connected to existing exhaust system with control capabilities (on/off switch). 

While only four alternatives are presented, all potential measures that would reduce energy use, promote laboratory safety, and be acceptable to the departments should be explored on a case-by-case basis. 

The level of acceptance from CFH users and actual cost for this approach are difficult to estimate without a performing a thorough survey to determine which solution is best for each CFH.  Estimated average cost for each solution is $14,000-$25,000 to remove a CFH, $2,500 to convert a hood to a storage cabinet, $9,500 to install alternative exhaust equipment and provide control, and $500 to mothball a hood. 

Recommendations

Conduct a study on each CFH to determine departmental interest this approach, and calculate cost impact and energy savings.  In order to conduct the study, an online survey tool needs to be developed that gathers operational data and hazard information on each existing CFH, and requests from users the type(s) of alteration, if any, that would be acceptable for each CFH.  The estimated cost to create the tool for a single survey is $2,650 and would cost about $570 to host annually.  Additional funds would be needed if the data entered into the tool is to be updated as needed to continually track CFH status.  Additional funds would need to be provided for data analysis by F&S Engineering Services, S&C, Energy Services, Construction Services, DRS, and departmental personnel.   

It is estimated to take approximately three months to create the online tool.  Each department would be allowed up to three months to provide the requested information.  Analysis of the data, calculation of cost impacts, and calculation of energy savings for all 1673 CFHs could take up to a year or more.