Priestley Refurbishment

Chemistry Teaching Laboratory Fume Cupboard Refurbishment University of Leeds

Bob DouglassEnergy Officer

Good Afternoon and welcome to University of Leeds, my name is Bob Douglass I am a member of the Estates Engineering Team tasked with implementing the Universiteis Carbon Management Plan. Today I am going to give a short presentation of the refurbishment of the Priestley Laboratory in our Chemistry Building, hopefully most of you will already have had a chance to visit the laboratory with me either this morning or over lunch.1University Targets

35% Carbon emission reductions against 2005/6 baseline by 2020.Target is annual emissions of 24,400 tonnes of carbon by 20202012/13 data:

Energy Cost 13,245,508Total energy used 193,310MWhCarbon emitted 57,063 tonnes

Like most other Universities we have challenging targets to meet. 2Implementing the CMPThe aims of the Universities Carbon Management Plan are threefold:

To make a significant contribution to government carbon targets.To help the University deliver its core business in a more sustainable wayTo save money

Delivered by embedding energy reduction into everything we do e.g. procurement & day-to-day management systems.

However, majority of savings coming through building disposal, refurbishment (fabric & services improvement) & engineering solutions.

3Energy DataKey Performance figures2012/132011/12Carbon emitted (tonnes)57,06370,874Energy consumption (MWh)193,310217,414Energy costs13,245,50813,005,778The figure s in the table are taken from the Estates Management Statistics report 2012/13 and demonstrate the savings made so far and illustrate how far we ae yet to go..

4Intervention Carbon savingsResidential property improvements covering heating and controls, lighting and controls together with roof insulation improvements54 tonnesNon-residential measures associated with Faculty projects covering lighting and control improvements together heating and control improvements.4 tonnesCarbon budget interventions.850Property disposal4,000Fume Cupboard Energy Savings

Over 270 ducted fume cupboards on main campusEach cupboard can potentially consume the equivalent energy of 2-3 houses over the course of a year. Equivalent to 18 tonnes of Carbon per cupboard per annumEnergy costs can be significantly reduced through good design and simple management steps

With regard to fume cupboard at the University we have:5Priestley Laboratory Fume Cupboard Refurbishment.

Chemistry building selected for review as second largest energy consumer Priestley Laboratory large 765m2 teaching laboratory with 63 fume cupboards.Total energy used for year 2012 - 2103 measured as 4360MWh, 1171 tonnes carbon. 187,500.00 + VAT345,000 from Carbon Management Plan budget spent upgrading fume cupboard systems

The chemistry building being the second largest energy consuming building after the Worsley building was selected for review.

The Priestley lab with a floor space of 765m2 and 63 fume cupboards was an obvious choice for analysis.6The Process - Key ElementsEngage with stakeholders, before, during and after the project

Multi-disciplinary proactive internal planning team.

Risk and Feasibility Analysis

Design consultant with a documented track record in sustainable design, working with Fume Cupboard and BMS specialist.

Measurable goals with metrics tracked consistently during and after the design process. The primary metrics being user safety, ease of use and maintainability and energy efficiency.

Project review

Early consultation with the building users was very important to the success of this scheme, rather than being a scheme sponsored by the users for the users this was an outside body i.e. Estates coming in and looking to disturb a very busy laboratory with the primary intention of saving energy. Savings the department may not directly benefit from.The planning team consisted of the Head of School, the Technical Services Manager (H&S Manager), Laboratory Manager, Head of Engineering, Project Manager and later in the process a Sustainability team representative. With regard to risk analysis particular attention was paid to how the Laboratory was used and the Coshh assessment for the processes being undertaken. The separation of the storage cupboard extraction and an understanding of the processes being undertaken in the laboratory and the operational systems in place enabled some bold decisions to be made as to how the laboratory ventilation system would operate.This team in conjunction with the design consultant reviewed the feasibility of the various project elements and defined the scope of the design brief. The options considered will be discussed in the next slide. Metering of steam and electrical energy consumption were already in place and provided the raw data needed to evaluate the various options open to the design team. These meters have been essential in proving the operation of the system and identifying anomalies in usage which we have discussed with the users.The success of the scheme and the role of the laboratory staff in that success has been highlighted to senior management both through energy use updates and via the Universities Sustainability Award ceremony. 7Containment

One particular area of concern to the users was the proposed reduction of air face velocity from 0.5m/s to 0.4m/s. To allay these concerns we arranged for a specialist contractor to undertake an on-site robustness test to BS EN14175 using sulphur hexafluoride (SF6) as the trace gas. The test results showed that at 0.4m/s the containment of the cupboard was proven with a containment of less than 0.01ppm recorded. Subsequent SF6 testing was undertaken at the end of the project to ensure containment was achieved.One particular area of concern to the users was the proposed reduction of air face velocity from 0.5m/s to 0.4m/s. To allay these concerns we arranged for a specialist contractor to undertake an on-site robustness test to BS EN14175 using sulphur hexafluoride (SF6) as the trace gas. The test results showed that at 0.4m/s the containment of the cupboard was proven with a containment of less than 0.01ppm recorded. Subsequent SF6 testing was undertaken at the end of the project to ensure containment was achieved.

In addition to containment testing, measurements of air face velocity were taken at the same time so future performance could be verified against air face velocity providing known containment.8Feasibility

Gordon SharpPD pressure dropHR heat recovery See attached notes9Constant Volume Fume CupboardsExisting duct work systems and cupboards upgraded to changed from constant volume to variable volume operation.

MechairThis slide and the following demonstrate the principles of a constant volume fume cupboard and a variable air volume fume cupboard. In the example above when the sash is raised 100% of the extracted air is drawn through the sash opening, when the sash is lowered 30% of the air is drawn through the sash opening and 70% through the bypass so the extract volume remains constant regardless of the sash position.10Variable Air Volume Cupboards

MechairThis slide shows how the volume of extract air is reduced when the sash is in the lowered postion. With the bypass blanked off the air velocity through the sash opening increases. This increase is sensed by the cupboard controller and a motorised damper above the cupboard modulates to reduce the extracted air velocity and hence volume.11Control Schematic

The schematic shows how the various elements combine to provide a variable air volume system. The VAV controller mounted on the cupboard senses changes in air velocity due to changes in sash height and adjusts the damper actuator directly above the cupboard to reduce the air volume. This action causes the negative pressure in the extract duct to become more negative which is sensed by the fresh air bleed controller, which in turn adjusts the bleed damper to compensate. In most system of this type the volume of air delivered into the laboratory is controlled by a room pressure sensor controller which adjusts supply air volume to maintain the lab at a slightly negative pressure -5 to -10 pascals. Due to the configuration of the laboratory and the two independent systems serving it our system is slightly different. The volume of supply air into our laboratory is determined by adding up the total measured extracted air volume from each cupboard and using a lookup table to adjust the fan speed and hence air volume.12To turn the fume cupboards into VAV systems fast acting motorised dampers were fitted to each of the 63 fume cupboards along with new cupboard controllers. To maintain stack discharge velocity and reduce control volatility motorised bleed damper were fitted to the eight roof mounted extract fan systems, these modulating to maintain a constant duct pressure. Each extract fan serves up to eight cupboards in the laboratory below.

Motorised DampersTo turn the fume cupboards into VAV systems fast acting motorised dampers were fitted to each of the 63 fume cupboards along with new cupboard controllers. To maintain stack discharge velocity and reduce control volatility motorised bleed damper were fitted to the eight roof mounted extract fan systems, these modulating to maintain a constant duct pressure. Each extract fan serves up to eight cupboards in the laboratory below.

13Dedicated Storage ExtractIndependent solvent and chemical storage cupboard ventilation system installed to extract from end of line and under cupboard storage cabinets.

Independent solvent and chemical storage cupboard ventilation system installed to extract from end of line and under cupboard storage cabinets.

This system collects from all of the solvent storage and under cupboard storage cabinets, (the large blue cupboard on the end) and discharges into a separate dilution system which, like the storage cupboard extraction system, needs to run continuously. This arrangement enables the isolation of the Priestley central supply and extract systems when the laboratory is not in use. 14

Passive Infra-red sash prompts fitted to cupboards to prompt users to close sashes if left open and unattended for more than 2 minutes. Controller sound alarm and flashes warning text advising user to shut sash.Sash Prompts

Passive Infra-red sash prompts fitted to cupboards to prompt users to close sashes if left open and unattended for more than 2 minutes. Controller sound alarm and flashes warning text advising user to shut sash

The sash alarm is particularly important as whilst significant savings are being made by the careful and diligent use of the local controls; the in use savings are made by ensuring sashes are in the closed position whenever possible15User Controls

Improved local controls to enable lab staff to select appropriate number of fume cupboards for class size and isolate those cupboards not required. Improved local controls to enable lab staff to select appropriate number of fume cupboards for class size and isolate those cupboards not required.

Staff are encouraged to use extract fan no.4 for out of hours experiments as it is configured to discharge into a separate discharge stack which services research laboratories which operate continuously. This means that outside of classroom hours the majority of the ventilation plant can be turned off. 16

Install remote monitoring system using a SIP modbus interface to export data and energy sub metering to Trend BMS graphics page and M&T software package.

Remote MonitoringThe upgraded TEL controllers on the fume cupboards provided an opportunity to export operational data to the existing Trend BMS system. The addition of a sash height indicator to each cupboard meant we could collect data such as sash height , sash velocity and therefore extract volume. The latter data point being very important as the cumulative value of the cupboard volumes provided the set point for the fan speed look up table. The Trend BMS was also programmed to provide data on the damper status, extract duct pressure and inverter operation. 17Behavioural Change

Promoted behavioural change with Sustainability Service Shut the Sash campaignThe shut the sash campaign was run University wide and has prompted a number of enquiries from departments about the energy use of their labs.The shutting of sashes in the Priestley Laboratory not only provides health and safety benefits it also enables the volume of extracted conditioned air to be significantly reduced during operation. 18Out of Hours Bypass

Install a bypass duct from dilution system 5 to dilution system 4 to allow bank of eight cupboards to run outside of normal hours without having to enable full systemInstall a bypass duct from dilution system 5 to dilution system 4 to allow bank of eight cupboards to run outside of normal hours without having to enable full system

This action along with the separation of the solvent cupboard extract system allows the very large dilution fan no.5 to be isolated when only limited laboratory extraction is required. This saves approximately 9500.00 per annum on fan power electrical energy consumption.19From Space

20SummaryExisting duct work systems and cupboards upgraded to change from constant volume to variable volume operation.Independent solvent and chemical storage cupboard ventilation system installedDuct work altered to provide energy efficient facility for 8 Cupboards to operate outside of normal operational hours Passive Infra-red sash prompts fitted to cupboards to prompt users to close sashes if left open for more than 2 minutes.Improved local controls to enable lab staff to select appropriate number of fume cupboards for class size and isolate those cupboards not required. Install remote monitoring system and energy sub metering to check operation. Promoted behavioural change with Sustainability Shut the Sash campaignThis is a summary of what we did:Existing duct work systems and cupboards upgraded to change from constant volume to variable volume operation.Independent solvent and chemical storage cupboard ventilation system installedDuct work altered to provide energy efficient facility for 8 Cupboards to operate outside of normal operational hours Passive Infra-red sash prompts fitted to cupboards to prompt users to close sashes if left open for more than 2 minutes.Improved local controls to enable lab staff to select appropriate number of fume cupboards for class size and isolate those cupboards not required. Install remote monitoring system and energy sub metering to check operation. Promoted behavioural change with Sustainability Shut the Sash campaign

21What did we achieve?

Over a 6 month period we recorded the following savings:A reduction in thermal energy of 1647MWhthA reduction in electrical energy of 347MWheEnergy costs reduced by 81,217.00 net511 tonnes of carbon saved.Over a 6 month period we recorded the following savings:A reduction in thermal energy of 1647MWhthA reduction in electrical energy of 347MWheEnergy costs reduced by 81,217.00 net511 tonnes of carbon saved.

22In addition:

Raised awareness amongst staff and students of fume cupboard operational costs and in particular the role they can play in reducing costs.

Behavioural change in use of fume cupboard sashes resulting in safer and more energy efficient operation.

Improved reporting, monitoring and analysis of fume cupboard use.

A quieter and more comfortable working environment due to the reduction in supply and extract air volumes.

Raised awareness amongst staff and students of fume cupboard operational costs and in particular the role they can play in reducing costs.

Behavioural change in use of fume cupboard sashes resulting in safer and more energy efficient operation.

Improved reporting, monitoring and analysis of fume cupboard use.

A quieter and more comfortable working environment due to the reduction in supply and extract air volumes.

23Priestley Laboratory Steam Consumption

This graph shows the steam energy consumed by the laboratory during the past three year. The green bars are this years consumption.24Chemistry South Wing Electrical Consumption (kWh)

This graph shows the electrical energy consumption for the buildings south wing which houses the Priestley laboratory, the following heat map slide demonstrates the close correlation between energy usage and laboratory usage.25

The teaching laboratory has overnight experiments running Mon-Tue and Wed-Thur most weekdays, however, this pattern changes depending on the class and experiment being taught. This inconsistency in fume cupboard usage was one of the main reasons why we provided the local control function so that the staff could select the most appropriate arrangement for the situation in hand.26Any Questions

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