Fume cupboards and microbiological safety cabinets

Transcription

1 Fume cupboards and microbiological safety cabinets Aesthetic To be agreed. Functional requirements General Fume cupboard Employers Requirements: BS/EN14175 All general fume cupboard installations must be designed in accordance with BS/EN All fume cupboards must be connected to dedicated fume extract systems via a fully seam welded PVC/Polypropylene/Stainless steel ducting system, or other types as appropriate to suit use of system. Where exposure to ultra-violet degradation is experienced, ductwork, fan housing and motor assembly must be treated to avoid degradation from sunlight and weather. Fume cupboard airflow types: All new fume cupboards to be designed to a face velocity design to be no greater 0.3 m/s average face velocity at 500mm sash height, using purpose designed low flow type fume cupboards only. (0.5m/s face velocity designed fume cupboard with a reduced flow will not be permitted) All general fume cupboard system designs must incorporate the ability to run the 0.3 m/s fume cupboard at a face velocity in a range of 0.2 m/s to 0.5m/s regardless of type of cupboard. All cupboards will be commissioned to their correct velocities by use of variable speed devices (invertors) and not by damper adjustments. Dampers to be provided for fine tuning only (e.g. < +/ 5%) Where multiple fumes cupboards are connected to a common extract duct (not recommended) balancing dampers will be provided for fine-tune balancing only. 1All velocity/volume control to be via VSD s. Under-bench Solvent cabinets must have separate extract systems (one per room) and not be part of individual fume cupboard installations. Use of supported face flow technology must be adopted to ensure ventilation systems are not compromised. Should supportive flow not be used, then a full non-linear 3D modelling exercise must be carried out for supply air distribution into the fume cupboard areas. Full laminar flow supply grilles must be adopted and use of ceiling voids as plenums will NOT be permitted. Where risk assessment of processes precludes low flow cupboards, the Chair of Fume cupboard Working Group and an Estates Maintenance Engineering Services representative

2 must give written authority for designers to use of higher flow rates after the appropriate consultation with Head(s) of department(s) concerned. An appropriate request form for this action will be required to be completed. This will account for both Safety and Energy issues associated with higher flow rate cupboards. A charge may be made for the additional energy use over and above 0.3 m/s, based upon actual flow rates and hours of use. Containment, Spillage and Robustness Fume cupboard minimum containment factors must be at least 2.1 x 10 3 for all new installations. The minimum containment factor of 2.1 x 10 3 will be expected at both 0.5m/s and at 0.3 m/s face velocities at 500mm sash height and at 900mm full face sash opening height. These will be ratified once commissioned by an independent assessor. Spillage testing to BS/EN must be carried out and results must show that there is less than 0.01ppm spillage of SF 6 at all test positions at 0.3m/s AND 0.5m/s at sash heights of 500mm, 900mm and with the horizontal sash slid fully sideways open and vertical sash fully closed position On-site robustness tests in accordance with EN shall be included for all new and recommissioned fume cupboards. Type-testing will be provided as a supplementary certificate but alone will not be sufficient without the on-site testing. Controls All fume cupboards to be complete with auxiliary no-volt relays for Run, start and fault signals and these must be connected back to the University Building Energy Management Systems. All fume cupboards to be complete with energy saving auto-sash closing devices and 0-10v control signalling to the VSD BeMS controller to maximise energy savings when the fume cupboard is unattended and left running. All sashes shall be vertically opening types and in addition will have a 50:50 split horizontally opening sash ability for the entire sash height. Fume cupboard fans must NOT be fed from HVAC or BeMS control panels but must have their own dedicated supplies to ensure maintenance on HVAC/BeMS panels can be carried out without compromising the fume cupboard supplies. Fume cupboard enable signalling cable must be directly wired to each corresponding motor and reliance upon comm s must not be used. Roof Ductwork All ductwork to have protection against mechanical damage. Any positions where ductwork traverses roof must have purpose made bridge walkways to prevent personnel stepping on ductwork. Ductwork is to be dedicated for fume cupboards and should not incorporate general extract.

3 No fire dampers will be fitted in fume cupboard extract ducts. 1 hour rated intumescent fire protection wrap and collars will be used where ducts pass through fire barrier/ fire zoned areas. Flexible ductwork connection to fan must be chemically resistant to the same specification as the ductwork. Lightning arrestor tape to be fitted to each outlet terminal to terminate within 150mm of top of outlet. Outlets to terminate a minimum of 5 metres above finished floor level. Removal cap air test points to be provided within the ductwork on the suction and discharge side of fan, each within 1 metre of the fan. Terminal outlet to be fitted with concentric cone reducing piece on top of the terminal to ensure a minimum face velocity of 10m/s is maintained. Specialist cupboards that require different ductwork materials and design must be separately approved by the fume cupboard working group and via individual risk assessment. (e.g. radioisotope and very high risk containment) Fume cupboard extract Motor Class IE3 (EFF0) high efficiency three phase motor to BSEN to a minimum of IP65X with Variable Speed Device (VSD) and mains combined Electro-Magnetic Interference (EMI)/ Radio Frequency Interference (RFI) filter for each and every VSD. Or IE4 Synchronous permanent magnet motors Motor to be installed on anti-vibration mounts. All motors to be sited in such a way to be immediately adjacent to the outlet and keeping positive pressure ductwork in atmosphere wherever possible. Fan Direct drive to motor via coupled connection to avoid the need to remove impellor. Belt drive connections between motor and fan not permitted. In-line fans will not be generally used. Where no other option is available and approved by the fume cupboard working group, bifurcated fans will be used. Fume cupboard to be connected to an individual dedicated extract system and not shared system wherever possible. VSD manufacturer to be used will be Trend or ABB. Notes: IE1 (EFF2), IE2 (EFF1) (to BSEN ) or lesser standard motors are not permitted and must be removed and replaced at the contractors cost if found on site. Maximum length of run from VSD device to motor must be indicated. All cabling from VSD to motor must be screened for EMI/RFI. VSD to be located within plant space and not on roof or adjacent to its own fume cupboard in a dedicated ventilated enclosure provided cable runs between VSD and motor does not exceed 20 metres.

4 Fans and motor sizes must match to ensure motor is correctly rated to run between 30% and 100% full load speed rating. Motor Isolation All poles to be isolated with lockable isolator to a minimum of IP65X immediately adjacent to each motor. Isolator to be provided to VSD Labelling: An identical unique fume cupboard number must be allocated by Estates Division. Each fume cupboard number will be labelled on both the fume cupboard itself and on the motor isolator on the roof. Labels must be permanently fixed and not self adhesive. All mains and control cables will be fully labelled both on outer sheathing and on individual cores to detail location, panel, way No and cable marker number. Fume cupboard sizes Range of sizes to be in 300mm modular format and will include 1200mm, 1500mm, 1800mm and 2100mm Low headroom versions required Make-up Air The entire supply and extract systems must be designed to provide the correct volumes and airflow patterns to suite the fume cupboard requirements. Air supply air grilles in fume cupboard areas must be of the laminar flow type with a maximum face velocity not exceeding 0.5 m/s and must not be within 1.5 metre zone of the face of any fume cupboard installation Ceiling void for plenum usage must be avoided wherever possible and fully ducted systems are preferred. Where ceiling void plenums cannot be avoided, the plenum must not traverse over the top of the fume cupboards and should not be within 1.5metre of any fume cupboard installation footprint. Make-up air design must be agreed in writing with the potential fume cupboard manufacturer(s) prior to going out to tender. Fume cupboard Construction Construction of frame must adequately show contrasting colours to ensure visually impaired personnel can distinguish frame from handles, etc. Colours: White - sikkens Colormap 439 A1 - Carcasses - Front panels

5 - Parts of panels - aluminium parts - Fume cupboard panel, top - Special storage units Grey - Sikkens Colormap 498 C3 Platine grey - RAL Worktops Construction: - Handles - Sash frames Panel external carcasses -Steel or Aluminium -10mm minimum Water resistant Medium Density Particle board lined with 6mm solid laminate and all edges sealed. Internal fume cupboard compartment bases (dependant upon Fume cupboard useage): 10mm minimum raised edge on all sides Thickness minimum 33mm Types available - Stoneware - Solid ceramic base - Solid Laminate (Trespa) - Polypropylene grade stainless steel Regardless of base type, all drainage outlets must be located in the bases and must be recessed with at least 1mm recess from lowest part of base to prevent any liquids from being retained from spillages/wash-down processes. Side panel services spines Each side panel services spine shall be capable of housing a minimum of 4 No single socket outlets, 6 No mechanical valve outlets, 1 No 75mm double-grommetted, fully ducted service hole (into each respective internal side of the fume cupboard) and indicators as necessary. Internal fume cupboard compartment sides (dependant upon Fume cupboard useage): Types available - Stoneware

6 - Glazed walling - 6mm minimum thickness solid laminate - 12mm minimum thickness polypropylene grade stainless steel Note: Faced particle board of any type will not be permitted. Sash Glass All to be Kite marked tempered safety glass (TSG) clear in all cases. 1 front frame with fixed pane of tempered safety glass (TSG) 1 vertical, weight-relieving sash with double anti-slip device and two horizontal sliding panes of tempered safety glass (TSG) Hydrofluoric acid usage circumstances may require special sash materials. Fume cupboard electrical supply Each fume cupboard shall be supplied via a dedicated 32A supply from a local fume cupboard fuseboard. This supply shall terminate of the front of each fume cupboard top valance to the main isolator of the fuseboard which must be located in an accessible position without the need to remove any panels. The fume cupboard manufacturer shall supply and install an eight module single phase and neutral metalclad flush mounted fuseboard complete with M9 rated miniature circuit breakers. The fuseboard will be manufactured by one of the following: TBC, all complete with integral isolators. The outgoing ways shall be provided for the following:- Module No s 1 & 2 63A double pole isolator Module No s 3 & 4 16A 30mA RCBO outlet feeding 1 No fume cupboard radial circuit to RHS of cupboard with 4 No 13A single high integrity earth double pole switched socket outlets installed in the RHS side services spine only. Module No s 5 & 6 16A 30mA RCBO outlet feeding 1 No fume cupboard radial circuit to LHS of cupboard with 4 No 13A single high integrity earth double pole switched socket outlets installed in the LHS side services spine only. Module No 7 10A MCB feeding fume cupboard controller Module No 8 6A MCB feeding fume cupboard lighting. Socket outlets radial circuit: From each 16A RCBO, the fume cupboard manufacturer shall connect a TBC corrugated PVC-U conduit complete with nylon adaptors to supply a dedicated LSF/PVC/Cu 6491Y singles in conduit installation using 2.5mm 2 radial circuit + 2.5mm 2 dual earthing conductors to BS7671 latest edition. All socket outlets will be of the TBC series high integrity earth double pole switched 1 gang type. Sockets must be installed in side pillars and not in the front of the open hood area to prevent back-wash turbulence from users. Flexible cables will not be permitted.

7 Fume cupboard Lighting Cabling from fume cupboard fuseboard will be wired in 1.5mm 2 LSF/PVC/Cu singles (Brown live phase, Blue neutral phase, green/yellow earth) in TBC corrugated PVC-U conduit from 6A outgoing MCB. Flexible cables will not be permitted. Luminaires to be of the high frequency electronic type or LED dimmable only. Linear fittings will be used throughout with T5 triphosphor tubes only. LED lighting may be considered as an option. PL, PLC or 2D lamps will not be permitted. Tube/fitting changes must be possible without accessing internal working space of fume cupboard to avoid the need for decontamination processes. Lighting level of 500 Lux with uniformity in excess of 0.95 and low glare factor required. Luminaires not installed to this specification will cause the fume cupboard installation to be rejected. Any other wiring will be LSF/PVC/Cu singles (Brown live phase, Blue neutral phase, green/yellow earth) in TBC corrugated PVC-U conduit. Fume cupboard controllers to incorporate:-on/off switch c/w on LED indicator. Sash high LED indicator and audible alarm (min 60dB(A) at 1 metre). Low flow/flow failure LED indicator and audible alarm (min 60dB(A) at 1 metre. Timed Sash mute button with LED indicator to show mute in operation. (Timer to be engineer adjustable from 5 seconds to 10 minutes) Audible alarm when in operation must be non-mutable except on dedicated mute button. Note: - Alarm outlet must not be able to be blocked with any form of compound e.g. plasticine, Blue-tak or similar. Fume cupboard mechanical supplies All mechanical services to each cupboard must have individual, easily accessible lockable isolation devices provided at the point of intake to each cupboard. All piped services connections from mains to cupboards will be installed in non-flexible pipework, suitable bracketed to British standards/en swater services installation must comply with the WRaS approval scheme with all fittings kite-marked and tested to the WRaS scheme requirements. Flexible hose of any type will not be permitted. All pipework will be end-feed soldered or brazed only. Compression or push-fit joints will not be permitted. Water services outlets must be directly over drain outlets to avoid flooding of the fume cupboards. All internal pipework in fume cupboards will also be installed in non-flexible pipework throughout. Mechanical services outlets will be installed in positions not to interfere with the operations of the fume cupboard and will not be installed over access points.

8 A List of approved Fume cupboard manufacturers will be supplied by the University of Bath. Testing/Commissioning Independent testing and commissioning will follow the manufacturer s own set-up testing commissioning and must be witnessed by the University of Bath L.E.V. group representatives. Inclusion for face velocity tests, and on-site robustness tests in accordance with EN shall be included for all new and recommissioned fume cupboards. Type-testing alone will not be sufficient. Where new cupboards or material alterations are made in existing laboratories, all fume cupboards in that laboratory must be recommissioned. No fume cupboard can be put into service unless signed off in writing by the chair or nominated representative of the University LEV group. Fire Conditions Under fire alarm activation the fume cupboard extract system will continue to operate. The makeup air into the space will be deactivated. A fireman's override switch (Normal/Off) is to be provided at the main reception adjacent to any fire alarm panel to enable them to switch off the fume cupboard extract, if required. Switch to be clearly labelled "Fire Switch", "Fume Cupboard Extract System Shut off". Lifecycle Minimum of 15 years. Approved manufacturers Microbiological Safety Cabinets: TBC Fume Cupboards: TBC Fume Cupboard Controls: TBC

9 Accessories: TBC Spares No requirements.