Current Thinking in School Lab Design (REVISED) 1of3-1

8/6/2019 Current Thinking in School Lab Design (REVISED) 1of3-1

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Current thinkingin school labdesign


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Table of Content

Current Thinking in School Lab Design 2

1. Design Considerations2. Building Material3. Mechanical Ventilation and Air Conditioning System4. Electrical System5. Lab Gases and Pure Water

6. Chemical Drainage System7. Plumbing and Drainage8. Fire Services9. Chemical Storage and Handling10. Waste Treatment/Management

11. Lab Safety12. Lab Furniture13. Fume Cupboards14. Case Studies


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1. Design Considerations of

Teaching Laboratory in High School

Provide a safe working and learningenvironment for groups of students

Capacity of the Laboratory is less than 30 inmany high school classes



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1. Design Considerations of

Teaching Laboratory in High School

Two Laboratory types: Wet Laboratories and Dry Laboratories

Wet Laboratories Chemistry Teaching Laboratory Employbench experiments that use liquid, solid and gaseouschemicals, heating devices and open flames. Theexperiments may discharge both gaseous and liquid effluents

Dry Laboratories Use few liquid chemicals as Physics,

Engineering and Biology teaching laboratories. Experimentinvolves the use of electrical components, light generatorsand optical instruments, mechanical devices and microscopes.There will be limited use of fuel gas and water



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Laboratory Layout


Require a maximum number of work stations in a minimum area

Dimension of Teaching Laboratory- 3m2 of floor space per student is minimum- 6.5m2 of floor space per student if the storage and cleanup areas within the teaching laboratory

Benches should be so located that easy, multidirectional movementand exit are maintained

Ease of movement is needed to facilitate getting to and from supplypoints, shared instruments and fume hoods

Efficient use of space & Safety of Laboratory


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Laboratory Layout


Instructors must be able to move about freely, to see allareas and students and to provide quick response toemergency situations

Island-type benches for teaching laboratories arerecommended for classes of 12 or more students

The distance between benches when students work

back to back must not be less than 2m. Otherwise, safecirculation is not possible for students and instructorswho might be carrying chemicals, equipment, or othermaterials


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Laboratory Layout


The fume hoods should be located at the rear of the room arrayedside by side with shared benches between hoods. Each studentworks facing a hood. This allows instructors to see students workingat the hoods as well as to look directly into the work hood area andbe able to quickly recognize when an obvious hazard is developing,

such as a fire or runaway reaction

A disadvantage of the arrangement shown in the layout is thatstudents may use the aisle in front of the hoods to transverse thelaboratory, producing sufficient traffic in front of fume hoods to

compromise effective contaminated air capture

To reduce traffic in front of the hoods, commonly used instruments,supplies should be located at the ends of the benches toward theinstructors demonstration table


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Laboratory Layout


Exit

Minimum of two exits from each teaching laboratory with

each exit opening into a separate escape routeconstructed by 1 hour FRP fire rated material (Code ofPractice for Means of Escape, MOE)

When teaching laboratory is large, additional exits maybe required to be certain that the travel distance to anexit never exceed 18m


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Laboratory Layout


Preparation Room

There should be a room associated with each teaching

laboratory, or group of teaching laboratories, that can beused for the preparation of experimental equipment andmaterials.

Chemical stored in the preparation room should be keptin approved storage cabinets with exhaust in adequatenumbers to handle all flammable liquids


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Sample Layout of Teaching Laboratory



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2. Building Materials


Fire Rated Construction, say, 1 hour FRP to separate thecorridor

Durable Hygiene wall painting. It can withstand repeatedcleaning and disinfection

Seamless vinyl or epoxy flooring should be used. Themonolithic floor covering should be carried up the wall basewith a smooth cove joint

Ceiling (Optional)If necessary, easy cleaning material as epoxy coated metalceiling should be selected


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3.Mechanical Ventilation and

Air Conditioning System


Ventilation

6 ACH( Air change per hour) is considered sufficient for

school teaching laboratory

The supply air flow rate is 0.6m3/s or 600L/s for a 120m2laboratory with 3 meter ceiling height

(6x120x3

3600=0.6m3

/s)

ACH = The number of room volumes exchanged in an hour


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Pressure Regime

Minimum -5Pa at Laboratories for safety

To achieve thisve pressure, the Exhaust Flow rate much larger

than supply flow

Offset = Exhaust flow Supply flow

Offset is around 500 L/s for a 120m2 laboratory

Exhaust flow = General Exhaust + Fume Exhaust

Fume Exhaust Flow = Fume Cupboard Exhaust(Variable for VAVType) +Chemical Storage Cabinet Exhaust (24 hours operation)


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Design and Build for Universal Display Corporations at HK Science Park

- Fitting out Works- E&M Installation- 5 Low Flow ESCO Fume cupboards 2X1800m,3X1200m- Completed in Year 2011


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Lab Control System (Variable Air Volume Control) When no fume cupboard in operation, the Exhaust Flow =

General Exhaust + Fume Exhaust (Chemical Storage CabinetExhaust)

When the numbers of operation fume cupboards increase, theFume Exhaust increase, therefore the General Exhaustdecreases to keep and achieve the room negative pressure

Since the General Exhaust fan is operated under FrequencyInvertor and the minimum operation speed is around 25 HZ,

therefore, make up air is required (i.e. supply flow rate increase) iffurther increase of the number of operation for fume cupboards tokeep the negative pressure

Refer to the T&C report for Air Balancing of a Research Lab


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Human Comfort

22-25Room Temperature adjustable for each Lab

Re-heat coil installed at supply air valve can beconsidered to maintain the lab temperature when largeamount of mix up air inside the lab when more fumecupboards in operation and make the room temperaturetoo low

Relative Humidity control is expensive for airconditioning system. It can be ignored if not required byequipments. RH is not sensitive for human being


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Monitoring System

Pressure Indicator shall be installed inside thelab to display the negative pressure of the labcompared to the corridor or open air. It will havetemporarily fluctuation when the door opening

or the fume cupboard starting into operation

A visual and audio alarm at above MainEntrance Door (Inside and Outside) when theEmergency Button is activated to alert thepersonnel working inside to evacuate and stopthe entry of outsiders

Remarks: Photos taken from Nano AdvancedMaterial Institute at Hong Kong Science Parkcompleted in Year 2009


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Photos: Equipment of Lab control


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4. Electrical System


a) Normal Power

- Electrical Distribution Board (MCB Board) provided atLaboratory

- 100A 380V TPN (3 Phase) should be sufficient for Teachinglab with 30 students

- 13A Twin socket outlets are provided at Work Bench for

Bench top equipment and Computer, etc

- 30A 380V (3 phase) Isolator are provided for free standingequipment as Laser, UV machine, etc


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b) Essential Power

- MCB Board provided at each Laboratory

- 30A TPN should be sufficient for Teaching lab with 30students

- MVAC Equipment as Lab Control System, FumeExhaust Fans, Fire Services Alarm, etc are connected toEssential Power


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c) Lighting

- Maintain 500-600 Lux at Bench top level

d) Emergency Lighting

- Back up battery should be provided for lighting near theexit to fulfill FSD requirement


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5. Lab Gases and Pure Water


- Nitrogen, Compressed Air, Vacuum, Town Gas & DI Water are normallyused

- Technical Gas

Remarks: Unlike universities, it is not cost effective to provide central plantfor Nitrogen Compressed air, vacuum and DI water system, localcompressor, vacuum blower and nitrogen cylinder bottle and water purifierare provided in individual lab if needed

Services Quality Pressure Remarks

Nitrogen 4N 4 Bar

Compressed Air Dryness:-40 PressureDew PointOil Content: less than 0.5ppm

4 Bar

DI Water(Type 2)

Respectively>1MTOC50ppbSilica1 Bar If 18M water is required, apolisher should be installedfor overall cost saving


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6. Chemical Drainage System


1) Polypropylene Pipes (Vulcatherne System)

- 2.3 Liter Dilution Trap are provided for each Fume Cupboard and sinkunit

- Mechanical Joint fitting connection is used above ground for easyroutine maintenance

- Enfusion Joint fitting (leakage proof) is used below ground formaintenance free

- All joints should be enfusion to reduce the risk of leakage and andinfection during maintenance for Cat 3 Lab

2) Neutralization Tank System should be provided to fulfill EPDdischarge requirement (Water Pollution Control Ordinance,WPCO)


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7. Plumbing & Drainage


Plumbing

1) Hot & Cold Water are provided at each sink units (6kwInstant type water heater is provided at each sink)

2) Cold Water tap and Cold Water Aspirator tap are provided foreach fume cupboard

3) Emergency Shower and Eyewash is provided at Exit for each

Lab for safety

4) Hand wash basin with intra-red sensor should be providednear the exit of clinical lab


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8. Fire Services


Fulfill Statutory Requirement of HK Fire Services Dept.,c/w

- Sprinkler System

- Alarm Bell

- Visual Alarm

- Emergency Lighting

- Exit Sign

- Directional Sign for large lab


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9. Chemical Storage and Handling


The quantity of chemicals stored in a laboratory shouldbe kept to a minimum at all times and they should be

stored by methods and location appropriate to theirhazard classification

There should be a central storage room for bulk supplies

Flammable liquid should be stored in safety storagecabinets comply with EN 14470-1


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Safety requirements

- Minimization of the fire risk associated with the storage of flammable materials

- Protection of the contents of the cabinet in the event of fire for a known (and tested)period of time

- Minimization of the fumes released to the working environment

- Exhaust for the cabinets

- Retention of any possible leakage within the cabinet

- Provision of enough time, in the event of fire, for personnel to leave the room, andsufficient time for fire service personnel to enter the building before the storedmaterials turn a small, fire into an uncontrollable blaze


EN 14470-1 European Standard for

Safety Storage Cabinets


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Fire protection

- In the event of a fire the cabinet must ensure that, over a period of timedefined by the manufacturer (but in any event at least 15 minutes), itscontents do not present an additional risk that the fire will spread

- The fire resistance of cabinets manufactured to this standard isclassified into 4 categories of fire protection(ratings Type 15,30,60,90)The type numbers correspond with the fire resistance of the cabinet inminutes and is the time taken for the internal temperature of the cabinetto rise by 180 when tested in a furnace according to EN1636-1

- Given ambient temp. of 20, this means the temp. within the cabinetwill be held at below 200 for the respective designated period of time,which is generally below the auto ignition temp. of most petrolchemicalsand solvents





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Doors

- The cabinet doors must close automatically and entirely,

starting from any position (closing time max. 20 seconds)

- Avoiding risk of injury: the closing force of the doors

must not exceed 100N

- One-handed operation must be possible, and the doorsmust close entirely





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Side and rear walls

- The side and rear walls of the cabinet must have the same

thickness and comparable structures

Air inlet and outlet openings

- The cabinets must have openings for air inlet and outlet

- 10 Air change per hour is recommended



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Storage locations (shelves or drawers)

- Storage surfaces must be able to support the loadingspecified by the manufacturer over the period of the test in the

furnace. Design evidence of the load-carrying capacity ofshelves and drawers in the event of fire based on EN 1365(fire resistance tests for self-supporting components)

Spill containment sump

- The spill containment sump must retain its ability to functionafter the fire resistance test



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L b G S D


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Chemical Storage

- Comply to Dangerous Goods Regulation (including exemption)

- Fire Services Department

- The exempt quantity by HK Fire Services Department of commonly used labgases for each laboratory


Laboratory Gases Storage/ Dangerous

Good Storage

Name Category Exempt Quantity Label

Argon Cat. 2 1 cylinder -

Carbon Dioxide Cat. 2 1 cylinder -

Hydrogen Cat. 2 1 cylinder B3

Nitrogen Cat. 2 1 cylinder -


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10. Waste Treatment/Management


A. Chemical Liquid Waste should be neutralized to control the pH valuebetween 6 pH 10 before discharge to public sewer

B. Chemical Waste containing heavy metals/solvents

- A chemical waste handling and storage area or room should beseparated from all other building occupancies

- Waste procedures should register with EPD and stored in designatedcontainers with approved labels, drawings and catalogue for collection

- Secondary containment should be provided for storage beforecollection

- Waste Collectors with licensed to collect for proper disposal (pleaserefer to EPD website for the authorized collectors)


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10. Waste Treatment/Management


C. Clinical Wastes e.g. animal tissue, blood and dressing

- A Producer of clinical waste who intends to operate an

on-site collection point to take in clinical waste generatedby him in another premises or from other small wasteproducers must first apply for an Authorization from EPD

- Waste Collectors must apply to EPD for a Clinical WasteCollection License to operate or start a business tocollect, remove or deliver clinical waste to a disposal site


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A. Emergency Shower and Eye Washer

- Location for access, 18m travel distancemaximum

- 10 seconds travelling time

- 75L/min Water Flow Rate

- Regular routine checking say at least quarterly,to ensure the valve does not become so difficultto operate

B. Emergency Shut off Valve for Town Gas

- Accessible Location

11. Lab Safety


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C. Emergency Exhaust System

- Pull the emergency exhaust button toincrease the room exhaust flow rate andincrease the room negative pressure andventilation

D. Dual motor for exhaust fan of the FumeCupboard and essential power back up thelab control system and fume exhaust fan

E. Gas Leakage Detection System fortoxic/flammable gas as HF, NH3 & H2

F. CO2 Fire Extinguisher, sand bucket, etc

G. First Aided Kit


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Photos taken from Material Lab, City University

12 Lab Furniture


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12. Lab Furniture

Laboratory WorksurfaceWorksurface Evaluation CriteriaWorksurface evaluations should be based upon individual labrequirements for: Resistance to the chemicals to be used Heat resistance Liquid absorption Load bearing capabilities Impact and abrasion resistance Electrical conductivity Liquid containment and liquid disposal (especially in sink areas and

fume hoods)

Ease of maintenance Ergonomics Availability Color Overall appearance Special requirements (i.e. irregular shapes, minimal joints, etc.)



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Laboratory Worksurface

Chemistry Use Area (i.e. Organic, Inorganic, Bio-chemical, Analytical) consideration should be given tochemical resistance, ease of cleaning, color suitability,strength, abrasion resistance and thermal shockresistance

Physics Use Area consideration should be given tophysical strength, abrasion resistance, impact resistanceand heat resistance

Biology Use Area consideration should be given tostain resistance, ease of cleaning, abrasion resistanceplus bacteria and fungus resistance



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Laboratory Worksurface Special Purpose Use Areas Where Chemical Resistance is a Prime

Consideration (i.e. pathology/hematology and other specialbiochemical areas) consideration should be given toimpermeability and ease of cleaning

Special Purpose Use Areas Where Chemical Resistance is Not a

Prime Consideration:- Electronics consideration should be given to physicalstrength and other task specific characteristics- Electrical consideration should be given to insulationcharacteristics, dielectric strength and physical strength- Mechanical (i.e. metallurgical, geographical, etc)consideration should be given to resistance to physical abuse- Radioactive consideration should be given to contaminationby radioactive material- Thermal consideration should be given to temperaturerequirements



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Worktop Materials

Melamine laminate, standard material

Melamine laminate, TopResist

Trespa Athlon

Trespa Toplab Plus Ceramic/ composite ceramic

Tile

Stainless steel

Epoxy resin Polypropylene



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Worktop Materials



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13. Laboratory Furniture

Wesemann wood laboratory system

Kottermann steel laboratory system



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Current Thinking in School Lab Design (REVISED) 1of3-1

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