Colt International Ltd

Colt International Ltd
Welcome This is a CPD Certified presentation by Colt International Ltd on Pressurisation Systems. Pressurisation systems in residential and commercial buildings Colt CPD Technical Seminar “People feel better in Colt conditions” |

A brief history of Colt A private company founded in 1931
I J O’Hea OBE ( ) 2016 Group turnover £158 million 2016 UK turnover £ 35 million Manufacture in the UK, Holland, Germany and China I J O’Hea Colt Founder

Colt UK Business Markets
Project Versatility Scope: Design Manufacture Supply Install & wire Commission Maintain Project Value Small works: £0 - £30k Contracting: £30k - £6m Accreditations Achilles Altius Gateway CHAS Construction Line Safe Contractor Worksafe Contractor PPQ still required by clients ISO 9001: 2015 By investing in innovation, products, services and people, Colt International has established itself as an international leader in the fields of: Smoke Control Solar Shading Natural Ventilation Louvre Environmental Comfort Control (HVAC) Air Handling Systems ISO 14001: 2015

Colt UK Business Markets
Residential common corridors Fire Fighting Shaft Systems SHEVS – Shopping Centres, Atria, Warehouses, Factories, etc Smoke Curtains Fire Curtains Pressurisation Custodial Car Parks Smoke Control Solar Shading Natural Ventilation Louvre Environmental Comfort Control (HVAC) Maintenance & Service By investing in innovation, products, services and people, Colt International has established itself as an international leader in the fields of: Smoke Control Solar Shading Natural Ventilation Louvre Environmental Comfort Control (HVAC) Air Handling Systems

Pressurisation Systems - Why pressurise?
Approved Document B to the Building Regulations requires smoke ventilation to escape stairs in residential buildings and to fire fighting stairs in all buildings and, under most circumstances, adjacent common lobbies and/or corridors. Pressurisation is one way of meeting this requirement Alternatives to pressurisation are: Natural AOVs Natural Shafts Mechanical ColtShaft Pressurisation can be used for various applications, although in a lot of cases there are a number of options available to designers

Alternative to natural ventilation when escape stairs or fire fighting stairs are landlocked Note: BRE shaft and Colt Shaft have significantly reduced this market for pressurisation of fire fighting stairs A requirement for some fire fighting stairs An alternative to lobbies and/or discounting of a stair in some buildings Pressurisation systems should conform to the requirements of EN :2005 While these other methods often meet the requirements of the building codes, none of these are quite as effective as pressurisation for keeping a space smoke free. Where pressurisation is selected, it should be designed to the EN standard

BS 9999: 2008 recommends Pressurisation (designed to EN ) to: Replace separation of dead end corridors with a fire door Replace protected lobbies in single stair buildings, buildings over 18m, buildings with phased evacuation and buildings where a stair has not been discounted in the sizing of escape widths Allow a single stair to extend down to a basement Protect fire fighting shafts over 10m deep and over 30m tall (Class B) The latest fire safety standard, BS 9999 also refers to pressurisation for specific applications

Pressurisation Systems - Installations
West India Quay, London Colt have experience in the design of systems for all varieties of buildings from apartments to high rise offices Oxford Road, Leicester

Pressurisation Systems - Installations
To fire fighting stairs to basements and hotels Beetham Tower, Birmingham Holiday Inn Express, Hull

Pressurisation Systems - EN 12101 - 6 Building Classification
System Class Application Typical Building Type A Means of Escape Stay put policy Residential B Means of Escape and Fire fighting Where fire fighting core is required C Simultaneous Evac. Commercial D Sleeping Risk Hotels/Hospitals E Phased Evacuation High rise offices Press. Systems are classified into 5 groups, each with different design criteria, depending on the risk/application

Pressurisation Systems - Basic principles
The system must protect against smoke entering the stairs or travelling between storeys via lifts accessed from protected lobbies The intent is to have the highest pressure in the stairs and a reducing pressure gradient through to the accommodation All ‘pressures’ described are actually pressure differentials to the accommodation Press. Systems work by maintaining a higher ‘differential’ pressure in the protected space than in the surrounding spaces where fires could possibly occur. The pressures achieved are all relative to the reference point, that is, the room containing the fire.

Pressurisation Systems - Basic principles
All pressurisation systems require 3 basic components: A means of supplying clean air to pressurised areas A means of ensuring excessive pressure differentials do not occur A means of relieving pressure from the accommodation Press. Systems must have a means of getting clean air into the building, a means of preventing too much pressure occurring and a means of getting the air out of the unpressurised space.

Pressurisation Systems - Which areas do we pressurise?
The first decision to make for any system Depends upon class of pressurisation Depends upon building layout Is there a lift? Where is suitable for accommodation air release The class of press. System will depend on the type of building, the buildings use, the type of stair to be pressurised and why it is being pressurised.

Pressurisation Systems - Stairs (with simple lobby)
Pressurise the stairs only. Only used where the staircase is entered via a simple lobby (i.e. a lobby without lifts or other possible escape route) or directly from the accommodation. Stairs +ve Simple lobby The simplest systems require only the staircase to be pressurised. In which case, air is supplied direct into the staircase and allowed to leak from the adjacent lobby Air supply Accommodation

Pressurisation Systems - Stairs, lobby & lift
Pressurise stairs and lobbies. Used to extend protection to lobbies Lift +ve Accommodation Air supply Where the layout is more complex it may be necessary to supply air to both the stair and the lobby. +ve Stairs

Pressurise stairs and lift. Used when the lobby is not pressurised to prevent smoke from spreading via the lift well. The lobby becomes a simple lobby +ve Lift Air supply Accommodation +ve Stairs

Generally only used in fire fighting – Class B +ve Lift +ve Lobby Accommodation Air supply Fire fighting cores will usually contain a protected stair, protected lobby and fire fighting lift – all 3 need pressurising the lobby should be slightly lower than the stairs and lift. +ve Stairs

Pressurisation Systems - What performance is required?
Depending upon the class of system we have set criteria to achieve: Pressure differentials Velocity through open door Limited door opening force The different classifications of system have different criteria to meet, but the basic requirements are a pressure differential in the stair/lobby/lift and a velocity through the door when open to the accommodation space. The different classifications will specify what pressures/velocities should be achieved when certain doors or combinations of doors are open/closed

Pressurisation Systems - Class A - Doors closed
Duty Pressure relief damper /standby fan 50Pa FIRE FLOOR (LOBBY/CORR) Automatic air release (above ventilator accomm odation) Ductwork system Smoke detector Door opening force not to exceed 100N Class A should achieve 50Pa in the staircase when all the stair doors are closed. the door opening force should not exceed 100N – this is of particular importance to doors opening into the pressurised space. Stairs First floor Ground floor

Pressurisation Systems - Class A - Door open
Duty Pressure relief damper /standby fan FIRE FLOOR (LOBBY/CORR) Accommodation air release 0.75 m/s average velocity ventilator Ductwork system Smoke detector When the door to the accommodation is open, the system should achieve an average velocity of 0.75m/s across the door Stairs First floor Ground floor

Pressurisation Systems - Class A - Means of escape - Stay put policy
Do not attempt to pressurise the corridors up to dwelling front doors Provide air release from the corridor or lobby Long corridors will be fitted with smoke seal doors - air release needs to be on stairs side of nearest doors Class A applies to residential buildings, but the air relief path cannot be through the occupants apartment – this would rely on the owner of the apartment maintaining components of the system and not tampering with them. The air relief system must be kept in common areas.

Pressurisation Systems - Class A
Accommodation Air release via ventilator Air release via shaft Where an outside wall is available, a natural vent can be used, although to comply with the standard completely, this should be on two separate facades. Alternatively a common shaft system may be used.

Pressurisation Systems - Class B - Fire Fighting Stairs
Requirement for stairs set by ADB and BS or BS 9999 Pressurised lobbies essential Lobbies may contain fire fighting lift, which also needs to be pressurised A fire fighting stair has the most onerous design criteria and all associated areas must be protected.

Pressurisation Systems - Class B - Doors closed
Duty Pressure relief damper /standby fan Supply to stair, lift and lobby 50 Pa 45 Pa above above FIRE FLOOR accomm accomm Accommodation air release odation odation ventilator Ductwork system Smoke detector Door opening force not to exceed 100N Stairs When all doors are closed, the system must achieve 50Pa in the staircase and lift and 45Pa in the lobby, relative to the accommodation rooms. In addition, the door opening force should not exceed 100N – this is of particular importance to doors opening into the pressurised space. First floor Ground floor

Pressurisation Systems - Class B - Doors open
Duty Pressure relief damper /standby fan FIRE FLOOR 2 m/s average velocity Accommodation air release ventilator Ductwork system Smoke detector Lift door open if fitted Stairs In the open door condition, the system must achieve an average velocity of 2m/s across the door into the accommodation space with the lobby door and stair door open on the fire floor, the stair door and the lift door open on the floor below and the final exit door open at the bottom of the staircase. If the stair has a lobby at the fire service access level and an external rising main inlet point, then this final open door may be discounted First floor Ground floor

Closed Door Requirements
Pressurisation Systems Closed Door Requirements Open Door Requirement Class Stair (Pa) Lift Shaft (Pa) Lobby (Pa) Velocity (m/s) Open Doors A 50 50* 45* 0.75 Stair door on fire floor B 45 2.0 Stair door on floor below Lobby door on fire floor Lift door on floor below Final exit door C Stair door on fire floor + 10Pa pressure difference with final exit door open only D Stair door on fire floor and final exit door + 10 Pa pressure difference with final exit door open and one stair door other than the fire floor E Stair door on fire floor and another floor and final exit door + 10 Pa pressure difference with final exit door and two stair doors open other than the fire floor In the open door condition, the system must achieve an average velocity of 2m/s across the door into the accommodation space with the lobby door and stair door open on the fire floor, the stair door and the lift door open on the floor below and the final exit door open at the bottom of the staircase. If the stair has a lobby at the fire service access level and an external rising main inlet point, then this final open door may be discounted * Pressurising these spaces is at the discretion of the system designer

Pressurisation Systems - Class C Doors closed
Duty Pressure relief damper /standby fan 50Pa Accommodation air release above FIRE FLOOR ventilator accomm odation Ductwork system Smoke detector Door opening force not to exceed 100N Class C applies to commercial buildings and should achieve 50Pa in the staircase when all the stair doors are closed. Door opening force should again not exceed 100N Stairs First floor Ground floor

Pressurisation Systems - Class C - Exit door open
Duty Pressure relief damper /standby fan 10 Pa above FIRE FLOOR accomm Accommodation air release odation ventilator Ductwork system Smoke detector When the final exit door is open, the pressure in the stair should be at least 10 Pa above the accommodation space Stairs First floor Ground floor

Pressurisation Systems - Class C - Door open
Duty Pressure relief damper /standby fan FIRE FLOOR Accommodation air release 0.75 m/s average velocity ventilator Ductwork system Smoke detector When the door to the fire floor only is open, an average velocity of 0.75m/s must be achieved across the door. Stairs First floor Ground floor

Pressurisation Systems - Class D - Doors closed
Duty Pressure relief damper /standby fan 50Pa Accommodation air release above FIRE FLOOR ventilator accomm odation Ductwork system Smoke detector Door opening force not to exceed 100N Class D applies to buildings where occupants may be asleep, e.g. hotels. System should achieve 50Pa in the staircase when all the stair doors are closed. Door opening force should again not exceed 100N Stairs First floor Ground floor

Pressurisation Systems - Class D - Exit door open
Duty Pressure relief damper /standby fan 10 Pa above FIRE FLOOR accomm Accommodation air release odation ventilator Ductwork system Smoke detector When the final exit door is open, the pressure in the stair should be at least 10 Pa above the accommodation space Stairs First floor Ground floor

Pressurisation Systems - Class D - Doors open
Duty Pressure relief damper /standby fan FIRE FLOOR Accommodation air release 0.75 m/s average velocity ventilator Ductwork system Smoke detector When the both the final exit door and the door to the fire floor only is open, an average velocity of 0.75m/s must be achieved across the door. Stairs First floor Ground floor

Pressurisation Systems - Class E - Doors closed
Duty Pressure relief damper /standby fan FIRE FLOOR Accommodation air release 0.75 m/s average velocity ventilator Ductwork system Smoke detector Class E applies to buildings designed with phased evacuation, i.e. where the building is not all evacuated at once. System should achieve 50Pa in the staircase when all the stair doors are closed. Door opening force should again not exceed 100N Stairs First floor Ground floor

Pressurisation Systems - Class E – Exit Door open
Duty Pressure relief damper /standby fan Accommodation air release ventilator Ductwork system Smoke detector 10 Pa FIRE FLOOR above accomm odation Stairs System should achieve 10Pa between stair and fire floor when doors on two floors remote from the fire floor, plus the final exit door are open First floor Ground floor

Pressurisation Systems - Class E - Doors open
Duty Pressure relief damper /standby fan Smoke detector Ductwork system FIRE FLOOR 0.75 m/s average velocity Accommodation air release ventilator In the open door condition, the system must achieve an average velocity of 0.75m/s across the door into the accommodation space with the stair door open on the fire floor, the stair door on another floor and the final exit door open at the bottom of the staircase. Stairs First floor Ground floor

Pressurisation Systems - Equipment
Fans ambient rated duty + standby (or standby motor) if only one MOE route; usually in series to save space One fan set may supply stairs, lobbies and lift shaft not usually attenuated unless needed for test periods In 1 hour fire rated enclosure or roof Power supplies primary + secondary Mains + generator or separate mains supply Pressure relief usually gravity damper in stair inverter control of fans possible but difficult due to response speed requirement Run and standby fans are required along with standby power supplies – pressure relief is required in the staircase to relieve excess air between the door open and door closed scenarios. EN has a stringent limitation on the response time of the system which makes the use of inverters very difficult although in some instances, there is little choice.

Ductwork separate vertical ducts for stair, lobbies, lift shaft ambient rated unless breaching fire compartmentation Builders work shafts are suitable if well sealed VCD required at each tee and grille for balancing Two separate inlets facing different directions with smoke detector operated inlet dampers if at roof level Grilles one per 3 storeys in stair one per lobby one per 30m in lift shaft If multiple pressurised spaces are required e.g. stair/lobby/lift, there should be separate ducts serving each. For systems being fed from high level, two inlets are required, facing onto differing facades of the building, with a smoke detector on the primary intake. If smoke is detected. The primary should close and hopefully the other intake will be on a smoke free façade. For systems fed at low level, only one intake is required – if smoke is detected, then the whole system shuts down. It is advisable to provide VCDS on every supply duct and at each branch/level, to make the system as flexible as possible for balancing purposes. The staircase should have input grilles on every third level.

Volume control dampers on each section of ducting Twin air intakes on separate facades of the building with motorised dampers and smoke detector control

Accommodation air release by leakage, ventilators, natural or mechanical shaft leakage can be from building fabric, HVAC ductwork, permanent trickle vents, but not window breakage ventilators must be provided on at least 2 sides, discount the side with the largest vent area (2.5m/s) Natural shaft terminations need to be located to minimise adverse wind effects (2m/s) Mechanical shafts should operate whenever the pressurisation system does and should not cause excess pressure differentials Accommodation air release is required to keep the fire floor at a neutral pressure. This can be provided by fixed or automatic vents to outside in which case these should be on two facades, to prevent wind pressures affecting the system – sized to allow air to be relieved at no more than 2.5m/s. A common shaft serving several levels – only the fire floor opens – sized at 2m/s Mechanical ventilation – again only form the fire floor and should not cause excess pressure differentials

Pressurisation Systems - Controls
Initiation – From automatic fire detection system Needs to identify fire floor (AAR only from fire floor) Locate detector close to door to pressurised space Class B initiation Can be manual switch from MOE state or direct from automatic fire detection system Accommodation air release only opened on fire floor (to prevent risk of fire/smoke spread) Fire fighter controls provided at base of stair Generally activation should be from an AFD system which identifies which floor the fire is on – class B systems can operate as another class (e.g. A or C) during escape phase and then be manually switched to FF mode. Acc air release should only operate on the fire floor itself.

Pressurisation Systems - Basic Principle
Pump air into a ball or a tyre and we have a positive pressure inside If there is a puncture then to maintain a positive pressure we need to keep pumping air in For a given pressure and a given puncture size we will require a fixed rate of air input to balance the air lost through the puncture A simple analogy to explain the principle

From Bernoulli’s equation: P = 0.5   ( Q2/A2 ) Rewriting and correcting for effective area Q = 0.83  (A P0.5 ) Q is the leakage rate from the pressurised space that we need to balance with supply air The science behind the design is relatively simple

Easy in principle but we have a complex network of leaks and conditions to fulfil Therefore the calculation becomes complex EN devotes a 12 page annex to this Results are: Closed door total air flow Open door total air flow 10Pa total air flow (C-E) Pressure relief air flow However the more complex the building is the more complicated the calculations become – EN gives a detailed explanation of the process.

Pressurisation Systems - Duct sizing
Select duct layout and dimensions ΔP = 0.5 ρ k v2 v is duct velocity k is the pressure loss coefficient for a duct fitting (bend, tee, grille, etc) By summing ΔP for all fittings and duct we obtain the resistance the fan has to overcome Obviously the operating pressure of the system should be added to the fan duty. The resistance of the supply duct system is also required to make the system operate at the calculated duty

Pressurisation Systems - Problems
Most difficulties are caused by building structure being leakier than allowed for Good liaison is needed with architect, builder and services contractor to get well sealed construction The design process makes numerous assumptions regarding leakage rates for walls, doors, windows, etc. The problem comes when the building doesn’t meet up to the rates specified. Often a poor understanding of the system by the architect or builder can lead to inadvertent leakage routes being left, causing the installation to fall short of the design criteria.

Pressurisation Systems - Problems
Design process requires: an assessment of the build quality and an allowance for additional unidentified leakage – this is in effect a ‘guess’ Loose, average or tight construction will affect the leakage rates used in calculation add 50% safety margin + 15% margin for duct leakage + 20% duct pressure loss margin There is often a temptation to reduce the allowances at design stage – this can lead to problems at completion of the project when pressures/velocities cannot be achieved. To compensate, a number of safety factors are added into the design process, but often there are still issues on site

Pressurisation Systems - Commissioning
Check equipment is installed as per design Carry out normal mechanical and electrical checks Set all dampers to fully open Check operation and direction of running of fans Before doing any performance tests - check the state of completion of the protected core Once the installation is complete, a complex commissioning process is then required

Pressurisation Systems - Checklist
Main power supply and standby supply Duty and standby fan Automatic change over Fan located in protected area Fan Inlet protected from effects of smoke Smoke detection provided adjacent to lobby/accommodation door Manual override provided Supply point located at every 3 floor levels Pressure relief damper provided in stair Venting provided from accommodation No smoke seals provided on doors First check that the system has been installed correctly

Pressurisation Systems - Checking the core
All doors must be fitted and close properly All finishes must be complete - carpets laid etc All false ceilings must be in place There must be no temporary openings or unsealed service penetrations Then check that the building and fittings are complete

Pressurisation Systems - Performance testing
While the test method aims to neutralise the effects of wind, testing on windy (and especially blustery) days should be avoided if possible Be prepared and organised before starting testing since there is a maximum time limit between test stages of 15 minutes Ensure all other H&V systems are shut down Once the system is up and running the system will need to be balanced and the performance verified

Pressurisation Systems - Measurement Techniques
Pressure differential Requires a manometer and 2 long flexible tubes Locate end of one tube in the accommodation and the other in the pressurised space, both away from draughts and at least 50mm above floor Manometer then reads pressure differential directly A manometer is used to measure the pressure differences 51

Pressurisation Systems - Measurement Techniques
Requires a rotating vane anemometer Standing to one side (out of air stream) place anemometer in the plane of the door Measure flow rate at 8 locations spread evenly Do not move the anemometer during readings Take arithmetic average of readings A rotating vane anemometer is used to measure the air velocity across the doors and calculate the average.

Before carrying out any tests set the system in operation and run it for at least 10 minutes to equalise temperatures (You can use this period to measure airflow at the fan). Switch off the fan(s), leaving all other components in operating mode. On each floor in turn open all doors, allow them to close and then measure pressure differential across each relevant door. Start by measuring the pressure on each level with the system off

Pressures On each floor in turn open all doors, allow them to close and then measure the pressure differential across each relevant door Measure the opening force required on each relevant door at the door handle Then measure the pressure on each level with the system running

Velocities On each floor in turn open doors as specified in EN and measure average air velocity For classes C, D, E on each floor in turn open doors as specified in EN and measure pressure differential between stair and accommodation Adjust system as necessary and retest until all pressures and velocities are correct Then measure the open door velocities as required by the system design

The procedure is simple, but in practice: Excessive leakage is often a problem and can lead to a need for multiple commissioning visits and arguments with the builder Testing and balancing large systems can be very time consuming, especially with pressurised lobbies The final commissioning procedure is often problematic – it is only at the final stage that it can be established that the pressure cannot be achieved and frantic sealing of building joints takes place. This final testing is best done out of hours as during normal hours, the stairs are generally in constant use by trades people

Pressurisation Systems - Summary
Do you need pressurisation? Select system Class Decide on areas to be pressurised Select AAR method Calculate flows Select equipment Install and commission There are moves to simplify EN but this will not be published until 2011 at the earliest.

Q&A Session… Pressurisation Systems – Performnce testing
Ventilation In Car Parks Thank You Q&A Session… “People feel better in Colt conditions” |

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