Refrigerated Storage
Contents
1. Aspirating Systems efrigerated Storage e oh y diki 1 194 E lt 11x04 T a a 11x304 SYSTEM S9 SENSOR Refrigerated Storage Application Notes Preface System Sensor has produced this Design Guide as a reference to be consulted when designing and specifying System Sensor fire protection solutions for freezers cold storage areas and loading bays with temperatures ranging from minus 40 C 40 F to 18 C 65 F Unlike most commonly used passive fire detection devices System Sensor detectors are able to function in sub zero climates without losing their very early warning smoke detection capabilities In this Design Guide we will discuss the relevant design considerations and make recommendations regarding the most effective way in which to install a System Sensor solution in the particular refrigerated storage facility for which it is being designed Important Note The information contained in this Design Guide should be used in conjunction with specific local fire codes and standards as well as the guidelines provided in the System Sensor System Design Manual Where applicable other regional industry practices should also be adhered to Note This document is intended only as a guide to the application of fire detection systems Reference must be made to relevant national and local standards Refrigerated Storage Application Notes2. 0 40 40 30 22 20 4 10 14 0 32 10 50 Sampled Air Temperature deg C F Figure 19 Estimated heat tape length Note This document is intended only as a guide to the application of fire detection systems page 22 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes References 1 System Sensor System Design Manual 2 NFPA Fire Analysis amp Research Division 2003 Se ections from the U S fire problem overview report Leading causes and other patterns and trends Storage properties excluding dwelling garages 3 Australian Standard AS NZS 4360 1999 Risk Management Standard 4 SFPE 2002 Handbook of Fire Protection Engineering 3 Edition 5 Australian Government State and Territories of Australia 2005 nternational Fire Engineering Guidelines 6 British Standard BS 7974 2001 Application of Fire Safety Engineering Principles to the Design of Buildings Code of Practice 7 SFPE 2000 Engineering Guide to Performance Based Fire Protection Analysis and Design of Buildings 8 SFPE amp ICC 2004 Zhe Code Officials Guide To Performance Based Design Review 9 NFPA 2002 National Fire Alarm Code 72 10 The Plastics Pipe Institute Inc 1999 Suggested Temperature Limitations for the Operation and Installation of Thermoplastic Pipes in Non pressure Applications TN 11 99 WWW D lasticpipes org 11 PPFA 2003
3. E tY E 40 I min S Bos z 3 25 4 8 7 3 a a 8 6 20 T 30 I min uw m a 5 15 4 20min 3 10 2 5 1 0 1 7 0 40 40 30 22 20 4 10 14 0 32 Sampled Air Temperature deg C F Figure 13 Chart showing the estimated required PE 80 PE 100 pipe extension for sampled air warming 4 2 Heat Tracing In extreme cases where there is no space to run pipe extensions or the external temperature varies widely heat tracing may be employed for sampled air warming However this approach to warming sampled air is NOT recommended by System Sensor as it has not been validated by Factory Mutual FM Important Note The Appendix contains information on the copper pipe and heat tape lengths required for sampled air warming No design guidelines will be given here If wishing to use heat tracing appropriately qualified Engineers MUST be consulted as to the most suitable method to be used 4 3 Exhaust Air Treatment Air from the System Sensor exhaust pipe MUST be returned to the area from which it was sampled as shown below Figure 14 To Detector gt Short Length Exhaust Port of Pipe 50 mm 2 Freezer Chill f Room Wall penetration Ceiling Penetration Figure 14 Examples ofa System Sensor exhaust pipe being fed back into the area from which the air sample was taken Note This document is intended only as a guide to the application of fire detection systems page 16 Reference must be made to relevant national a
4. The very early warning capability of System Sensor detectors means that they are able to detect the incipient pre combustion stage of a fire which drastically reduces business disruption asset damage and the potential risks to the safety of personnel The design flexibility of System Sensor systems also allows them to be used for the automatic activation of pre action suppression both gaseous and sprinkler The combustible nature of the types of materials normally stored in refrigerated environments combined with the very dry high airflow in such environments creates a significant fire risk Fires will spread rapidly between cardboard or plastics packaging grease impregnated materials food stuffs and wooden pallets Hence the earlier a fire can be detected the better The perishable nature of the goods commonly stored in freezers or coolers makes it essential that any rise in temperature be avoided Heat from a fire or a rise in temperature due to refrigeration system down time following a fire would both result in stock spoilage and hence loss of revenue Even an incipient fire in this type of environment can lead to significant losses if not detected and managed early Stock exposed to low levels of smoke over an extended period of time will become contaminated Other advantages of the System Sensor system are that with a properly designed system performance will be reliable and little influenced by condensation or the high airflows cause
5. Contents Background Information vinnie lon caea duieu ta adededaihaar 1 11 Fire Safety Considerations in Refrigerated Storage Areas csscsscsssssssscesessssscssesscsscescssessesacensesesaesaeeaeseseesnesneess 1 1 2 Perforimance Based DeSethvescasssscussceucvavecsnsessussaancecsseuavessasess EEE EEEE EEEE EES AE E ERa EEE ATE EEEE 1 1 3 Key 0658151 0011510608911 005 iaeei asa a e aaeeea iE aeaaaee a Aaa aa aa Eee Aaa 2 14 Why Use System Sensor Smoke Detection 2 Designing for Effective Fire Protection Kisses essences assets 3 2 1 Levels OF Protection cvs sedsccscessssceccessescsececvischeocsvesesecessescesteusevsescededvesstsssdycoss undvoces ensoovsssssiadededoesevbebdneusibsdsoousiyets 3 2 2 Sampling Pipe Mai acess kanan ea e AEs nS RSA NEKERD aS 4 2 3 Positioning Pipes and Sampling Holes cccscsssssecsseccsseececcessccsceeseceesecesseesscessscessensseeceacensaeenecesssceaseneeseaseees 4 2 4 Sampling Pipe Insulation Seeker ae 6 2 5 Sealing Sampling Pipe Penetration S ssscescssccvecesssdnazescacecccctvesecsaesatussntsszeusssaescasd evesssdcsoaasseveaderueuss vee 6 2 6 Compensating for Sampling Pipe Contraction sssssesessscececesssceseccssscecesssescsceasscsceseasscscceasaceceeeseeatsceeeaeatees 7 2 7 IA FACK Protectio Mscscssecsssctsscdvaccsessconsves
6. adequate with respect to being air tight What temperature range and humidity will be experienced by sampling pipes within the refrigerated storage facility sampling pipes in any other areas to be protected and the detectors themselves Are there likely to be any future changes with regard to the function of the area due to demand or operational needs For example might a refrigerated storage facility be converted to a cold storage area What are the airflow characteristics of the protected areas entrances and loading bays What are the sampling pipe insulation requirements What effects might the defrost cycles and associated condensation have on fire protection What is the possibility of condensation occurring both within and on the outside of the sampling pipe network What is the configuration of racking within the areas to be protected How well sealed are the wall and ceiling insulation panels Is pre action suppression to be included in the fire protection system and if so how will it be integrated with the System Sensor system SSC 0000 0 ONE 14 Why Use System Sensor Smoke Detection System Sensor Aspirating Smoke Detection ASD systems have been used to protect refrigerated storage facilities for many years Most fire protection technologies which are designed to operate in freezing conditions are not capable of early warning detection and are prone to being damaged by equipment such as forklift trucks
7. detection point spacing or maximum area of coverage per detection point for a variety of different airflow rates ceiling heights and structures etc In compliance with these prescriptive regulations System Sensor sampling holes would be located in the same positions as individual smoke detection devices Alternatively with reference to local codes the sampling pipe and sampling hole configuration can be determined by satisfying performance based design requirements Note For Factory Mutual FM approved refrigerated storage System Sensor installations the sampling holes should be placed as for heat detectors as outlined in the latest edition of the FM 8 29 Datasheet and Memorandum 0805 Sampling hole locations are usually represented by a grid like that shown below Figure 1 The letter X represents the sampling hole spacing required according to local codes and standards Note This document intended only as a guide to the application of fire detection systems Reference must be made to relevant national and local standards Refrigerated Storage Application Notes End Cap with Sampling Hole Freezer Entrance Sampling Holes Figure 1 Top view ofa grid layout for System Sensor sampling holes In some freezers depending on the effectiveness and frequency of defrosting management ice will build up around the entrances Under these circumstances System Sensor sampling holes in the immediate proximity may become blocked by
8. environments within Refrigerated Storage Facilities present a challenge to both early and reliable fire detection Detection system performance can be influenced by factors such as air change rate temperature humidity and the geometry of the area to be protected The flexibility of Performance Based Design concepts while still following rigorous engineering processes allows the fire protection system to be tailored to the specific requirements of each individual application s environment with the commercial drivers to manage the risks Detector spacing or for a System Sensor pipe sampling hole spacing is traditionally dictated by local prescriptive codes and standards In a Performance Based approach each installation is assessed according to its specific environmental conditions Sampling hole spacing and location can then be altered to meet the particular design objectives The Performance Based Design approach is widely used since it can provide evidence to justify divergence from prescriptive requirements particularly in cases where there are practical limitations or a need for an improved level of fire protection There are some specific guidelines for the use of Performance Based Design and risk management concepts Examples of these codes and standards are listed below AS NZ 4360 Risk Management Standard SFPE Handbook of Fire Protection Engineering Third Edition International Fire Engineering Guidelines Edition 2005 Briti
9. for Transport Time requirements 4 6 Battery Backup When using a System Sensor system for pre action suppression activation in the event of a power outage a secondary power supply MUST be available This power supply needs to be capable of running a single System Sensor detector for a total of 90 hours This is in compliance with the fact that approved control panels for the automatic release of pre action or deluge sprinkler systems must have go hours of standby power plus 10 minutes worth of power to operate the sprinkler system and alarms Where the System Sensor system is being used for very early warning smoke detection alone refer to local codes and standards for the battery backup required Note This document intended only as a guide to the application of fire detection systems page 19 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes 5 Ongoing Considerations 5 1 Running the System Sensor System For a new refrigerated storage facility it is preferable that the System Sensor system be powered up and running while the refrigerators are being commissioned This allows the detectors to adjust gradually to the decreasing sampled air temperature If installing System Sensor detectors in an existing facility it is recommended that the pipe network inside the refrigerated areas be installed first and that all points where pipes exit these areas be blocked off This preve
10. ice This is normal and can be managed by specifying an appropriate system airflow fault threshold The effects of blocked sampling holes could be compensated for as follows e By placing the sampling hole closest to the entrances as far away as is legally permitted by local codes and standards e By partial in rack sampling near the entrances Ice build up is usually at the ceiling above the doorways seldom within the racks e By placing System Sensor sampling pipes away from the path of chiller air supplies Note Sampling hole diameter MUST be larger than 3 mm Referring to the grid layout shown above Figure 1 there are two alternative approaches to sampling pipe network configuration design for optimal air sampling performance 1 The sampling pipes can be run along the ceiling inside the area to be protected as shown Figure 2 This technique minimizes the number of pipe penetrations through the walls or ceiling and can be applied in most practical situations Sampling holes MUST be drilled after installation in this case 2 The sampling pipes can be positioned outside the area to be protected with smaller diameter capillary tubes 16 mm 3 4 inches outer diameter fed through the ceiling insulation into the protected area as shown Figure 3 This method requires one ceiling penetration per capillary tube and more pipe connections All penetrations must be adequately sealed to prevent the formation of ice resulting from the entry of humid
11. large amounts of plastic present in this type of facility in the form of packaging materials a fire would produce large amounts of highly toxic and corrosive smoke which would damage assets and endanger personnel The large amounts of fuel available in the form of stock and the highly flammable light weight sandwich panels from which such facilities are constructed would also cause fires to spread quickly from one area to another Table 1 provides guidelines for those areas in a refrigerated storage facility that it is essential to protect Table 1 Guidelines for areas to be protected Area Essential Recommended Optional Freezers Chiller Rooms y Coolers 14 Plant and Maintenance 14 Areas Return Air Path Under the v Protected Area Loading Bays and v Surrounding Areas Office Monitoring Area y Ceiling Roof Voids 14 Within Racks 14 In cases where a pre action sprinkler system is to be included as part of the fire protection the System Sensor system can be used to activate the release mechanisms as discussed in Section 4 5 Note This document is intended only as a guide to the application of fire detection systems Reference must be made to relevant national and local standards Refrigerated Storage Application Notes 2 2 Sampling Pipe Material The choice of sampling pipe material will depend on where the pipe is to be located For instance installa
12. refer to the installation instructions as supplied
13. air or condensation This approach is only appropriate where the refrigerated storage facility has a ceiling void The capillary sampling tubes should be as short as possible less than 4 m 13 ft being recommended They MUST also be sealed during installation Note This document is intended only as a guide to the application of fire detection systems Reference must be made to relevant national and local standards Refrigerated Storage Application Notes Detector Ceiling Insulation Panel Saddle Clip Sampling Hole Figure 2 Ceiling mounted System Sensor sampling pipes Ceiling Void Capillary Tube Figure 3 Example of capillary air sampling Note It is recommended that all drilling of penetration points and the sealing of such points be performed by appropriately experienced personnel Sampling Pipe Insulation Where sampling pipe insulation is needed use a material such as Armaflex or similar Armaflex insulation has a temperature range of 40 C 40 F to 105 C 221 F a density of 88 to 105 kg m and is very flexible For a 25 mm 0 98 internal bore pipe a single layer of insulation 9 mm 0 35 thick is adequate Sealing Sampling Pipe Penetrations Sampling pipe penetrations through ceiling or wall insulation panels MUST be properly sealed with a solid Urethane foam and or flexible mastic material To enhance air tightness a seal and or insulation boot could also be inst
14. alled at the penetration point as shown below Figure 4 Consult local Wall Panel Suppliers for more detailed instructions Note This document intended only as a guide to the application of fire detection systems Reference must be made to relevant national and local standards 2 4 25 Refrigerated Storage Application Notes Figure Example of pipe penetration with an insulation boot and drip tray In order to avoid condensation formation at the penetration point the section of pipe exiting the protected area MUST be insulated as shown Figure 4 A tray can be used to collect any water condensation on the pipe surface 2 6 Compensating for Sampling Pipe Contraction Mounting clips used to secure System Sensor sampling pipes to the ceiling MUST not restrict longitudinal movement of the pipes as they expand or contract due to temperature variations This is especially important where the pipe network is installed before the refrigerators are turned on For example according to its thermal expansion coefficient an ABS pipe will contract by 0 1 for every 10 C 50 F drop in temperature This equates to a 40 mm 1 57 inch reduction in length for a 4o m 131 2 ft pipe and will result in disconnection of pipe sections in cases where the pipes were installed in temperatures well above the intended operating temperature Note Refer to Table 2 for the thermal properties of other commonly used pipe materials To prevent pipe disco
15. apillary air sampling is not recommended for in rack sampling 2 8 Ceiling Void Protection Very early smoke detection is essential due to the high incipient fire risk presented by the electrical cabling and refrigeration control equipment normally housed in the ceiling void Some local codes and standards specify that ceiling void protection must be a component of the fire protection system The sampling hole spacing is determined with reference to local codes and standards according to the grid presented earlier Figure 1 and is shown below Figure 7 oe Sampling Holes ilii lati Figure 7 Example of ceiling void air sampling Note This document intended only as a guide to the application of fire detection systems page 11 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes The System Sensor detectors used to protect the ceiling void MUST be configured as individual fire zones Ceiling void pipes MUST NOT enter any other areas nor should ceiling void detectors be used to simultaneously monitor areas outside the ceiling void 2 9 Other Areas to be Protected For non refrigerated storage areas such as those used for control monitoring loading and office space the sampling hole spacing and pipe network layout are identical to those for the general office environment described in the System Sensor System Design Guide with referen
16. ce to local codes and standards where applicable Detector sensitivity can be adjusted to meet performance requirements Note It is worth considering high sensitivity smoke detection in the areas containing refrigeration control and support equipment since smoke or fire damage in these areas would disrupt business 3 Preventing Condensation and Crystallization 3 1 The Effects of a Temperature Drop Condensation will occur when the air temperature drops below its due point The result is the formation of water droplets if the due point is above 0 C 32 F or ice crystals if the due point is below 0 C 32 F Inside the System Sensor sampling pipe network condensation is unlikely and will only occur if the sampled air is cooled as it passes along the pipe through an area of lower temperature than that from which it was sampled On the outer surface of sampling pipes condensation is expected and can be tolerated During system design all areas to be protected must be categorised according to the criteria listed below e The temperature and humidity changes that will occur if the function of the protected area is changed for example from a chiller to a cooler e The points in the pipe network which are most likely to be prone to condensation This is done by assessing the temperature of the sampled air and the temperature of the air surrounding the sampling pipe network e The air tightness of the pipe network including the detector e
17. d by blast chillers Note This document intended only as a guide to the application of fire detection systems Reference must be made to relevant national and local standards Refrigerated Storage Application Notes The deficiencies of other detector technologies in low temperatures are recognized by many international codes and standards which regulate against the use of them in environments where the ambient temperature is less than 0 C 32 F Linear heat cables are permitted in freezers but are prone to damage by forklift trucks and other common work procedures Since System Sensor detectors are installed outside the protected area only the sampling pipe network is exposed to sub zero temperatures Being on the ceiling and inside voids makes it unlikely that the System Sensor sampling pipes will be damaged Note Unlike the System Sensor system linear heat cables are specifically for the activation of pre action suppression and cannot simultaneously provide the very early warning smoke detection which may prevent the need for suppression 2 Designing for Effective Fire Protection In this section design methodologies will be described with consideration for the different requirements depending on the function of the particular area being protected Important Note The latest version of PipelQ the System Sensor sampling pipe modelling program should be used for all pipe network designs 2A Levels of Protection Due to the
18. ection 6 2 Extra Large gt 1500 m 16200 sq ft 1 0bs m 0 31 obs ft 1 0bs m 0 31 obs ft 110 Table 3 Design guidelines for System Sensor fire alarm settings Large 1000 1500 m 10800 16200 sq ft 1 5 0bs m 0 46 obs ft 1 o0bs m 0 31 o0bs ft 110 Medium 500 1000 m 5400 10800 sq ft 2 obs m 0 61 obs ft 1 5 0bs m 0 46 obs ft 110 Small lt 500 m 5400 sq ft 2 obs m 0 61 0bs ft 1 5007 0 46 obs ft See Note Below and consult local codes This document is intended only as a guide to the application of fire detection systems Reference must be made to relevant national and local standards Any Fire 1 alarm shall put all sprinkler valves in that particular fire zone into armed mode Enclosure Size Fire Alarm General 10 m 30 ft or less Fire Alarm High Ceiling more than 10 m 30 ft Maximum Transport Time Allowed per Zone s page 18 Refrigerated Storage Application Notes Note For small enclosures the Maximum Transport Time Allowed is a function of the ceiling height H and equals 0 14H 0 8H 80 If the Maximum Transport Time Allowed cannot be achieved install additional detectors in the area If the Transport Time is close to the maximum allowed consider reducing the fire alarm threshold by 10 to 20 to compensate Ceiling height restrictions are for FM approval Remember also to consult local codes and standards
19. g pipe and release it via the stop valve Alternatively an end cap can be put on the pipe in place of a stop valve If no condensation is evident after some time the need for a water trap can be dismissed The water trap is intended to catch sampling pipe condensation and prevent water from reaching the detector If the water trap fills up and water enters the main sampling pipe a major flow fault will be raised in the System Sensor system which should then prompt the operator to check the status of the water trap before investigating the sampling holes in the freezer Important Note Water trap stop valves and end caps MUST be replaced as soon as the water has been drained Leaving the pipe open will affect the airflow Important Note Water traps that involve use of a u bend in the pipe and rely upon condensate to reduce air flow in the pipe network have benefits in terms of maintenance where a large amount of condensate gathers but are generally not recommended because of the risk of all condensate evaporating causing air entry into the pipe network and a system imbalance Integration with Pre action Sprinklers The System Sensor smoke detection system can also be used to activate pre action sprinklers if installed For the purposes of pre action sprinkler activation System Sensor protection in rack is usually not required even where there are in rack sprinklers However it is important to refer to the FM memorandum 0805 for further detail
20. ing Considerations sabes assessors ise 17 5 1 Running the System Sensor SyStemM csccsssccssssescsessssessccssessscesssscesessssssseceesecceseessceescsesecescessaecensecsesenseceeees 17 5 2 System COMMISSIONING scc rcsccsevevees vend voces taneercesvacesseevaane ia A a RI ESER EE E SE ESTEE ENE TERENE EES AREER aaa 17 5 3 Selvice afd Maiitelan CE iiss saetan ats aes 17 Appendix Heat Tracing 18 9161611665 sise asas sale aes enema a E cease 20 Note This document intended only as a guide to the application of fire detection systems Reference must be made to relevant national and local standards Refrigerated Storage Application Notes 1 Background Information 1 1 Fire Safety Considerations in Refrigerated Storage Areas According to statistics released by the NFPA the major fire risks within a refrigerated storage facility arise from the following Electrical or mechanical faults in conveyor and other transport equipment Electrical equipment wiring and other equipment housed in the roof space The lighting system Hot spots resulting from maintenance operations Discarded cigarette butts Arson 1 2 Performance Based Design The unique
21. led air including water heaters electrically heated tape and passing the pipe through an area that has been heated to 5 10 C 41 50 F Electrically heated tape is preferred as it is easy to install An example of a pipe covered with heat tape is shown below Figure 17 If the surface temperature is over 30 C 86 F the pipe must be insulated Detector Heat tape around Sampling Pipe covered by insulation A 7 To Power Supply Ceiling Insulation Panel Figure 17 Example of heat tracing with heat tape Raychem heat tape 5BTV2 CT or 3BTV1 CR can be used The following charts provide estimates of copper pipe and heat tape lengths required for heat tracing Variations in ambient temperature are assumed to be negligible due to pipe insulation The surface of the pipe is kept at a temperature of 35 C 95 F and the tape is wound around it at 100 mm 4 intervals along its length E 2 g E E 6 5 40 I min 5 2 o 5 2 a 5 6 4 1 2 0 5 0 0 40 40 30 22 20 4 10 14 0 32 10 50 Sampled Air Temperature deg C F Figure 18 Estimates of copper pipe length for heat tape Note This document intended only as a guide to the application of fire detection systems page 21 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes 3 10 E E 3 5 S 18 e 8 E Le T 4 1 2 0
22. mendation on system design for compliance with any codes or standards that may apply nor have any tests been conducted to assess the appropriateness of any recommendations on system design Any person or organization accessing or using a recommendation on system design should at its own cost and expense procure that the recommendation on system design complies in all respects with the provision of all legislation acts of government regulations rules and by laws for the time being in force and all orders or directions which may be made or given by any statutory or any other competent authority in respect of or affecting the recommendation on system design in any jurisdiction in which it may be implemented System Sensor products must only be installed configured and used strictly in accordance with the General Terms and Conditions User Manual and product documents available from System Sensor System Sensor accepts no liability for the performance of the recommendation on system design or for any products utilized in the implementation of the recommendation on system design aside from the General Terms and Conditions User Manual and product documents No statement of fact drawing or representation made by System Sensor either in this document or orally in relation to this recommendation on system design is to be construed as a representation undertaking or warranty To the extent permitted by law System Sensor excludes liability for all indirect a
23. nd consequential damages however arising For the purposes of this clause consequential damage shall include but not be limited to loss of profit or goodwill or similar financial loss or any payment made or due to any third party Recommendations on system design are provided exclusively to assist in design of systems using System Sensor products No portion of this recommendation on system design can be reproduced without the prior approval in writing of System Sensor Copyright and any associated intellectual property in any such recommendations on system design or documentation remains the property of System Sensor Note This document is intended only as a guide to the application of fire detection systems 0889 Reference must be made to relevant national and local standards SYSTEM SENSOR LTR1 2 S System Sensor Europe Technical Services Charles Avenue Burgess Hill RH15 9TQ United Kingdom Tel 44 0 1444 238820 Fax 44 0 1444 248123 Email sse technical systemsensor com European Manufacturing Centre System Sensor Via Caboto 19 3 34147 Trieste Italy Tel 39 040 949 0111 Fax 39 040 382 137 Email sse sales systemsensor com www systemsensoreurope com Copyright 2009 System Sensor All rights reserved All technical data is correct at time of publication and is subject to change without notice All trademarks acknowledged Installation information in order to ensure full functionality
24. nd local standards Refrigerated Storage Application Notes This closed loop system will prevent pressure differences caused when the System Sensor detector is powered down for any length of time from introducing warm and humid air into the refrigerated storage area via the System Sensor exhaust port Pressure differences will also result in unwanted airflow faults The return pipe from the exhaust should be as short as possible and its penetration into the protected area MUST be air tight Important Note Allinlet and exhaust pipes MUST be closed off whenever the system is powered down or detectors are removed for maintenance Water Traps Water traps are not a requirement of the System Sensor smoke detection system As discussed previously they are only necessary under vastly varying environmental conditions where internal sampling pipe condensation is a possibility An example of a water trap is shown below Figure 15 Penetration From Freezer e N Slopes Down to Draw Away Condensation to Water Trap Detector 7 i ha Figure 15 Example ofa water trap To install a water trap a T section of pipe must be fitted to the pipe entering the detector Water will pool at the stop valve on the downwards pointing arm of the T The transparent section of pipe allows maintenance personnel to see when water is building up before it rises above the intersection with the main samplin
25. nds should be used The chiller air supply is several degrees lower than the air in the rest of the chiller so to prevent ice from forming and blocking the sampling holes sampling pipes MUST NOT be installed in the direct path of the chiller s supply air vent Doing so will lead to crystallisation when the warmer ambient air in the protected area enters the cool pipe If for practical reasons this cannot be avoided the pipe MUST be insulated as shown below Figure 10 Y ee EE PI ARATE SET aera SS EY X xX X 2 Figure 10 Example of pipe insulation to combat ice formation in pipes directly in the path of the chiller air supply the top is a good design the bottom is not Important Note Sampling pipes MUST NOT run from a high temperature area into a lower temperature area Separate System Sensor detectors should be installed in the chiller cooler ceiling void and office areas 4 Installation Considerations 4 1 Sampled Air Warming For optimum detection and ease of maintenance access the System Sensor detector MUST be installed in a location where it is unlikely to experience sub zero temperatures Low temperature sampled air can be easily warmed up before it reaches the detector by extending the sample pipe length beyond its point of exit from the cooler protected area The warmer air outside the pipe near the detector will heat the cold sampled air within it Usually only a short pipe extension is nece
26. nformation amp Technical Guide ABS Pipes amp Fittings WWW P pfa home org 12 Clipsal 2003 HFT Conduits amp Fittings WWW C li psa l com 13 Fisher G 2002 Planning Fundamentals Industrial Piping Systems N N N p i p in 8 0 sher com 14 FM Global 2000 Property Loss Prevention Datasheets 8 29 15 FM 2006 Memorandum Engineering Bulletin 08 05 16 ASHRAE 2003 Psychometric Chart www ashrae com 17 FM Global 2003 Property Loss Prevention Data Sheet 5 40 Fire Alarm Systems Note This document intended only as a guide to the application of fire detection systems page 23 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes Disclaimer On The Provision Of General System Design Recommendations Any recommendation on system design provided by System Sensor is an indication only of what is considered to be the most suitable solution to meet the needs of the common application environments described In some cases the recommendations on system design provided may not suit the unique set of conditions experienced in a particular application environment System Sensor has made no inquiry nor undertaken any due diligence that any of the recommendations supplied will meet any particular application System Sensor makes no warranty as to the suitability or performance of any recommendation on system design System Sensor has not assessed the recom
27. nnections make allowance for pipe contraction along the length of the pipes Saddle or offset clips should be use to secure the System Sensor sampling pipes to the ceiling as shown below Figure 5 Saddle Clip Offset Clip Pipe Clip UK Figure 5 Examples of pipe network supports Note This document is intended only as a guide to the application of fire detection systems page 10 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes Offset clips are preferable since they attach to the ceiling via an adhesive pad and if required can be screwed on to the ceiling The design of offset clips also allows easy movement of the pipes during expansion or contraction To further minimise the possibility of pipe disconnections pipe mounting clips MUST not be positioned next to pipe joiners Clips MUST also be more than 300 mm from the ends of the pipes so that a pipe contraction will not cause its end caps to be forced off 27 In rack Protection In most cases placing a System Sensor sampling pipe network on the ceiling is all that is needed However sampling pipes can also be located along the racks used for storage in the refrigerated area as shown below Figure 6 Figure 6 Example of in rack air sampling Wherever possible the in rack sampling pipe should enter the protected area through the wall at the height that the pipe will be positioned in the rack Note C
28. nts humid air being transferred into the protected area from outside The blockages can be removed once the rest of the pipe network and detectors outside the refrigerated areas have been installed and connected Note It may be necessary to construct enclosures around detectors to protect them from the weather or mechanical damage 5 2 System Commissioning Once the System Sensor system has been installed its performance and pipe network integrity can be verified using the PipelQ pipe modelling program A range of sampled air temperatures may be input to determine Maximum Transport Times for each zone Calculated Transport Times should be applied conservatively Smoke tests can then be used to check system performance for both smoke detection and pre action suppression activation 5 3 Service and Maintenance The System Sensor system shall be serviced and maintained according to both the local codes and standards and the instructions provided in the Maintenance section of the System Sensor System Design Manual The frequency of sampling pipe inspection and testing can be determined by the rate of ice build up to ensure that sampling holes do not become blocked Note This document is intended only as a guide to the application of fire detection systems page 20 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes Appendix Heat Tracing There are several techniques for warming samp
29. s The procedure for integrating System Sensor with pre action sprinklers is outlined below Note This document intended only as a guide to the application of fire detection systems page 17 Reference must be made to relevant national and local standards 4 4 4 5 Refrigerated Storage Application Notes 1 Use ASPIRE2 to design the pipe network and determine Maximum permissible Transport Time For FM approved refrigerated storage System Sensor installations sampling hole spacing should be the same as heat detector spacing as per the latest edition of the FM8 29 Detector Figure 16 Arrangement of the System Sensor sampling pipe network and sprinkler heads on the ceiling Ceiling 14 15 Datasheet and Memorandum 08 05 Install the System Sensor sampling pipe network on the ceiling as shown below Figure 16 Sprinkler Hozzle 3 Set the A ertalarm threshold for early detection and intervention 4 Set the Fire 2 alarm threshold for pre action sprinkler activation as indicated in Table 3 Delays can be configured for both of these alarms Note The smoke thresholds in Table 3 are absolute values hence the environmental background level must be taken into account All values are recommendations only actual values being dependent on individual site conditions such as air change rate storage rack height etc Before using any values the system performance MUST be verified by the commissioning test refer to s
30. seesvesosseadveusecesvvavessoasgasnussavessvessesssduessestsseudsn aS 2 8 Ceiling Void Protection 2 9 OtherAreas to be Protected zsccsc c cczesccscseveseschestasccecsnsersncssstesoieasatehascandeesnseaesaceacesnssseedenns cteed evevssdansscetsseosezevensns 9 Preventing Condensation and Crystallization csscccsssscssssssseesssesessenssssssssseessessssssesssasssesesesessssasssssersnees 9 3 1 The Effects of a Temperatiiie DIOP Alana aaa aaah Sa aaa SSG 9 3 2 Condensation on the Sampling Pipe Outer SUrfaC 44s0s0cussssescesesseneseeneneenesesneneseeneneeneseanensnenenenenees 9 3 3 Crystallization on the Sampling Pipe Outer Surface 10 3 4 Condensation Inside Sampling Pipes ssscssssccsseccssesescessscescecesseesscesscescscescesescessceseesesceseaceaesaeeesecessensaceess 10 3 5 Crystallization Inside Sampling PIPES saison ois 11 INStallation Considerations irate SSSR a 11 4 1 Sampl d Air Warminster aaa 11 4 2 Heat TACs RESA aaa 13 4 3 Exhaust Air Treatment israse aiitra rianan TAERE iain Sao 13 4 4 Water Wraps 6 e aaea e ANE 14 4 5 Integration with Pre action Sprinklers cssscsccscsccecessecececceceececessessscssesceceseescesescececeesesesensee eens 14 4 6 Battery BACK Up cesses Se 16 Ongo
31. sh Standard BS7974 SFPE Engineering Guide to Performance Based Fire Protection Note The SFPE Code Officials Guide to Performance Based Design Review is a very good source of information for Authorities Having Jurisdiction AHJs reviewing and assessing a System Sensor system design for a refrigerated storage facility Performance Based fire protection solutions can be made to comply with local and national codes and standards for buildings and life safety Assessments of the environmental risks and performance requirements specific to the particular Refrigerated Storage Facility are conducted as part of the design process Note This document is intended only as a guide to the application of fire detection systems Reference must be made to relevant national and local standards Refrigerated Storage Application Notes 1 3 Key Design Considerations For the purposes of this Design Guide the following temperature ranges apply to the various areas to be protected e Freezers 40 C to 15 C 40 F to 5 F e Chillers 9 C to 2 C 16 F to 36 F e Coolers and Loading Bays 0 C to 18 C 32 F to 65 F Important Note System Sensor Detectors MUST NOT be installed in sub freezing environments The following should be considered when designing a System Sensor system for a refrigerated storage facility What level of protection is required and how will fire safety be managed Is the integrity of the sampling pipe network
32. ssary The charts below Figure 11 to Figure 13 provide conservative estimates of the pipe extensions required to raise the temperature of the sampled air to an acceptable value for a number of commonly used pipe materials and range of flow rates All calculations assume an external ambient temperature of 20 C 68 F and a sampled air temperature of 4 C 39 F Note This document is intended only as a guide to the application of fire detection systems page 14 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes 12 40 40 l min 1 35 10 30 ABS Pipe Length m ABS Pipe Length ft 30 l min 20 20 I min 40 40 30 22 20 4 10 14 0 32 Sampled Air Temperature deg C F Figure 11 Chart showing the estimated required ABS pipe extension for sampled air warming 6 0 E lt gt lt 5 5 3 6 4 o o 2 a 5 a 2 30 min 20 l min 40 40 30 22 20 4 10 14 0 32 10 50 Sampled Air Temperature deg C F Figure 12 Chart showing the estimated required Copper pipe extension for sampled air warming Note This document intended only as a guide to the application of fire detection systems page 15 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes
33. th silicone to prevent ice formation Section of Pipe Not Sprayed wath Silicone Figure 9 Example of ice formation on sampling pipes close to the refrigerator entrance 3 4 Condensation Inside Sampling Pipes Condensation inside sampling pipes outside the protected area is rare However it can occur if the function of the protected area changes and or as a result of seasonal temperature variations For example if a chiller 9 C 16 F is converted to a cooler 8 C 46 F condensation may form inside the pipes outside the cooler during winter when the temperature could conceivably drop below 8 C 46 F The following measures will ensure that condensation forming in the pipes does not enter the detector e Install the detector with the pipe running below the detector Rise the pipe above the detector as close as practicable to enter from the top Figure 2 e Install a water trap as discussed later in Section 4 4 Note This document intended only as a guide to the application of fire detection systems page 13 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes 3 5 Crystallization Inside Sampling Pipes In order to minimise the possibility of ice plug formation inside the sampling pipe 90 elbow junctions between pipe sections should be avoided Where it is essential to change the orientation of the pipe from horizontal to vertical or vice versa large radius be
34. tion of ceiling mounted sampling pipes can be made easier by using long lengths of pipe material suited to coping with low temperatures and internal temperature fluctuations Such materials include the Halogen free Fire retardant high Temperature HFT plastics Acrylonitrile Butadiene Styrene ABS and High Density Polyethylene HDPE Suitable materials and their properties are presented in Table 2 below Table 2 Properties and recommended applications for sampling pipe material Material Operating Temperature Thermal Contraction Recommended Applications PVC 18 C 40 to 120 F 7 0 mm per 10 m per 10 C Above 18 C 0 F 0 28 per 32 8 ft per 18 F HFT 40 to 140 C 7 0 mm per 10 m per 10 C Above 40 C 40 F 40 to 284 F 0 28 per 32 8 ft per 18 F ABS 40 to 80 C 10 1 mm per 10 m per 10 C Above 40 C 40 F 40 to 176 F 0 4 per 32 8 ft per 18 F CPVC 18 to 94 C 6 7 mm per 10 m per 10 C Above 20 C 0 F 0 to 201 F 0 26 per 32 8 ft per 18 F PE 80 50 to 60 C 20 mm per 10 m per 10 C Above 50 C 58 F 58 to 140 F 0 79 per 32 8 ft per 18 C PE 100 50 to 60 C 13 mm per 10 m per 10 C Above 50 C 58 F 58 to 140 F 0 52 per 32 8 ft per 18 F An added advantage of using a continuous semi flexible pipe material such as HDPE is the reduction in the number of pipe junctions required 2 3 Positioning Pipes and Sampling Holes The various international codes and standards specify
35. xhaust pipe e The distances from both the protected area entrances and chiller air supply paths of both the sampling pipe and sampling holes 32 Condensation on the Sampling Pipe Outer Surface Condensation occurs on the outer surface of the sampling pipes and capillary tubes where they exit the cold storage area and enter warmer environments such as a ceiling void or other non freezer areas Depending on the temperature of the pipe surface in these areas water droplets or ice crystals will form A water tray should be used to collect any liquid before it spills over the ceiling insulation panels as shown below Figure 8 Note The water tray must be large enough to allow evaporation to occur at an acceptable rate to prevent overflow Note This document is intended only as a guide to the application of fire detection systems page 12 Reference must be made to relevant national and local standards Refrigerated Storage Application Notes Figure 8 Example of a water tray 3 3 Crystallization on the Sampling Pipe Outer Surface Occasionally ice will form on the exterior of the sections of sampling pipe close to the refrigerator entrances as shown below Figure 9 This ice build up is normal and has no adverse effect on the operation of the System Sensor system provided that sampling holes are not located in the susceptible sections of pipe where they can become blocked Sampling holes nearest to the entrances should be sprayed wi
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