SMOKE CONTROL DOORS AND SHUTTERS

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1 FIRE AND SECURITY EGOLF WORKSHOP Hosted by The January 30th and 31th 2018, Copenhagen, Denmark SMOKE CONTROL DOORS AND SHUTTERS There are several problematic issues in standard EN See the enclosed problem overview. DBI has therefore gladly accepted to host to a workshop for Testing Professionals from Egolf laboratories, where we will discuss the problems and issues in standard EN set up by DBI. The aim of the workshop is to come up with a set of suggestions for improvement for a revision proposal of standard EN The revision proposal will be sent to TC127 - WG3 It is essential that attendees have experience in performing smoke control tests and have considered the attached issues establish by DBI. If attendees have other issues with standard EN , DBI encourage to send them to DBI prior to the workshop so they can be discussed. >>Sign-up here WORKSHOP LEADERS Christian B. Andersen Master of Engineering can@brandogsikring.dk Niklas O. Lauersen M.Sc. Eng nol@brandogsikring.dk DBI Jernholmen Hvidovre Tlf: dbi@brandogsikring.dk

2 FIRE AND SECURITY PROGRAM TUESDAY JANUARY 30 TH 8:30 9:00 Registration 9:00 9:15 Opening and welcome 9:15 10:30 Presentation of problems to discuss 10:30 10:45 Coffee break 10:45 12:00 Discussions 12:00 12:30 Lunch break 12:30 14:00 Discussions 14:00 14:30 Coffee break and walk to laboratory 14:30 15:30 Smoke control test Discussion of practical problems 15:30 16:00 Round up practical discussions Afternoon/evening Social event/dinner WEDNESDAY JANUARY 31 TH 9:00 10:30 Discussions 10:30 10:45 Coffee break 10:45 12:00 Discussions 12:00 12:30 Lunch break 12:30 13:30 Conclusions and closing DBI Jernholmen Hvidovre Tlf:

3 Issues regarding EN : Smoke control doors and shutters. This helpdesk mainly concerns test at medium temperature (S m classification): 1. Heating control Problem: The heating/cooling of the air in the chamber greatly affects the pressure inside the test chamber. The smoke control test apparatus DBI uses is made by ift Rosenheim and heats up the air inside the test chamber with large electrical heat exchanger. When the temperature of 200 C is reached the test rig I programmed to keep the temperature at 200. It does this by turning the heat exchanger on and off and it can easily keep it 200±5 C for the duration of the test. The problem occurs when the pressure is measured inside the test chamber during this phase. The pressure is very unstable and goes up when the heater turns on and goes down when it turns off. The temperature does not vary a lot but the pressure does. We have tried to calculate what happens inside the chamber when the heater turns on. A rise in the average temperature from 200 C to 201 C of the air inside an air tight chamber (no leakage) with a constant volume and a starting pressure of 1 atm = Pa will raise the pressure with 214 Pa, se equations below: = = = = = = = =214 In reality there will not be an increase of 214 Pa in the test chamber when the temperature goes from 200 C to 201 C due the fact that the test chamber is not completely air tight. Both the test rig and the test specimen allow for equalizing of the pressure and the test rig is also flexible so the volume is also increased when the pressure goes up reducing the effect of the temperature increase. But still this shows how important the temperature control is for the test result. The only demand in the standard is to keep the temperature between 200 C ±20 C during the test and that the pressure difference shall be maintained for 2 min and the value of Q t established at the end of this period. With an allowed temperature of 200 C ±20 C it will be completely random which result the door will get, when a 1 C temperature change can affect the pressure by 214Pa. The statement from the standard, that the pressure shall be maintained for 2 minutes does not help a lot when there is not given any range of the allowed pressure variations ex. +-5 Pa and the pressure can be stabile while the temperature goes up/down because the leakage rate is controlled to keep the pressure at a given point. Suggestion: DBI suggests that when the temperature in the test chamber reaches 200 C the temperature is controlled by setting the effect of the heat exchanger to a specific setting and moving it up and down until Page 1 of 6

4 the temperature is stabile. The effect needed to keep the temperature on 200 C is on our test rig normally between 50-60% depending on the test specimen. It takes approx. 2 minutes to find the correct setting and to get stabile conditions. With this method we insure that the heater does not affect the pressure by turning on and off and the heating of the air in the test chamber will be even and controlled in steps down to 0.1%. With this method the temperature can be controlled with a precision of ±2 C and the pressure will be much more stabile and reliable. 2. Pressure gradient / Placement of pressure measuring device Problem: The standard does not take the pressure gradient inside the test chamber during the medium test into account. The pressure gradient inside the chamber is approx. 4.5 Pa/m when the air in chamber is 200 C and the air outside the chamber is 20 C, see the equation below: = = =4.496 / The standard prescribes that the pressure inside the test chamber should be measured at the center of the test specimen. The pressure in the center of the test specimen will therefore depend on how high up the specimen is mounted in the test rig and in which height the opening valve (zero point) is placed. Also DBI s smoke control test apparatus was delivered with a moveable pressure measuring device that entered from the top of the test specimen and could then pulled down and placed at the center of the test 100 mm form the test specimen. This does not make any sense, since the pressure always will be measured at the height where the hose/tube leaves the chamber (because the air in the pressure tube inside the camber will quickly rise to the camber temperature). The whole sentence in 9.2 in the standard should be rewritten, so it makes more sense. Suggestion: DBI suggests that the pressure can be measured at any point inside the chamber approx. 100 mm in from the specimen/test frame. The pressure should be reset/zeroed before the fan system is started; this is explained in detail further down. When the pressure is reset/zeroed beforehand then it does not matter in which height the pressure is measured because now we are measuring a pressure difference, so the placement of the pressure gradient is taken out of the equation. 3. Moisture Vapor pressure Problem: The moisture in the test specimen, supporting construction and in the air has a great impact on the pressure in the test chamber. When the air in the test chamber has reached 200 C the heat will start to dry out the test specimen and the supporting construction and the released moisture will be absorbed in the chamber air. Page 2 of 6

5 The following calculation shows that if the moisture level of the air in the chamber is increased with 1 gram of water per cubic meter the pressure will rise with 217 Pa. = = = = = =217 Again in reality the increase in pressure will not be this high, the test rig and test specimen are not completely air tight and will reduce the effect. But if the moisture keeps evaporating from the supporting construction and test specimen the pressure will stabilize and our experience is that the pressure in the chamber will end at approx Pa with the opening valve open and Pa with the opening valve closed. This implies that if we measure the air flow now we will get minus values for flow rate at 15 Pa and 25 Pa because the pressure will be higher than the limit and air will flow backwards through flow meter. At 50 Pa the flow will have a possible value but the flow only have to increase the pressure from Pa to 50 Pa and only the flow needed for this is measured. This means that a wet supporting construction with the current method will help (reduce the volume flow measurement) the test specimen. Suggestion: DBI cannot see a way to take the vapor pressure into account; it will never be a fixed value, it will depend on the moisture of the supporting construction and the test specimen. DBI suggests that after the chamber has reached 200 C the opening valve is closed and the pressure will reach an equilibrium stage while the temperature in the chamber is getting stabile. After the chamber has reached stabile conditioned the pressure is zeroed/reset or noted. The flow is now measured with an increase in pressure of 15 ΔPa 25 ΔPa and 50 ΔPa. In this way the increase in flow rate will directly increase the pressure by 15, 25 and 50 pa and the measured flows will be correct. Of course the door will experience a higher pressure but the flow rate is only measured from the increase in pressure from the starting value or the 0 value after the reset. The standard could specify the effects of high/low moisture content in the supporting construction/ test chamber and maybe specify that the moisture content in the chamber should be measured during the tests in order to see the effects of the moisture content on the leakage results. 4. The adjustment of leakage rate to 20 C Problem: Egolf recommendation EGR 65:2012 states that the leakage rate shall be adjusted to standard reference conditions 20 C and pressure Pa. The actual leakage from the test rig and test specimen (V 2 ) at stabile conditions with 50 Pa inside the chamber and an measured volume flow (V 1 ) blown into the chamber of 20 C air at 10 m 3 /h will be: Page 3 of 6

6 = = = = = h =16.13 h This shows that when the actual leakage from the specimen and test rig is m 3 /h, the leakage rate reported in the test report would be 10 m 3 /h. This will with DBI s experience end with results showing that the leakage rates through the test specimen drops from the ambient to the medium test, making the test specimen seem tighter at 200 C than at 20 C even though this is not the case. Suggestion: DBI suggests that the leakage rate reported in the test report should be the actual leakage at 200 C. To adjust the volume leakage to ambient conditions 20 C at 1 atm, as EGR 65:2012 suggests do not make much sense to us. It will also be easier to see a correspondence in the leakage at ambient and medium temperature if the actual leakage is used. This would affect the pass/failure criteria limit for Sm classification, but we believe that the limit of 20 m 3 /h for single leaf doorset and 30 m 3 /h for double leaf doorset could still be used. 5. Reducing the number of measurement points DBI suggests removing the measurements at 15 Pa for ambient temperature tests and the measurements at 15 Pa and 25 Pa for medium temperature test. These measurements are not critical and do not give important information to the client, and it is DBI experience the volume flow always is lower than the measurement at higher pressures. Especially the two measurements at 15 Pa and 25 Pa during the medium test, can course some problems because it takes a lot of time to get stabile conditions and all the measurements need to be taken within 10 minutes. The time to reach temperature stability at 200 C takes time and it must be reestablished each time the designated pressure is changed due to the fact that additional 20 C air is blown inside the chamber increasing the leakage and the heating needed to keep a stabile temperature. There will be more time to reach stable condition and to do the measurements if only the volume flow at 50 Pa shall be measured. This will allow for the volume flow measurement to be taken over a longer period increasing the accuracy of the measurement. 6. Background test after the leakage tests Problem: The standard describes in section d) that the leakage rate of the apparatus and the supporting construction should be measured at medium temperature after the total leakage test at medium temperature only. For a single leaf door, the limit to get the classification S m, is a specimen leakage under 20m³/h. The specimen leakage is the total leakage minus the leakage of the apparatus and supporting construction. This means that if the total leakage exceeds 20m³/h the client will have to wait until after the background test to know if the test specimen passed. Page 4 of 6

7 Suggestion: DBI suggests that the leakage rate of the apparatus and the supporting construction at medium temperature should be measured prior to the tests and before the test chamber leakage at ambient is verified to be less than 10m³/h. The client then knows the precise volume flow needed to achieve the S m classification. It also has another advantage because if the medium background leakage is done before the leakage tests, the supporting construction will have been heated up before the test and some of the moisture would have left the construction reducing the effect of the vapor pressure during the real test. With this method the leakage from the supporting construction is measured before the specimen has been installed, tested and removed from the test frame instead of doing it afterwards. If the background leakage test is done afterwards there is an increased possibility that the supporting construction will be slightly damaged resulting in an increased background leakage compared to if the background was done beforehand. 7. Sealing the threshold at ambient temperature tests The test standard describes in section 6.4 and section the possibility to seal the threshold gap with an impermeable material during the ambient temperature test. In DBI s view this part should be taken out of the standard. It makes little sense to measure the air leakage of a door if the biggest gap in the door is sealed during the leakage test. In some situations the smoke layer will be above the threshold but this will depend on the position of the door and how it is intended to be used. We believe that allowing a S a door to have a large gap at the threshold will in practices make It useless. 8. Heating up period The sentence in the standard in During the heating up period, neutral pressure shall be maintained in the test chamber should be removed or rewritten, because the statement is not physically possible. During the heating phase the pressure in the chamber will increase a lot due to the expansion of the air. The only thing to do is to open the opening valve to reduce the increase in pressure but with DBI s experience the pressure will nonetheless rise to approx. 100 Pa at the beginning of the heating phase. Page 5 of 6

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