Targeted Forced Extraction System in a Electrical Switchroom 2

[Ian3142]

I’m not a HVAC eng and would like information / advice on the following

As part of a project I am working on we are adding a targeted forced extraction system in a Electrical Switchroom – this is on an FPSO ( Floating Production Storage and Off take Vessel) situated about 80 miles from Aberdeen in the north sea.

The extract system targets 6 of the “hottest“ pieces of equipment in the switchroom and draws the hot air through a duct and exhausts through a fire damper to atmosphere .

I think that we will require smoke detectors in the ducts so that if one of the panels we are targeting goes on fire we can notify the Fire and Gas system – there is smoke detection in the switchroom but I think that any smoke will be drawn into the ducts rather than released into the switchroom.

The vendor we are using have manufactured this system before and have never put in smoke detection before, they are advising using one detector just before the fire damper if at all. Would this be sufficient or would it be better /safer to put one in each branch of the ductwork (basically there are three branches in an “E” shape).

Are there any regulations regarding forced extraction systems?

The ducts are 350mm round can you get smoke detectors to fit in these?

Thanks

Ian


It sounds like English, but I can't understand a word you're saying

 

[quark]

Check with Notifier at

http://www.notifier.com.

They have duct sensors which can sense the smallest spec of carbon (ok.... exaggerating a little bit but they are the best IMHO). They have those sizes.

What type of fire dampers you have? Electronic? If so, why to duplicate an input? You can ask your fire damper to communicate to the fire/smoke system. If they are fusible link type then a proximity sensor will do the work.

No. of smoke detectors depend depend upon the criticality of your equipment and sensitivity of the sensor. Keep in mind that you are diluting smoke concentration to 1/3rd of the original concentration. Still it seems to be ok to me.

BTW, english is not my mother tongue

Regards,

 

[friartuck]

I would put a sensor in each duct. Younthen need to decide if you want to shut the vent plant down in the event of a fire or use the fans to continue running in fire mode to aid the fire fighters so they can see the fire.

Smoke rated fans are available from NuAire. They do a special that will run at over 1000 degrees C.

NUAIRE.com or nuaire.co.uk? I think Their smokeclearer range

Friar Tuck of Sherwood