DavidCR
Mechanical
- Jan 10, 2002
- 355
Hi everybody.
In an hydroelectric power house with a main hall of 76m(250') long, 20m(66')wide, 18m(60') high we want to know if smoke detector can be omited on this space.
All other floors bellow grade level and all equipment has propper fire detection.
We have considered all the implications of spot type, air sampling(vesda) and proyected beam(Ossid or regular beam) smoke detectors.
I appreciate if someone can give me some hints or criteria to support the idea of omitting smoke detection on this area.
Some thoughts on this:
- Our company follows NFPA 72.
- Heat detection spacing rules for high ceilings rules does not apply for this case, (double than max of 30'), smoke issues on this are not clear.
- We are not interested on a performance based design. We need simple rules to follow for our local AHJ. We would install smoke detection only to follow the rule of general smoke detection as we have used for other smaller plants.
- On smaller power plants we install beam type smoke detection (one beam covers all the hall), frecuent maintenence but not as complicated as in this case.
- Air sampling is atractive due to ease of maintenance, but sampling pipe installation is a complicated uggly job.
- The only equipment located in this area is the travelling overhead crane. The other equipment (generator and electical cabinets are bellow floor level and have local smoke detection. On the hall there are ocassional assembly operations that might include the risk of fire.
- The ambient temperature is not high so stratification might or might not be an issue.
- There is a constant light dust mist, and insects love to make nests on anything you install on this areas, so maintennace need frequent but dangerous and expensive.
- User agree taht smoke detecion will not be a significant plus, all equipment areas has smoke detection and plant has 24/7 operators.
In an hydroelectric power house with a main hall of 76m(250') long, 20m(66')wide, 18m(60') high we want to know if smoke detector can be omited on this space.
All other floors bellow grade level and all equipment has propper fire detection.
We have considered all the implications of spot type, air sampling(vesda) and proyected beam(Ossid or regular beam) smoke detectors.
I appreciate if someone can give me some hints or criteria to support the idea of omitting smoke detection on this area.
Some thoughts on this:
- Our company follows NFPA 72.
- Heat detection spacing rules for high ceilings rules does not apply for this case, (double than max of 30'), smoke issues on this are not clear.
- We are not interested on a performance based design. We need simple rules to follow for our local AHJ. We would install smoke detection only to follow the rule of general smoke detection as we have used for other smaller plants.
- On smaller power plants we install beam type smoke detection (one beam covers all the hall), frecuent maintenence but not as complicated as in this case.
- Air sampling is atractive due to ease of maintenance, but sampling pipe installation is a complicated uggly job.
- The only equipment located in this area is the travelling overhead crane. The other equipment (generator and electical cabinets are bellow floor level and have local smoke detection. On the hall there are ocassional assembly operations that might include the risk of fire.
- The ambient temperature is not high so stratification might or might not be an issue.
- There is a constant light dust mist, and insects love to make nests on anything you install on this areas, so maintennace need frequent but dangerous and expensive.
- User agree taht smoke detecion will not be a significant plus, all equipment areas has smoke detection and plant has 24/7 operators.