I posted this here because I want good coverage and feedback. Not everyone goes to the code section.
Here it is...
New Facility Manager comes to town. He hits me up with Standard Mechanical Code,
Section 606, Smoke Detection Systems Control subsection 606.2.1
Well, he hits me with the code change from 01-01-2001 and of course he is fresh out of engineering college.Return air systems
Smoke detectors shall be installed in the return air systems with a design capacity greater than 2,000 CFM (0.9M3/s), in the return air duct or plenum upstream of any filters, exhaust air connections, outdoor air connections, or decontamination equipment and appliances.
Supply air systems
Smoke detectors shall be installed in the supply air systems with a design capacity greater than 2,000 CFM (0.9M3/s), in the return air duct or plenum upstream of any filters, exhaust air connections, outdoor air connections, or decontamination equipment and appliances.
I am old school; I use only Ionization or Low-Flow Photoelectric. None of this fire stat stuff. I believe Ionization and Photoelectric smoke detectors work better in undiluted air mounted low in the return. This is the way I was brought up and I dont understand why they changed the code. I also understand they are more sensitive this way and with an exhaust hood malfunction they will trip and cause a nuisance. All things being equal, and of course they are not, I believe in safety first and shutting down air handlers that circulate smoke in a public building should be shut as soon as possible.
They come in the return air chamber by some of the Manufacturers. I have seen sampling tube end caps melted off because they were too close to the HX. I have also seen low voltage wiring melted for the same reason. (Hack install I know, but I have seen it) I have seen them mounted in both the return and supply at the same time and with or without alarm systems. Code 606.4.1
Yes, I realize it is my job to keep up with all of the code changes but I wanted to know how you felt about this change. Is my thinking wrong?
I await your replies with humility.