Fire suppression control

[MTW]

100F in the duct throat sounds sensitive enough, but the cut sheet linked to earlier starts at 140F min. That's why I asked whats working for him, placement and temp rating.

Going on memory, the ones my fire contractor were supplying for hoods were 160F. I don't think a single burner on low would catch that in 15 minutes.

The one in the photo is adjustable, for use in a dust collector hopper, needs to be adjusted to the hopper temperature. A hopper sighted in the direct sun affects the setting point.

MTW

 

[MTW]

I don't have access to International Mechanical Code (IMC) 507 to look for myself what the temperature rating should be and it's why I'm asking.

But looking at the manual for the Hooddepot On demand control panel, I find an answer to my question of monitoring a manual single burner, a gas detector.

• Gas Sensor Input - An optional gas sensor can be provided to turn on the hood fans if the gas sensor
reads a preset level of gas PPM. This assures safety to personnel in case cooking occurs without
turning the hoods on. The sensor will have a set of dry contacts and the com wire will need to be wired
to the 5v terminal while the no wire will must be wired to the MISC IN terminal.
• Temperature Sensor - To meet IFC and FMC 507.2.1.1, a temperature sensor can be installed in
the duct to turn on fans automatically if the temperature rises above a preset level. Once the temperature
falls below the setpoint by two degrees, the fans will turn off again.

It seems from that manual clip, that the fans do not need to stay on for 10 minutes as in Larry's spec, but until the temp drops two degrees below the setpoint.

Here the fire marshals are only requiring the duct temp sensor, and not the off delay timer that Larry's area requires.

With recent rule changes (here, at least), the systems with cable-operated valves must also have thermostatic sensing that triggers the exhaust fan to operate upon reaching 100 degrees in the hood or duct, and for 10 minutes after the under-hood temperature drops back below 100.

This is because the exhaust does not have to be on for the gas to flow. The owners of kitchens with standing-pilot ignitions prefer adding this operation to having to light pilots every day.

I have another one of these to do in a coupe weeks, and haven't heard of that requirement before around these parts, but it's a new fire contractor on this one, so we shall see.

MTW