Fire Saftey Shutoff

K2

Tens years ago I was trying to work on an inexpensive fire/smoke detection system that could shut down power to a whole house fan or a powered attic vent. I kinda gave up because i lacked the technical skills for something like that.

Now that someone invented the internet I can just ask. Is there anything like what i mentioned in the under $200 range?? Thanks for any replies. K2

mdshunk

Yeah, they've existed since the 60's The generic term for them is "Firestat".

mdshunk

There is another type of fire safety called a "fusible link switch" often used over or near fossil fuel heating equipment.

K2

Thank you. Maybe it was 40 years ago I was working on my idea. Time is becoming a blurr. I'll google firestat.

mdshunk

If you wanted to farm-rig something, they do sell relays that work off the inter-tie wire of hardwired smoke detectors. You could wire the fan(s) through a set of normally closed contacts in a contactor that would be energized by the accessory relay in the smoke unit.

Sparky Joe

We've always used "ice cube relays" very easy to to understand, very durable and and can work for plenty other applications(it's just a relay)

K2

That's kinda where I got to but sensing smoke with the whole house fan going was ify.

K2

I'll check them out. I'm interested in anything that is easy to understand.

Sparky Joe

So you're saying you want something that shuts down the house fan before the fire starts? Good Luck with that search.

K2

Well not before but maybe while the fire is small. If the fire is too big I'd rather kick the fan on and let the insurance handle it.

Sparky Joe

They do have things called "duct detectors" which capture air in a 'windy' path and channel it through an ordinary smoke detector.

Also the fusible link MD mention reacts to heat, similar to what a heat detector would do.



I heard recently, on a similar subject, that the requirements for smoke detectors is that they only need to work 50% of the time for them to be approved for sale. A buddy told me about it and that knowing it he opted for a system that ran around 120$ per detector. Kinda scary if you think about it.

K2

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Yes, I load up my small rentals with about 6 dectectors in each unit with both hard wire and batts. Between not working and people disconnecting them at least i can say I made an attempt.

I eliminated all whole house fan and powered attic fans in rentals.

We live in a climate where ac is not necessary and fans can do the trick but fans and fire don't do well together.

Thanks for the info Joe. I need to get to Salt Lake and visit that violin making school. K2

Sparky Joe

Never heard of it.

Inspectors around here don't require us to have fans, swamp coolers or roof top units to be shut off with the fire system (aka 'universal shutdown') unless the fan can blow 2500 cfm or more. I know whole house fans move a lot of air(used to love them when I had to work in attics), but not sure if they fall into that category.