So what if the cooltube fan fails? FIRE?!
- Thread starter Zagon
- Start date
Good question. I've thought about this too. I don't think it would get temps so hot that the surroundings would catch fire. I do think the bulb would eventually explode and a worst case scenario is that a small fire could start in the cooltube but would probably burn out quickly.
This is why I don't believe in using cheap booster fans to cool a hood. Booster fans will die on you. A quality high velocity fan is a better/safer option.
This is why I don't believe in using cheap booster fans to cool a hood. Booster fans will die on you. A quality high velocity fan is a better/safer option.
ASMALLVOICE
Well-Known Member
I run a 600 watt cool tube and have tested that very scenario, the newer bulbs/ballasts will turn out after a certain temperature/current draw, I am not sure if it is something in the digital ballast that detects it or just the rate of rise in the bulb temp. After about 35mins with no fan, right before it goes out, I can assure you it, as well as with any forced air cooled hood, it will be hotter than a $2 pistol. That is where you keep all things flammable away from the light. I use 6" metal hose clamps instead of long tyraps to secure the ducting to the tube. I use chain to hang the fixture and keep all combustibles out of the way, no loose wires touching it as well.
I also have mine automated and if I do not get a "status" ( feedback via a current switch) on my fan within 30 seconds of start-up, it will shut the light down until the fan shows it is running. I would do this no matter the fixture I choose to use No fan, I don't want no light either, safety first.
Peace and Great Grows
Asmallvoice
I also have mine automated and if I do not get a "status" ( feedback via a current switch) on my fan within 30 seconds of start-up, it will shut the light down until the fan shows it is running. I would do this no matter the fixture I choose to use No fan, I don't want no light either, safety first.
Peace and Great Grows
Asmallvoice
ILoveYouSweetLeaf
Well-Known Member
so if your fan fails anytime the light will turn off ? can you explain how you do this please?
brotherjericho
Well-Known Member
If the fan fails your grow room will get hotter. It will not be enough for a fire...even paper needs 425F to catch on fire!
contraptionated
New Member
You could have 2 fans inline . A lower cfm behind a higher cfm rated fan. One would not bog down the other if you keep the cfm ratings close. If one fails, chances are the other will keep going. Although I wouldnt do that redundancy inline with cheap duct boosters with molded plastic impellers.Kind of like the concept of using more than one exhaust fan/filter combo for a grow room. If one fails, you will get higher temps but not as high as if there was nothing going at all. Unless an intake fan is in place that is only undersized when 2 fans are working (that's why passive intake is better). Slightly off topic...
contraptionated
New Member
If you ran it with no fan , why bother with the cool tube?
i too ran a 400w hps without a fan (it broke down) for about 1 week and there werent any real problems
ASMALLVOICE
Well-Known Member
Yes, the fan is monitored through a "current switch" meaning as long as the fan is pulling current "running" the contacts are closed, if the fan stops, the contacts open, telling the automation system the fan has failed and the output to the light will turn off and I get an alarm on my laptop. It has a small "dead band" time to allow for initial startup and power blips.
Like I said, it gets damn hot, but as long as there are no combustibles touching it, you should be okay for a spell.
Peace and Great Grows
Asmallvoice
Learn about the flash point of the materials you are growing around, and you will realize that the only dipshits burning their grows down are those who improperly wire their grow rooms or get water where it doesn't belong.
Stop being scared about the .0000001% chance that your metal hood and glass bulb are some how going to catch fire, and explode into an inferno that will burn your whole house down around it.
Stop being scared about the .0000001% chance that your metal hood and glass bulb are some how going to catch fire, and explode into an inferno that will burn your whole house down around it.
contraptionated
New Member
That setup won't protect you from a locked rotor condition on the fan. Although a locked rotor is unusual on these small centrifugal fans , it has happened to me once before on a 4" Dayton blower. In industrial facilities where a loss of air movement isn't acceptable for more than an instant, redundancy is always the simplest and most reliable choice. Like I wrote before; two fans inline with one another , the lower cfm fan behind the higher cfm fan. The chance of both fans failing is slim to none. No lights ever need to be shut off. No unnecessary alarm peripherals either.
qwizoking
Well-Known Member
if you were asking me why i have a cooltube and dont have a fan...2 reasons, first and foremost im working with a low budget,second my flowering cabs are the exact width of the cooltube so the openings are outside the grow..slighty heats the room,cab stays much cooler than no cooltube.obviously i plan on getting a fan eventually..
ASMALLVOICE
Well-Known Member
You're right, but since axial motors have a very hard time suffering that fate, it is amply sufficient. When I am using a centrifugal fan, like my charcoal filter setup, I use an airflow switch for my status, and it covers all of the faults that can occur with a vortex style fan, as if there is no air flow, there is no status and I turn off the output to the fan and alarm at the pc ( safety first ). Not to mention, all pumps and fans are on a GFCI circuit. I like automation, I do it for a living, and I will always enjoy knowing of a problem the moment it happens. Tis much better to be proactive, than reactive in most all situations.
Peace and Great Grows
Asmallvoice
contraptionated
New Member
Now an airflow switch (sail switch) that makes sense. Although you didn't state that before so I couldn't be a mind reader. But let me tell you why it's better to have redundancy instead of only your set up, not that your set up isn't good for safety (because it definitely is). What if your on vacation someplace far away? The light shuts off because there is no flow and you aren't around to investigate. What do you do then? How do you change out the cool tube fan then? Do you go without light for a week until you get back from vacation? The nature of your alarm system is pro active but it requires you to be reactive, much to the contrary of what you stated earlier.
To prevent a total loss of air flow , it is much more effective to have 2 fans inline(in the cool tube example which this thread is about, nobody mentioned a carbon filter) in the order I stated in my last post. One goes out, fat chance the other fan isn't still going. No need to be notified until you visit the grow again. Like I said before, your system can't change the fan out while you're away so why not have 2 inline and better still a hybrid system of your idea and mine. One fan stays on and the other stays off. When you get an alarm status on one (via ct switch) it can choose to turn the other one on.
This way you don't just have an automatic alarm and safety but rather a remedy. Although my way is a remedy just without the alarm. I like your ideas. What program do you use for the annunciation (alarm on the pc)?
Oh , by the way... GFCI receptacles are not intended for permanently connected and energized fans. They could be used for your pumps because there is a small chance of incidental contact between accidentally current carrying objects to ground but not a bit of possibility there with a fan. GFCI's are avoided when powering an inductive load with a metal housing unless that load was temporarily cord and plug connected. You could check the NEC for that one so you know that I'm not pulling that out of thin air.
ASMALLVOICE
Well-Known Member
It is an older version of a web based building automation system called Interop. I can get alarms and room data from anywhere, as long as I have an internet connection.(with pc anywhere) I can change schedules, adjust temp/hum and CO2 settings. The trending capabilities are awesome as well, every point and it writes them to a file once a week so I can see if there have been any issues. I have been doing this every since I get out of the plants as an industrial electrician/instrumentation technician for 12 years and that was 20 +years ago. I switched to automation and will never place nomex on my body again.( I sincerely hope not to anyway). I assure you M8, my electrical system is above and beyond anything the code would require. I have had mid level ocd my entire life and it is proving a good ally in this hobby
I use hd axial fans for all my non-pressured applications, as their life expectancy (60,000+hrs) is off the charts compared to any cent. fan, I have a 235 cfm axial on a 600 watt cool tube with a total length of 9 feet of ducting and I can touch my tube even on the hottest of days. The fan will more than likely last longer than 5 fixtures...lol
To stay on topic with the OP's question, if the fan fails, is there a fire? I say as long as the combustibles are kept at bay, doubtful the fixture will burn, the aluminum duct shouldn't contribute and all wiring and such are out of the way, doubtful, but always a possibility, so me, I err always on the side of caution, cause there are more that live under my roof than me.
Peace and Safe Grows
Asmallvoice
contraptionated
New Member
Awesome info ASMALLVOICE! I was never sure of how to annunciate equipment status through a pc but now I feel confident enough to look farther into it. Thank you!
ASMALLVOICE
Well-Known Member
Absolutely, there are several models of low pressure switches for the hvac industry that work with small amounts of pressure, such as the kinds produced by the equipment we all use. There are a couple of ways, cheapest, might be a switch with a low voltage circuit to a relay to break the 120v circuit, but unless you are running a monster fan, like a 12" and up, the contact ratings on a lot of them will break the load of a small fan motor with room to spare.( usually around 5 amps)( always pay attention to the contact ratings) I prefer to use a relay and not have 120v going thru small devices like that. I use a 24v transformer to run all the controls and then fire a relay which handles the 120 or even 240v gear if needed..
Here is a very simple schematic, you can add anything before it in the 24 volt side to do whatever your heart desires.( I am no artist...lol)
Peace and Safe Grows
Asmallvoice