I am currently in the process of getting an existing space certified by 3PCertz and had some questions.
The space has been drywalled with 1 hour fire rated drywall on both sides of the wall as well as a fire rated door. We have a sounder, RKI sensor, C1D1 rated lighting, C1D1 intake and exhaust fan, certified closed loop, and C1D1 scale.
We are planning on switching all wiring to C1D1 sealed conduit, and all pass throughs sealed with fire rated caulking.
The engineer has requested the sensor alarms be set to increase the CFM of the exhaust fan. Is there any variable speed C1D1 fan that would be recommended? For a budget build I was thinking about using 2 Canarm exhaust fans, with the second one being energized at the lower alarm. Would this fly?
We were also instructed by RKI to use a slave relay to energize and de-energize devices. Is this what other people have used and is it reliable?
Thanks ahead of time for any help that can be offered!
So many excellent questions to help end my day. <3 <3 <3
In my last 2 AHJ builds, 4-hr firewalls were required. You should probably check that just in case.
There are many variable speed fans out there. Without knowing more about the size of your space - I wouldn’t know the size to recommend. They are normal - and assuming that you already have a PLC that is running the sensors and what not in your space, getting a signal from your room sensor should not be that complicated.
I have 100% seen people use more than one fan where the second fan turns on to bring the airflow up. I’ve also seen people use 3 fans (because there is more than one stage AND redundancy). Then you take that same signal you would have sent to a VFD and instead send it to the other fan controller.
I mean… you could use a slave relay - what else do you have in your PLC right now? Sounds like you could instead be using a motor starter. But really - its going to depend on what electricity you have, what other controls you are already using, and if you decide to go with a variable speed fan or multiple fans.
There are kits built for this already by… Larson Electronics. If you don’t want to figure it out yourself.
Someone will still need to do a R&ID for your PLC and other electrical wiring. And you’ll still need that to be stamped off by an electrician (at least that is the case in Michigan, Colorado, and California…)
I know I posted a couple of days ago that I’m available for the first time in years to help with this kind of work. So if my answers just made you want to ask more questions, feel free to hit the DMs and we can work something out to get you where you are going.
Any reason you decided to go with 3PCertz instead of a local 3rd party engineering firm?
I was hoping to get a reply from you Cassin! Thanks for this information, going to review the terms and see if I can wrap my head around it. I will be trying to talk the boss into letting you handle this design because I am feeling lost.
The AHJ is our state fire Marshall, he was fine with the 2 hour rated drywall so really hoping we do not have to change that.
Ill check out the kits from Larson and see if I can get a better idea of what I am dealing with.
The AHJ does not have much experience with this. He only had one other inspection and they had a field report from 3PCertz so that is what he requested. I was also going to add some modifications to our OSS extractor so was going to have them do a new cert for that. Not sure if it would be cheaper to do a local firm for the room and then use 3PC for the extractor.
Having a local firm can also help you with things like getting stamped drawings and what not for future projects and that kind of stuff.
I’ve worked with 3PCertz they will get the job done. They are a little more expensive than the local engineers I have used in the past - and they have been only mildly helpful (maybe even not helpful?) in actually getting through inspections. My local engineers though - every one I have used in every state. They are always helpful and often know the AHJ and their special wants and needs.
I always feel good about making sure local folks get my business as well - so all the good jobs aren’t heading out of state.
Let me know how it works out. If you haven’t already there is a chapter of NFPA 1 that is specific to cannabis extraction rooms and equipment that you should be very familiar with. If you have jumped through all those hoops (there are many!) then you should be good to go with getting through engineering review and inspection.
As previously stated there are two popular methods for “kicking up” the airflow. Two fans or bigger fan with vfd. I designed my setup to use a VFD to “ramp” up the airflow as hydrocarbon detection increases. As mentioned it does require integration with a PLC or control system, but that should be pretty easy. Your c1d1 exhaust fan setup may have a single phase motor on it, replace it with the same HP, frame size, and rpm three phase motor so a vfd can be used. If your setup is on single phase power oversize the VFD and it will be able to run of single phase power.
Just be sure to cover all the failure scenarios they will be looking for:
-Loss of power, generator power
-Loss of sensor power, alarm/ high airflow/ electrical interlock
-electrical interlock functionality
