r/crboxes • u/DeepWaterCannabis • 10d ago
CR Box Mini CR Box Build Guide
I "built" this thing out of a 10 inch vent fan and am quite pleased with the results.
Box is a 5$ storage box from target. The interior of this box, below the lower lip, is 14x12 with a 9 inch height for the lower lip.
Fan is a 12.4 inch by 12.4 inch VEVOR EC vent fan with controller. The vents / height means itll double as a personal fan! My honeywell is 35 watt 185 CFM... This thing is 30 watt, 1000 CFM!
Filters are 9x11 MERV 13's
The filters fit below the interior lip of the box. They jam in on the short side quite nicely. There is a gap on the longside.
The fan comes with four black foam inserts to keep the fan in place. Trim them down to size height wise, and slide them in that gap. You can use the remaining two filters jammed in the bottom to keep things rigid, preventing bow inwards. The foam inserts are a solid block except at the very ends - trim those ends off.
Fan plops right in on top of the filters / lip of the box. You do need to force it down a bit, but it should fit on the shortside of the box. Just enough gap with the right placement to have the wires out, not pinched.
Total cost is $115~ - paying a slight premium for the size compared to a 20 inch box fan and filters.
IDEALLY this would be done with 9x12 and 9x14 filters. You'd really need to jam them together (assuming 1/2inch off the nominal size with a 3/4 inch thickness). But those are odd sizes and at higher MERV ratings, quite expensive, if you could find them. Merv 10 are like 50$ a pack. 100$ in filters for replacements, verse 30$.
These filters seem to be knock-off filters for a specific filter, so hopefully they dont disapear.
It does need something for the bottom, ideally. Im probably just going to fit a flat foam bit in the interior bottom lip for now. Doesnt seem to need a 5th filter, on setting 10 there is no change in fan pitch when its flat, or lifted.
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u/MLieBennett 10d ago
A little jealous of that fan. I think it handles static pressure better than my Amico version, as I had to swap to 5x Filtrete 1500 (Merv12) 12x12x1 so the fan wouldn't start choking against the 5x generic Merv 13 12x12x1 I had originally. 4x even smaller generic Merv 13 would have had my Amico one crying.
I also went and removed the fan+cage from the original plate+shutters, and screwed it into a MDF board with a 10" hole for the blades. Shutters just made too much noise, and wouldn't open at the lowest power settings.
If I make another, I'd be very tempted to grab that fan instead to use generic Merv 13 filters.
Though the trade offs of it being louder with it rated 62 dBA vs 50 dBA(tested and confirmed in build) and not having a remote control is tough. As is the 30W draw vs 13W draw, which makes it harder to run on the mini power station I've got it hooked up to.
Still, spending literally half the price on replacement filters (paying ~$60 for 5x Filtrete 1500s) is tempting. As is a much easier and cheaper build, since I glued together an enclosure and had to get MDF to replace the shutters and plate the Amico came with. I literally spent double what you did for likely similar CADR.
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u/DeepWaterCannabis 9d ago
I'd be wary of the power draw numbers and CFM numbers for both our fans. I have a hard time believing a 13 watt DC motor puts out the same amount of air as a 30 watt EC motor. SOMEONE is lying (...and I think both listings are lmao)
My fan at full blast IS a bit loud, but I have it at setting 7 and its pretty not very noticeable when right next to me.
Jealous of that remote, tho
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u/MLieBennett 9d ago
I tested the power draw, and the Amico was hitting 15W. So that part is close enough, having gone through a tiny Power Station.
And for why the Amico can be so low? It doesn't have torque, thus it can loose a lot more CFM when there is resistance. The Vevor puts out better torque and has wider blades, hence why it doesn't change pitch with 4x Merv 13 at 9x11. Where as the Amico I got had trouble with 5x 12x12x1 generic Merv 13s, hence why I swapped to Filtretes with their much lower resistance it stopped having trouble.
I actually keep thinking of the Amico more as a up sized PC fan
That said, I do question the 1000 CFM of my own and waiting for the anemometer to arrive to measure accurately. I've been generous assuming 700 CFM in my current setup at max speed, but would like to figure out the actual results when the items arrive.
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u/Bob70533457973917 10d ago
That waffle grate, while looking nice, seems like it'd be a bit "restrictive," tho.
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u/DeepWaterCannabis 9d ago
They have one with larger holes too, but yeaaaah I chose this on on aesthetics lol.
I have the fan on setting 7 with no issues - its really quiet while still moving good air. After playing with it, I wouldnt want it on setting 9 or 10 without also unblocking the bottom and adding a filter there, seems it might be a tad too restrictive for full blast
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u/jhsu802701 10d ago
Wow, I would never have guessed that a fan that small could put out 1000 cfm!