Server Closet Cooling - Intake Fan Recommendations?

[BigDave]

I don't want to slap myself on the head wondering why ambient is 105F and have to do any rework.

Well @MatthewSteinhoff has made statements that hint to me that you made need to start out with only
a grill installed in the bottom of the door. If this one fan in the ceiling method fails to work you can always
add a second fan for use during Hotlanta's months of cooler weather when the A/C system will be unused.
I feel that you are a bit reluctant to use my projected "exposed duct" method (you never mentioned the drawing):p

 

[Redcoat]

hoping to do something like:
1. SC836 vertically mounted
2. Below that switch / UPS / etc traditionally horizontally mounted

Hmmm... that does look like it could be a non-optimal solution to me - you have the potential to limit the air flow through the server by the gap clearance to the horizontally mounted kit and you'll be bathing at least the top item with warm air.

Given that you seem to have more restrictions that you initially indicated, @BigDave's concept may be a good one to put cold air where you need it - and one that you could try out with a combination of cheap metal ducting in a vertical run up the side wall and flexible dryer exhaust duct or the like from that to the point(s) of use - provided that you get a blower fan strong enough (producing enough static pressure) to overcome the ducting resistance. Static pressure is the problem with low cost axial flow fans - their designs and clearances are such that modest resistance will kill their air flow. So the Broan Losone could again be a good choice for an inlet blower if one is needed.

 

[svtkobra7]

Well @MatthewSteinhoff has made statements that hint to me that you made need to start out with only
a grill installed in the bottom of the door. If this one fan in the ceiling method fails to work you can always
add a second fan for use during Hotlanta's months of cooler weather when the A/C system will be unused.
I feel that you are a bit reluctant to use my projected "exposed duct" method (you never mentioned the drawing):p

Are you kidding me right now? I love your drawing so much I hung it beneath my Picasso.;)

My apologies for failure to mention it - I haven't been my usual thorough self today, but hopefully you feel better now. ;) I'm not opposed to going the inline fan route, but considering the labor hours invested thus far, I would tweak installation as to hide it somehow. When it comes time to sell the property, I'd rather invest as few hours as possible "reverting" it to base state. Using my "working idea" (henceforth discredited), I liked that the only work on the back end was to be: 1. Removal of server rack and plywood backer, 2. Patching a few holes in the drywall behind it, and 3. Patching the drywall for the through wall fan. Obviously your approach would sub door replacement for #3.

Forgive my poor since of humor, my remarks are made entirely in jest of course.

 

[BigDave]

re you kidding me right now? I love your drawing so much I hung it beneath my Picasso.;)

Of course I'm kidding...
The picture rated a very hardy belly laugh and it's great to know my kindergarten grade drawing rates right
below Pablo Picasso :D

I gave some thought to the door and was thinking that you could remove the existing door, buy a cheap hollow core
to rig an intake vent/grill/whatever, then when it's time to sell just remount the original door.

 

[MatthewSteinhoff]

was hoping to do something like:
1. SC836 vertically mounted
2. Below that switch / UPS / etc traditionally horizontally mounted.

That's a non-optimal idea. The server pulls air from the front and exhausts in the rear. Hot air rises. You're trying to pull cool air from the top, push it downwards and exit at the bottom. You're fighting the laws of physics.

We always mount our closet systems with the intake on the right and the exhaust on the left. That way they pull front to back just like they would if they were in a typical rack. We cheat the exhaust fan (when used) to the left (back side) of the servers to further encourage sensible air flow.

Here is the full backboard...



Were this closet more narrow, we would have mounted the AT&T and Comcast internet modems above or below the rest of the equipment. This configuration can fit in the tiniest of closets.

The other problem with putting the server face up is that anything that falls into the top of the server gets sucked into the box by both gravity and suction. What could possibly fall in? In my experience, everything. Coffee is bad. But so are the little copper wire trimmings from the network terminations. Mostly, whenever the ceiling tiles are touched, the box is dusted with ceiling droppings.

Cheers,
Matt

 

[svtkobra7]

Hmmm... that does look like it could be a non-optimal solution to me - you have the potential to limit the air flow through the server by the gap clearance to the horizontally mounted kit and you'll be bathing at least the top item with warm air.

• Good point.

Given that you seem to have more restrictions that you initially indicated

• My intent was of course NOT to say: "Hey, I need help" ... let suggestions come in ... and then say "Sorry can't do that".
• Speaking to paintings, I should have painted a better picture of the scenario/requirements from the beginning, but to take a crack at that now, I would list them in order of importance as per below. My apologies as not adequately disclosing my objectives and constraints. This was not the best use of my time or yours.

Cooling Solution Objectives / Constraints

• Considers environmental variables that can't easily be adjusted, namely: (a) the space above the closet ceiling is only 21.5" in height and contained within that 21.5" space (and directly above the closet ceiling) is both PEX and an HVAC branch, (b) existence of a structured media center (14" x 14") with the lowest point being a surge protected j box 56.5" above the floor, and (c) a plethora of wires running into the closet (Cat5e, HDMI, coax, USB). Those wires are easily moved, for the most part save for the uplink, and all terminate in keystones which fit in a 2 gang wall plate.
  
• Provides sufficient air flow / cooling on the first attempt, or if "re-configurable" allows for "re-calibration" without reopening the walls. Although as I type that out, and thinking, I suppose I can "simulate" the effectiveness of any solution prior to rehanging sheetrock by using cardboard boxes with painters tape. My point: Testing that fan right now without drywall surrounding it isn't going to tell me anything, but if enclose the ceiling and rear of the closet with cardboard, it would tell me whether I should scrap that fan, right?
• Achieves a "reasonable" sound pressure level. And by that, I don't mean inaudible. I struggled getting the SC836 in line temp wise and don't want to see those efforts abated by installing a fan that is 80 dB. My expectations here have been adequately managed by living with a server for weeks with fans running on the Supermicro "Full Speed" profile in order to achieve sub-40C HDD temps. Thankfully I was able to resolve that (with help of the forum), which allows me to pursue completion of the project and the current situation.
  
• When viewed holistically (cooling + mounting), allows for current gear (server + switch + UPS) to be contained in the system (41" wide x 26" deep) and allows some room for future additions (possibly addition of a 10 GigE switch and another 1 or 2 RUs of space if I were to add another server). Note my current UPS is a non-rack mountable CyberPower, but I had intended to swap that out for something rack mountable.
• Doesn't require a huge amount of effort to revert to a salable state.
• Isn't extremely aesthetically displeasing. Example: 24" x 24" air intake.
• Additional expense doesn't exceed $500 (rack included).

Fair?

@BigDave's concept may be a good one to put cold air where you need it - and one that you could try out with a combination of cheap metal ducting in a vertical run up the side wall and flexible dryer exhaust duct or the like from that to the point(s) of use - provided that you get a blower fan strong enough (producing enough static pressure) to overcome the ducting resistance. Static pressure is the problem with low cost axial flow fans - their designs and clearances are such that modest resistance will kill their air flow. So the Broan Losone could again be a good choice for an inlet blower if one is needed.

• Directionally, @BigDave's intake solution isn't that different from what I initially proposed (a through wall fan that is intended to fit between the walls), and I had considered the need to tweak air supply delivery post-install to optimize.
• I was surprised to see that fan specified at or below 2.0 sonnes (I have no idea what the static pressure would be of course) given that it can move ~200 CFM. https://www.zoro.com/broan-fan-in-line-200-cfm-l200l/i/G1702626/?q=L200L
  
• Supporting your point, I should have better defined relevant variables in my original post, but due to the dimensions of the L200L (12.25" L x 12.25" W x 11.75" H) there isn't room for it above the closet ceiling without moving the PEX or HVAC branch.

 

[svtkobra7]

Of course I'm kidding...

I know, I know ... ;)

The picture rated a very hardy belly laugh and it's great to know my kindergarten grade drawing rates right below Pablo Picasso :D

LOL ... I aim to please :)

I gave some thought to the door and was thinking that you could remove the existing door, buy a cheap hollow core to rig an intake vent/grill/whatever, then when it's time to sell just remount the original door.

Definitely not opposed to that. Stupid question: How to you tell whether a door is hollow or solid core without taking a Sawzall to it? I have a feeling the existing door may be hollow core. One night, walking rather briskly from my office to bedroom, with the lights off and prior to my eyes having readjusted after starting at computer screens for hours, I ran into one and and broke it. Better than new with careful gluing, clamps, and set time, but I think that suggests the existing door is hollow core, and to an extent "disposable."

 

[BigDave]

to be contained in the system (41" wide x 26" deep) and allows some room for future additions

So you have 40" of back wall in the closet? This would be prime for installing based on @MatthewSteinhoff example. Use a pair of the 4U brackets to mount the rack ears of your chassis and a third bracket to support the rear end of the server thus ending the upsidedown airflow issue now, by being horizontally mounted on it's side.
Being approx. 26" long, this leaves plenty of room to work at each end AND will come off the "rack" with greater ease.
It hurt my back just to think about having to lift that monster 26" straight up to clear the one pictured earlier.

Stupid question: How to you tell whether a door is hollow or solid core without taking a Sawzall to it?

Knock on it really hard with your knuckles, if it does not hurt like hell, it's hollow core construction.

As you can see, the interior is very stiff cardboard that provide the outer skins a bit of rigidity. Most interior
doors are made this way.

 

[svtkobra7]

That's a non-optimal idea. The server pulls air from the front and exhausts in the rear. Hot air rises. You're trying to pull cool air from the top, push it downwards and exit at the bottom. You're fighting the laws of physics.

• Understand. Not opposed to mounting it upside down, but I don't think that can be done with either the vertical wall mount rack I envisioned or the brackets that you proposed.
• My switch and UPS doesn't throw off much heat, so even if you remove them from the equation that issue remains. Did you have a solution in mind? Apologies if I missed it.

We always mount our closet systems with the intake on the right and the exhaust on the left. That way they pull front to back just like they would if they were in a typical rack. We cheat the exhaust fan (when used) to the left (back side) of the servers to further encourage sensible air flow.

• Makes complete sense.
• Are you suggesting I emulate that concept in my instance? If so, it would fit either with the chassis bottom against the wall or more conventionally with the chassis bottom parrallel to the floor.
• I'm assuming you use the brackets referenced earlier as intended (vertical) and mount by the rack ears omitting rails, but ..
• What if you used a pair of those brackets, connecting one to the rear of the rails and one to the front, with the chassis bottom against the wall? [similar configuration as the picture you posted, but here we are contending with the weight of a server v. switching equipment]

The other problem with putting the server face up is that anything that falls into the top of the server gets sucked into the box by both gravity and suction. What could possibly fall in? In my experience, everything. Coffee is bad. But so are the little copper wire trimmings from the network terminations. Mostly, whenever the ceiling tiles are touched, the box is dusted with ceiling droppings.

LOL @ "everything". I added a front bezel to mine should I want to enjoy a coffee break in the server closet. It wouldn't protect against the coffee, but perhaps the doughnut crumbs. ;)

 

[svtkobra7]

So you have 40" of back wall in the closet?

Correct.

This would be prime for installing based on @MatthewSteinhoff example. Use a pair of the 4U brackets to mount the rack ears of your chassis and a third bracket to support the rear end of the server thus ending the upsidedown airflow issue now, by being horizontally mounted on it's side.

• I can dig it.
• And I'd put a through wall fan / passive vent (no ducting needed in closet either way) where the X is with the front of the server facing it? The thing with an arrow on it is a built in computer desk, so quite easy to put an intake at floor level (above trim) tucked in that corner. I've never used that "desk" (piece of granite at desk height) and who could, you can't even line up two monitors side by side ... sheesh (kidding).
• 
• I've never used the brackets @MatthewSteinhoff described (or even horizontally mounted a server to be honest), and get the need for a third (or second as I proposed at nearly the same time), but why do you need two for the front?
• Finally, what is a reasonable "height" for the lowest point of the server above floor? I get that the correct answer is as low as possible, where the densest, coolest air resides, but I would think that you would want some buffer between it and the floor (or is the 3.75" provided by the trim enough)?

It hurt my back just to think about having to lift that monster 26" staright up to clear the one pictured earlier.

Your back? The close encounter with the hollow door hurt my face! Kidding, I'm sure i ran into it chest first.

As you can see, the interior is very stiff cardboard that provide the outer skins a bit of rigidity. Most interior doors are made this way.

Definitely hollow core - thanks

 

[anodos]

• Understand. Not opposed to mounting it upside down, but I don't think that can be done with either the vertical wall mount rack I envisioned or the brackets that you proposed.
• My switch and UPS doesn't throw off much heat, so even if you remove them from the equation that issue remains. Did you have a solution in mind? Apologies if I missed it.

• Makes complete sense.
• Are you suggesting I emulate that concept in my instance? If so, it would fit either with the chassis bottom against the wall or more conventionally with the chassis bottom parrallel to the floor.
• I'm assuming you use the brackets referenced earlier as intended (vertical) and mount by the rack ears omitting rails, but ..
• What if you used a pair of those brackets, connecting one to the rear of the rails and one to the front, with the chassis bottom against the wall? [similar configuration as the picture you posted, but here we are contending with the weight of a server v. switching equipment]

LOL @ "everything". I added a front bezel to mine should I want to enjoy a coffee break in the server closet. It wouldn't protect against the coffee, but perhaps the doughnut crumbs. ;)

Ah, the server closet. The ever-present air-conditioned hideyhole for escaping from colleagues who might ask me to do something for them.

 

[BigDave]

Are you suggesting I emulate that concept in my instance? If so, it would fit either with the chassis bottom against the wall

Once you mount the rack ears with the bottom of the chassis facing the wall (yes I would do both ears for stability),
you would then mount a third bracket to support the ass end (it would be the actual side) purely for weight support.

Mounting in this position (keep in mind) you must have room to change out a hotswap tray (between the front bezel and the wall) say approx. 6in. required.
The space left over would not have enough room at the back end to slid out a power supply (about 18in.)
You would have to unmount and remove the chassis from the brackets to get the PSU out, granted, how many
times would you actually end up having to do this...

Finally, what is a reasonable "height" for the lowest point of the server above floor? I get that the correct answer is as low as possible, where the densest, coolest air resides, but I would think that you would want some buffer between it and the floor (or is the 3.75" provided by the trim enough)?

I would mount the bottom about 14-16" high enough to comfortably work on the box while sitting on the floor.
If you mount it at base board height, you'd have to get on your stomach to get to much of anything
You condo has 3.75" base boards in the frikin closet :p

 

[svtkobra7]

Once you mount the rack ears with the bottom of the chassis facing the wall (yes I would do both ears for stability),

Sorry to clarify, I don't get how you mount the front to two ears?

you would then mount a third bracket to support the ass end (it would be the actual side) purely for weight support.

I get this.

Mounting in this position (keep in mind) you must have room to change out a hotswap tray (between the front bezel and the wall) say approx. 6in. required.

Check - Mounted on center, there is 7.5" on each side (41" - 26" = 15" / 2 = 7/5").

The space left over would not have enough room at the back end to slid out a power supply (about 18in.)

Not check - not worried though. I pulled 1 PSU anyway to reduce noise, so no difference from today (from a redundancy perspective). As per your point, it isn't as though this is a prod server for an enterprise.

I would mount the bottom about 14-16" high enough to comfortably work on the box while sitting on the floor.

Can I have 5 more inches? No, no, I'm good there ... I mean 5 more inches up so I don't have to move a j box.

If you mount it at base board height, you'd have to get on your stomach to get to much of anything

Agreed - much prefer to be on my knees.

You condo has 3.75" base boards in the frikin closet :p

Not sure I understand ... is that weird? Not to mention a tv in the bathroom. It is great for watching pr0n in the shower. But I had to put a mirror on the opposite wall so I could watch tv while making a poop. Granted I put that there, but the baseboards came with pre-installed. Kidding about the pr0n and the mirror, I actually can't remember the last time I turned that TV on. When I installed it years ago, I thought it would be neat to watch the news in the morning showering, shaving, etc.

 

[BigDave]

Sorry to clarify, I don't get how you mount the front to two ears?

Turn from the position shown above, 90 degrees to the left or right depending on where you want the
front of the chassis to face (right or left).

 

[svtkobra7]

hrm ... I may not have much of a problem to solve ...

She has been suffocating in the closet with the door closed and no intake for the past hour. Regarding HDD temps, of those 60 minutes, only 4 were spent above 40C @ 41C and then the full speed fan profile kicks in to knock them back down. Ambient outside the closet is ~80F. Ref fan script log below (from 6:47 - 7:05 I was running a stress test in a 32 core VM I spun up, not that should drive up HDD temps, but def ambient in the closet).

When I say no intake, I mean no intake. I covered the closet floor with cardboard and taped it down cleanly with painter's tape (to protect the hardwood) so that takes up ~1/8" of the gap between the door and the floor. On one end of the door their is less than 1/8" of a gap and on the other no gap. I can feel the suction when I put my face at the floor. This is with no ceiling installed.

So, what does this look like with a ceiling installed (and even that crap fan I bought on) and the cardboard removed to allow here to breathe (without a separate air intake or maybe a tad of that door shaved to allow more air).

Code:

Jul 07 17 18:34:00 | Tmin,avg,max = 35,36,39°C | FAN MODE: [04]HEAVY I/O CHANGED TO [00]STANDARD
Jul 07 17 18:36:00 | Tmin,avg,max = 35,37,39°C | FAN MODE: [00]STANDARD NOT CHANGED
Jul 07 17 18:37:00 | Tmin,avg,max = 35,37,39°C | FAN MODE: [00]STANDARD NOT CHANGED
Jul 07 17 18:38:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [00]STANDARD CHANGED TO [04]HEAVY I/O
Jul 07 17 18:39:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:40:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:41:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:42:00 | Tmin,avg,max = 36,37,39°C | FAN MODE: [04]HEAVY I/O CHANGED TO [00]STANDARD
Jul 07 17 18:43:00 | Tmin,avg,max = 36,37,39°C | FAN MODE: [00]STANDARD NOT CHANGED
Jul 07 17 18:44:00 | Tmin,avg,max = 35,37,39°C | FAN MODE: [00]STANDARD NOT CHANGED
Jul 07 17 18:45:00 | Tmin,avg,max = 36,37,39°C | FAN MODE: [00]STANDARD NOT CHANGED
Jul 07 17 18:46:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [00]STANDARD CHANGED TO [04]HEAVY I/O
Jul 07 17 18:47:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:48:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:49:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:50:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:51:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:52:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:53:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:54:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:55:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:56:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:57:00 | Tmin,avg,max = 35,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:58:00 | Tmin,avg,max = 35,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 18:59:00 | Tmin,avg,max = 35,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:00:00 | Tmin,avg,max = 35,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:01:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:02:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:03:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:04:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:05:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:06:00 | Tmin,avg,max = 36,38,41°C | FAN MODE: [04]HEAVY I/O CHANGED TO [01]FULL
Jul 07 17 19:07:00 | Tmin,avg,max = 36,38,41°C | FAN MODE: [01]FULL NOT CHANGED
Jul 07 17 19:08:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [01]FULL CHANGED TO [04]HEAVY I/O
Jul 07 17 19:09:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:10:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:11:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:12:00 | Tmin,avg,max = 36,38,41°C | FAN MODE: [04]HEAVY I/O CHANGED TO [01]FULL
Jul 07 17 19:13:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [01]FULL CHANGED TO [04]HEAVY I/O
Jul 07 17 19:14:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:15:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:16:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:17:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:18:00 | Tmin,avg,max = 36,37,39°C | FAN MODE: [04]HEAVY I/O CHANGED TO [00]STANDARD
Jul 07 17 19:19:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [00]STANDARD CHANGED TO [04]HEAVY I/O
Jul 07 17 19:20:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:21:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:22:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:23:00 | Tmin,avg,max = 36,38,41°C | FAN MODE: [04]HEAVY I/O CHANGED TO [01]FULL
Jul 07 17 19:24:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [01]FULL CHANGED TO [04]HEAVY I/O
Jul 07 17 19:25:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:26:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:27:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:28:00 | Tmin,avg,max = 36,38,41°C | FAN MODE: [04]HEAVY I/O CHANGED TO [01]FULL
Jul 07 17 19:29:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [01]FULL CHANGED TO [04]HEAVY I/O
Jul 07 17 19:30:00 | Tmin,avg,max = 36,38,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:31:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:32:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:33:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED
Jul 07 17 19:34:00 | Tmin,avg,max = 36,37,40°C | FAN MODE: [04]HEAVY I/O NOT CHANGED

 

[svtkobra7]

Turn from the position shown above, 90 degrees to the left or right depending on where you want the
front of the chassis to face (right or left).

OK - done.

I still don't see how you use two on the "front" side.
Granted I'm not the sharpest tool in the shed as is and it has been a long week.

 

[BigDave]

Not sure I understand ... is that weird?

You typically don't find tall baseboards within the confines of a closet, It's not weird, just an expense most
builders would eliminate.

I mean 5 more inches up so I don't have to move a j box.

If moving up, then I would go 24" to the bottom of the chassis, perfect for working at chair height.

 

[BigDave]

OK - done.

I still don't see how you use two on the "front" side.
Granted I'm not the sharpest tool in the shed as is and it has been a long week.

There is two sets of square holes for mounting (that is the TWO I keep referencing), I'm
not thinking about the whole bracket being one piece of metal, but you're right, it's one
bracket with two mounting points. Sorry my bad! Where would we be
without pictures lol.

 

[BigDave]

hrm ... I may not have much of a problem to solve ...

She has been suffocating in the closet with the door closed and no intake for the past hour. Regarding HDD temps, of those 60 minutes, only 4 were spent above 40C @ 41C and then the full speed fan profile kicks in to knock them back down. Ambient outside the closet is ~80F. Ref fan script log below (from 6:47 - 7:05 I was running a stress test in a 32 core VM I spun up, not that should drive up HDD temps, but def ambient in the closet).

When I say no intake, I mean no intake. I covered the closet floor with cardboard and taped it down cleanly with painter's tape (to protect the hardwood) so that takes up ~1/8" of the gap between the door and the floor. On one end of the door their is less than 1/8" of a gap and on the other no gap. I can feel the suction when I put my face at the floor. This is with no ceiling installed.

So, what does this look like with a ceiling installed (and even that crap fan I bought on) and the cardboard removed to allow here to breathe (without a separate air intake or maybe a tad of that door shaved to allow more air).

I would be interested to see of the A/C was running when you felt the air moving under the closed closet door.
Try shutting off the A/C and see if you can still feel moving air going under the door. If the return air space
is above the closet sheetrock ceiling, then the updraft in the closet will end once the A/C blower stops.
If the A/C return air is drawing from the closet, once you sheetrock the ceiling and get the fan working and
trim the bottom of the door, this may work!

 

[svtkobra7]

There is two sets of square holes for mounting (that is the TWO I keep referencing), I'm not thinking about the whole bracket being one piece of metal, but you're right, it's one bracket with two mounting points. Sorry my bad! Where would we be without pictures lol.

10-4. Was worried my brain was boinked worse than it already is. I'm liking this idea.

I would be interested to see of the A/C was running when you felt the air moving under the closed closet door. Try shutting off the A/C and see if you can still feel moving air going under the door. If the return air space is above the closet sheetrock ceiling, then the updraft in the closet will end once the A/C blower stops. If the A/C return air is drawing from the closet, once you sheetrock the ceiling and get the fan working and trim the bottom of the door, this may work!

• Not sure if the air handler fan was on or off previously, but I just killed power to it and I still feel a slight movement of air. I guess that means the closet has negative differential pressure v. living area?
  
• There is one return air "vent" in the condo, and that sits on the underside of the air handler in the utility closet next to the server closet.
• That 21.5" plenum above the closet serves as an area for distribution of HVAC (believe I mentioned that previously) and the image below shows the gap in between the duct and sheet rock, which when the fan is on, would account for that pressure differential (or part thereof).
• Yet it persists even when off - interesting - not sure what to make of that.

I don't follow the comment about the handler drawing air from the closet with a ceiling in place? Perhaps you could explain that to me. Regardless, I should note, that I was just planning on putting an 8" piece of 4" duct on the end of that fan and then a curved elbow directing the exhaust straight at the concrete ceiling. Why? I've read that the minimum distance that you should keep ducting straight for is 2 x the diameter of the outlet and also I can't go much further than 8" anyway as the exhaust vent from the fan doesn't sit much higher than the drywall and any longer it would hit whatever you call the horizontal piece of metal that "frames" the ceiling of the closet (which you would screw the drywall into). In GA, it isn't against code to not externally terminate a vent in this case. Remarkably, bathroom vents don't even need to be externally terminated (which surprises me).