My apologies for the delayed reply, let me reply to several comments in one post. Thank you all for weighing in, I've learned quite a bit already.
There are a couple parameters you need to keep in mind...
First; it's preferable to force cool air in rather than draw hot air out. The cooler the air the denser it is; this translates to the same fan being able to push more cool air than warm. If you want to get real fancy you could have both a forced air fan at the bottom and an induced air fan at the top and balance their loads so the closet maintains a slightly positive pressure.
I will be honest, and not that it is any excuse for a lack of knowledge, but none of my degrees are scientific in nature (rather economics, business, and finance) and I'm certainly lacking in knowledge here.
If a fan moves X cubic feet of air per minute, it will move X cubic feet regardless of whether that air is hot or cold, right? Are you suggesting that due to the differential in density, that a fan is able to move more cool air? Not questioning whether you are right, just seeking academic understanding.
Second; air needs someplace to go... You can't force air into a plenum if there's no exit; it will simply pressurize the space. The corollary to this is you can't extract air from a space if there's no inlet; it will simply create a lower pressure inside the closet than out.
You have a solid point here, but allow me to humbly and ignorantly point out that your statement assumes the plenum is hermetically sealed, and while it is certainly "sealed" from view, it is by no means air tight. I assume that air expelled into that cavity, is displaced by "fresh" warmer air, and that cooler air, being denser sinks due to gravity and finds a way to "escape" perhaps between along the studs, etc. Further, I assume that pressure would not actually build with the type of fan I would be using (or maybe it does increase marginally). Perhaps a poor analogy, but as an example to the converse, when you turn a bathroom vent fan on and the bathroom door is closed, that fan doesn't cause the bathroom to implode.
That being said, what would actually occur in this scenario where you have a fan extracting warm air from a 59 cubic foot space into one that is at least 453 cubic feet? Also, what happens if I simply leave convection to do its magic with no fan? I imagine the temperature of those two spaces would balance and the solution would lose effectiveness?
Saying no to the ceiling fan you pictured because better choices exist. Like a multi speed exhaust fan and maybe just an opened ceiling + your plan for the louvers 6" above your floor, more below.
Thanks for the clarification. The link you provided is a search on Amazon for "quiet exhaust fans" and the fan I referenced (only directionally) actually appears as the third result.
Not sure of the power draw or noise of your previous equipment. Weatherstripping the door / sound absorption material is low cost fine-tuning you DIY project.
Not that you asked the question, but I looked it up on qnap.com:
- TVS-871: 82.51 watts (in operation) with 8 HDDs installed; 23.1 dB(A)*
- TS-453A: 32.35 watts (in operation) with 4 HDDs installed; 19.7 dB(A)*
- TS-231: 20.56 watts (in operation) with 2 HDDs installed, 15.4 dB(A)*
- * "Testing environment: Refer to ISO 7779; Maximum HDD loaded; Bystander Position ; Average data from 1 meter in front of operating NAS"
Convection may work, but I am not standing in your condo and have reread your description about the area above being closed off and am hesitant to say it will work.
Perhaps additional description of the plenum and diagram provided at the end of this post assist in providing additional detail needed to make such a determination?
It may be you can install a vent between the concrete and the enclosed area IE, there will be two openings in the dry wall. One in the top of the closet and one between the concrete uppermost drywall. Guessing it is drywall below the concrete (below the top red line in your photo). If so then convection is a probable course.
I don't quite follow your suggestion (if you could explain further it would be appreciated), but let me add that all space in the plenum is common and there are no internal barriers* between the horizontal drywall (21.5" below the concrete slab) and the concrete slab ceiling.
* By this I mean, as an example, there is a wall between the laundry room and the bathroom, and the metal studs certainly extend the full length between the concrete floor and concrete ceiling, but above that plane of horizontal drywall, there is not additional vertical drywall above it, only below it, to create the partition between those rooms.
-It really comes down to how much time you have to fine tune your cooling project.
Plenty, I'd rather it take longer and do it right. To add support to that comment, I actually have removed the drywall from the rear of the closet and will be replacing it tomorrow.
How about building a small platform on top of the wall on the left and put the server there?
Thank you for the suggestion. My apologies for the confusion, but that actually is not my condo. As mine is too much of a mess at the moment, I pulled a picture from a for sale listing to visually illustrate the plenum I was referring to.
That being said, I believe there are two reasons why a shelf wouldn't be a tenable solution:
- The "server closet" is where the Structured Media Enclosure is located and all of the Ethernet drops terminate, so my preference would be to keep everything consolidated in this space.
- My condo has metal studs, which are not meant to be load bearing and extremely flimsy. I won't pretend to know the physics behind this statement, but: Assume you have a box 19" wide by 5.25" tall by 30" deep, it is much easier to securely fasten that box to the wall by the side which is 19" x 30" as opposed to the side that is 19" x 5.25".
So I just looked at your picture and it looks like your idea might work but I have a few reservations.
That plenum above the kitchen has an opening running below the concrete ceiling, likely for return air so that's good if the area above the closet isn't separated. In fact if it's connected you might not need a fan as a pentration into that plenum will naturally draw air to your air handler.
However I don't think you'll get a lot of cool air with a vent from the utility closet unless it has it's own register.
I still think a louvered door would be best, or a vent in it or some wall leading to an air conditioned space. If the area above you server closet's ceiling is common to that plenum just adding a ceiling vent should take care of the warm air.
Using a picture of another floorplan was a mistake, that is actually not my condo. To respond to your comments:
- I actually have no clue what type of HVAC system is installed in my condo, but I can add that the utility closet contains an air handler (suspended above the water heater), the bottom of which is "open" and covered only by an air filter. Is it possible all of the vents are supply and that open air filter serves as the sole "return"?
- Perhaps I should have added this earlier, but the door to the utility closet is louvered. My (unstated) thinking was such that adding a floor level vent (for cool air) to the utility closet was sufficient as: (a) it would allow for cooler air to flow into the server closet thanks to the louvers on the utility closet door and (b) since whoever designed the condo thought the utility closet to have sufficient circulation for the air handler, that it would serve my needs as well. Assumption: Air handler moves significantly more air than I'm looking to expel from the server closet.
- The area included in that plenum is shaded grey in the attachment and includes space above the laundry room, bathroom, server closet, and entry to bathroom from bedroom. The aforementioned areas are connected to an area above the bedroom which leads to the exterior of the building and allows various vents to expel air to the outside world.
- That plenum area excludes the utility closet, as all four sides of that closet extend fully to the concrete slab above.
Does providing that additional information add additional needed detail to what I'm working with here? If so, how does it impact your recommendation?
Reference the diagram I have added to this message. The grey shading indicates the plenum area, inclusive to the area above the server closet, and there are no "internal" barriers.
