Equipment closet cooling

[video321]

I just picked up an Asus WL520GU

Don't want to take this off topic, but I have that same router running DD-WRT and absolutely love it!
It's doing SSH, DNS, Dual WiFi, VLANs, and more. It was the best $30 I spent in a long time.
If anyone is interested in DD-WRT and SSH I wrote a guide here on Cocoontech.

My PC was built for 24/7 server & HTPC use and gets HTPC use about 10hrs/day and at the same time I'm connected via SSH streaming music while at work and that is why I mentioned building a more power efficient computer. Even the exhaust fans blow only warm with heavy use. It uses more than half the amount of electricity as the Athlon XP Mobile it replaced.

 

[apostolakisl]

I would take your fan out of the closet. Blowing the air around makes the room hotter, not cooler. Unless you have a very directed air stream over the cpu you are making matters worse. The fan burns electricity which makes heat. Fans mostly cool people because people sweat and fans help evaporate the sweat cooling us off more efficiently. The effect is much less for a piece of computer equipment and would be more than negated by the overall rise in room temp.

Putting a return vent in the room would barely do a thing. The suction on a return vent is going to preference an area of your house where there is higher positive pressure from an inlet duct. So I would expect no significant draw.

Putting a duct into the room to move chilled (AC) air into the room is your highest success rate short of putting a dedicated HVAC unit in the closet. To get fancy, you could oversize it and put a damper that is controlled by a separate thermostat (quasi zoned). Close the vent during heating season. If the room is adjacent to an unheated attic or wall it is unlikely that it will over heat in winter.

I do agree that reducing the heat load is a very good idea.

Lastly, 90 degrees isn't the end of the world. I doubt you will see any hardware failure at that temp.

 

[Quixote_1]

Why don't you just put a giant stand-alone freezer in your closet with the back poking out of the wall behind it, put the two computers in the freezer along with a small dehumidifier, then run a hose from the dehumidifier's reservoir to a few of your house-plants?
That way you could cool your computer AND water your plants!

 

[kertofer]

Brilliant! I could also put my beer in there and up the temp on the freezer to about 34 and then I would rarely have to leave this part of the house!

 

[Quixote_1]

Brilliant! I could also put my beer in there and up the temp on the freezer to about 34 and then I would rarely have to leave this part of the house!

Now you're thinking!

 

[apostolakisl]

If you really want to keep the room temp on the money buy one of those portable AC units like they have at costco. They are freestanding compressor evaporator/condensor with a hose that exhausts the hot air from the condensor to the outside. They cost $350. These are not going to be as efficient as your primary home AC unit but becuase they vent to the outside they will be working together with your home AC.

 

[kertofer]

Lou, I am not terrible worried about the room temp being spot on, I just do not want my office to be 10 degrees hotter than the rest of the house and I do not want to leave the closet closed up with no circulation, causing it to get way up there and damage my gear.

 

[apostolakisl]

Lou, I am not terrible worried about the room temp being spot on, I just do not want my office to be 10 degrees hotter than the rest of the house and I do not want to leave the closet closed up with no circulation, causing it to get way up there and damage my gear.

I think I understand you to be saying that your office has a closet where you keep your equipment. If you close up the door, the closet gets too warm for your equipment. If you open the door, the temp in the office gets warmer than you would prefer but not too hot for safe operation of the equipment.

In this case, you might consider using that small portable AC unit in your office itself to keep you comfortable, and put top/bottom leuvers on the closet door to allow convective currents to keep the closet reasonable.

For $350 it is a one stop solution with little or no setup and you get the bonus of keeping your office at the perfect "working on the books" temp.

Other solutions might cost half of that if you did the work yourself, but would require quite a lot of labor and wouldn't result in the ability to have a perfect working temp at your desk.

I would revisit your equipment load, it does seem a like a lot of heat is getting kicked off of your stuff.

 

[tmbrown97]

Maybe I missed this in an earlier part of the thread - but are there any other walls on that closet that are shared with a more open space? For instance, in my closet, I wouldn't want to vent into the bedroom heating that up - if anything I'd most likely vent into the hallway near the return so it mixes the air better.

I personally think a dedicated A/C is overkill - and you don't want to pump the heat into your office; so it's time to look for other places to direct it.

Lou - I think the effect of the heat load really comes down to the construction of the house. I've lived in some older homes where there was enough natural airflow through and around the walls that you never had to worry about this; but the newest construction standards are extremely tight - and even with the tiny load I mentioned above and the larger closet, I have the same heat issues. Not all houses are built the same; and if it's a very airtight room, it doesn't take much to heat it up. 20 years ago they didn't do all the firebreaks and foam sealants and 3ft of blown-in insulation and the fire-caulk inside every drilled hole - there was a lot more room for air to circulate within the home. Nowadays houses are all but airtight with only the HVAC to move and exchange the air.

 

[apostolakisl]

Maybe I missed this in an earlier part of the thread - but are there any other walls on that closet that are shared with a more open space? For instance, in my closet, I wouldn't want to vent into the bedroom heating that up - if anything I'd most likely vent into the hallway near the return so it mixes the air better.

I personally think a dedicated A/C is overkill - and you don't want to pump the heat into your office; so it's time to look for other places to direct it.

Lou - I think the effect of the heat load really comes down to the construction of the house. I've lived in some older homes where there was enough natural airflow through and around the walls that you never had to worry about this; but the newest construction standards are extremely tight - and even with the tiny load I mentioned above and the larger closet, I have the same heat issues. Not all houses are built the same; and if it's a very airtight room, it doesn't take much to heat it up. 20 years ago they didn't do all the firebreaks and foam sealants and 3ft of blown-in insulation and the fire-caulk inside every drilled hole - there was a lot more room for air to circulate within the home. Nowadays houses are all but airtight with only the HVAC to move and exchange the air.

True, but I think Chewie is saying that the equipment is heating up his entire office to an uncomfortable level when the closet door is left open. I don't know the dimensions of the office, but unless it is very small, that seems like a lot of heating from just some home automation stuff.

So unless he produces less heat in the closet, there is going to be an imbalance in the homes HVAC system. The HVAC can be zoned to occomadate that at a very high cost. A separate unit could be installed in that room (a simpler way to basically zone a system) and would be minimal work. Or you could power vent the room to either the outside or into some other part of the house that is much larger than the office.

The last option could include putting a power vent that blows air out of the closet and into a return air vent. This will more or less distribute the air all over the house. In the winter that would be good. In the summer you could switch over to venting to the outside. Of course if you have a new super tight house without an ERV, you might have vacuum issues resulting in poor cfms. This cost of doing it this way would approach $350 in most cases depending on the details and take hours of work.

But again, I just think it is odd that a HA setup makes enough heat to turn an entire room uncomfortably warm.

 

[video321]

I just think it is odd that a HA setup makes enough heat to turn an entire room uncomfortably warm.

Lou, I absolutely agree and it goes back earlier when I asked him what exactly these computers were doing because there is something odd here.
I checked out my closet, which I described earlier, after the home theater receiver and PC were running for 12 hours and I was not getting any heat from my PC. My receiver, CCTV DVR, cable TV DVR, and VoIP box - well...that's a different story! But you know what, I only "feel" a couple degrees warmer in the closet vs. the room with all that running.

 

[kertofer]

Lou, the biggest reason that it heats up my office is that, of course, my office is in the back corner of the house and has the least amount of air flow.

I am, as I mentioned, in the process of looking into using some smaller low powered PC's for my file server and automation machines (2 of the ones I am looking at will only produce an average of 70-80 watts total as opposed to a couple of hundred watts in the current machines) as well as looking at some of the other ideas that have been thrown out in here. Basically this would not be a big deal if I did not spend a lot of time in an office that already has less airflow than the rest of the house, in an upstairs room in a house in Houston where is is routinely over a hundred degrees in the summertime. Winter time is nothing to me as it only lasts about 3 weeks. I just want my office to remain comfortable, so I am willing to go through more effort that is needed to get to good enough if you know what I mean.

I will be looking into several of the ideas above and will keep you guys updated on what I decide to do.

 

[apostolakisl]

I live in Austin, so I understand the heat issue. If you vent the closet to the outside, you will be drawing outside air into your house from somewhere else (cracks). So, if it is regularly 90 or 100 degrees, venting to the outside will force 90 or 100 degree air to get sucked into the house somewhere else. So, you might as well just keep the hot air from the closet in your house and blow it to a large room or into the return air plenum. You could use a higher CFM bathroom fan or, better than that, an in line duct blower. You could even automate it since, after all, this is an HA forum.

But it really sounds like you might need your HVAC balanced better. Solutions may include: 1) larger line into the room 2) undampering the line if it is dampered 3) adding a return air vent or improving the return air vent if already present, or 4) putting one of those portable AC units in. Also you might consider window treatments if it is getting direct sun (or plant a big tree).

If, in general, your HVAC unit barely keeps the house cool on whole in the summer, the portable AC unit is the only reasonably priced solution since shunting more central AC to the room will just be stealing it from the rest of the house.

 

[jlegault]

This is a great thread - it's the subject of some struggle I've had over the past 8 years in this house.

Here's a pic of my equipment room (upstairs) and current setup (a little messy as I just installed uverse and consolidated 4x8 port switches into one large 24port switch)

I had the luxury of building the house, so I could spec exactly what I wanted - though I was naive on the ventilation side of things. It has an A/C vent on the upstairs HVAC circuit.
The room has 2 PCs (1 for automation, 1 for media center, both overkill 4-core) and a large NAS drive (9TB), along with 3 receivers, one theater amp, a wholehouse audio amp, various other distribution/interface components (A/V, IR, Ethernet, etc), an ElkM1, A/V sources (ATV, DVD). The ELK turns off the HVAC vent with a damper when the system is heating.

Day one, there was a heat problem because there was no ventilation (duh). I've tried two ventilation systems.
1. A 75K BTU room A/C unit venting to attic (worked great, but used a ton of power)
2. A variable speed furnace blower that is on all the time, but slows when the A/C unit is not on. Mated with a 200CFM exhaust at the top most corner of the room, opposite the AC vent, dumping into the attic. The A/C vent is 8" (originally a 4" vent). I also have a large box fan running at low speed routing air across the equipment rack to aid with convection. This works OK, but temps can still spike in the summer.

Some temp trends this week:

Some things I'm going to do in the future:
- I need to integrate the exhaust back into the main system - but I've lacked the motivation because I still think dumping to the attic is more economical.
- Consolidate the media center PC and the automation center PC with a 35W i3 core, switch to an SSD for the main drive, consolidate all the extraneous drives to one 2TB unit. (lots of $ and fear of windows7 running my automation)
- (out there) If I ever get to installing a solar heater for hot water or the pool, I may circulate first through a heat exchanger in the equipment room. This waste heat is useful if I could harness it.

Ultimately, the PCs are the issue. They draw at least 400w between the two of them. That is where I would suggest focusing your time - energy efficiency.

 

[kertofer]

jlegault, sounds like you have a similar situation to mine. I am thinking my next step is going to be to put a return into the closet and possibly a duct fan to keep air circulating. Probably about a 4-6" line and T it into the main return for the upstairs AC unit. There are 2 reasons for this. First, during the summer and warmer months the upstairs AC runs quite a bit, which means that I should get overall pretty nice circulation out of this. Second, the main return for the upstairs is on the other side of the floor because the rooms that are my office and theater room are add ons and when the previous owners added them the return was not moved so there is much less circulation at this end of the house.

Another thing I have already started on is the energy efficiency. My Automation machine currently runs on a dual core, 8GB RAM, 2 hard drive machine. No reason for that, so I am moving it to a 30W Atom machine with 4GB RAM and a single drive. This will run my Automation and camera server (Only planning for 4 or 5 cameras so hopefully the Atom can handle that) and the next step will be to move my main server (Quad core, 8GB RAM, 2 2TB HDS) to another Atom with 4GB RAM and a single 2TB drive. Then I will have a single external drive that will be used to back both machines up. That alone should reduce my heat load tremendously as I will go from 200+ watts to 70-80.

Next step for me, once I get the temp in here taken care of, will be to move my Receiver, PS3 and a Cable Box into the closet, but that should not add tremendously to the heat load as those devices are only used for a couple of hours a day and powered off the remainder of the time.