Announcement

Collapse
No announcement yet.

Brainstorming Further Cooling Improvements To The Linux Benchmarking Room

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Brainstorming Further Cooling Improvements To The Linux Benchmarking Room

    Phoronix: Brainstorming Further Cooling Improvements To The Linux Benchmarking Room

    While the modifications I did to the big basement Linux server room back in December have been yielding excessive "free heat" and the heating bills this winter have been at a minimum, I've already begun thinking of ways to improve the cooling of our benchmarking basement by the time summer rolls around...

    http://www.phoronix.com/scan.php?pag...ver-Room-Floor

  • #2
    It's not exactly the weight of the rack that's a problem, but rather the pressure. You could consider putting wooden planks or something under the wheels. Maybe like 'rails' along the paths where you would ride the racks (if you move them around at all), but not big enough boards that they cover the entire area under the racks. That would negate the radiant cooling from the floor. Metal plates wouldn't though..

    As to actually replacing your floor: Wouldn't your tiles need an underlayment against moisture and such? Then the 'insulation loss' from switching to tiles would probably be a lot less.

    As to the cooling gain, it is possible to do some calculations about that (with guesses as to your materials/size of your floor/amount of heat produced/soil and concrete temperatures), maybe later tonight.

    Comment


    • #3
      Originally posted by lvlark View Post
      It's not exactly the weight of the rack that's a problem, but rather the pressure. You could consider putting wooden planks or something under the wheels. Maybe like 'rails' along the paths where you would ride the racks (if you move them around at all), but not big enough boards that they cover the entire area under the racks. That would negate the radiant cooling from the floor. Metal plates wouldn't though..
      Hmmm, good point, if I could find like some metal mats or something.

      Originally posted by lvlark View Post
      As to actually replacing your floor: Wouldn't your tiles need an underlayment against moisture and such? Then the 'insulation loss' from switching to tiles would probably be a lot less.

      As to the cooling gain, it is possible to do some calculations about that (with guesses as to your materials/size of your floor/amount of heat produced/soil and concrete temperatures), maybe later tonight.
      I don't believe I would need any underlayment for the tile in this case. Will do some more research but should be fine.

      If you're able to do some calculations, let me know if you need any other details. Thanks!
      Michael Larabel
      http://www.michaellarabel.com/

      Comment


      • #4
        Just some rough numbers to get started... (BTW a good seach term is earth-air heat exchanger)

        Concrete at typical density has an R-factor of maybe 0.1 per inch of thickness, so 0.4 for an average slab

        Last article I found said you were using about 4KW or 14,000 BTU/hr, which would give a ~17F rise over ground temperature ignoring (a) heat travelling in/out through walls and ceiling, (b) heat carried in/out via air flow to the rest of the house.

        Vinyl tile isn't a big factor in terms of heat flow, R-factor seems to be ~0.05 compared with 0.02 for ceramic tile. Porcelain tile R-factor might be a bit higher due to density & thickness but doesn't make much difference anyways.

        Underlayment is a different story - numbers seem to vary pretty widely but R-factor somewhere around 0.4 seems to be typical, which would pretty much double the temperature rise at floor level (so 34F rise over soil temp) compared with just the slab.

        So... assuming enough airflow to keep floor surface temp the same as the warm spots in the room (I imagine you already have this), at first glance you should be able to get a useful reduction in temperature by removing the underlayment. You would also lose more heat into the soil during the winter (so less free heating) but a couple of rugs covering most of the floor should get that back.

        Couple of questions:

        1. Is the slab insulated (eg foam under the slab) ? If it is, then don't bother changing anything

        2. Were you thinking about tile over bare concrete, or still some kind of underlayment ? If the tile needs an underlayment, maybe just epoxy paint the slab ?
        Last edited by bridgman; 16 January 2016, 01:12 PM.
        Test signature

        Comment


        • #5
          This is why they build data centres with chillers.

          Maybe a simple Mitsubishi Mr. Slim ductless system.
          I use the Big Mitsubishi CityMulti's a lot in the Bahamas. Very Efficient, even use them to heat water to 160F.
          Power in the Bahamas is expensive, I pay $400 a month for my 600 square foot condo, so efficient is the paramount.

          Without a load calc and psychometric data, this is just guess work.
          Get with a HVAC Engineer, HVAC is very regional, and they might be able to offer something. I do mean an engineer, not a HVAC installation company.

          By the way, this is funny, as I was typing about this, I just got an email from my boss, he wants to use the walk-in cooler compressor to heat a pool.
          http://www.supplyhouse.com/Heat-Exchangers-821000
          Last edited by kurly_b; 16 January 2016, 01:23 PM.

          Comment


          • #6
            I found a great article about earth to air exchange,
            here's the link
            http://www.scribd.com/doc/50861826/T...uthern-Nigeria
            Yeah, I know Nigeria, but it was a great read.

            Comment


            • #7
              Another thing to think about would be the schedule when the servers are run.
              It's cooler outside at night, so running most of the load early morning before sunrise would be optimal.

              Comment


              • #8
                Since you have a surplus of heat all year round, using the ground as thermal mass will not be that effective. You will warm the ground up... and that will be that.

                I think you best bet would be to set up a thermal siphon, if possible. Is there anyway you can duct air from the server room to the roof of the house? In the old days, this was the purpose of a cupola on the roof: the warm air would rise, and would be sucked out of the cupola, drawing fresh, cooler air in through open windows on the bottom floor. Exchanging air is much cheaper than cooling air. Even if you can't get a siphon going, if you can set up the ground floor with air exchange, block the AC, and insulate the ceiling, you could save a lot of money in the long run.

                If I were setting up a home server room, I would try to replicate a cold/hot isle system, and vent the hot air appropriately for the season. I would try to minimize the hot air space to reduce unwanted thermal transfer.

                Another option to consider is to turn a room on the top floor into a server room. As heat rises, the rest of the house will stay much cooler. Open a window and let the hot air pull cooler air in from the rest of the house. Maybe put a vent in the door. Then move the servers twice per year.

                Comment


                • #9
                  You might want to look at stone tiles over porcelain, they are much more attractive if you chip them versus porcelain where you get a very unsightly chip.

                  If sticking with the porcelain tiles try very hard to find ones where the base material is as close as possible to the glaze color. You do not want to be in my situation with a light cream glaze and dark red tile base, so very ugly when scratched or chipped and so much work to remove and replace.

                  Bases on the racks to preserve the floor can be pretty simple things, we have used poly glides with good success on both tile and stone floors.
                  Example: http://smile.amazon.com/Shepherd-Har...TKK1VVTMF9AKBX

                  If you find the hard floor too cold in winter adding carpet hall runners and area rugs will reduce the heat loss a fair amount.

                  Comment


                  • #10
                    Looking for an online example... can't find one.
                    But I tried this experimentally once, and it some what work, need to be refined.
                    But (2) fan coils with fans, (1) inlet, (1) exhaust, connected by copper pipes, filled with R134a to around +- 60 psi, can't remember exactly.
                    I got a deltaT of about 4 - 6 degrees F. The hotter the exhaust, the better the deltaT.
                    Was testing to lower the dew point of the makeup air in an area, so AC could run better. 80% humidity is a bitch.

                    Comment

                    Working...
                    X