Air con for my rack.

[Falloutboy]

I have just brought a 42 RU rack, I have arranged seiemic mounts for it and am building a high mass false floor, my major problem is I can not locate an in floor heat pump which can cool the air and blow it over my equipment from underneeth, everything seems to be wall mount or ceiling mount or ducted and I don't want these solutions, as heat naturally rises I want to blow chilled air from the bottom and let it make it's way out the top, waste air to literally go out the window.
Does anyone know of a manufacturer that makes such a solution or alternatively an in ceiling unit that can be rotated 180 degrees and run in the false floor.

I've gone to a lot of trouble to do this right and this is really @$#(*#$ me off.

 

[BlueFox]

Heat really only rises when there's no circulation, which is not going to be the case here. I don't exactly see how your hypothetical setup would work if not ducted. Why would you want air from the rear of the rack to be vented from the exterior if you have a heat pump anyway? Kinda defeats the whole point of refridgeration, does it not? Your condenser is going to be outside the building and where the heat will go.

 

[Falloutboy]

Heat really only rises when there's no circulation, which is not going to be the case here. I don't exactly see how your hypothetical setup would work if not ducted. Why would you want air from the rear of the rack to be vented from the exterior if you have a heat pump anyway? Kinda defeats the whole point of refridgeration, does it not? Your condenser is going to be outside the building and where the heat will go.

Correct ; however in a different location from where the heat goes out the window - the condensor is at the side, the window at the front.

 

[BlueFox]

I guess I'm still not understanding your proposed setup. Why wouldn't cooling the room work for you? Why do you want to exhaust air externally when you have refrigeration?

 

[Falloutboy]

I guess I'm still not understanding your proposed setup. Why wouldn't cooling the room work for you? Why do you want to exhaust air externally when you have refrigeration?

The room is my living room, it is 7m x 4m not counting the fact the kitchen is open plan, I am looking at simply cooling the contents of the rack, if I cool the whole room I am then subject to the temperatures required to cool the rack. I have a heat pump in this room that keeps my room temperature at 22.c I am looking at a unit specifically for the rack which will do 16 to 19.c.

I suffer from a genetic illness and temperatures outside of 22.c set off my skin, I would either end up with a skin rash from being overly hot or I could end up with a skin infection from being too cold. It's called Immuno Gamma Globulin E disorder for reference, it is a genetically inherited immune system disorder which leaves the immune system overactive.

Thus the need to cool the rack and not the room.

 

[BlueFox]

If you really want to isolate the rack, you don't want to exhaust any air externally. You want a loop with refrigeration in the middle, similar to a hot and cold aisle in a datacenter. I think 16-19C is unnecessary for rack inlet and per some whitepapers, actually worse for hard drive longevity compared to higher temperatures. With adequate circulation, you may be able to maintain 22C throughout your room using a single heat pump as well (sans the immediate area behind the rack), requiring no further changes to the rack.

If you exhaust externally, you're just going to overwork the one for the room as the exhausted air has to be replaced somehow (so, it too would come from the exterior at likely a much different temperature). Throw in a second heat pump and you're just wasting more electricity on top of that.

 

[Falloutboy]

The room is my living room, it is 7m x 4m not counting the fact the kitchen is open plan, I am looking at simply cooling the contents of the rack, if I cool the whole room I am then subject to the temperatures required to cool the rack. I have a heat pump in this room that keeps my room temperature at 22.c I am looking at a unit specifically for the rack which will do 16 to 19.c.

I suffer from a genetic illness and temperatures outside of 22.c set off my skin, I would either end up with a skin rash from being overly hot or I could end up with a skin infection from being too cold. It's called Immuno Gamma Globulin E disorder for reference, it is a genetically inherited immune system disorder which leaves the immune system overactive.

Thus the need to cool the rack and not the room.

A consumer freezer can't get cold enough to damage a hard drive. The minimal non-operational hard drive temperature is around minus 40 degrees Celsius. However, there are some extreme climates on the planet that get cold enough to damage a hard drive.

Nope it's not cooling that kills with hard drives, it is excessive vibration (shock) which is why I'm using a floating floor with 4 seismic mounts rated for 200Kg each max load with peak efficiency between 100 and 500kg. I consulted an engineer to avoid harmonic issues and spring song.

 

[BlueFox]

I didn't say damage, I said longevity. Failure rates increase considerably at low temperatures. Go read Google's paper (section 3.4): https://static.googleusercontent.com/media/research.google.com/en//archive/disk_failures.pdf

 

[Falloutboy]

I didn't say damage, I said longevity. Failure rates increase considerably at low temperatures. Go read Google's paper (section 3.4): https://static.googleusercontent.com/media/research.google.com/en//archive/disk_failures.pdf

Will do thanks for the info, ill check it out, in saying that though I would expect that the temperatures within my disks servers may get as high as 38 to 40 degrees in normal operation, there might be a slight variation above that during an excessive operation such as a patrol read but the air can't get directly into the case it would only be able to be drawn in or transferred conductively through the case so combining that heat with low temp air I would say I might knock off possibly as much as 8 degrees so it's not like they are going to be cold cold, maybe just slightly cooler than body temperature.