Please could you advise how many BTUs I would need to effectively cool this room through the peaks of the British summer:
Room 3.5m x 3.5m = 12.25 m squared or 131 feet squared. South facing with large windows. Has 2 large PCs with 500W power supplies. + 2 large
21 inch monitors. It doesn't have a door so there is an open doorway which opens to a hall area.Would 12000btu be about right?
A lot depends on how cool you need it and what the insulation is like, whether the sun shines in etc.
PCs tend to consume 100W or so max no matter what the power supply is. So the heat is predomiately from the sun (upto about 1kW/m^2 in the south) and the PCs are chucking out barely more than the people using them (100W a piece). But don't use this to budget.
You didn't say whether you wanted the room like a fridge.
Jon
The message from Jonathan Schneider contains these words:
That's rather a sweeping generalisation. Some Intel processors were ill known for pulling 90W - then there's the disc drives, the RAM, all the glue logic, the video card, the monitor. AMD's Athlon 64 FX-57 peaks at
134W flat out.
The big heat generators in the room described are probably the 21" monitors, if they are CRTs.
My computer room ( non-A/C, 4 PC systems, 2 servers running 24/7 and a pile of switches, routers, firewalls, PoE injectors, and a UPS ) runs noticably cooler now I've gone to LCD, ditching 3 19" CRT behemoths.
On 18 Jul 2006 07:12:08 -0700 someone who may be snipped-for-privacy@yahoo.com wrote this:-
BTUs,? Odd primitive things best avoided.
Is there any external or internal shading on these windows? If not then putting some shading in will be somewhat cheaper than the first and running costs of some gadget to cool down the room after the sun has got in.
And, how many people are there in the room? They will emit around
100W per person.Hi,
Thanks for your replies.
The 2 computers are both dual processor workstations each running 4 hard-disks so they do produce far more heat than the average machine. I need powerful machinary for graphics and video work. I'm in the room on my own.
I am renting the room from another company who uses the rest of the building to run their business. It is in a residential area and they may be pinickety about hanging something over the outside of the windows to stop the sun getting in as they may want to keep the outside of the building looking ordinary. If it was my building in an area where it wouldn't matter I would hang something over the windows but I suspect the other company wouldn't like it. The windows are unshaded from the outside but do have a black out roller blind that I can pull down on the inside. The trouble is that this blocks the windows which open at the top. The building recently has had cavity wall insulation fitted and 10 inches depth of insulation in the loft space. Apparently the building was far worse for heat on the top floor before this was done.
I don't need the room like a fridge. I'm okay to wear shorts so if I could get it down to some where near 25 degrees C that would be far more pleasant.
The figure of 1kW/m^2 for heat from the sun is dependent on the area of the windows not the floor space?
Thanks for any advice.
David Hansen wrote:
Hi,
Thanks for your replies.
The 2 computers are both dual processor workstations each running 4 hard-disks so they do produce far more heat than the average machine. I need powerful machinary for graphics and video work. I'm in the room on my own.
I am renting the room from another company who uses the rest of the building to run their business. It is in a residential area and they may be pinickety about hanging something over the outside of the windows to stop the sun getting in as they may want to keep the outside of the building looking ordinary. If it was my building in an area where it wouldn't matter I would hang something over the windows but I suspect the other company wouldn't like it. The windows are unshaded from the outside but do have a black out roller blind that I can pull down on the inside. The trouble is that this blocks the windows which open at the top. The building recently has had cavity wall insulation fitted and 10 inches depth of insulation in the loft space. Apparently the building was far worse for heat on the top floor before this was done.
I don't need the room like a fridge. I'm okay to wear shorts so if I could get it down to some where near 25 degrees C that would be far more pleasant.
The figure of 1kW/m^2 for heat from the sun is dependent on the area of the windows not the floor space?
Thanks for any advice.
David Hansen wrote:
hire a floor standing version for a week, see how you get on.
I moved my floor standing one into my study yesterday. There are 4 computers and me in here and it's West facing. The aircon is a 9000BTU one, and it couldn't even remotely cope. In fact, I thought it was broken.
No, double that and try and keep the sun out.
Open the windows, have proper shading too. Or lose weight. far too many obese people around.
How about some solar reflective film that could be stuck onto the glass? That may make a significant difference to the solar gain.
I have two machines running in my office (similar size to yours but with a north facing window). The uncooled temp today at 9pm was about 30 deg C. I have a 12k BTU monoblock air con which will make a significant difference to the comfort level in the room simply by dropping the RH, but it struggles on the warmest days to make that much impact on the temperature. It may reduce it to 27 if the uncooled ambient would otherwise be in the low to mid thirties.
Interestingly enough I can chart quite noticeable temperature shifts in the room dependent on the screen saver the PCs run! Using one of the grid computing cancer testing savers is enough to add about 4 degrees to the room temp!
Yup.
Most of the portable units sold today by the likes of Curry and B&Q etc are no more than personal coolers, If you can sit right in front of them they are ok, but as room coolers most of them are just plain inadequate.
You are more likely to need a split system of about 24000BTU to cool your room to comfortable working temps.
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