
Discussion BoardsOpen MenuDiscussion Boards Open Menu
 Welcome to the Community
 1 categories, 7 boards
 Live with HP Experts
 1 boards
 Converged Systems
 1 categories, 1 boards
 Desktops and Workstations
 1 categories, 12 boards
 Mobile
 7 boards
 Networking
 6 categories, 22 boards
 Operating Systems
 7 categories, 77 boards
 Printing and Digital Imaging
 1 categories, 18 boards

BlogsOpen MenuBlogs Open Menu

Community Knowledge BaseOpen MenuCommunity Knowledge Base Open Menu

EnglishOpen Menu
 Community Home
 >
 Servers
 >
 Planning
 >
 Calculating BTU's in Computer room for Air conditi...
 Subscribe
 Mark Topic as New
 Mark Topic as Read
 Float this Topic to the Top
 Bookmark
 Subscribe
 Printer Friendly Page
Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02222005 06:11 AM
http://web.ask.com/redir?u=http%3a%2f%2ftm.wc.ask.
Solved! Go to Solution.
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02222005 06:40 AM
Off hand, we use temperature targets. The specifications for the machine note the operating temperature range and we get enough power to keep it comfortably within that range.
I don't think power supply watts to BTU is a good approach. You need to know how much heat every device in the room gives off at full capacity, disks included.
SEP
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02222005 06:51 AM
â ¢ A BTU = 3.412 * Watts
â ¢ A ton = BTUâ s / 12,000
â ¢ The 30 ton air units we use cost about $26,638.88 to operate, per year, at full load.
â ¢ To cool a ton of air costs $888.00 per year.
** Always use maximum wattage of a server
** Concern yourself with HOTSPOTS
Yes, it costs money to operate air conditioners. I used these numbers to justify the removal of all Kclass equipment with virtually partitioned Nclass servers.
live free or die
h
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02222005 07:10 AM
You have to realize that for all practical purposes (and to greater than 99.9% accuracy) computers are nothing but heaters  expensive heaters but heaters nonetheless.
This means that if you have the input power, you have the output heat dissipation  they are one and the same. As long as you use the maximum values listed on the power supply for your calculations then what that power is doing (running disk drives, memory, powering chipmunks) doesn't matter; it's all going to be converted to heat.
To approximate power dissipation, you can multiply rated input voltage by rated current to get VoltAmps. Then multiply by a power factor (usually about 0.8 to get watts  remember this is AC 1VA is usually not 1WA because we have those pesky phase angles) If you want to be very conservative, use a pf of 1.0 and some HP computers run a pf of 0.99. If you use a power factor of 1.0 then you will always be safe. The one other formula I should throw at you is how to calculate 3phase power. It's simply P = IV * 3 ^ 0.5 * pf where P = power in watts, I = current in Amperes, V = Voltage, 3 ^ 0.5 ==> square root of 3 (or the appropriate number of phases), and pf = power factor (again somewhere between 0.8 and 1.0). Power factor is actually the cosine of the between the phase angle of the current and voltage.
Example :
Suppose the power supply label indicates 10 A at 200V; what is the maximum thermal dissipation?
10A x 200V = 2000VA x 0.8 (pf) = 1600W.
1600W x 3.412 BTU/HRW = 5460 BTU/HR.
The other conversion factor you need to know is that 12000 BTU/hr = 1Ton Cooling Capacity
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02222005 07:13 AM
live free or die
harry d brown jr
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02222005 08:15 AM
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02222005 10:35 AM
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02222005 10:20 PM
I expected to see you pop up here, but what confuses me is this:
"1600W x 3.412 BTU/HRW = 5460 BTU/HR."
This seems to be converting watts to BTU. However, your second reply states:
"it is impossible to convert BTU's to Watts or viceversa", yet you seem to be doing just that. Which is it? Vice? Or versa? What am I missing?
Pete
Pete
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02232005 02:08 AM
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02232005 04:50 AM
VA7410 (labeled on each of 2 power supplies)
100240v
8.23.4A 50/60hz
3 of the 2405 enclosers (labeled to on each one)
4.11.7A 50/60hs
1) These are plugged into a 110 power strip. So am I to read it as 8.2 amps max but if I had it plugged into 240 the amps would be 3.4 amps max?
2) This is probably a silly question. it seems low, so I guess I to add the hard drives on to this too? they are not visable so I guess I need to grab the white papters?
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02232005 08:04 AM
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02232005 08:07 AM
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02232005 08:40 AM
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
02232005 10:00 PM
Pete
Pete
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
07122005 12:06 AM
Equipment designed for computer rooms is designed with this in mind, but there is still latent work being performed.
It would be a good thing to consult with a HVAC professional or forum dedicated to HVAC to answer more questions.
And, no... you don't have to buy Liebert to make it work correctly.
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
07122005 12:46 AM
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
05162007 07:02 AM
I just read your blog about converting watts to BTU's/hr for sizing air conditioning needed for your computer room. As a Data Center Facilities Designer, I have been designing data centers for 7+ years.
Based on the method described (maximum input ratings of the power supplies), you would derive numbers which are way too high.
The numbers indicated on the power supplies are the maximum input power, assuming every available device option is installed, and all these devices are running 24 hours/day.
In my experience, typical computer systems draw less than half of the rated input power stamped on the power supply. As a result, using these numbers would derive a figure approximately tripple your actual loads. And you probably bought way too much air conditioning for your data center (don't worry about it. I once made the same mistake myself).
Just guessing, but I would bet that you still have plenty of cooling capacity in your data center, even after two years of adding equipment. Am I correct?..
Jeff
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
05162007 09:16 AM
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
06012007 01:06 AM
Re: Calculating BTU's in Computer room for Air conditioning puposes
 Mark as New
 Bookmark
 Subscribe
 Subscribe to RSS Feed
 Highlight
 Email to a Friend
 Report Inappropriate Content
07052007 04:20 PM