My house support an additional 10,000 watts?

Reply

  #1  
Old 02-25-10, 01:56 PM
Member
Thread Starter
Join Date: Feb 2010
Posts: 6
Received 0 Votes on 0 Posts
My house support an additional 10,000 watts?

Hi all,

I am thinking of setting up a computer project in my unfinished basement. The project will consist of 100 Apple Mac Mini computers (Apple - Mac mini - Technical Specifications if you need more electrical specs). Each computer, as far as I can tell, is rated at 110W. So I would be drawing about 11,100 watts if my math is correct.

The computers would run 24x7 and thus would always be drawing at least 10,000 watts. Putting aside cooling or other topics, will my house support such an additional power draw? My house was built in 2001 and is about 4100 sq feet. We disconnected an outdoor hot tub this year and I was wondering/hoping if I could use the same breaker (meaning, does it supply enough power?)/junction box for my computer project. The old hot tub was wired to the junction box.

Yes, I am aware I will need to hire someone to come out and wire the basement properly but I am wondering if this is some kind of insane project that I should not be doing possibly due to code regulations (maybe homes are only allowed to draw so much power?). I've done some Googling on the internet and it seems several items in the home draw 3000-10,000 watts (central air, furnaces, large refrigerators, etc.).

Is this a type of job that someone could do within my house or would it require going outside and/or calling the electric company for more power or some kind of permit or other specialty request? According to my electric bill, I am using about 30 kWh per month in the winter.

Thanks so much in advance!

-Eric

p.s. I live in CT
 
Sponsored Links
  #2  
Old 02-25-10, 02:11 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: Twin Cities, MN
Posts: 12,936
Received 55 Votes on 48 Posts
It would depend on the size of your service but I would be willing to bet you will be ok. Your adding about 41 amps load on your house. You could do a load calculation and just add the 41amps to that and see what you come up with.

Just for your info: 10K watts or 10KW X 24hrs in a day = 240Kwh per day x 30 days = 7200Kwh per month x .10 per kwh = $720 added to your electrical bill.
 
  #3  
Old 02-25-10, 02:42 PM
Member
Thread Starter
Join Date: Feb 2010
Posts: 6
Received 0 Votes on 0 Posts
Thanks Tolyn...yeah, I know the price will not be cheap. I am thinking of starting a non-profit in my home and thus a fundraiser will be needed to pay for the equipment and the monthly bills.

Thanks again!

-Eric
 
  #4  
Old 02-25-10, 03:32 PM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
Is this a computer lab/office type set-up? If so, you need to count the monitors too and the network gear, printers, and other misc stuff like projectors which can use a surprising amount of power. The upside though is that in this situation the computers rarely draw the maximum so you can plan for a lower wattage (web browsing and e-mail uses like 2% of the CPU).

If it's more like a compute-cluster where machines operate at full capacity, then I would strongly suggest considering purpose-built rack servers which get you a better return on CPU cycles per watt on your power bill.

You can't discount the cooling either. 10kW of heat is 10kW of additional load on your A/C. You can certainly reap some benefit from outdoor air circulation, but a 10kW equivalent heater will need some supplemental cooling.

If your existing hot tub circuit is the typical 50A four-wire, its maximum continuous capacity is 9,600W. (240V * 50A * 80%)
 
  #5  
Old 02-25-10, 04:56 PM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,485
Received 28 Votes on 22 Posts
Originally Posted by ericelectric View Post
According to my electric bill, I am using about 30 kWh per month in the winter.

-Eric

p.s. I live in CT
I suspect that you are using a whole lot more than 30 kWh per month, probably more like an average of 30 kWh per day over the course of the month.

At 30 kWh per month even if you were paying 25 cents per kilowatt hour your monthly bill would only be around $7.50 a month. I live alone and I average 11 kWh per day.
 
  #6  
Old 02-25-10, 05:07 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,967
Received 2 Votes on 2 Posts
Aaah, non-profit....fund raising. Gives me an idea, since I probably didn't make a profit last year, maybe I could have a fund raiser
 
  #7  
Old 02-25-10, 06:21 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,981
Received 22 Votes on 17 Posts
The typical hot tub uses a 50 amp single phase circuit. Your 100 computers @ 110 watts each totals to 11,000 continuous watts plus the peripherals that were mentioned. 11,000 watts translates to 45.8 amps. Since this load is continuous, you can't load the circuit or the 50 amp breaker over 80% of it's rated capacity which would be 40 amps. One of your questions was whether the existing hot tub circuit would support this load. In consideration of the above, it is my opinion that the existing hot tub circuit will not support your project and that you need to have a new circuit of no less than 60 amps installed. 70 or 80 amps would be better. I have no doubt that your home's service will support the load with the proper circuit and distribution to the computers..
 
  #8  
Old 02-26-10, 07:03 AM
Member
Thread Starter
Join Date: Feb 2010
Posts: 6
Received 0 Votes on 0 Posts
Originally Posted by ibpooks View Post
Is this a computer lab/office type set-up? If so, you need to count the monitors too and the network gear, printers, and other misc stuff like projectors which can use a surprising amount of power. The upside though is that in this situation the computers rarely draw the maximum so you can plan for a lower wattage (web browsing and e-mail uses like 2% of the CPU).

If it's more like a compute-cluster where machines operate at full capacity, then I would strongly suggest considering purpose-built rack servers which get you a better return on CPU cycles per watt on your power bill.
This is a project where 100 machines will run at full speed crunching computer data to help solve cancer. Thus the computers will be running full power.

Rack machines really don't offer the benefits when you stack it all up (no pun intended) for my project...rack machines are much more expensive than a Mac Mini ($900), require rack hardware (unlike the Mini), require more specialty maintenance, and do not offer WIFI.

My Minis will likely run on 2 long pieces of wood about 15' each. There will only be 1-2 monitors for the entire project. The Minis will utilize WIFI and hit the home network a different times of the day to avoid network saturation. Likely I will plug every 5 machines into a $70 UPS which will provide 20 mins of backup electricity in case of an outtage...so I would need 20 of these devices, which yes, I need to calculate in.

It's not so much the electric bill I am worried about as my project will likely become a non-profit and will have fundraisers to pay for the electricity ($700-$1000 a month).

The cooling is a concern...I do have central air in the house so I could just easily open up the a/c vent in the basement that passes over the computer setup in the summertime (or all year if need be). In the winter, I would likely relocate the 100 machines to the attic where the temperature is much cooler (maybe 32-40 degrees Nov-April) to save on cooling...not to mention the attic's ceiling is 2x as tall as the unfinished basement's. Unfortunately the 2 windows in my basement do not open...but I could change that to let in cold air in the winter to save on a/c.

***********

-Eric
 

Last edited by GregH; 02-26-10 at 02:20 PM. Reason: We are more than happy to help you with your project but you can not promote it here.
  #9  
Old 02-26-10, 08:15 AM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
Originally Posted by ericelectric View Post
Rack machines really don't offer the benefits when you stack it all up
I was thinking more along the lines of durability and duty cycle. The fans, power supplies and disks in rack machines are designed for 24/7 operation in dense environments, unlike commodity PC parts. Actually doing cluster computing you would probably want no hard disks and network boot Linux or a BSD for less maintenance, power and heat.

I'm not entirely sure the price is as different at you think. HP DL1** rack machines have quad core Xeon 5500 series CPUs for $1,250 whereas it takes two mac minis at $1,800 to get those cycles. The Xeon 5500 is quite a bit better chip for number crunching than the core 2 duo anyway.

My Minis will likely run on 2 long pieces of wood about 15' each.
I'm pretty sure that will cook them. If they aren't exposed to circulating air they will not be able to keep cool.

In the winter, I would likely relocate the 100 machines to the attic where the temperature is much cooler
Just leave them in your basement to offset the furnace bill. With 10kW in the basement, the furnace probably would never need to come on.
 
  #10  
Old 02-26-10, 08:43 AM
Member
Thread Starter
Join Date: Feb 2010
Posts: 6
Received 0 Votes on 0 Posts
Originally Posted by ibpooks View Post
I was thinking more along the lines of durability and duty cycle. The fans, power supplies and disks in rack machines are designed for 24/7 operation in dense environments, unlike commodity PC parts. Actually doing cluster computing you would probably want no hard disks and network boot Linux or a BSD for less maintenance, power and heat.

I'm not entirely sure the price is as different at you think. HP DL1** rack machines have quad core Xeon 5500 series CPUs for $1,250 whereas it takes two mac minis at $1,800 to get those cycles. The Xeon 5500 is quite a bit better chip for number crunching than the core 2 duo anyway.
Hmmm, I will have to look more into this. I'm a techie but I believe most of the "server" offerings by HP and Dell (and others) do not include an OS. Therefore, I need to spend time and money to buy an OS and install it and configure it. Then there's the lack of WIFI support (the BOINC application allows me to set when each machine can hit the network at specific hours/days). And most of these servers eat more than 110W of electricity...the HP DL series eat 400W and up...so even if the heat was slightly less, the electric bill would be 2-4 times the cost of Minis. I have been running BOINC projects for roughly 10 years...on all my home machines (2 pcs and 1 Mac currently) they have been running 24x7 for years and I've never had an issue such as burnt chips or heat issues or anything like that. The BOINC application is really all about CPU and RAM utilization.

Also, I would likely swap out the Minis every 2 years...currently the Mini is not quad core but very likely it would be quad core by the September release...again, computer specs change all the time so I am trying to look at every aspect of this project since I will be the only one managing it...out of my home. Trying to find/build computers with 0 hard drives again just adds more time and energy for me to set up. The Mac Mini will be up and running in 10 minutes when I first power it on...then 5 mins later it will be crunching via BOINC.


Originally Posted by ibpooks View Post
I'm pretty sure that will cook them. If they aren't exposed to circulating air they will not be able to keep cool.
Yeah, I should have been more clear...I am not going to pile the Minis on wood. I have a Mac Mini so I can speak from experience and how I envision doing this: First, the Minis will be on their side which is a supported position...the fan faces the rear (there are no vents on the sides)...the only side that ever gets warm is the bottom (which would be sideways). Next, the machines would be about 6-12 inches off the cement floor. Also, the machines will either be on cinder blocks or some old granite countertop slabs...or something else that is not going to catch on fire. The machines will likely be in 2 rows of 50...so the heat should not be 1 big plume heading to the ceiling in a small space...50 computers side by side will take up about 16 horizontal feet. The basement ceiling is 7+ feet from the cement floor. The windows in the basement actually do open (I was mistaken in my previous post) which would allow for some nice 20-45 Farenheit degree air from Nov-April. Directly above the Minis is a central a/c duct that I can aim at the Minis instead of upstairs into a rarely-used room in the summer months.

Originally Posted by ibpooks View Post
Just leave them in your basement to offset the furnace bill. With 10kW in the basement, the furnace probably would never need to come on.
I'm not sure what you mean...I would still need to heat the 1st and 2nd floors of my home. The basement is completely unfinished...so we don't go down there. Maybe 5-10 years from now we might turn it into another room (it is at least 700 sq feet large).

Lastly, part of my project is to promote to people all over the world the ability to cure cancer with standard home machines. My project takes it to the extreme by running dedicated machines 24x7.
 

Last edited by ericelectric; 02-26-10 at 09:14 AM.
  #11  
Old 02-26-10, 09:54 PM
braether3's Avatar
Member
Join Date: Nov 2009
Location: wisconsin
Posts: 415
Received 0 Votes on 0 Posts
you could install a small duct booster fan in reverse to capture some of this heat in the winter and blow it into your home.


Ben..Hvac-r tech
 
  #12  
Old 02-27-10, 08:30 AM
Member
Join Date: Jul 2009
Location: SE Iowa
Posts: 71
Received 0 Votes on 0 Posts
Some quick thoughts:

1) You would probably want a subpanel located close by to the computers. Do multiple runs of 20A circuits.

2) As heat rises, it is very likely the computers will make the 1st floor warm without the furnace running. This could definitely be an issue in the summer, but it might not be too bad. My basement stays fairly cool even on the hottest days.

3) Be sure to check with your insurance company that over $100,000 worth of kit is going to be covered. Also, if there are any water pipes nearby the computer area, be sure your insurance covers flooding caused by broken/damaged water pipes. It would be terrible to come home to water spraying right on the computers and destroying all of your hard work.

4) Does the software have a way to disable the Wi-Fi until needed? If not, the OS will likely pull updates and other information over the Wi-Fi connection. So while not all 100 computers will be continuously pulling huge amounts of info, there will be 100 connections, which very few home routers can support. I'd highly encourage using industrial network switches and wired connections.

5) Take lots of pictures!
 
  #13  
Old 02-27-10, 08:48 AM
Member
Join Date: Feb 2002
Location: port chester n y
Posts: 2,117
Received 0 Votes on 0 Posts
Have you considered obtaining permits from the local inspectors who have the authority to enforce both local , state, and national fire and safety codes , and local zoning and property rules and regulations ?
 
  #14  
Old 02-27-10, 09:21 AM
Member
Thread Starter
Join Date: Feb 2010
Posts: 6
Received 0 Votes on 0 Posts
A few answers and comments:


1)I intend on doing this project the most legal and tax-careful way...meaning, if I need to start a NonProfit or similar, I will do that...this will then answer my questions about responsibility for insurance, permits, taxation, etc. This is the biggest area that I have no clue about and want to sit down with someone for 15-30 mins and just run through my plan. Again, I'm doing this out of the kindness of my heart but don't want to break any laws, pay excessive taxes, or violate any insurance contracts. I have estimated that the first year cost for this project below.

2)On a day like today with it being 32 outside, the basement is 57. Again, it is a very large basement. I am sure the computers will heat up the area pretty well and I would guess that the entire basement would (in the winter being 34 or below outside) never exceed 95 degrees. In the winter I can open 2 windows (1 is directly above where I would place the computers) to allow air in (as well as use some fans to move the air around). In the summer, my guess is the basement is likely 65 degrees while it is an average 82 degree day...but I don't know. The central air conditioning ducts run above where I would place the computers...therefore I could either a)create a new "zone" in the basement to have my own control of the basement or b)simply cut open the duct myself and when the 1st floor zone is on, some of the air would stay in the basement instead of going into the Dining Room. I know computers like to run cool and in a perfect world I'd like to keep the basement at ~67 too keep them nice and cool...but I believe computers can run well in temps in the mid 80s or even 90s (as I have done accidentally with 2 machines running for several days in a room at 91).

3)I am uncertain exactly how I can turn off the Mac OS' ability to automatically ping the mothership for updates...I am pretty positive it can be done.

4)Yes, having 100 computers attached to 1 home router may be a stretch. I am seeing if there is a way for me to have 2-5 computers act as collection points for all network traffic using the BOINC platform. In other distributed computing projects I've worked on, it was possible to do this. However, I would still need 100 computers on some kind of network. Therefore, I will need to architect this a bit and see if I should be making subnets or if there is an industrial $400 router I can buy that will promise to hold 400 computers.

5)The reverse duct booster is a great idea! I was thinking of something like that but have no clue on the terminology or how to do (I would likely pay someone or ask a buddy who's pretty familiar with it).

Here is my overall project price (always best to over estimate such as electric bill):

Initial costs:
--------------
100 computers @ $800 per computer = $80,000 + tax if applicable
Electrical work to ensure proper power is supplied: $2000
20 Uninteruptable Power Supplies @ $50 = $1000
Some kind of air conditioning/ventilation work: $2000
TOTAL=$85,000

Monthly costs:
--------------
Electricity: $1200/month ($14,400/year)
Internet Access: $75/month ($900/year)
TOTAL=$1275 per month

First year costs: $101,300
Second year costs: $15,300



Thanks again all for your tips!

-Eric
 
  #15  
Old 02-27-10, 09:56 AM
Member
Join Date: Feb 2002
Location: port chester n y
Posts: 2,117
Received 0 Votes on 0 Posts
It's possible that the local building officials will not grant approval of your plan to establish this faciity in you residence. I suggest you consult with them before proceding any further with the design of the system.

Be prepared to accept many demands from the authorities for specific and detailed information on many aspects of this project are code-related.
 
  #16  
Old 02-27-10, 01:42 PM
Member
Thread Starter
Join Date: Feb 2010
Posts: 6
Received 0 Votes on 0 Posts
Originally Posted by PATTBAA View Post
It's possible that the local building officials will not grant approval of your plan to establish this faciity in you residence. I suggest you consult with them before proceding any further with the design of the system.

Be prepared to accept many demands from the authorities for specific and detailed information on many aspects of this project are code-related.
Right...I'm not doing/buying a single thing until I talk to:

1)the town about my project overall
2)someone to help me figure out if I should/can set up a Non Profit or some other organization (I will need to raise funds)
3)the town specifically about my energy usage as it will go from roughly $200/month in electricity to $1000 or more...want to make sure everyone's on the same page and that my project is not any kind of danger (heat, explosion, whatever) in their eyes.


The way I see it it, these are very small machines which will take up a small footprint of the unfinished (I stress unfinished as there are no rugs or walls to catch fire) basement and each draw only about as much power as a 100w lightbulb (and I would say the bulb gives off more heat than the Mini...you can't even touch a 100w bulb after it's been on for 15 mins). Each machine gives off a fair or small amount of heat (again, I have a Mini and it's never hot to the touch or the fan's cranking out steaming hot air) and of course having 100 of them will make the basement warm...that's common sense.

On a side note, even if town was against me with crazy remarks about heat dangers, what's to stop me from installing 50 instead of 100 and not telling anyone? My house alone has 4 computers that are on almost 24x7. Many friends and neighbors run 3-5 machines all the time. Yes, I know they are in different parts of the house but still...I'm taking very careful consideration of these machines as they are not normal desktops that draw 300-500watts each...nor are they using monitors and rarely using the hard drive...so electricity consumption is quite small in my project, per se.

-Eric
 
  #17  
Old 02-28-10, 11:06 AM
Member
Join Date: Feb 2002
Location: port chester n y
Posts: 2,117
Received 0 Votes on 0 Posts
Please allow me to refer you to two Code articles that may be relevant to your project-design----

Art 645 , Information Technology Equiptments----ex; "645.4 ; Special requirements for ITE room ----- "

Art 518 . Assembly Occupancies
 
  #18  
Old 03-01-10, 01:02 PM
Member
Join Date: Jun 2008
Location: SE-PA USA
Posts: 342
Received 0 Votes on 0 Posts
11,000 watts is 37,543 BTU's or over three tons of A/C required for cooling. That's a few thousand right there, a typical 3 ton installation will be $6,000-8,000. As far as heat, all of the power the machines consume will be heat when the smoke settles.
 
  #19  
Old 03-01-10, 02:27 PM
Member
Join Date: Feb 2010
Posts: 6
Received 0 Votes on 0 Posts
Get a Kill A Watt Electricity Load Meter and Monitor and plug a computer into it and see exactly how much wattage the system is using. For example:
Amazon.com: P3 International P4400 Kill A Watt Electricity Usage Monitor: Electronics
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: