×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Copper Rod for Cooling

Copper Rod for Cooling

Copper Rod for Cooling

(OP)
Hi Everyone,

   I have an interesting problem that I hope you can
help with.  I am building an insulated wine storage
cabinet with a volume of about 13.5 cu ft.  The outside
is solid wood and the inside is lined with 1" rigid
foam.

  I heard that you can "cool" a cabinet by driving
large copper rods into the ground and have them
stick into the cabinet.

  The question is how can I calculate the size and
number of rods that I would need?

  Here are some other parameters:

1) We should be able to determine the performance
   of the insulation.

2) We should be able to determine the performance of
   the dual-pane cabinet glass door.

3) The temperature of the ground at 6' is steady at
   62 deg F year round (Santa Clara, California)

4) The temp inside the cabinet does not have to change fast.

5) The ambient temp of the room averages 74 deg F

6) The cabinet is made of 3/4 cherry with a 1" quartzite
   counter top covering it.

7) 1"-2" (10 feet long) copper rod is very expensive

The next material down the list of thermal conductivity
is significantly worse and the only thing better is
diamond :)

Is there some way to determine what would work?

Thanks,

  Victor

 

RE: Copper Rod for Cooling

You want to store your wine at about 55F or so, right?

You have the ground as a source of 62F.

You can't get there from here.

RE: Copper Rod for Cooling

(OP)
Agreed.  It will never get below the ground temp of 62 deg F.
62 is better than 74 though.

RE: Copper Rod for Cooling

There are better conductors, silver for one, being CA I guess money is no object. But as noted, you can't get there with conduction. But a Thompson (and or Peltier) heat pump could do it; especially by burying the second end as you propose. There are small inexpensive, portable cooler/heaters available (by reversing the applied voltage you can put heat in or take it out of your box.) It would require customizing, not practical , but very interesting.  

RE: Copper Rod for Cooling

Actually this is done with heat pipes.  The are tubes with a wick inside and a low boiling point fluid.  The fluid boils on the hot end and condensers on the cold end.
The can't be driven, but holes would need to be bored and then back filled around them.  They are passive.

How cool is the ground 12' down?  My hunch is that you should be able to get within 5deg of that temp.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Copper Rod for Cooling

Heat pipes are usually much more efficient at transferring heat upward or horizontally than downward. Capillary action can only raise fluid to a limited height.

Wine cellars are called cellars for a reason. If there were an easier way, it would already be done that way. The alternatives are non-passive cooling.

RE: Copper Rod for Cooling

My take is that you'd be better off plumbing a closed loop water line into a buried heat exchanger.  Alternately, you could directly plumb your cold water supply through the cooler.

TTFN

FAQ731-376: Eng-Tips.com Forum Policies

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources