Results 1 to 5 of 5
  1. #1
    Join Date
    Aug 2008
    Location
    Shepparton *ugh*
    Age
    49
    Posts
    107

    Default In this house we obey the laws of thermodynamics

    I don't suppose anyone knows how high hot water will rise above cold water? I'm guessing "all the way" but here's my situation...

    I have a "spare" chiminea on my bush block that I thought I'd make a water jacket for (or just coil copper pipe around connected to a tank) so I can have a separate hot water system. While the chiminea would be on the ground, I would like to have the main reservoir on the roof (+3m) so that it can gravity feed into sink faucets and a shower.

    Any forseeable problems with getting the water up to that height purely by heating it? Also, any problems with getting the cold water back down to warm it back up? (it would be a purely gravity/physics base recirc system).

    Normally I'd run my own tests etc but at the risk of wasting a bunch of dollars on unnecessary piping I though it would be prudent to ask first
    Every time you make a typo, the errorists win.

  2. #2
    Join Date
    Nov 2004
    Location
    Millmerran,QLD
    Age
    74
    Posts
    1,761

    Default

    Quote Originally Posted by RedShirtGuy View Post
    I don't suppose anyone knows how high hot water will rise above cold water? I'm guessing "all the way" but here's my situation...

    I have a "spare" chiminea on my bush block that I thought I'd make a water jacket for (or just coil copper pipe around connected to a tank) so I can have a separate hot water system. While the chiminea would be on the ground, I would like to have the main reservoir on the roof (+3m) so that it can gravity feed into sink faucets and a shower.

    Any forseeable problems with getting the water up to that height purely by heating it? Also, any problems with getting the cold water back down to warm it back up? (it would be a purely gravity/physics base recirc system).

    Normally I'd run my own tests etc but at the risk of wasting a bunch of dollars on unnecessary piping I though it would be prudent to ask first
    RSG

    You may find that the pipe diameter is critical to minimise frictional losses. When you use natural circulation (as opposed to forced by pump) the pipe size should normally be larger. A friend just building his house and using evacuated tubes used either 5/8" or 3/4" pipe. When I built a house years back we used 1" pipe. Make sure you get a continuous rise in the pipework to avoid airlocks. I would also consider insulating the hot pipes in particular.

    Regards
    Paul
    Bushmiller;

    "Power tends to corrupt. Absolute power corrupts, absolutely!"

  3. #3
    Join Date
    Nov 2007
    Location
    Dundowran Beach
    Age
    77
    Posts
    0

    Post

    Take note of what Paul says about continuous rise in the piping to the hot water storage tank
    and the need for insulation.

    I can't offer any advice on pipe size but a plumber mate of mine always said he could
    push water forever with the use of heat.

    If the level of your supply tank is the same as the hot water storage tank you won't have any trouble at all.

  4. #4
    Join Date
    Jun 2005
    Location
    Helensburgh
    Posts
    608

  5. #5
    Join Date
    Aug 2008
    Location
    Shepparton *ugh*
    Age
    49
    Posts
    107

    Default

    Thanks for the diameter tip Paul. I probably would have used smaller. I should probably do a bit more reading on that part.

    I figured eventually I would have had the whole lot insulated. The reservoir is a small old Rheem thingy that I was going to tweak so it's already pretty good.

    Love that rocket stove heater Chris. It's always good to see projects like that revisited to find out how well they've worked and survived. It's all fine and dandy to make something in the first place, but if it doesn't withstand the test of time there's not much point.
    Every time you make a typo, the errorists win.

Similar Threads

  1. Love, honour and obey....?
    By MBM888 in forum JOKES
    Replies: 0
    Last Post: 22nd June 2013, 12:44 PM
  2. Laws of the Universe
    By Rodgera in forum JOKES
    Replies: 1
    Last Post: 25th March 2011, 01:04 PM
  3. Laws of Cat Physics
    By Rodgera in forum JOKES
    Replies: 1
    Last Post: 4th June 2008, 03:23 PM
  4. Convert Fibro House to Cement Rendered House
    By krm66 in forum CONCRETING
    Replies: 9
    Last Post: 6th January 2007, 02:34 AM
  5. New IR laws...
    By Toolin Around in forum NOTHING AT ALL TO DO WITH RENOVATION
    Replies: 72
    Last Post: 2nd June 2006, 12:24 AM

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •