Lake loops

Discussion in 'General Discussions' started by meyricl, Sep 9, 2008.

  1. reducing 1 Million lbs of water from 35* to 32* (3* ) would take 3 million BTUs.
    how do you get 150 million btus?
  2. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    latent heat of fusion

    Freezing 32* water into 32* ice requires 144 btu / lb.

    I added 144 to 3 (147) and rounded up to 150 (OK, I figured, since I rounded down the mass of water by 3%)
  3. right, 144 btus to ice.
  4. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    A nifty trick would be to...

    ...roll out an R100 tarp on top of the pond just before the ice thinks about melting, and then have about 40 EER all summer.
  5. neat trick

    That would keep the pond warmer, and therefore more efficient, but not necessary.
  6. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I was busy doing a manual J

    most of yesterday.

    Zach: Nice work. It is unclear in the pictures I have seen of your pond if it has a spill way/run off. If it does, and it runs in the winter the pond will never freeze solid.

    We were at that job yesterday working with the owner on the heating system design for the Mc Mansion to be built this year and the pond was ice free. Never went exploring the ice as you did. The surface is about three acres and about 18 ft deep in the center. The pictures of when we installed the loops were taken before the pond was completely full. Our loops then were in 5 to 8 foot deep water, and the level is up an additional 2 feet.

    This pond is fed by rain water only. It generated EWT of 39* to 41* on January 10, 2008 with 3" of ice on the surface. I don't have much additional data as the next day we left OH for CT. Since the building is finished, R-22 or so in the walls and R-40 or so in the ceiling, (average height of 14') the 30' by 60' barn has heated all this winter on the water to water heat pump only.

    We disabled the aux heater in the buffering tank last spring. Thermostat is set at 65, floor (5" concrete) is at 68*, we mix down the water from the buffering tank to about 85* to get about our design delta T of 20*.
    The system will run at higher temps, but the owner found with all the cars tools racks and benches warm and emitting heat that he was too warm to work at higher set points.

    Engineer nice math.

    Lake, latent heat makes this all work.
  7. sizer tool

    Mark what is the exact name of your sizer tool? I would like to find it on line.

  8. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Green Air

    Hello and welcome.

    The tool I was referring to is called System Sizer and is by Bell & Gossett, the pump manufacturer. It may be available as a down load from their site.
  9. zach

    zach Member Forum Leader

  10. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Hi Zack

    How are you folks.

    Yes that is it.

    Did you get a "Snow Day"

    Does your pond have an overflow?
  11. zach

    zach Member Forum Leader


    We are just west of the big snow. Snowing some now, but nuisance variety only.

    We are well, thanks

    Yes, the pond does have a spillway over in one corner. Not sure it runs this time of year. I will have to walk over and look tomorrow AM.

    I am giving thought to pumping it down and doing some work to it to include putting some stone down so the kids can swim. It is all clay/muck now. Water clarity is good but it is no fun to play in.

    Also, a few years ago, there was a muskrat who burrowed a hole in the dyke. It was repaired but refacing the dyke would not hurt.

    we'll see
  12. Mark,

    Do you have any photos of the lake loop you were working on yesterday? I'm always eager to see other installations.
    I did get a "snow day" even though it was not very welcome.
    At work now tho.

    "Have tools, do travel" is good to know. I'm sure we will be in contact.
  13. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader


    How many do you want?

    The pictures you have seen here is the job we were doing the manual J for yesterday. The manual J is for the 6500 sq ft house.

    I am out of space here for photo attachments I'll pick up your email off the web site if you do not want to give it out here, or drop me a note at [email:2cigah4e][/email:2cigah4e]
  14. No problem,

    I'd like to see as many as you care to send.
    My email is ""

    You're alright, I don't care what the other guys say.:)

    Thanks so much,
  15. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    You have


  16. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    What I was getting at was carrying 500 tons of ice into summer for cooling
  17. ah ha, interesting concept.
  18. zach

    zach Member Forum Leader


    Can you elaborate on this point?
    "I'm not at all sure typical pond loop design contemplates the loop tubes freezing much of the pond right near them."


  19. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Zack, My guess is

    the last time your pond froze solid we where hunting woolly elephants with clubs and flint tipped sticks.

    Engineer did a good math projection on a perhaps flawed perception. Do you know how many gallons of water your pond holds? If you are really going to do some P/M on the pond before using it to heat and cool your home, please measure the volume of water removed and then we can give you real numbers.

    I have lake Erie as my back yard so I have watched water freeze and thaw for a while.

    Your pond will work. Go look at the overflow on your hike and let me know if it is running liquid.
  20. zach

    zach Member Forum Leader

    pond volume


    Pond is 170' long by, on average, 50' wide. If I make an educated assumption the pond averages 5' of depth, we have the following:

    42,500 cubic feet of water
    317,922 gallons of water
    2,648,691 Lb's of water

    In the AM I will walk down to the spillway and take a look

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