Snow melt system

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by thompsonblake, Jan 20, 2012.

  1. thompsonblake

    thompsonblake New Member

    Messages:
    7
    Location:
    Nova Scotia
    Currently working on installing a closed loop snowmelt system for a driveway roughly 38x18. Using 3 loops (1 zone) at around 300 feet runs (3/4 HePex, 9 inch centres) Im adding this system to an existing boiler that does have enough BTUs to heat the system. Laying the pipe and building the headers is fairly straight forward and I have done countless times. However my journeyman has always handled the more detailed boiler work such as, pump size, heat exchanger, expansion tank size. More importantly i have calculated that i need a 40% glycol mixture but am not sure the best method for adding and maintaining the glycol in the system.

    Any help would be appreciated but i guess I'm looking for the best method for adding glycol and maintaining glycol levels, and possibly a simple diagram boiler system.
  2. DonL

    DonL Banned

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    3,979
    Location:
    Houston, TX
    I know this is not much help to your question, but Don't they have snow shovels in Canada ?

    Seems like there could be a better and Cheaper way to get your project done.
  3. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,334
    Location:
    Yakima WA
    A good snow blower would be more sensible. Even if you could devise a way to melt the snow, it then becomes water. Where will the water go? As soon as it is off of the driveway it will freeze and make and ice dam. Soon you will have a hockey rink. I know hockey is the favorite sport of Canadians, but in your driveway?
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,932
    Location:
    New England
    Hey, lots of places use radiant systems to melt the snow...you do need to account for a place for that draining water to go, but properly engineered, as long as you can pay for it, it is a nice convenience. I tried to get our condo association to do it to the front access hill where we are currently paying a plow guy on average $10K per year. We figured that it would cost about $2K per year for fuel to heat the snow melt system, but the install costs made it a very long-term proposition, and could create problems if it needed maintenance when trying to find someone to plow while it was being fixed.

    Much of downtown in Holland Michigan is done with radiant. The sidewalks, and main roads in the shopping district. Many hospitals and businesses use it too along with the occasional airport runway and ramp. The place where I used to work had the entire front sidewalks done with it to minimize liability issues. You need to take care of both drainage and manage wind-blown snow, but if properly engineered, it is a true pleasure. Plus, take a situation where you have 5' of snow...a shovel gets really old very quickly trying to throw the snow up that far!
  5. DonL

    DonL Banned

    Messages:
    3,979
    Location:
    Houston, TX
    There is a place for systems like this.

    But my experience has been, If you have 5 feet of snow in your driveway, Even if you do get out of it, You can not go anywhere, safely.

    Using a Boiler system to de-ice a driveway don't make good sense.


    Best just to stay home where it is safe with your Loved ones.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,932
    Location:
    New England
    Some places regularly get that much or more and it doesn't melt for the season...after awhile, there's no place to put it. Have you lived in TX all your life? How often does Houston get snow? Not too often, then it melts on its own...lots of places, that doesn't happen!
  7. DonL

    DonL Banned

    Messages:
    3,979
    Location:
    Houston, TX
    No, I grew up in Ohio and Indiana, I know all about snow.

    I shoveled my way to work many times. I once got stuck Inside of a 10 foot snow drift.

    That is why I moved to Texas. There is vary rarely any snow here.
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,522
    Location:
    Cave Creek, Arizona
    You have to "pump" the glycol mixture into the system in order to pressurize it. Then you have to lower the water temperature so you do not fracture the concrete, but maintain enough velocity so the liquid retains temperature throughout the coils. If the concrete is not insulated from the ground below it, you will lose a LOT of btus.
  9. T_Hartigan

    T_Hartigan New Member

    Messages:
    35
    Location:
    Ohio
    9" centers may not be close enough to do a good job. What insulation are u putting underneath?

    I used gravity to add my glycol to my system. Step ladder and funnel. After initial filling ran pumps and kept bleeding the system. I then used a small hand pump to put about 6 pounds in the system. Pressure fluctuates some.

    My only regret is the spacing. I'm about nine inches and wish it was about four. When the wind blows it can make ice between the lines.
  10. thompsonblake

    thompsonblake New Member

    Messages:
    7
    Location:
    Nova Scotia
    Thanks guys was considering a manual fill as well, or just getting a small pump to fill the system. I was planning on using a heat exchanger on the supply and return lines to decrease the initial temperature of the fluid before it hits the concrete to avoid shock and fracturing. My only other problem is I don't want to add glycol to the whole system as it will decrease the effectiveness of the the cast iron rad heating system currently heating the house. I was told to use a second heat exchanger in a different forum but wasn't sure if the proper method was to the have the supply to my snow melt headers and glycol mixture on one side and the a small loop from the boiler on the other side of the exchanger. Would that set up be effective enough to work?

    As for the debate about the snowmelt systems in general, I have seen it used and it works great. I don't have it in my house but if a client wants it they get.
  11. DonL

    DonL Banned

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    3,979
    Location:
    Houston, TX
    Don't they make heat tape systems just for that application ?

    Seems like that would be cheaper and more efficient.


    Please let us know how you turn out when you get it finished.
  12. T_Hartigan

    T_Hartigan New Member

    Messages:
    35
    Location:
    Ohio
    I use a tekmar snowmelt controller for mine with heat exchanger. I only use glycol in the snowmelt.
  13. DonL

    DonL Banned

    Messages:
    3,979
    Location:
    Houston, TX
    Mr. T,

    What would you estimate the cost to run what you have ?

    Sounds good if it works. I did not have that luxury when I lived in Ohio.
  14. thompsonblake

    thompsonblake New Member

    Messages:
    7
    Location:
    Nova Scotia
    T_Hartigan, i think the heat exchange makes the most sense. I have personally never used one before although i am familiar with them. Just for clarification i should run my glycol loop in one half the of the exchanger and s small hot loop from boiler on the other side. Do you recommend pumps on both sides need pumps on both sides? A diagram would make my day.
  15. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,932
    Location:
    New England
    Think of the heat exchanger as a boiler - it is a heat source for the snowmelt side so yes, you need a pump on both sides, one to get heat to the heat exchanger and a second to move it around in the driveway. I posted a link on your other thread, which is why it's easier to keep one project, one thread so you don't get duplicates and disconnects.

    Depending on the class of snowmelt system you want to achieve will dictate home many max BTUs you need per square foot. The classes are defined by whether it will keep snow off as it falls, regardless (like maybe at a hospital entrance ramp or heliport), or if it is allowed to melt on slow or small storms, or take a bit of time, from minutes to hours to eventually clear things off.
    Last edited: Jan 21, 2012
  16. DonL

    DonL Banned

    Messages:
    3,979
    Location:
    Houston, TX

    This is what they use in Houston.

    Bunch of Wimps...lol

    Plow.jpg
  17. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    1} One can understand why so much of the world is disgusted by Americans that melt snow for their BMW's and Ferraris with an amount of fuel that would heat an entire village in Slovakia.

    2} Move to Phoenix

    3} Ever hear of sand and salt? Your unemployed neighborhood kid used to be the snowblower of choice, and him, plus the sand and salt HELP someone rather than suck the blood of the enviroment.

    4} Not that I particularly care about India, but I wonder what those kids drinking from a mud puddle, and cooking on manure and twig and leaf stoves would think of that boiler and pipe scenario. I think the occupy Wall street guys should set up camp on this guys driveway.
  18. MACPLUMB 777

    MACPLUMB 777 TROJAN WORLDWIDE SALES RP

    Messages:
    679
    Location:
    Houston, Texas, United States
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