Replies

1. 
   Guest_ | Feb 18, 2000 09:06pm | #1

   *
   In San Diego we know jack about snow, but it seems obvious to me that unless the thing is heated all the time it is going to turn to ice. Unless you have free energy where you live this is going to cost a fortune to run. Forget the construction costs and just calculate the energy costs and I think he'll buy the snow blower.

1. 
   Guest_ | Feb 19, 2000 01:13am | #2

   *John - There are others here who are more knowledgable about this than I am, but basically what you are looking at is a radiant heat system for the driveway. Price is gonna be very dependent on size and of course the conditions, what type of driveway, etc. but I think it's fair to say they are not cheap. Depending on the size and heat loss calculations it might take a large dedicated boiler or other heat source. Price to run will be fairly expensive.Wirsbo is probably the largest manufacturer of these types of systems, and their web site should give you some good info.try http://www.wirsbo.com

1. 
   Guest_ | Feb 19, 2000 01:56am | #3

   *Here I go again. I tried not to say this, but maybe some of these spoiled, rich people should do something more helpful with their extra money, and stop trying to impress their friends with these sort of gimmicks. And in Indianapolis? Like the snow sticks around very long down there! What a waste of money. Give them a shovel and a bag of salt and tell them to grow up.MD

1. 
   Guest_ | Feb 19, 2000 02:08am | #4

   *Tell them to do what I saw a transplanted southerner do in a Chicago burb -- sprayed the driveway down with hot water from the washer tap. Melted the snow slicker than you know what. No problem until he tried to go up the driveway that evening.

1. 
   Guest_ | Feb 19, 2000 02:17am | #5

   *Mad Dog,I had the same reaction (spoiled, rich) twenty years ago to underground sprinkler systems, and now they're as common as sparrows. So, what seems absurd today may well be commonplace in a few years. Admittedly, this driveway heater is a bigger resource waste than the sprinkler system.

2. 
   Guest_ | Feb 19, 2000 02:48am | #6

   *John, Your customer has a wish and you've gotta deliver it, If you're only working on the driveway You are in for a huge expense to accomplish this and his utility is going to love him. To get your information I would get in contact with IPL (Indiana Power & Light) and they should have several resources and I believe they had a couple of tests going on in demo/situations. Per a recent seminar. Wirsbo is a very good heating choice for the house or shop. But it is not for slabs that largely go unheated. (You may not have the frost problems we have in Minnesota)I would tell your customer to take his wishes and incorporate them in the next home he builds and include it in a heat pump/exchanger and it will be a side expense instead of major bucks. Also make sure he checks his zoning and/or buys a big enough lot to allow the heat exchanger to be put in. If you have to pay to heat the medium - he is going to cry when the bill comes. No matter how big his billfold is.

3. 
   Guest_ | Feb 19, 2000 06:32pm | #7

   *Thanks for the input. Unlike sprinkler systems, I hope heated exterior slabs never catch on. As far as I'm concerned, I think they're a huge waste of money and future resources. I can just imagine the kind of power it takes to warm a 1200 sq. ft. slab from 18 degrees to above freezing so that they can impress their friends. And what happens when the slab cracks? does it shear the cables? That's my theory. But once again the customer is always right and if their pockets are deep enough, who am I to talk them out of throwing away money.

4. 
   Guest_ | Feb 19, 2000 08:59pm | #8

   *I didn't want to lead you astray on where the heat grid would go. Typically on concrete slabs the electric grid is placed below the slab in sand and not in the concrete as it is indoors. This applies to the H2O/glycol loops also. This sand is often a habitat for creatures big and small and they get their share fouling these systems up.Don't think these systems are uncommon though. In commmercial and speciality buildings they are very common in entrances, sidewalks and on roof tops. These often are put in place with a heat exchanger (exhaust/air) and run very efficently.

5. 
   Guest_ | Feb 20, 2000 06:28am | #9

   *I have to admit. I have several dozen of these "stupid" systems in use. Both electric and hydronic.What is really "stupid" about these seemingly ridiculous systems is the perception of operational costs.A few of these "stupid" systems also provide almost "free" heat for other uses such as hot tubs, swimming pools and domestic hot water during temperate weather. One such system I designed to assist in reducing the a/c load during the warm days of summer.You sometimes have to look beyond the forest to see the trees.Jeffps: Almost ALL heating cable and hydronic tube is placed within the slab when using concrete nowadays. Hydronic tubing is also placed directly in asphalt in most situations. Ever wonder where all the sun's BTU's absorbed by that asphalt could be used? I know!!

6. 
   Guest_ | Feb 21, 2000 07:42pm | #10

   *Hey Jeff,I was hoping you'd see this thread. I knew you'd have some experience with it. Good point about incorporating into a system to do other things with it, probably the only way it would make sense to me.Dog**********

7. 
   Guest_ | Feb 22, 2000 01:32am | #11

   *No experience (yet) but I've done my share of asking around. For those who think it's excessive, maybe you don't have to shovel often enough for the novelty to wear off (not sure where Indianapolis fits the picture). Snow here is something we deal with nonstop from the end of October to the beginning of April (after which we switch to the mosquito season). Not to say that snow melt is the answer everywhere, but I'd be willing to spend some dollars to save the yearly shovelling (or cranking a frozen snowblower to life).Cheaper to get a snow blower - you bet. But indirectly. If your going to put pipe in a slab, then you're going to need a thicker slab, on a better base, with extra bar to prevent shearing the pipes. The pipe itself is a minor cost. But then again if you had the choice wouldn't a higher quality driveway (heated or not) be more economical in the long run?If you don't have an existing boiler system capable of handling the extra load then you're stuck with electric heat or a new boiler system for the drive. Both expensive here, no arguments. But if you're already setup with hydronic heat and have the means to tap off it, then the price could come in faily reasonable.Some misconceptions about snow melt systems I have learned:1) When the snow melts the water run off creates ice else where. First of all, a snow melt system is dealing with snow one fall at a time (unlike a roof which tries to dump the entire winter's worth of snow in a few short humid days). An individual snowfall doesn't amount to a whole lot of water once it's melted and since the winter air is significantly drier, it evaporates quickly usually leaving nothing behind.2) It takes a tremendous amount of energy to heat a driveway in winter. It probably would, if it were heated 24 hrs a day, 7 days a week but snow melt systems are meant to be turned on only when new snow hits the ground until it's gone, and even at that, only a few degrees above freezing. Kind of like an extreme example of turning the heat down in an unused room until you need it. Around here, on the really cold days, there isn't enough moisture in the air to create new snow, so snow days are mild days and the system doesn't have to work against the worst cold of winter. Now add to this some strategic use of the sun's rays and you can melt away the snow with even less energy.This is what I've learned anyway, be it right or wrong. Still looking for more first hand knowledge in my climate to back it up.

2. 
   John_Lazaro | Feb 22, 2000 01:32am | #12

   *
   I've got a customer that would like a heated driveway to melt the snow (when it snows in Indianapolis). I've tried to tell them that a snowblower is ALOT less expensive and possibly less headaaches. Has anyone done one of these and can point me in the right direction as far as if who to contact to get pricing and install info?
   Also any experience or horror stories on the topic might be nice to hear. The wife said that if the price was high enough it might stear the hubby away from the idea, but I want to be honest with them on the price and cons, if any.
   Thanks,
   John

3. 
   Raokman | Jul 09, 2005 06:25pm | #13

   Everyone seems to be missing the most important reason for these systems:

   When you first get home in the evening, or rather, your WIFE first gets home in the evening and is looking at 12" of snow in the driveway, and isn't able to park on the street because of village snow parking bans inforce to allow snow plows to get through.  What to do?  New systems come with automatic controls that'll turn on the snow-melting system when it begins to snow...so you can come home to a clear driveway, and pull off the street.  If time is available, and your back is willing, you can forego the "system" and shovel/snowblow it yourself. 

   So, does anyone know any good installlers in the Chicago area?  Anyone know where to buy the supplies to do it yourself?  Tubing right now is most critical, and info as to whether to insulate the bottom of the sidewalks and if the metal mesh/grid is specialized in any way (clips for tubing...).

   Will be pouring a new sidewalk shortly, and even if the whole system doesn't get installed now, would like to provide for it in the future.

   Thanks

    

1. 
   constantin | Jul 10, 2005 05:39pm | #17

   I suggest you go through the archives of the Wall over at heatinghelp.com to get your answers. They have chewed over this very problem many, many times.IIRC, the average per sq. ft heat load of a driveway or walkway is in the vicinity of 150BTU/hr. Thus, you very quickly get into dedicated heating systems just for the snow load. The Andrettis of the world have banks of munchkins and other low-temp-capable, condensing boilers just waiting for the opportunity to light off.The placement of tubing is critical, as is the proper selection of ID, considering how the glycol makes the mix a lot more viscuous. IIRC, the smallest pipe diameter the guys on the Wall use is 5/8". Depending on the length of the driveway, you may need to run large diameter tubing down to distribution stations, then fork out from there. Glycol is a must, as is very careful site prep to deal with all the resultant water. Drains are needed to carry it away, and careful consideration should be given on how to insulate the whole area from below and how to drive the heat from the pipes into the road surface above. For example, embedding the pipes in sand is a really bad idea, you might as well use fiberglass insulation.Etc. You'll see, there is a lot of info on the wall to peruse at your leisure.Now as for the energy-wasting aspect of the whole thing, that is a matter of debate for a different forum. I think the coming energy-crisis will resolve the issue from a supply-side, that is until we have limitless power via fusion-reactors (maybe).

1. 
   DavidThomas | Jul 10, 2005 07:44pm | #18

   Constantin makes good points.  Yes, it has to be gycol and yes, that changes tubing sizes a bit.  Going with bigger tubing means you buy a bit more gycol.  Installing too-small tubing (or too-long loops) and you won't get the BTU delivery you need.  In an extreme case, you'd never get the far end hot.  In a less extreme, you'd need to run it longer (and therefore use more BTUs) than if the tubing was right-sized.David Thomas   Overlooking Cook Inlet in Kenai, Alaska

4. 
   Danusan11 | Jul 09, 2005 09:54pm | #14

   John, I come from a area that recieves considerable amounts of snow, not to say that I'am a expert in heated drives, however I'll give you my experiences with this system.

   If you have a sloped drive that is difficult to get in and out of due to snow and ice they will work fine, however that will only apply to a few inches of snow and ice coating.

   If you really get dumped on you will still have to remove the heavy snows, before system will operate effectively. Remember snow will act like a large insulating blanket. You will melt the snow but to think that if you are going to melt 6" plus is pure folly. 

   Most of the systems that are used here are hot water and boiler types. Once major snow is removed the system will melt drive fairly fast, but if your customer thinks that he will pull into drive during major storm and wake up to clean snow and ice free drive without some removal beforhand he will be very disappointed.

   As far as some of the other comments here, hey if your client wants to spend the money, knows the limitations of the system, and still wants to proceed. My recommendation is give them what they want. Its his money and he can spend it any damm way he pleases

    

5. 
   GCourter | Jul 09, 2005 11:04pm | #15

   John, it looks like you are getting a great deal of advise from "Guests", that is people that do not take the time to let you know who they are.  If you are pouring a new driveway why not put in the tubing?  A good snow melt system will monitor the outside weather and the slab temp, it will start to warm the slab before the surface freezes.  Ice melt systems are used in commercial applications all across the north country, they work great.  I feel that the reason that they are not used more in residential applications is that contractors do not understand them.  "the snow forms an insulating blanket", the snow does not build up because it will not freeze on 40 degree concrete.  Yes, if you shut the system off untill you have a foot of snow you will have a problem.  The good snow melt systems use a outside monitoring program to keep the snow off the drive way.

1. 
   BillHartmann | Jul 10, 2005 07:51pm | #19

   "John, it looks like you are getting a great deal of advise from "Guests", that is people that do not take the time to let you know who they are. "If you check the dates you will see that those are all 2000 dates. When the forum software was changed a lot of the archived message ended up with "generic" guest as the poster.They all had names at one time.

1. 
   GCourter | Jul 11, 2005 06:51pm | #20

   Thanks for the info.

2. 
   Yogi | Jul 11, 2005 08:05pm | #21

   What difference would it make if those fellas were new to the forum or hadn't shared what they might feel to be their private lives?  Good advice is good to get, regardless of it's origins- 

6. 
   cliffy | Jul 10, 2005 07:57am | #16

   Check out the Tekmar controls.

   Have a good day

   Cliffy