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Megasteam question

If you aren't using the coil for its primary purpose, then I too would suggest using the coil for the hot water zones. This will need to be piped with a PR Valve, Expansion tank and air eliminator and relief valve just as if it were like a boiler. Vacuum loops do function well but do require more maintainance such as purging, etc..

The person you spoke to is just being truthful with you. We do encounter many more applications where the coil is already being used for domestic water than we do otherwise. Second floor vacuum loops can also be somewhat problematic in getting airbound and that may be part of what he was describing to you. I can only recall about a half dozen instances in 35 years of a coil being used for a zone of heat or two. Hope this helps.

Glenn Stanton

Manager of Technical Development

Burnham Hydronics

U.S. Boiler Co., Inc.

Comments

  • lchmb
    lchmb Member Posts: 2,997
    any suggestion's

    Let me run this by the collected intellect of the wall. I have an upcoming project that will involve a megasteam and 2 small heat zone's and an indirect water heater. I had thought to pipe these three zone's off the coil (I know I've seen this before, Ron Jr?) but when I discussed it with Burnham tech support they said the have never heard any good comment's from it and suggested I use the tapping for the indirect and return through the wet returns...

    A little knowledge, the two zone's are on the second floor of the residence and will probably not run much to speak of. I'm thinking that most of the heat will travel up the stairs from the radiators. The boiler will be large enough to handle both so either way is not an issue. Any thought's? Glenn/Steamhead do you have any input for me on this? I'm looking to do it right. Thanks for any and all suggestions....:)
  • I would use the coil

    for those 2 water heat zones . I know you can circulate water up maybe 30 feet under a vacuum , but we go back to too many jobs that get airlocked for some reason or other .

    With the coil you don't have to worry about spooged up circs from dirty steam water after a few years . Or deterioration from prolonged high temps . Our last install like this was a few months ago using a Burnham V84 and coil for 2 zones . Worked fantastic . Unless there is an extra BB zone below the boiler water level , using a coil is our preferred way to handle it .

    On a few installs with alot of BB flowing through the coil , the water zones actually prevented the boiler from steaming till they shut down . Maybe think about a multizone relay with the steam zone as priority , just in case ?

    Good luck lchmb , take some pics so we can check it out .
  • Tom Hopkins
    Tom Hopkins Member Posts: 552
    I'm

    with Ron on this.Did a similar job last year.Peerless ECT Steam,2 HWBB zones and Indirect.Used a L8124,SR-503 and SR 501 for the Riello.Wired the 501 and 8124 T-T to the X-X on the SR-503.The 503 gives the DHW priority over the HWBB and the 8124 lets you maintain a lower temp on the boiler than you would need with a 4006

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  • lchmb
    lchmb Member Posts: 2,997
    Thanks Ron

    I knew you had done this in a number of job's and some had included the Burnham. That's why I was a little surprised when tech support said they only had issue's with it. Would you by any chance have any pic's of a steamer you had piped with zones? And I'll take pic's, I am hoping to include a drop header in to this one to join the "elite club"...:)
    Thanks again..
  • lchmb
    lchmb Member Posts: 2,997
    Thanks Robert

    I had planned to give the indirect priority and had thought of wiring the boiler so it would not produce steam on a call for a zone. Not sure if it would be necessary but I'll check with Taco to see if their would be any issue with high temps on the circ's.
    Thanks for the info. And if anyone else want's to add in I'm all ears. Well, other than tomorrow since I'm going fishing!!!!!! :)
  • I'll check right now

    for pics . Sorry , I missed what you said about using an indirect too . Robert is dead on with the way to prioritize the indirect and the steam zone . If they're real small zones I wouldn't worry about heat priority though . I'm not quite sure but I think the house that wouldn't steam up was real , real cold when we started the new system .

    I see nothing but benefits by using a coil . But it is a new boiler . Maybe it hasn't been done before on the Mega yet ?

    I found one so far , 1 zone off the coil . I'll keep looking for the 2 zoner . Man , I gotta clean up my work pics folder , I can't find anything easily .
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928


    I've only studied--never worked with--steam. That said, Ron Jr.'s suggestions [seem] exceptional. Merely using wet returns and "trapped" water to lift would be less expensive, but IMHO more trouble-prone--particularly when you suspect the rads supplied by such will require little (if any) heat input in most situations.

    [Added] I would NOT however take this approach unless it receives at least a statement of "it can't hurt the boiler" from the manufacturer--better yet if it receives full blessing...
  • lchmb
    lchmb Member Posts: 2,997
    Glenn

    Thank you very much Glenn. It was your word I was waiting to hear on. I will pass this on to my supervisor and actually look forward to doing this job.
  • lchmb
    lchmb Member Posts: 2,997
    owe you one

    Thanks very much Ron, I owe you one. Worst part to this now is I'll have to do as good a job as you guys do..:) Thanks for the suggestions and the pics!!
  • Mad Dog_2
    Mad Dog_2 Member Posts: 6,915
    On our first Megasteam, I too had planned to pick up a baseboard

    zone and an indirect off the coil. When we got the boiler down, we saw that it wasn't even a 5 gallon coil, but less than 3 g.p.m.s. I wish Burnham would make them with the largest coil possible AND 3/4" tappings. There was another 3 1/2 to 4" s of room inside the boiler. We wound up pulling the bb zone off that and piping the indirect with a brass wye strainer off the bottom tappings which DID work out well, but it was not what we had planned to do or told the HO we were going to do. We scrambled around trying to find a larger capacity coil to no avail and then revamped our plan. Other than that it went well....don't seem much heavier than a Buderus though. Mad Dog

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  • lchmb
    lchmb Member Posts: 2,997
    Thanks Mad Dog

    I appreciate the information on the gpm. I was trying to find that the other day and never completed that task (memory is shot). Since it is that small I think I can do as you did and handle the two small heat zone's from the coil. I won't know for sure until the heat loss is completed. Thanks for this invaluable information. You guy's are the best!!!
  • Matt

    There has always been this myth that a larger capacity coil will always give you more capacity. The capacity of a tankless heater is a direct function of available btu's for production. This coil is the same across the line and has varying output capacities of 3 gpm to 4 gpm based on the btu capacity of the boiler. This is based on a 100°F (40°F to 140°F) temperature rise through the coil though in a higher pressure application with higher friction losses through the coil. In a system loop application the coil will only have to raise the water temperature 20 to 40°F during most of it's operation and will do very well without having to be physically larger. Of course you will need to size your circulator to overcome the friction loss. Here is some math to demonstrate the fact.

    GPM = BTUH / °F Temperature Rise x 500

    Domestic Production:

    GPM = 150,000 / 100°F x 500 or 3 gpm

    GPM = 200,000 / 100°F x 500 or 4 gpm

    Heating Loop Application:

    GPM = 150,000 / 30°F x 500 or 10 gpm effective flow rate

    GPM = 200,000 / 30°F x 500 or 13.3 gpm effective flow rate

    By the way, what's this comparison of the Megasteam to Buderus all about? Last time I checked they didn't make a steam boiler nor any boiler with a tankless! Just busting ya! How did the first MegaSteam run and what kind of combustion numbers did you get with it?

    Glenn Stanton

    Manager of Technical Development

    Burnham Hydronics

    U.S. Boiler Co., Inc.
  • lchmb
    lchmb Member Posts: 2,997
    ok

    Glenn, If I'm following you correctly, and I appoligize if I'm not, your saying the coil should not have any issue's handling two small heating zone's or the Alliance water heater? I just want to make sure I'm not asking to much of the coil. I will be putting the indirect on priority if that make's a difference. Thank you for your time with this..
  • Tom

    I was just trying to dispel the old myth that a bigger coil will give you bigger flow rates in my post to Matt. If it is a smaller indirect of 27 to 40 gallons capacity it works fine. If you are looking for more capacity in the indirect you will need more btu's to get the steady state recovery and that's where piping it direct pays off. I have absolutely no problem with Matt's method and concerns about flow rates. I see more vacuum loop installations than I do coil installations. My bigger concern involves the 2nd floor heating loops getting air bound in a vacuum loop installation.

    I'm not sure how Matt piped his but we provide a dedicated 1" supply tapping in the rear section just above the flue connection for an Indirect. Adjacent to it is a 1/2" tapping for an immersion aquastat to serve as a high limit. The return pipes into the botto return tapping.

    Glenn Stanton

    Manager of Technical Development

    Burnham Hydronics

    U.S. Boiler Co., Inc.
  • lchmb
    lchmb Member Posts: 2,997
    Thanks Glenn

    Thank's for the valuable information. Even though I believe it's only a 40 gallon tank, I think I'll play it safe and pipe the indirect off the back and the zone's off the coil. Thanks a bunch for the help from everyone!!
  • Mad Dog_2
    Mad Dog_2 Member Posts: 6,915
    Hi Glenn

    I appreciate all the math and I don't disagree totally, but
    I think a larger capacity coil could only help us in our installs and it seems that there is room for a bigger one. I mentioned Buderus because they too are 3-pass and several guys who install both mentioned how heaevy the megasteam was compared to other boilers. Never checked the weights but it didn't seem drastically heavier. That was about six weeks ago, but I think we saw stack temps in the low 300s. Very nice boiler...loved the extra tappings. We have to go back and tidy up that job, but the HO found termites. I will be posting pics of that job soon. Mad Dog

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  • Thanks Matt

    Can't wait to see the pictures. As I stated, a bigger coil will not give you any appreciable amount of extra gpm output without extra btu's from the boiler. Sure it will give you somewhat greater standby capacity but once the water starts moving through the coil the performance will be about the same.

    Glenn Stanton

    Manager of Technical Development

    Burnham Hydronics

    U.S. Boiler Co., Inc.
This discussion has been closed.