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MNPLUMBER Member Posts: 28
New here, first post.  I'm a Master Plumber from  Minnesota, with 20 plus years experience. Just starting out learning about radiant heating and boilers. I guess it's never too late to learn.  I'll have lot's of questions in the future I'm sure. I have read most of Dan's books and trying to learn all I can.

Has anyone installed or have experience with the DiaNorm Panel Radiators? I just got done reading over 48 pages in their technical section of their website.  I was interested because of space space restrictions in some installations.

I see they recommend a "homerun" type installation but I don't see why it wouldn't work with a regular loop installation. I do see on the installation guide they show the "Pumping Away" set up,  thought that was right on! I wonder where they got that from? LOL

Has anyone here installed these before, what do you think? I see they have a compression fitting for the inlet and outlet? Are there threads that can be used instead? How do they hold up over time? Anything else you can tell me.



  • AFred
    AFred Member Posts: 81
    Dia Norm

    Hey brother to the north, I install quite a few Dia Norm panels. I like them, the brackets are better than other panels I have put in, their adapter setup is pretty slick(no leakers yet after 4-5 years, make sure you get the copper compression fittings tight!), they come packaged well(less dented corners and trim peices).

    As for piping, they are a bit restrictive, they dont work to well when you stick them in the same zone as cast iron(always makes me laugh). They are a convector/radiator, they like HOT water. Careful, if you look in their catalog, they rate the output with supply temp of 190, take that into consideration when sizing.

    And remember that supply and return matter!


    Minneapolis fitter
  • icesailor
    icesailor Member Posts: 7,265
    Panel Radiators:

    I'm not familiar with the panel radiators you speak of. But most panel radiators have a larger volume of water in them over fin tube baseboard. If you connect panel radiators in a series loop situation, the first radiator gets hot and by the time the last radiator gets water, it may be cold. Making the zone extremely difficult to control. The first area will be hot and the end area will be cooler. If the thermostat controls the hot area, the end area will be cold. If it is the other way around, and the thermostat controls the cold area, the first area will be too hot.

    They need to be connected as a one pipe system or what is common is running small PEX and home runs. It takes a lot of tube. You can do a true reverse return or a direct return. The idea is to get the same hot water to all panels. Unlike someone in my customer base. You can use manifold blocks on home runs but I personally try to do a reverse return to keep the pipe runs down. If I use manifold blocks, I always connect them as a reverse return. Left to right, Supply:1,2,3,4,5,6. Return, 6,5,4,3,2,1.  A direct return would be with the supplies and returns opposite each other. Balance is the name of the game.

    But that works for me. 
    MNPLUMBER Member Posts: 28

    Andy if I run 1/2" Viega pex to these panels is there special fittings and a different way to make the connection? You mention the copper compression fittings?

    Getting hot water to all the panels is the key. What if I had a mix of slantfin radiators and some panel radiators and wanted all radiators on at the same time and using one single pump from the boiler? Instead of isolating the zones I would want them all to flow at the same time. Could I run the panels off the manifold in 1/2" and then also the slantfin off the same manifold? But the slant fin would need 3/4" I believe and then wouldn't that restrict water from going to the 1/2" panels? Hmmmm so many questions, still learning.
  • EricAune
    EricAune Member Posts: 432
    Home on the range'

    Great to see a couple fellow Minnesotans here.  If you ever find yourself in the Zimmerman area and want to sit down and talk shop give me a ring.  [email protected]

    DiaNorm panel rads are a very nice product.  Great quality when compared to most others.  Most importantly would be their availability to you, along with parts and stock on hand.  After all, who cares how great they are if you cannot get them when you need them?
    "If you don't like change, your going to like irrelevance even less"
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    Welcome to the Worlds Greatest Hydronic Education resource...

    Hanging out here is extremely addictive, but you will be much better off for the time spent here. Be careful with Fosta PEX. The OD is different that other tubing and may cause a problem with connections.

    Parallel reverse return works best with ANY heat emitter.

    These radiators CAN be piped in series, with an integral bypass valve, but as with any heat emitter, as you flow through the circuit, the emitters MUST get larger in order to compensate for the reduced temperature. It works, but if you can do parallel reverse return, you would be better off.

    Also, look into the use of TRV's (thermostatic radiator valves). These will guarantee comfort on all levels, by avoiding high temperature overshoot when necessary.

    A "Long running" 2 pipe main will save a lot more material and labor over the manifolded home run system.

    Be sure and wander off The Wall. Go check out the Resources button up above, and go to the Library. The history of hydronics is very interesting, and will give you a much clearer picture of why we do what we do and when.

    Finned tube base board can be incorporated into the same circuit if you'd like, but you need to be aware, and need to make your customer aware that the level of comfort is going to be noticeable. As the name implies, the RADIATORS will significantly affect the Mean Radiant Temperature, and MRT drives the bus of human comfort. Even though air temperature sensing thermometers in both situations may read the same, your body will sense the difference, and it will prefer to be near the radiators...

    Another web site you should check out is A LOT of good information there that can make the difference between a "heating" contractor, and a good "comfort" contractor.

    Welcome to the Wall , where education NEVER ends...

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
    MNPLUMBER Member Posts: 28
    Da Range

    My first radiant job will be for my own home, want to replace a dusty old forced air system. That's what I'm working on now trying to figure it out. Two story older home with basement. Because of space restrictions I may have to use the panels upstairs and also one in the kitchen. The living room, dining room and basement I could use slant fin.  I just have to figure out how it's going to be run.

    I'm leaning towards the Slantfin Victory cast iron boiler with the direct vent,  no longer have a working chimney in the house.

    I've been through Zimmerman on my way down south. Have  a sister who lives down in New Ulm.  Do ya ever get up to Da Range?

    We have Goodin Company in Duluth who carries these panels and the parts so it shouldn't be a problem getting them.

    With all the reading I've done I feel pretty confident about the near boiler piping but still have questions about it. Still have questions about the wiring though it seems simple enough with a basic packaged boiler. Is it correct to assume with a packaged boiler like the one I mentioned with the pump already there and without zone valves the only wiring would the the T-stat?
    MNPLUMBER Member Posts: 28

    Thanks Mark! I didn't realize Fosta Pex is a different size? I've used Viega for a long time, Fosta Pex too and didn't notice the difference. Do you mean it's different before you cut off the shield and make the connection? I could see it being bigger if someone tried using a compression fitting on the outside of the stuff.

    I'm going to use Viegapex Barrier piping for my installs. It's the black pex with the red line down the side Viega makes for radiant heating. Ever use this stuff?

    Can you explain the Parallel reverse return? Does that mean it's piped directly from the manifold to the radiator and returned directly back to the return manifold?
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    I've never actually used it....

    But did get a demonstration in my office one day, and was told then to be aware of the slight difference in tubing diameter. I'd suggest you run it by the manufacturers rep before you commit.

    Explaining the difference between direct return and reverse return is tough to do without pictures. Ice took a good shot at it, and I understand what he is saying, but for someone un-familiar with the piping techniques, it could be confusing. I can't generate a decent drawing on this machine (Macintosh, imagine THAT) and will have to use another machine. In fact, I have drawings explaining these differences on my office PC downstairs that I will find and post for our perusal.

    One way of explaining reverse versus direct return is to think of a ladder, standing vertical. The rungs are the radiators. The sides of the ladder are the supply and return mains. The ladder, as is, is piped direct return. Water is wet lazy and stupid, and always wants to follow the path of least resistance, which would be the first few rungs of the ladder. The top of the ladder gets starved for flow. The water going UP the left hand side of the ladder is the supply. The return on the right hand side of the ladder goes in the opposite direction (down).

    Now, leaving the ladder vertical, cut the leg off of the lower right hand side (you will now have a one legged ladder), and cut the extension of the upper left hand side of the ladder off where it goes past the top rung. Now, the supply (on the left) and return (on the right) both flow in the same direction, that being upwards in this case. Provided that the pressure drop across the rungs of the ladder are essentially the same, the flow through the runs will all be identical, and the rungs will all see the hottest water available, with perfectly balanced flow. If the rungs have significantly different pressure drops, you will need to "balance" the flow through the rungs with restriction to guarantee equal and even flow. The panel radiators actually have adjustable balance valves built into the body of the radiators.

    If you are doing a long running manifold (parallel reverse return piping on the exterior perimeter of the home), the ladder is essentially running all the way around the home. Obviously, if your home is not square, route manner and method will vary. The supply main MUST be sized to handle to TOTAL load (flow) and the first branch of the return is small, but increases in size as it picks up additional return loads. The supply main tapers DOWN in size as it drops flows to the loads. Use a 30 degree delta T for your flows, and you will be fine.

    Does that clear it up, or do I need to go find the other drawings?

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
    MNPLUMBER Member Posts: 28
    That helps

    Thanks Mark that does help out a lot. Since we've been discussing this UPS just dropped off another book (course) for me to start reading. It's big and looks intimidating and will take time. It's called the "I=B=R Guide RHH Residential Hydronic Heating". It looks like this one covers everything. I'll let you know what I think but give me a couple weeks! LOL
  • NRT_Rob
    NRT_Rob Member Posts: 1,013

    is just pex after you prepare it for a fitting.

    you can't use the same plates, or warmboard, things that go along the pipe, but for connections it can be used anywhere 1/2" pex can be used.

    I will home run ROOMS but not radiators. so if a room needs more than one radiator I will usually run them in series with a TRV on just one... it will modulate flow for the whole circuit.

    consider a new ECM pump like Grundfos alpha, Wilo EcoStratos, etc.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
    MNPLUMBER Member Posts: 28
    edited May 2011

    One more question about the DiaNorm panels. In my supply book it says they have a "R20 Male Metric connections", or "approximately 3/4 inch".

    I would rather not use compression fittings if I don't have to. Has anyone threaded on a standard 3/4" female fitting?

    Also on figuring out my first layout I would like to use a few of the panel radiators upstairs (piping restrictions) along with fin tube radiators downstairs.  From what I'm hearing it would be best to pipe directly to and from the panels upstairs without looping using 1/2" pex off a manifold.  The rest of the system would be either a simple series loop or a series loop with two circuits. I would like to most likely use the packaged pump that comes with the boiler (on the supply side) and have everything run at the same time (no zoning) for even heat throughout the house. The house isn't very large but it does have upstairs bedrooms. It needs even heating otherwise if I just heat the downstairs and attempt to keep the upstairs cooler I get a cold air circulation problem coming down the stairs.

    I'm well within my limits for lengths of piping using 3/4" for the loops and 1/2" for the upstairs panels.

    The problem I'm having is I have not yet seen such a setup using a loop system with 3/4" piping for my fin tube along with a manifold with the 1/2" piping for the upstairs panels. Can the manifold just be a second circuit coming off the near boiler piping?

    Thanks again and sorry if I'm not describing this correctly, I'm still learning.
  • AFred
    AFred Member Posts: 81

    Talk to your wholesaler, have them show you the fittings, they have the adapters to copper or pex( they work great).

    The threads on the panels are goofy aka metric, silly europeans.
    MNPLUMBER Member Posts: 28
    edited May 2011
    That's what I'll do

    I have some training coming up with Slantfin  next month for their ModCon boilers, I'll check out the fittings then, thanks.

    Still trying to figure out the proper set up for my near boiler piping to use a combination of a loop system for my fin tube run and then also incorporating a larger manifold with at least 8  -- 1/2" ports for others such as the panels.

    I was thinking maybe coming from the supply after the expansion tank and circulator I would drop down to 1" copper piping, have a 1x3/4" tee, the 3/4" going to my fintube loop. Then going straight ahead past the tee on the original supply piping and install the manifold with the 1/2" outlets. Could I also come off with one more 1x3/4" tee before the manifold looping my basement radiators?

    I'm not sure if I would need any kind of diverter tee's on my near boiler supply piping? From what I'm reading the water will follow the path of least resistance and should do ok with this setup?
  • EricAune
    EricAune Member Posts: 432
    Been away, been busy!

    Sorry I missed your response.  I do get up to the range once in a while.  My sister lives in Hoyt Lakes.

    If you would like, I am always up for a phone conversation or email exchange.  You can send me a message from this site to get started.  I will receive an email for and could then contact you. 
    "If you don't like change, your going to like irrelevance even less"
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