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adding a radiant heat zone

Randy_9
Randy_9 Member Posts: 18
HR- I have read the article and understand most of the concepts, but not all. How does one decide which is the right choice or the right system? I know that I need to connect another zone, but does it make a difference that my existing citculator is on the baseboard return and that the radiant circulator would be on the supply? And is there any chance of condensation?

Randy

Comments

  • Randy_9
    Randy_9 Member Posts: 18
    Zoning radiant heat

    OK, I am adding radiant floor heating to my kitchen during a remodel. I understand the tubing layout and installation, but I have some confusion on the connections at the boiler. Currently, we have a Burnham RSA-110 with a 1" (maybe 1 1/4") output to basebaord heat with 2 zones. The zone valves are on the return side of the 1st and 2nd floor pipes and the circulator is located after the zone valves. If I add the radiant, does it need it's own circulator and zone valve, and what other components would be needed besides the tubing manifold? Should I tap off the existing supply after the expansion tank?

    Randy
  • hr
    hr Member Posts: 6,106
    A good article on that can be found here. Copy and paste this l

    > OK, I am adding radiant floor heating to my

    > kitchen during a remodel. I understand the

    > tubing layout and installation, but I have some

    > confusion on the connections at the boiler.

    > Currently, we have a Burnham RSA-110 with a 1"

    > (maybe 1 1/4") output to basebaord heat with 2

    > zones. The zone valves are on the return side of

    > the 1st and 2nd floor pipes and the circulator is

    > located after the zone valves. If I add the

    > radiant, does it need it's own circulator and

    > zone valve, and what other components would be

    > needed besides the tubing manifold? Should I tap

    > off the existing supply after the expansion

    > tank?

    >

    > Randy





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  • hr
    hr Member Posts: 6,106
    A good article on that can be found here. Copy and paste this l

    > OK, I am adding radiant floor heating to my

    > kitchen during a remodel. I understand the

    > tubing layout and installation, but I have some

    > confusion on the connections at the boiler.

    > Currently, we have a Burnham RSA-110 with a 1"

    > (maybe 1 1/4") output to basebaord heat with 2

    > zones. The zone valves are on the return side of

    > the 1st and 2nd floor pipes and the circulator is

    > located after the zone valves. If I add the

    > radiant, does it need it's own circulator and

    > zone valve, and what other components would be

    > needed besides the tubing manifold? Should I tap

    > off the existing supply after the expansion

    > tank?

    >

    > Randy





    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
  • hr
    hr Member Posts: 6,106
    The choice depends on the control-ability you want.

    > HR- I have read the article and understand most

    > of the concepts, but not all. How does one

    > decide which is the right choice or the right

    > system? I know that I need to connect another

    > zone, but does it make a difference that my

    > existing citculator is on the baseboard return

    > and that the radiant circulator would be on the

    > supply? And is there any chance of

    > condensation?

    >

    > Randy





    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
  • hr
    hr Member Posts: 6,106
    The choice depends on the control-ability you want.

    > HR- I have read the article and understand most

    > of the concepts, but not all. How does one

    > decide which is the right choice or the right

    > system? I know that I need to connect another

    > zone, but does it make a difference that my

    > existing citculator is on the baseboard return

    > and that the radiant circulator would be on the

    > supply? And is there any chance of

    > condensation?

    >

    > Randy





    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
  • hr
    hr Member Posts: 6,106
    The choice depends on the control-ability you want.

    > HR- I have read the article and understand most

    > of the concepts, but not all. How does one

    > decide which is the right choice or the right

    > system? I know that I need to connect another

    > zone, but does it make a difference that my

    > existing citculator is on the baseboard return

    > and that the radiant circulator would be on the

    > supply? And is there any chance of

    > condensation?

    >

    > Randy





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  • hr
    hr Member Posts: 6,106
    Depends on the control-ability

    you desire:) In some of those drawings the baseboard zone would need to be running to get the radiant load.

    My feeling is if the radiant load is 1/4 or smaller than the boiler output condensation shouldn't be an issue. Ice cold slabs may be an exception :)

    Hard to say which would fit your system best, really need to "be there" and see your piping arrangement.

    hot rod

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  • Randy_9
    Randy_9 Member Posts: 18
    How about some general concepts

    In the past few days, I have read an dlearned a lot from this forum and other sources, but a few items and terms escape me. Perhaps you could indulge an amateur with the following concepts. First, in a P/S piping setup, is the primary loop just a source to all of the secondary loops and it never really goes to heat an individual space? Second, if a floor of the house is fed by two loops around the perimeter and have a common return, do the loops have to be similar in length for balance? What if a portion of one loop is removed, does that uupset the balance? Should a circulator be placed pumping to or away from a boiler? Should sone valves be used on the supply or the return, or can circulators perform the same function? What is head, and how is it measured? I am really just looking to evaluate what I have and see if there is more that could be done to make my heating system more efficient. I totally appreciate the help and insight provided here.

    Randy
  • hr
    hr Member Posts: 6,106
    In it's simplest form, the boiler is within the primary loop

    I use some version of PS on all my boilers, unless it's a simple one or two zone baseboard job.

    The primary loop is a distribution center. It can recieve inputs from boilers, solar panels, wood boilers, etc, etc. It can also distribute to "loads" Baseboard, radiant, indirect tanks, concrete dogs, etc, etc.

    The pump on this loop JUST needs to handle the total gpm of the loop, and this is usually the total building load. This pump is also sized for the pressure drop of the PS loop and boiler IF the boiler is in the loop. If the boiler is a secondary, then it's pump is sized only for that loop and pressure drop through the boiler.

    In other words a PS loop could have a small pump. Whereas a high head pump could be on a boiler secondary loop if needed. Sounds like you have this concept down??

    I always zone on the return side. I have never had problems with "banging" ZVs, even with medium head pumps, when I zone on the return. Personal preference, really. Either will work.

    Head is the energy added to the system by the circulator, basically. Circulators work by lowering the pressure at the intake side and raising the outlet side. If you were to put a gauge at both sided of the circulator you could calculate the work or "head" the circulator is adding to the system. A circ pump wouldn't work as a sump pump. They are not designed to lift. Circ work by "slapping" or spanking the fluid, so to speak, to create the pressure difference.

    Unequal length loops generally have balance valves, or circuit setters, to assure both loops get the flow they need or are designed for.

    Keep reading, you are getting the idea :)

    hot rod

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  • Randy_9
    Randy_9 Member Posts: 18
    OK, now to apply the concept

    I have an oil-fired Burnham RSA-110 with 2 zones of baseboard. One is for the first floor and one for the second. I am adding the kitchen with a radiant floor sleeper system, replacing the baseboard in that space. So, in an ideal setup, would a P/S loop begin at the boiler, hit a circ. (sized appropriately), hit a secondary to the first floor, with it's own circ., then a secondary for the second floor, with it's own circ. and then the manifold for the radiant, again with it's own circ. Then all of the returns join and go into the boiler. Obviously, this is a simplified setup, and I don't think it's just that easy, but conceptually, is that an efficient way to go? I understand that there are check valves and flow valves and things like that. Also, it is understood that there is an expansion tank in th beginning, before the 1st circ.

    Randy
  • hr
    hr Member Posts: 6,106
    First off

    make sure the radiant floor in the kitchen can meet the load, and provide as much heat as the baseboard you are removing.

    Sometimes kitchens do not have enough floor area, when cabinet square footage is considered, to meet the load, with just radiant. A simple heat loss calc will provide that info.

    Here is a "simple as it gets" p/s conceptual drawing. Using a 3 way thermostatic mix valve for the radiant temperature. If the kitchen radiant load is 15 btus or less per square foot you could do a suspended tube and run it at boiler temperature. Stay below 180° F to be within the PEX limitations.

    A boiler reset control would be a nice addition to allow lower operating temperatures on mild days.

    Beyond this info and drawing, your next best bet would be to pay a hydronic contractor stop by :)

    hot rod

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  • Randy_9
    Randy_9 Member Posts: 18


    Hot Rod- I comppletely understand what you are saying and the diagram is almost exactly what I had pictured. I cannot tell you how much I appreciate your time and energy here. FYI, the radiant design was completed by a fellow member of the RPA with the initials TT. I have followed both of your posts for several weeks while researching this process. If I ever get to the point where I think I am outside my league, I will have no problem calling in a hydronics company. My boiler servicemen are aware of the project and offered assistance if needed. I would like to think that I am not so vain as to assume I can gain a lifetime of knowledge in 5 weeks on the web. However, I also hope that this project is something that a competent DIY'er can accomplish. Again, thanx.

    Randy
  • hr
    hr Member Posts: 6,106
    If it's the TT

    that I think it is from the RPA site, your in good hands.

    Unquestionably the world foremost expert on ALL things radiant. Although he is shy about admitting it :)

    hot rod

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  • Randy_9
    Randy_9 Member Posts: 18
    The very same

    By the way, IF I were to move forward with re-piping this P/S loop, I would need to relocate the xisting circ. which is attached on the return right at the boiler. How do you drain and fill when you are so close to the tank?

    Randy
  • hr
    hr Member Posts: 6,106
    Not really

    it's more important to pump away from the PONC. Where is the expansion tank located?

    Often times a primary loop consists of 10 feet or less of pipe. If you pump is located within 5 feet of the expansion tank (half way around the loop) you are still, theoretically, pumping away from the PONC. Pumping into the return isn't that big of a sin, it's been done for decades. Lots of boilers are still shipped that way!

    Seems if you are going to the trouble of repiping to build a PS loop, it would be easy to butt the pump up to the air purger and expansion tank location and avoid a visit from the ponpc/PS cops :)

    hot rod

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  • Randy_9
    Randy_9 Member Posts: 18


    The expansion tank is at the beginning of the supply loop, 4 ft. from the boiler. I was thinking of moving the circ. to there, right after the exp.tank.

    Randy
  • hr
    hr Member Posts: 6,106
  • Randy_9
    Randy_9 Member Posts: 18
    Thanx for your time

    Have a good night. If possible, I'll post pictures.

    Randy
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