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Looking for general layout advice

samnewsamnew Member Posts: 15
Hello!
I'm doing a full gut remodel of my house in the desert Southwest, and have decided to make a foray into hydronics, for a few reasons (all HVAC contractors in my area are too busy to talk to me, I'd prefer to avoid losing the space a ducted system would eat up, and hot water heat seems, well, cool!)

In brief, I'm beefing up the insulation of the house significantly (to around r-30 in the walls) I have a basement (insulated) that has lots of room for utility chases and pipes. My floorplan is rectangular, about 23'x55', so not a big house or complicated layout. I had a heat loss calc done by an engineer and so I have numbers for each room of the house. Total load is about 36k BTU, 19k on ground level and 17k in the basement. I plan to have one zone for the basement and one for the ground level.

There is a local contractor who I'm occasionally able to ask questions of if I catch him at 8am with a box of donuts or something. He has advised me to basically install a series loop system, with 1/2" pex, using milti/pak 80 slant fin baseboards and a Weil-McLane aquabalance 80 boiler. I did a basic pump head calc using Taco's "Radiant Made Easy" guide and arrived at something like an 003 or 006, to which the contractor said, "Just use a 007, they're cheaper and will work."

I've been doing a lot of reading (Pumping Away, and lots of thread browsing on these forums, the manual of the boiler I want to use) and I'm a bit confused as to whether or not a series loop is a dumb idea. I'm guessing it was recommended to me by Local Contractor guy because it's simple and will work well enough, which I'm all for. I just want to be reasonably sure I'm not making a huge mistake before buying a bunch of equipment.

I have also read a bit on here and in Dan Holohan's books about diverter tee systems and reverse-return systems, which seem more efficient. My basement has a central supporting wall with an i-beam at the top running the length of the house, I could see running the main supply and return along a chase there and running the easy way through my joist bays to each baseboard, above or below.

Am I in way over my head? Am I on the right track? Should I even be considering a more complex 2 pipe system with my limited experience?



Thanks,
Sam


Comments

  • hot_rodhot_rod Member Posts: 13,500
    Do you want more than one zone? I would think the master bed/ bath separate from the living/ kitchen, maybe the basement separate. So 3 zones at least. Storage to be heated? that would be a good 4th zone.

    So a single circulator, the ECM type and zone valves for the various zones would be my suggestion. Is radiant in the basement and storage an option. A nice clean easy way to heat slab areas.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • Alan (California Radiant) ForbesAlan (California Radiant) Forbes Member Posts: 2,358
    edited July 17
    A series loop is not ideal. As the water cools from one heat emitter to the next, you will have to make the emitters larger and larger.

    If that were my house, I would install two manifolds; one for upstairs and one for downstairs with a supply and return to each emitter. That way, you get the same water temperature to each unit. And if you ever wanted separate thermostats in the bedrooms and living areas, it would be easy by adding manifold actuators.

    And if you wanted to splurge a bit and had plans to live in the house for awhile , I would heat the floors upstairs.
    Often wrong, never in doubt.

    Click here to learn more about this contractor.
  • samnewsamnew Member Posts: 15
    I guess zone-wise i would be fine with a single zone on each floor, 2 zones total.

    My main concern is in trying to install a system that is really complex. I am pretty good at research and following diagrams. If a series loop is not ideal, will it still work in a tight house? Is the expense of installing ANY kind of hydronic system such that I shouldn’t bother installing it unless i’m going to make it very efficient?

    @Alan (California Radiant) Forbes the manifold system you are talking about, is that the same as a ‘home run’ system?
  • hot_rodhot_rod Member Posts: 13,500
    Yep, a homerun or manifold system, super easy for a DIYer to install.

    Also an example of the two piping methods.
    With baseboard in series you have temperature drop thru each fin tube, takes more pump power.

    Manifold home run assures each fin tube receives the same temperature.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • samnewsamnew Member Posts: 15
    Ok, so say i have two zones (upstairs and downstairs), would it be advantageous to put it in a primary/secondary arrangement? I imagine this would result in needing three circulators, one on the primary loop and one for each zone. Would it be better to zone with valves instead? You mentioned an ecm circulator earlier with zone valves, does that still apply in this scenario?
  • hot_rodhot_rod Member Posts: 13,500
    The Weil manual is advising primary secondary. personally I prefer a hydraulic separator to a P/S. It gives you 4 or 5 necessary functions in one device, super simple piping.

    If you chose P/S, look into this horseshoe piping arrangement. It puts the distribution circulators in parallel, same supply temperature to each zone.

    In either case after the sep you could zone valve two zones, or do a homer manifold. It depends on how you prefer to pipe, probably a half of dozen ways it could be piped.

    Home runs would require 3/8 or 1/2 pex to each baseboard.

    Zone valved may require 3/4 pex or copper loop.

    Most pros use all the different types of piping system based on installation ease, cost, zoning options now or in the future.

    If I were to do a fin tube job today, especially my own, I would design for 120 SWT, upsize the fin tube, or use high output baseboard, to work at that low temperature. That will maximize the boiler efficiency, and future proof if for example you or someone decided on a heat pump, for example down the road.

    Crunch number, decide on priorities. Some additional cost on the front end, upsizing emitters for example, could be a gift that keeps on giving.

    In the desert SW with 300 plus days of sunshine, in the future the system could be a PV powered heat pump, heat, cooling and DHW from the sun :)



    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • hot_rodhot_rod Member Posts: 13,500
    Idronics 25 is a good read for new and existing systems. Goes into detail about the how and why of low temperature systems, regardless of the type of heat emitter.

    A bit more to think about regarding heat pumps. Air to water A2WHP are a viable option, even in a cold upstate NY climate they are performing. What are your local fuel costs?

    Air conditioning plans?


    https://www.caleffi.com/sites/default/files/file/idronics_25_na.pdf
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • samnewsamnew Member Posts: 15
    Current natural gas pricing is $8.37/MCF or just over $8/MMBTU

    My cooling plan is low-tech: evaporative cooler on existing duct in attic with operable drops into each room. I've lived this way for years and it's really fine. This house is well shaded, and the roof is oriented poorly for consistent sun exposure, which is why I'm not looking into PV or solar tube stuff at this time. The shade keeps things really, really cool compared to surrounding yards. I have a quonset hut next door that I may eventually raze and rebuild into a proper shop, which would have much better solar exposure, but that's a whole other cannoli.

    I had considered a ducted forced air system (installed by someone else, with an AC coil) but the duct in the basement really kills the headroom and makes the space less usable, plus it would make my drains much harder to run, etc....

    The hydraulic separator looks slick, I'll probably be coming out of the boiler at 1", so at $370ish it looks like not really that much more expensive than a dirt and air separator plus a bypass valve on the end of the manifold, and simpler. I think I understand basically how it is similar to the primary/secondary.

    @hot_rod In your hand-drawn diagrams and in the idronics pages you attached, it looks like the "pumping away" concept i've read about so consistently is being violated. I see what looks like an expansion tank on the return side of the boiler, with pumps on the supply side. Outside of primary/secondary arrangements, does this not matter as much? or is the concept still being applied somehow?

    Sam


  • samnewsamnew Member Posts: 15
    Also, I keep looking at using a slant fin emitter with a 3/4 connection. is it silly to run 1/2" and then step up into a 3/4" emitter?
  • samnewsamnew Member Posts: 15
    Gettin' sorta trigger happy with questions today, so I'd like to interject here and say:
    THANK YOU for responding to my posts so far. This is an extremely valuable resource for someone like me. If there's some way I can contribute (looks like the site is advertising-funded), I would gladly do so.

    After thinking about the actual piping runs, it seems best to do 4 zones off of a manifold or header in the boiler room, as you suggested: Living space, upstairs beds, basement beds, storage. I think each of these are short series loops, because it seems quite expensive to have a manifold for each of these, unless I'm barking up the wrong tree.

    These zones will have, say, between 14 and 26 feet of baseboard each. Do I need some kind of balancing mechanism beyond a pressure-sensitive circulator, like a TRV or a balance valve on the manifold, or does the circulator's sensitivity take care of that?

    Thanks,
    Sam
  • hot_rodhot_rod Member Posts: 13,500
    I like the plan, 4 zones, separator, I’d use a single delta P circulator with zone valves. GRUNDFOS Alpha, most any of the new Tacos, B&G Vario, Armstrong Compass, pick a color😉

    Your baseboard lengths, based on what supply temperature?

    Be nice to design at 120F, it will cost more for the fin tube, but with a mod con the lower the SWT the better. I highly recommend the lowest SWT you can afford.

    Not much sense in using a mod cod if you design at 180F, use a sealed combustion cast boiler If you go high temperature , simple, reliable, but lower efficiency.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • hot_rodhot_rod Member Posts: 13,500




    @hot_rod In your hand-drawn diagrams and in the idronics pages you attached, it looks like the "pumping away" concept i've read about so consistently is being violated. I see what looks like an expansion tank on the return side of the boiler, with pumps on the supply side. Outside of primary/secondary arrangements, does this not matter as much? or is the concept still being applied somehow

    As odd as it looks all circulators in those drawings are pumping away from the PONPC. The large diameter "horseshoe" assures that ponpc extends from the tank to the distribution circs, in this example.

    Something I learned recently when chatting with Dan, whichever loop has the expansion tank connected becomes the primary loop. It could be the boiler, secondary or tertiary.
    In this example the horseshoe loop is the primary loop. Dan, via Gil Carlson.

    Also in this example the horseshoe would be sized for total gpm at low flow velocity, no more than 2 fps. So that loop would maybe be 1-1/4 or larger depending the total gpm of all the distribution circulators. Think of it as a low loss header.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • samnewsamnew Member Posts: 15
    A few more questions:

    When using a delta P circulator, is it less important to calculate the exact head loss for each zone, as the circulator is more flexible?
    Should I also be using a delta P circulator for the boiler loop circulator?

    Is there a meaningful difference between a manifold and a header? The zone valve layouts I'm looking at just look like built-up manifolds...and I'm getting the impression that it should be a "low-loss" header. I was looking at a manifold with balancing valves on it, if I take the zones off of a short 1" header instead of a manifold, do I need a balancing valve somewhere in the loop to tweak the flow?

    Thanks!
    Sam
  • hot_rodhot_rod Member Posts: 13,500
    samnew said:

    A few more questions:

    When using a delta P circulator, is it less important to calculate the exact head loss for each zone, as the circulator is more flexible?
    Should I also be using a delta P circulator for the boiler loop circulator?

    Is there a meaningful difference between a manifold and a header? The zone valve layouts I'm looking at just look like built-up manifolds...and I'm getting the impression that it should be a "low-loss" header. I was looking at a manifold with balancing valves on it, if I take the zones off of a short 1" header instead of a manifold, do I need a balancing valve somewhere in the loop to tweak the flow?

    Thanks!
    Sam

    It sounds like you are on a lean and earn mission, if so it is a good idea to calculate all the piping, gpm and head, attached is a journal to walk you through the process.

    https://www.caleffi.com/sites/default/files/coll_attach_file/idronics_16_na_0.pdf

    A seasoned pro could guesstimate a circulator size based on experience with like systems. Todays ECM have a wide range of adjustability so you should be able to get one adjusted d to exactly what the system requires.

    No need for delta P on the boiler, I would still use an ECM properly sized, in fixed speed, just for the 50% or more power savings.

    The device between the boiler and distribution can be know as a hydraulic separator, low loss header, primary secondary, 4 in 1, Sep 4. They all serve the same purpose, as far as hydraulic separation between the boiler loop and distribution loop.

    Manifolds can be for different functions also. Some have zoning, flow meters, & balance valves. Or it could be a simple stack of tees connected together on the jobsite. I suppose manifolds and headers could be considered the same device or function.
    At the very least you want isolation valves and a single or multiple purge points. Flowmeters are nice to confirm and adjust to the number you calculated, look into the Quicksetters, it could serve as isolation and a means to observe and adjust flow.

    https://www.caleffi.com/usa/en-us/catalogue/quicksettertm-balancing-valve-132432a

    This pic shows a hydraulic sep, zone valves on a manifold with multiple loops.


    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • samnewsamnew Member Posts: 15
    you're right about learn and earn, i got this house for a pretty good deal in a good market, and i'm having a good time fooling around with it. looking forward to living in it, though.
  • Erin Holohan HaskellErin Holohan Haskell Member, Moderator, Administrator Posts: 1,344
    samnew said:

    Gettin' sorta trigger happy with questions today, so I'd like to interject here and say:
    THANK YOU for responding to my posts so far. This is an extremely valuable resource for someone like me. If there's some way I can contribute (looks like the site is advertising-funded), I would gladly do so.

    Thanks, @samnew. Just pay it forward and help someone else.
    President
    HeatingHelp.com
    Zman
  • samnewsamnew Member Posts: 15
    Ok, I'm planning the runs so I can calc the volume and head loss, etc. The manifolds and quicksetter valves I've been looking at have different ranges of flow, like from .5-1.75 gpm or 2-7gpm. Many manifolds seem to typically have 1/2" outlets. I've been thinking I need to run 3/4" pex to each emitter, as the baseboard i plan to use has a 3/4" tube in the element. Also, I've been using the 4gpm BTUH rating for 120 degree water, as it gets me a little more bang for the buck. 1/2" pipe at 4gpm yields about 6.5fps, which I have read as too fast. I'm getting a little mixed up at where I should start designing from...is it not a big deal to run 1/2" pex to a 3/4 emitter? should I size the whole thing based on velocity?
    Thanks!
    Sam
  • hot_rodhot_rod Member Posts: 13,500
    So 1/2" pex maybe 1.5 gpm, which would carry 15,000 BTU/hr.

    This is a handy calculator if you can guesstimate the entire circuit, fittings, etc. Then you have a pressure drop and can see if 3/4 makes better sense. With the short loop lengths you mentioned 1/2 may work, since you are busting it up into zones..

    http://www.plasticpipecalculator.com/PressureDropHeadLoss.aspx

    Use 1/2" CTS (copper tube size) pex
    I'd stay below 5 fps 2- 4fps is a common recommendation.
    Depending on the manifold type or brand, most allow 1/2, 5/8, and 3/4 tube connectors.

    Look at the various brands and models of fin tube, sometimes 1/2" has higher output than 3/4". It's more about the fin size, shape, and spacing :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • dopey27177dopey27177 Member Posts: 306
    I am from the old school of kiss (keep it simple stupid)

    If were my house I would install pumping away. Pumping away removes air continually. assures that the proper pressure differentials are maintained in the system.

    Addtionally, I would install 2 zones with zone valves and one circulating pump and use the reverse return piping set up. reverse return piping assures that the circulating water is the same temperature entering every convector or radiator in each zone. Although the piping system is about 1/3 more expensive it will save you the cost of using larger convectors to make up for the drop in water temperature as the the water cools when it passes thru the convectors closest to the boiler.

    Jake
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