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Seeking design advise for subfloor radiant heat install - NJ

Hello Everyone.

I had been introduced to this blog by a friend am posting here the first time.
I am not an experienced professional in this field so please bear with me on the terminology and my understanding. Having said that, I would like to request your input on the project I have started.

I live in 07836 zip in a colonial 2-story house which is 2005 built with energy star rating. I am trying to add radiant heat as a supplemental source to the current forced-air system.
The current air furnace for this zone is rated at 110000 BTU.
I am trying to install an underfloor radiant heating system for the first floor of the house. The first floor has 3/4” Oak hardwood installed on a 23/32” subfloor.


The basement is about 2200 sq ft. with a 9ft ceiling. The joists had fiberglass R-13 insulation and I have taken that out and am planning to eventually replace it with Roxul insulation (> R-13). The walls are uninsulated.
I have bought/installed Noritz CB199-DV(120K BTU capacity output), cleaned up the joists from nails, and put the RadianTec Thermofin plates in the joists. The boiler would be exclusively used for radiant heat application only.
I used watts radiant software for the heat loss calculations, which came out to 60000 BTUH for 70 Delta T.

I have attached a sketch of my design drawing. I would like to request, please, professional feedback/suggestions/critic of the design and installation/missing components, etc to make the design efficient and effective. Thanks.

Comments

  • ultimatedesi
    ultimatedesi Member Posts: 7
    Inserting the design diagram.
  • hot_rod
    hot_rod Member Posts: 15,065
    close, but no primary loop circ? One of these 3 would work better.
    With the pumped primary loop option, mix valve connects via closely spaced tees.

    Do you need a mixing valve? What are the sunroom heat emitters?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hcpatel78
    hcpatel78 Member Posts: 141
    edited March 19
    HI Bob... @ultimatedesi is my friend and we are working together so please also consider my post/comment same as his.

    The joist bays are 24" wide engineered I beam joists. Basement is unfinished and has walk out door on one side and other side 1/2 berried and quarter of the 9' wall exposed to outdoor .

    The heat emitter in the sunroom are same Radiant Tec extruded plate. But in the sunroom we are adding third row of plates in between two raw. We considered higher heat loss in sunroom as Sunroom has 3 sides windows and only one side attahced to main house which doesn't comprise windows.
    The joist bay cavities will be insulated once job done with minimum R15 Rockwool ROXUL insulation.

    Sunroom has a carpet flooring installed directly on plywood subfloor. To be safer side because of the higher heat loss in sunroom we added separate high temperature zone compare to other two zones from rest of the house.


    Thank you,
    Hiren Patel
  • Zman
    Zman Member Posts: 7,009
    I am not seeing any major issues.
    You will need to add check valves on the zone circs and a handful of drain/purge points.
    The mixing valve will need a check on the A side to prevent reverse flow when only P1 is running.
    You should move the high temp zone return to the other side of the low temp returns so you don't get two-way traffic (and mixing) across that section of pipe.
    There may be a cleaner way to pipe this, but I think it generally works.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    Steve Minnich
  • ultimatedesi
    ultimatedesi Member Posts: 7
    @hot_rod, @Zman - Thank you for the quick review/comments on the design earlier.
    I have added the primary circulator and would definitely add the checks valves/drain/purge points. Can I please request another review and help with some of the following questions?

    1) The return of the high SWT circuit - should I use option1 or option2? (attached file: Option1ReturnCloses.jpg and Option2ReturnFurthest.jpg)

    2) For the pump location on circuits that have 60 ft lead, should it be option A or option B? (attached file: PumpLocationOptions.jpg)

    3) Are pump selections appropriate for the primary circulator and the 3 circuits (give 2 of them have 60ft lead pipe). All the circuits would have 300ft max 1/2” HEPEX loops.

    @Zman - Any suggestions on the cleaner way to pipe these circuits?







  • Zman
    Zman Member Posts: 7,009
    edited March 23
    I think you are doing primary/secondary on top of primary secondary.
    I was suggesting this

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Zman
    Zman Member Posts: 7,009
    To answer the other question, your circulator wants to be as close to the expansion tank as possible and "pumping away"
    Option B would be better than option A.
    How many loops do you have per zone? I don't think you will likely need any circs bigger than 15-55, Since you will be running fixed speed, the 15-58 might be the better choice.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • ultimatedesi
    ultimatedesi Member Posts: 7
    Hi Zman,
    Thanks for the review and comments. I have at most 5 loops per zone. I would put the circulators for zone2 and zone3 near the tank and take the lead to the manifold after that.

    I would like to understand your other comment please: "I think you are doing primary-secondary on top of the primary-secondary." Seems this happened because I added a circulator to the primary circuit. Not sure if I understood comments from hot_rod earlier. The boiler circulator would suffice to run the primary circuit and hence there is no need to add another circulator?

    @hot_rod - can you please suggest if I misunderstood your comment?

    Thanks again you guys for your help with the review and change suggestions/comments.
  • Zman
    Zman Member Posts: 7,009
    The purpose of primary/secondary is to give the boiler the minimum flow it requires while letting the zones and mixing valves do their own thing. The zones may need more flow than the boiler at times and very little or no flow when the mixing valves are throttled down.
    When you add that loop in the middle, you are just whipping water around in a circle for no reason.

    Unless you have super long loops, the 26-99 is way bigger than you need. You also don't need a variable speed circ for the zones. A regular 15-58 would work well. If you prefer ECM, maybe a simple Taco 007e.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • hot_rod
    hot_rod Member Posts: 15,065
    common primary secondary piping options. Any one of these could have mixing devices plumbed into them also.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream