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Should manifold be on second floor?

Krash
Krash Member Posts: 17
New to forum, so Hi to all!

I am building a two story home in the mountains at 8,000 feet. The house will have hydronic heating. My boiler room is on the ground floor which has my pex loops in the concrete floor. The second story will have staple up pex with Aluminum radiant panels. The system has 8 loops with 2 zones initially, covering about 2100 sq. ft. total.

I am a little concerned about removing air out of the second floor of the system with its manifold on the ground floor. I can easily place a manifold on the second floor, and wonder if I should in order to make bleeding the system easier?

I have no reason to place the manifold on the second floor other than the bleeding of the air out may be easier. If bleeding is just as easy with a manifold 5 feet under all the pex tubing, I would prefer to keep both manifolds in the boiler/mechanical room.

Opinions?

Comments

  • As far as air bleeding, a manifold in the basement will be fine. Just make sure you install a proper purge assembly in your piping. 
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • RodHot
    RodHot Member Posts: 22
    I assume each loop would then be 10 feet longer if you place the manifold in the basement. How many loops are you anticipating on the second floor. Not sure details of your layout, but placing it on the second floor might be easier.
  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    I'd be putting the manifold on the 2nd floor and make sure it has venting port(s). I'd also make sure it is piped with a 2nd temperature because the slab temp requirements will be much lower than the staple-up.
    JUGHNE
  • TAG
    TAG Member Posts: 755
    Have you done a heat load and matched the plate system to the load needed ?

    I was able to get my output closer using the heaviest extruded plates to the other types in the house.

    need to know the water temps
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited December 2020
    When installing the manifolds on the second floor, provide a drain pipe near the manifold purge valve. Make up a clear vinyl hose with a connection to the purge valve that will reach the dedicated drain pipe near the manifold. This will facilitate purging operations as needed on commissioning and subsequent maintenance/repair servicing.

    The drain can exit to a storm drain or to the lawn unless you plan of using antifreeze or chemicals that are not environmentally friendly.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • Krash
    Krash Member Posts: 17
    RodHot said:

    I assume each loop would then be 10 feet longer if you place the manifold in the basement. How many loops are you anticipating on the second floor. Not sure details of your layout, but placing it on the second floor might be easier.

    4 loops up, and 4 loops down. Yes, the staple up loops are a few feet longer each when the manifold is in the basement.

    I'd be putting the manifold on the 2nd floor and make sure it has venting port(s). I'd also make sure it is piped with a 2nd temperature because the slab temp requirements will be much lower than the staple-up.

    This is will absolutly be done.

    When installing the manifolds on the second floor, provide a drain pipe near the manifold purge valve. Make up a clear vinyl hose with a connection to the purge valve that will reach the dedicated drain pipe near the manifold. This will facilitate purging operations as needed on commissioning and subsequent maintenance/repair servicing.

    The drain can exit to a storm drain or to the lawn unless you plan of using antifreeze or chemicals that are not environmentally friendly.

    Great advice. My boiler room is right in the middle of the house as is the main stack. That should make this very easy.

  • JUGHNE
    JUGHNE Member Posts: 11,042
    I have one of each;
    Tube in slab on grade, manifold in basement with floor drains.
    Tube in basement floor with manifold 2' above floor also with floor drains.
    Tube under bath floor and in walls, manifold in closet of bath, tub for draining purging. Iso and purge valves in basement for that manifold and also repeat at manifold. But purging in basement was enough for that system.

    Under wood floor and in walls have the heavy aluminum plates.
    More than needed tubing installed allows the system to all run at the same temp and heats well.
  • Krash
    Krash Member Posts: 17
    I am not convinced I want to spring for the extruded aluminum plates, and will probably go with stamped omega plates.
    kcopp
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    Krash said:

    RodHot said:

    I assume each loop would then be 10 feet longer if you place the manifold in the basement. How many loops are you anticipating on the second floor. Not sure details of your layout, but placing it on the second floor might be easier.

    4 loops up, and 4 loops down. Yes, the staple up loops are a few feet longer each when the manifold is in the basement.

    I'd be putting the manifold on the 2nd floor and make sure it has venting port(s). I'd also make sure it is piped with a 2nd temperature because the slab temp requirements will be much lower than the staple-up.

    This is will absolutly be done.

    When installing the manifolds on the second floor, provide a drain pipe near the manifold purge valve. Make up a clear vinyl hose with a connection to the purge valve that will reach the dedicated drain pipe near the manifold. This will facilitate purging operations as needed on commissioning and subsequent maintenance/repair servicing.

    The drain can exit to a storm drain or to the lawn unless you plan of using antifreeze or chemicals that are not environmentally friendly.

    Great advice. My boiler room is right in the middle of the house as is the main stack. That should make this very easy.

    You can hit the LIKE (or AWESOME in my case) at the bottom of our comments.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    Krash
  • TAG
    TAG Member Posts: 755
    Krash said:

    I am not convinced I want to spring for the extruded aluminum plates, and will probably go with stamped omega plates.

    It's a question of getting the output at a given water temp --- your slab is going to need the lowest temp water. The water temp for some of the retrofit systems can be quite high ... using the heavy plates got the output up and the water temp down.

    How are you lowering the temp water to the slab
  • Krash
    Krash Member Posts: 17
    To be honest, I hadn't considered a different temp for the slab and under floor. I was just going to use one temp and adjust the cycle time with the thermostats. Something in the 100 degree range, give or take. I guess I have a little more research to do. Thanks!
  • TAG
    TAG Member Posts: 755
    Krash said:

    To be honest, I hadn't considered a different temp for the slab and under floor. I was just going to use one temp and adjust the cycle time with the thermostats. Something in the 100 degree range, give or take. I guess I have a little more research to do. Thanks!

    Google around and you will see the differing max outputs of the various types. From staple up w/o any plates -- to the difference between the two heavy kinds of extruded. You need to do a heat load on your building to make sure that the type you pick can even deliver what you need .. obviously staple up w/o plates has the lowest output with the hottest water.

    I'm rebuilding a fire damaged church conversion --- it's a property I have owned for many years. Anyway -- The upper most floor of the building is the 900sf living room ... not damaged in the fire so we left it in place. After doing a heat load for that space and looking at the water temps needed -- it was close enough to the rest of the buildings radiant to make it work.

    It's only been working for a few weeks -- but -- so far with temps in the 20's it working well and balanced.

    You can always use mixing valves to get the different temps.

    I have 4 manifolds -- we ran 1.25" copper pipe about 30' for two remote ones -- two are with the boiler in the mechanical room
  • GW
    GW Member Posts: 4,691
    edited December 2020
    Radiant control- the Wild West. You’ll get comments all of the spectrum. You have the low end “fixed mix”, “on-off” controlling to higher end “constant circulation”, “modulating mixing” controls. 

    There’s pros and cons to everything. 

    Manifold upstairs- you need two people to “fast feed” the purging process (or just feed slowly, just takes more time). As stated you need to deal with the water you’re  purging too. 

    Manifold downstairs- now all your closets are normal upstairs; you have quicker access to your feed valve. You don’t need to run a hose or carry buckets from the second floor. 

    Either choice is fine, flip a coin 😊

    I recently activated the slab heat in my basement project after many years. It’s not fully functional yet (not eager to spend the money!). I have a Tekmar 3 way mixing valve simply knocking temperature down from the “above the wood sub floor” radiant system in the main living level. The basement system is piped off a main boiler loop with “close-spaced tees”, as is the main living level (main living level is pimped out with Tekmar modulation/mixing) 

    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
    Krash
  • psb75
    psb75 Member Posts: 828
    You'll regret not using the extruded aluminum plates. Don't use the 'beer can' stuff. Keep all manifolds in boiler room. Absolutely no problem, filling and bleeding loops that way if you have proper manifolds. Why, remote manifolds? No advantage.
    BillyOkcopp
  • BillyO
    BillyO Member Posts: 277
    I used to put manifolds remote, now only in boiler room. Such a hassle purging and repairing in customers closets. Great idea when under construction with no clothes, boxes, bags, shoes etc.... . Just my opinion
  • TAG
    TAG Member Posts: 755
    agree with the remote manifolds ... If possible keep them together in a place where purging and maintenance is easier. It's just not possible in some situations. In my case it would have added at least 65 feet to each loop on the one and we had no space for the PEX. The plates used 3/8 tubing and I was already at 11 loops on that one and it another 5' away ......

    You have to give some thought about future maintenance --
  • Krash
    Krash Member Posts: 17
    So, it seems the general consensus is that keeping the manifold in the boiler room on the lower floor will present no problem for purging the air from the system. That being the case, that is what I will do.

    As for the aluminum plates, I will think about thick extruded vs thin stamped.

    Thanks to all for the great responses.
  • GW
    GW Member Posts: 4,691
    Cool

    and, the more R value your floor has, the more money you want to spend on heat transfer plates. Floor insulation is key also of course 
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • TAG
    TAG Member Posts: 755
    picture of mine with the heavy plates -- We used the 3/8 tubing on advise from this forum. The 3/8 required more loops as they need to be under 200' ... but it's much easier to work with when retrofitting
    KrashBillyO
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 3,979
    edited December 2020
    The main reason to have a remote manifold is for the convenience of keeping the loop tails as short as possible. The disadvantage shows up when the manifold needs servicing.

    And how often have you gone to a new customer's house where they have no idea where the manifolds are and all the closets are loaded to the gills with stuff they don't need and the only way to find the manifold is with an infrared camera.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    BillyO