Radiant Heat custom manifold with spaced out T

DrVit

Question to pro radiant heat installers - would system work if instead of doing home runs for loops to one location manifold, I will use a 20' of 3/4" copper on one end of the wall for supply, another 3/4" on another side of the wall for return, cut T's for each section of 200-250' of loops, and use valves on each run for adjusting water flow?

billtheplmbr3845

Yes, but do a reverse return. First supplied last return. Also depending on the amount off loops being connected, make sure you can get enough g.p.m and btu's thru 3/4", you may have to change the mains accordingly

ch4man

remote manifolds are done all the time.

GroundUp

billtheplmbr3845 said:

Yes, but do a reverse return. First supplied last return. Also depending on the amount off loops being connected, make sure you can get enough g.p.m and btu's thru 3/4", you may have to change the mains accordingly

In most cases, reverse return kind of defeats the purpose of what I think he's trying to do. I should already have an answer to this but I don't so I'll ask you; why?

I've got an underfloor system done in the manner the OP is describing, in a direct return fashion. It took some time to get balanced, but works perfectly since. When reverse return is not an option, we go to plan B right?

DrVit

Attached is the design I've had in mind. I'm assuming reversed returns are for balancing out water flow? I was thinking about having valves on each loop so I can balance out flow if that's a case.

Also, radiant I'm doing is purposed just to have warm floor for a comfort. I have existing baseboard heat to supplement BTU if radiant will not be sufficient. Based on layout of the open space in basement - I'm planning to do 5 loops totaling about 1200' of 1/2" Pex. Was planning to use 1 mixing valve, 1 pump, 3/4" headers, and just one Tstat. Do adjustments mostly with valves on loops if needed. Hope this idea is workable.

hot_rod

Here is another piping and mixing that would allow outdoor reset on the high and low temperature zones, plus boiler return protection with proper mixing device.

Pipe it this way and ODR could be added later.

Your drawing for the radiant is correct, first loop supplied is last returned.

Zman

That type of header arrangement will work just fine with balancing valves or reverse return.
1000 sq/ft at 8" centers will take more than 3 loops, probably 5 loops at 250'-300'.
Be sure the mixing valve is designed for radiant,
I don't understand the near boiler piping.

Gordy

Looks like near boiler piping is doing the high temp baseboard, and the radiant is taking off of that with mixing valve.

How will this be controlled? One or the other? Both together? Or radiant with baseboard as supplemental when temps drop?

If I understand correctly you want to run both together?

DrVit

Thank you guys for your inputs !
Near boiler diagram is just a schematic to show existing heating. Which is 1" supply line branching out as it goes, and separate returns with zones valves. I have attached a photo of the space on the wall where I was thinking of connecting mix valve and pump. With cutting into 1" pipe to get hot and using one of the existing stub outs on return. There is no primary/secondary, no outdoor temp controls - just basic boiler install.

- was thinking about coming from mix valve with 3/4 copper, T-out for first 2 loops in one direction ~ 250-280', then supply 3/4" to another spot for 2 loops (they will be under floor with transfer plates), and 1 last loop ~ 180' will be above floor in bathroom with transfer plates under tile (sleepers, transfer plates, durok, tile).

- system will be used along side with existing baseboard heat. Purpose is to add a comfort of warm floor to walk barefoot. So what ever heat loss needs to be supplemented - existing baseboard will be a backup.

I'm figuring 3/4" copper for supply would be sufficient?
Also I was thinking just using 1 mixing valve and 1 pump, and put everything on 1 T-stat. Do adjustments with valves on loops.

Also, any suggestions for possibly prefab 2 ports 3/4" x 1/2" pex valves? Not sure if I should just custom build, or buy some prefab copper-to-pex valves.

Also if I need to add some kind of flow meters, gauges, etc on each loop for "scientific" adjustments, or just use basic valves and adjust based on comfort level.

P.S. Side question - is there a way in this forum to get notified when someone is posting a comment? Like email notification?

Thanks for all of your help !

DrVit

Also - as far as T-stat - what kind of solution would you recommend?
- floor censors or wall T-stat?
- any particular brand? My brother (its his house I'm helping him with) likes Nest T-stat. I doubt they have floor sensor, unless it can be wired in somehow
- put say outdoor sensor and turn on when winter is here and off when summer comes? And just adjust flow so floor is not too hot?

Gordy

You'll have to rethink a new SWT to the baseboard. Possibly the same as floors. Otherwise the baseboard will satisfy the tstat before floors warm. All you are doing is adding more emitter to the system which is already able to carry the load I'm assuming. All you want is the neutral floors?

I'd recommend the floors as the primary emitter, and baseboard as secondary when floors can't carry the load. This way you always benefit from the floors.

rick in Alaska

Right next to the title of this post, Radiant Heat custom manifold with spaced out T, is a "star". Click on it and it will highlight yellow, and then you will be notified if anyone posts any more comments.
Rick