Best Place to install balancing valves

stuman

I have the primary side now all done, using a Boiler feeding into a low loss header.
On the secondary side I have 1/2 " pex staples on the plywood on the first floor. There are 4 loops, all different lengths. To balance the flow and have even floor heat, where should I place the manifold with the small valves, on the pressure going into 1/2" pex or on the return side and which would work better ?

Zman

The return side works better.

stuman

Is there a reason or just your personal recommendation ?

GroundUp

Almost all premade manifolds have the flowmeters on the supply side (which are also the balancing valves most of the time), and the shutoffs on the return. Flowmeters will not operate on the return, as there is no venturi effect. The shutoffs can be used as balancing valves, but their actual purpose is only a shutoff.

Zman

You see folks put them in either location. I agree with this way of thinking. http://www.haysfluidcontrols.com/blog/benefits-of-installing-balancing-valves-on-the-return-side-of-coils/

The venturi exists anytime there is flow. I have observed that the valves are easier to adjust and are not as prone to erosion wear when they are on the return.

stuman

thks for explanation....I will put them on the return,also trying to save a few bucks

GroundUp

Zman said:

You see folks put them in either location. I agree with this way of thinking. http://www.haysfluidcontrols.com/blog/benefits-of-installing-balancing-valves-on-the-return-side-of-coils/

The venturi exists anytime there is flow. I have observed that the valves are easier to adjust and are not as prone to erosion wear when they are on the return.

Pipe a set of radiant manifolds backwards and let me know how good the flowmeters work. Spoiler: they don't.

stuman

like putting in a check valve backwards...

Zman

GroundUp said:

Zman said:

You see folks put them in either location. I agree with this way of thinking. http://www.haysfluidcontrols.com/blog/benefits-of-installing-balancing-valves-on-the-return-side-of-coils/

The venturi exists anytime there is flow. I have observed that the valves are easier to adjust and are not as prone to erosion wear when they are on the return.

Pipe a set of radiant manifolds backwards and let me know how good the flowmeters work. Spoiler: they don't.

That would be because they are designed to be directional.
@stuman do you have a specific product in mind or is your question general in nature.

stuman

general questions before starting to pipe secondary side and thks for information

stuman

Another question is do I need need valves on both supply and return to balance system, is there any advantage to piping on both ? Would this make it easier to remove air from branch

Big Ed_4

Use reverse return piping on the manifold first then use the balance valves to fine tune ....

dopey27177

I agree with ZMAN And Ground up.

Another feature is keeping a higher pressure on the inlet of the zone assures there will always be better circulation in that zone. Higher pressure always go to the lwer pressure side of the zone.

Jake

GroundUp

Are you planning to use a premade manifold set and are wondering which way they should be piped, or are you planning to use tee style manifolds with external balancing valves? The way the original question was worded, I understood that you had a premade set in mind and were wondering which (supply or return) side the balancing valves were supposed to be on. If that's the case, the side with the flowmeters (typically glass globes with plungers inside to show flow) ALWAYS goes on the supply side. The flowmeters will NOT work at all if they're on the return manifold. The flowmeters almost always double as balancing valves, so again, the supply side is where they belong- the knobs on the opposite manifold are just shutoffs though could be used for balancing purposes. If you're building manifolds out of tees or using copper log manifolds or something similar, then yes the balancing valves should be on the return. Having a means of isolation on each loop is always a good idea, no matter what. Both for purging air and potential future service, the ability to completely isolate each loop separately is a valuable option. Reverse return is completely unnecessary if you have balancing valves

stuman

I'm looking at making my own using copper tees for the supply side and premade with valves on the return side,sound like it would be good idea to have valves on the supply side too.Sounds like a great idea to be able to isolate each loop awhile....will do that as well.

GroundUp

Copper manifolds with 8 shutoffs and 4 balancing valves are likely going to cost a whole lot more than a basic stainless or brass manifold set which already includes both as well as flowmeters, isolation valves, drains, unions, and thermometers. Is there a particular reason you want to make them yourself?

stuman

Thinking.... it would be cheaper to make the unit yourself. Want to keep them very simple as well.

GroundUp

You can buy a set of SS manifolds with everything you need for less money than you can buy the 4 balancing valves alone. And they'll perform better, look better, and be simpler than nearly anything you could build.

stuman

thanks for all the useful info , I have ordered a SS manifold.