TRV's and manifolds??

Dave_22

This may be a dumb question, but how important is it on panel rads with TRV's, in a homerun piped system, to have flow setters on the manifold? You could set initial flow on them, but the TRV's gonna modulate flow anyways. What do you guys do???? Thanks.

Mike T., Swampeast MO

Not dumb at all. As you suspect, no need. You only need to size your branch piping and TRV to the branch design flow and use just enough circulator power to overcome the headloss at your total system flow.

If you would use flow setters, you wouldn't set for flow--you would set them so that the head loss across each TRV branch is the same. (If all TRVs are the same size and all branch piping the same size, then identical flow in all loops would mean identical head loss.)

With Floor Heat Valves (FHVs)--well at least those from Danfoss--there is a built-in "flow-setter" for the express purpose of keeping head loss in all loops identical regardless of their length. VERY important with floors because you want to minimize the chance of overheating when you crank the operator. Without this adjustment it would be very easy to overheat shorter loops.

Mark Eatherton1

Could be a dumb question....

except there is no such thing as a dumb question, just dumb mistakes made by people afraid of asking what they perceive to be a dumb question...:-)

In all my years of doing this, I can think of 2 situations where we had to use the adjustments on the radiators. Both of them were short circuiting through the path of least resistance. The balance valves came in very handy. In most cases, the TRV's will be self balancing, but theoretically, when you get to design conditions, ALL the TRV's would be wide open, and then the fluid WILL follow the path of least resistance.

It's nice that they're there, but I wouldn't worry about adjusting them unless it becomes an issue.

JMHO

ME

S Ebels

Never used 'em

We've never used either the manifold circuit setter or the flow setter on the rad. In the instance that we have a huge difference in length we will remote mount a manifold out toward the "far" side of the building and reverse return betwenn the first manifold and the second. From there the TRV's have always done the trick. I wouldn't get hung up on it. You really have to have some seriously different lengths to stir up a problem.

Weezbo

I recognize that rad ! *~/:)

I really thank you for that post last month...My Buddy Fred is really tring to get to see the super cool rads ...I chirped up the track one you made and Fred is like into the sublime and easily catches real sharp ideas ..mostly he really has hisown line of thinking going on and i see many of his headers as Art he makes things that he figures will work one of his thoughts is to put in radiant floor and ceiling and use copper panels Kathy his wife makes cool stuff too *~:) shes electroplating and abead making person Sorta reminds me of a story book by herman hesse Glass bead game....

Mark Eatherton1

Copper Radiators...

I have one on the ceiling of my office. But to be honest, I wouldn't do it that way again:-) The copper sheet was bonded to the tubing by means of a copper epoxy. It came apart and lost good contact on over half of it's developed length. My next step will be to remove the coper sheet, install sections of extruded heat transmision plates, and then fasten the copper sheet to the aluminum plates usiing rivets.

Also, although pretty in appearance, the raw copper emmiter sucked at emmiting heat. I painted it flat white, and the output TRIPLED.

I'll see if I can dig up soome photos some place.

There was actually a company in Bellvue Washington that was going to make an all copper heat transmision plate/tube assembly. THey shipped me some for testing up at the college. Seemed to work reasonably well. Copper Cricket or Copper Wings, or Hot Wings or something like that.. They frequented the Wall, maybe they'll drop in a post a photo.

If you can imagine it, it can be done...

ME