"Seeing" Inside an Over-pumped Radiator

icesailor

Hot Rads:

Steamhead,

One of these days, you will have the opportunity to put that Taco 4-way valve in a system and see what I am saying.

What did they say in Plumbing class? Oh I remember, it takes a 7 12 degree rise in temperature to cause circulation.

The hotter the water, the greater chance for striation. It gets back to Mark Ethertons lazy former Brother In Law. I'll bet you a 30 pack (I don't drink) if you  dropped the system temperature to 130 degrees, when the system is cold, it would mix fine and the whole radiator would get warm/hot at once. Like what happened to me when I installed one in a converted/pumped gravity system and EVERY RADIATOR in the whole house got warm at the same time. No matter how far away from the boiler it was. I have been there on numerous times since, and I never see the system running at over 130 degrees. And that was on a day when it was 10 degrees out. It is usually running at 120 degrees.

If you could, go back there and turn the limit down to 130 and let it run. I'd be curious to see. You won't get condensation with the 4-way valve because you can set the system return to the boiler to either 120 degrees or 140 degrees with a DIP switch.

The valve ends up becoming the boiler and controls the system temperature. It doesn't give a dog dropping what the boiler temperature is, as long as the water coming from the boiler and back to the boiler is above the set point. It diverts it back into the system to stop condensation. When the boiler is over the set point (you could have it set for 170 degrees), the system will always be set for the ODR temperature. And the boiler on a call is at the set-point of the high limit.

icesailor

Stacking:

Also, isn't one of the biggest problems with oil fired tank type water heaters a problem called "Stacking"?

I've solved that problem by putting return circulation into the bottom of a heater.

Steamhead

If we can show fuel savings on that job

with the work we've done- and I think we can- the owner might go for more. We'll see. I wouldn't want to put reset on that system without some form of mix-down to keep the boiler from condensing.



The pipes on this job are not insulated either. I'm going to recommend doing that next. That's a no-brainer.



Can you take some pics of that job you mentioned and post them? Also would be interested to know how much radiation it has, what boiler it has and what circs you used.

SWEI

piping the rads

Top set is piped bottom to bottom like a steamer.



Bottom set is piped top & bottom on the same side.



Any reason why they wouldn't pipe bottom to top diagonally like a modern panel radiator is installed?

Steamhead

On a gravity system

the circulation is so gentle it probably didn't matter. We usually find rads connected top-and-bottom in bedrooms so the valves are easier to operate.

Steamhead

Radiator Warming Up

Got these today as we started up the system- converted gravity where one set of mains is 4-1/2" pipe (!) and this 3rd-floor rad had been turned off. I turned the valve on and got this warm-up sequence. The system has 1479 square feet EDR (sunroom rads were removed and the kitchen is now on a separate loop) and a new Grundfos UP-43-44-F pumping it at 50 GPM or so.



The "rest of the story" on these rads is here:



http://www.heatinghelp.com/forum-thread/140986/Our-First-Solaia-Commercial-Beckett-CG-10-Install

Steamhead

Air-bound Radiator

This room was originally two small bathrooms and was re-configured as one large one, which is why it has two radiators. In the first pic, the one on the right has some air at the top, while the one on the left is full of water. I bled the one on the right, let the flow normalize and got the "after" image.