Whats the problem

Tom_10

with having cast iron sun rads on a monoflo loop along with two separate zones of fin tube. Zone valves operate all. Full port 1" zv for indirect. Three zones in all for heat and a zone for indirect tank. Can I expect a problem of some sort? I'm being told not to "mix" the two(iron and fin tube). Is there a downside here? Thanks in advance guys.

Bill NTSG

In your situation....

probably not a problem. In some cases when the fin tube and the C/I are on the same zone , the fin will heat up quickly and cool off quickly, where the cast iron will radiate warmth long after the fintube is cool. It could cause uneven temperatures in some applications. Other than that....... . Four zones off the same mono-flo loop? Are the zones really necessary ? Hey, just asking , I was never there, just curious.

Steamhead

Zone flow will vary

depending on how many zones are calling at the same time. This is why I prefer an individual, properly-sized circ for each zone. With a single circ sized to run all zones at once, and only one zone calling, that zone may be noisy. If the circ is not big enough, you may not get enough heat in all zones if they all call at once.

Of course, it's more expensive to provide an indivudual circ, flo-check and relay for each zone. But the results are worth it.

Each zone should have all the same type of radiation (fin-tube or cast-iron). They should all be sized to use the same water temperature, or you'll need to provide different temps to different zones.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

[Deleted User]

If ya wants to mix it up....

the least you can do is use the same NETRV on each individual branch and set it up continuous circ with outdoor and indoor reset.

The rooms will be at what ever temperature you set them for. However, the MRT will be affected differently and that will be noticeable. You could end up with a "cold 70" syndrome.

Thats what one pipe was designed for. Good steady MRT..

ME

P.S. Saw Siggies new software for analyzing these kind of things this week. Can't WAIT to get my hands on a beta copy of that. In this case, I'm sure that the pressure drop when all circuts were calling will be less than when they're not. That's the way THEY were designed...

M

Tom_10

Its laid out like this

first floor just re-done. Used 5 new properly sized for each room sun rads. Had an outdoor porch on a concrete slab which was turned into an indoor bedroom addition. Could not reasonably get piping to the outside wall without a major problem so made that is own zone w/ 3/4" fintube. Third zone is the indirect. The fourth zone, for now, will be fin tube on the second floor because at some point in the next two to three years, the top will be ripped off in favor of a second story addition. At that point it will also be cast iron rads.Just not now. Just need to get all zones "on the same page" for now with regard to temp/flow rate ect. Will it be impossible? I don't see this as a problem, but rather a challenge. Should I be using some sort of TRV's?