monoflow system

Phil_6

http://www.heatinghelp.com/heating_howcome3.cfm

Phil_6

monoflow system

I was looking at a job the other day with a steel pipe monoflow system. The main zone is split into two 1-1/4 loops, one for each side of the house, each with maybe 5 sunrads. Everything is feeding through a Honeywell 1" regular zone valve with an Armstrong s-25 circulator on the return.On the side with the bedrooms, the last room is over the garage and the two radiators in there get the water last and don't really get that hot. No suprise there. My question is will a zone valve with a larger port increase the flow enough, should we change the circulator also, or should we just repipe the boiler and take that zone off with it's own circulator and flow valve (like I'm sure it was when the house was built) I'm seeing a lot of messed up monoflow systems lately...what a shame..

Weezbo

something is different about that system...

do you have an extraodinary size home ? really leaky ,lots of glass,no crawl space, uninsulated floors ,under ground walls ,not much insulation in the celings? monoflow systems with inch and a quater with individual take offs for each emmitter and two loops.... every emmitter should be working like clockwork. maybe something is blocking flow thru the boiler on the return...look see if there is mud in it ....

Phil_6

the only difference

between this system and one that should work that I can see is that some previous person installed these zone valves on the system when some additional rooms were added on years ago and I doubt the main zone worked right since.

It's just a basic builder type house from the 50's with a garage on the basement level under the master bedroom. That's the room that gets the coldest since it's over the garage and the darn radiators in there are last on that side of the loop and don't get very hot, maybe 115 deg on the last one.

Uni R

H-O-O

Home-owners opinion...

If it is just that last bedroom that is cold, I would first try a different circulator. That Armstrong can't handle much head and have good flow and those ZVs aren't helping. Monoflos need good flow. I'd also look at insulation between the garage and the bedroom and see if the heat loss could be minimized there. The other thing you could possibly do is pipe directly through that last rad if it is 3/4" HWBB or do dual 3/4" paths.

Phil_6

update

and thanks for the input. We changed the zone valve to a full flow type and installed a more robust circulator and those suckers are cranking now :-)

Water-Lou Mancusi

Monoflo Tees

Hello!
I have some specific questions regarding the exact placement of the tee. Is there a minimum/maximum distance that should be maintained on the basement loop between monoflo tees on the same radiator? Is there a minimum/maximum distance on the basement loop that should be maintained between the outlet of one radiator and inlet of the next radiator? Should the monoflo tee be used on both the supply and return of the radiator risers? Is it wise to use just one monoflo tee on the supply riser with a standard tee on the return? Is it wise to use just one monoflo tee on the return riser with a standard tee on the supply riser?

Water-Lou Mancusi

Thank you, Phil!

I want to thank you personally for your help. I'll be buying another of Don's books.