# can someone explain why monoflow systems are used?



## 907plumber

Ive been doing a little research on monoflow systems. I get the jist of how they work, but I see no reason to use them over the simplier one pipe method.

I have only seen one monoflow system in the field and I wasnt there to work on it.

I have a call tommorow. A guy ran 3 floors of monoflow baseboard heat and its all on one zone. He wants it in 3 zones now. 

Ill take pics of the job and repost once I see it.


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## incarnatopnh

Have fun with that just had to re zone a monoflow system myself. Nice idea until you have to re zone it. Just takes a little more thinking.


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## BROOKLYN\PLUMB

Its done so that you can isolate a single rad and not shut down the loop. Also I believe it is a more even heat as the rads should get hot about the same time (at least on the same floors).


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## OldSchool

MonoFlow systems are one of the best ways you can do hydronics.

Each tee has a diverter that forces the water to the side outlet... one is installed each for the supply and return both in opposite directions...this way the water is forced up into the rad and the return of the rad is diverted into the main loop...

very seldom will you get air locked in the rads with this type of system...

The whole idea was that each rad can be turned off or throttled to control flow and heat in rad individually and it would not affect the main loop.


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## 907plumber

Well I told dude I would install whatever he wants where he wants it. It's going to involve zone valves at each room installed at the baseboard. I told him I would just work by the hour. I'll guarantee against leaks but that's it. He called me back today and I got the job.


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## Scott K

What about thermostatic radiator valves? Or does he want true thermostat control?


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## 907plumber

yeah he wants a zone valve right on the baseboard element controlled by a thermostat on the wall.


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## RealLivePlumber

907plumber said:


> yeah he wants a zone valve right on the baseboard element controlled by a thermostat on the wall.


And you're gonna get rid of the monoflo system?:blink::whistling2::no:


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## 907plumber

RealLivePlumber said:


> And you're gonna get rid of the monoflo system?:blink::whistling2::no:


no, he said he has a bypass loop under the register. So when the zone is closed it will just go through pipe under the floor and continue on to its way to the other rooms. I would think that would be alot of resistance for the system. But it is heating his house right now.

I saw on a different site http://www.comfort-calc.net/monoflo_system.html where they had a diagram for zoning the registers and they were recomending 3-way zone valves. I drew out that diagram for him but he said thats what hes got. But that is why I told him I want no part in any of the responsibility for a system he designed and half installed. I still dont understand what he wants me in there for. Im kind of regretting accepting the job. But work is work I guess


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## bikefitter0

need to know what kind of rads, how many on each floor. you might think of repiping 3 seperate series loop zones in the basement , thats probly the only access you have.


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## bikefitter0

me again, a zone valve would have to be three way. or you would restrict the flow to the rest of the system. thermostatic would be same problem


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## mtfallsmikey

RealLivePlumber said:


> And you're gonna get rid of the monoflo system?:blink::whistling2::no:


Yeah, really....unless it was installed by a hack/dork, it's hard to beat a good 'ole Monoflo system. I would go w/TRV's, if anything.


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## Protech

I've got a question for you 907: how di you guys keep everything from freezing up there? Drains and potable that is. Also, how do you get well water and do drain fuelds when the ground us permanently frozen?


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## OldSchool

Protech said:


> I've got a question for you 907: how di you guys keep everything from freezing up there? Drains and potable that is. Also, how do you get well water and do drain fuelds when the ground us permanently frozen?


Feild bed and septic tank creates enough heat on its own to keep it above freezing


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## pilot light

Reverse Return, first in last out, last in first back!


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## GrumpyPlumber

Every fall, guaranteed, I get calls for Mono-flo systems with air-bound radiators.

Excluding myself from debate on "mono-flo's are good or bad", take from that what you will.


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## OldSchool

pilot light said:


> Reverse Return, first in last out, last in first back!


Some times you make me wonder.... Exactly who is teaching you this stuff

Sent from my miniature laptop


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## pilot light

OldSchool said:


> Some times you make me wonder.... Exactly who is teaching you this stuff
> 
> Sent from my miniature laptop


 Why?


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## OldSchool

pilot light said:


> Why?


Why .....

No really who is your mentor....

Sent from my miniature laptop


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## rjbphd

GrumpyPlumber said:


> Every fall, guaranteed, I get calls for Mono-flo systems with air-bound radiators.
> 
> Excluding myself from debate on "mono-flo's are good or bad", take from that what you will.


 That's because the hi vel pump(s) are on the wrong side of boiler... and if its a Junkirk boiler, you got problems, sir.. that's where my 'invention'of the air scoop nipple comes in.


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## pilot light

OldSchool said:


> Why .....
> 
> No really who is your mentor....
> 
> Sent from my miniature laptop


 What does it matter? I have had a few!


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## OldSchool

pilot light said:


> What does it matter? I have had a few!


It's because some of the things you say just don't add up some times

Sent from my miniature laptop


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## rjbphd

pilot light said:


> What does it matter? I have had a few!


 Ethier you are on or off a few meds.


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## pilot light

rjbphd said:


> That's because the hi vel pump(s) are on the wrong side of boiler... and if its a Junkirk boiler, you got problems, sir.. that's where my 'invention'of the air scoop nipple comes in.


 Air scoop nipple?


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## GrumpyPlumber

rjbphd said:


> That's because the hi vel pump(s) are on the wrong side of boiler... and if its a Junkirk boiler, you got problems, sir.. that's where my 'invention'of the air scoop nipple comes in.


This is only true when the balancing configuration on the venturi is set sideways on an airscoop that's engineered to purge both air and sediment, otherwise you use a torque wrench to re-balance the flux capacitor....or, you're saying you have a way to squeeze a can vent on a rad.

If you're scratching your head, relax, I was kidding...on the first part.


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## pilot light

OldSchool said:


> It's because some of the things you say just don't add up some times
> 
> Sent from my miniature laptop


 I dont know just call them like I see them. If i missed important points I am sorry will try harder for additionally clarity in the future.:thumbsup:


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## pilot light

pilot light said:


> I dont know just call them like I see them. If i missed important points I am sorry will try harder for additionally clarity in the future.:thumbsup:


 Yes monoflow system is the best I have 100000 monoflow tees from 1/2 inch to 3/4 to sell also 1 inch! If interested will send price list! WTF! :laughing:


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## BROOKLYN\PLUMB

pilot light said:


> Yes monoflow system is the best I have 100000 monoflow tees from 1/2 inch to 3/4 to sell also 1 inch! If interested will send price list! WTF! :laughing:


I'm curious, do you understand your posts??? Because I can't make heads or thermocouples out of them 

€¤¤{{  ¥& <¤¢|{{¤¢& ¤  €€  {] [{<& & > {¥¢~~~^°=¬\/¬/\


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## rjbphd

BROOKLYN\PLUMB said:


> I'm curious, do you understand your posts??? Because I can't make heads or thermocouples out of them
> 
> €¤¤{{  ¥& <¤¢|{{¤¢& ¤  €€  {] [{<& & > {¥¢~~~^°=¬\/¬/\


 Either he taking too much or not enough meds.


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## OldSchool

I think he is posting from some call center in India

Sent from my miniature laptop


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## GrumpyPlumber

OldSchool said:


> I think he is posting from some call center in India
> 
> Sent from my miniature laptop


:laughing:


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## pilot light

OldSchool said:


> I think he is posting from some call center in India
> 
> Sent from my miniature laptop


 No it is from Pakistan, which is north of India!:laughing:


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## rjbphd

pilot light said:


> No it is from Pakistan, which is north of India!:laughing:


 Somebody, blow his light out,please..


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## pilot light

rjbphd said:


> Somebody, blow his light out,please..


 Hey if you dont like me tell me the truth!


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## pilot light

rjbphd said:


> Somebody, blow his light out,please..


Tip#1: I have found that it is more safe to turn off the fuel supply than just blowing out the pilot! Thanks!


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## jackwilliams111092

OldSchool said:


> MonoFlow systems are one of the best ways you can do hydronics. Each tee has a diverter that forces the water to the side outlet... one is installed each for the supply and return both in opposite directions...this way the water is forced up into the rad and the return of the rad is diverted into the main loop... very seldom will you get air locked in the rads with this type of system... The whole idea was that each rad can be turned off or throttled to control flow and heat in rad individually and it would not affect the main loop.


 Contractors, please stick to making material lists, logistics/scheduling, and caring for your tools. Leave it to engineers for design. I worked for a good contractor out of engineering college for a few years (like 100 people) and thought I knew everything too. The world would be better and your still going to have your service calls. Mono flow is definitely not the best; maybe cheaper/faster. I only learned it from a low-end Residential contractor after a decade of professionally engineering mechanical systems in commercial and residential buildings, so I had to dig deeper on the topic. Mono flow in my opinion, is only good if your doing a FULL CIRCLE LOOP on a LARGE FOOTPRINT floor to save on piping. The zone pump and diverter tees would need to be PRECISELY BALANCED with NO LOCAL CONTROL valves. I wouldn’t even put the shut-off valves in plain sight. Not much room for errors. A little simple engineering principle: A) PARALLEL RESISTANCE IS MUCH LESS than a single path resistance. If you had a local control valve and SHUT OFF A RADIATOR (call it a terminal for simplicity), full flow through the diverter valve would cause a large pressure drop downstream and may disrupt the balancing of the downstream terminals. B) MIXING into a common header would cause the SUPPLY TEMPERATURE TO DECREASE as you go DOWNSTREAM. You can interpolate the effect of each terminal if you consider the initial supply temperature and the performance of the selected terminals. I’d you have many terminals on a loop, or a large terminal is towards the end of the loop, it could throw off the performance I. Those downstream terminals. Probably wouldn’t hurt a radiating baseboard but for some coils, it could greatly affect heat exchange performancefor a house, without too many terminals on one loop, it could work. Sorry for the caps, but we have to do that with lower end contractors who think they know everything but refuse to read anything, let alone research.


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## Lickitlikeafritter

A decade old thread and you’ve joined simply to bash plumbers. I’ve never been on a job that we could plumb it how the engineers drew it because of blatant mistakes, poor understanding of the real world, and just general stupidity on the part of the armchair quarterback who’s making $150k. Piss off @jackwilliams111092


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## skoronesa

jackwilliams111092 said:


> Contractors, please stick to making material lists, logistics/scheduling, and caring for your tools. Leave it to engineers for design. I worked for a good contractor out of engineering college for a few years (like 100 people) and thought I knew everything too. The world would be better and your still going to have your service calls. Mono flow is definitely not the best; maybe cheaper/faster. I only learned it from a low-end Residential contractor after a decade of professionally engineering mechanical systems in commercial and residential buildings, so I had to dig deeper on the topic. Mono flow in my opinion, is only good if your doing a FULL CIRCLE LOOP on a LARGE FOOTPRINT floor to save on piping. The zone pump and diverter tees would need to be PRECISELY BALANCED with NO LOCAL CONTROL valves. I wouldn’t even put the shut-off valves in plain sight. Not much room for errors. A little simple engineering principle: A) PARALLEL RESISTANCE IS MUCH LESS than a single path resistance. If you had a local control valve and SHUT OFF A RADIATOR (call it a terminal for simplicity), full flow through the diverter valve would cause a large pressure drop downstream and may disrupt the balancing of the downstream terminals. B) MIXING into a common header would cause the SUPPLY TEMPERATURE TO DECREASE as you go DOWNSTREAM. You can interpolate the effect of each terminal if you consider the initial supply temperature and the performance of the selected terminals. I’d you have many terminals on a loop, or a large terminal is towards the end of the loop, it could throw off the performance I. Those downstream terminals. Probably wouldn’t hurt a radiating baseboard but for some coils, it could greatly affect heat exchange performancefor a house, without too many terminals on one loop, it could work. Sorry for the caps, but we have to do that with lower end contractors who think they know everything but refuse to read anything, let alone research.


Just saving this for later....


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