Monoflow Continuous Circulation System

Re: Monoflow Continuous Circulation System

PostBy: Sting On: Tue Dec 29, 2009 12:55 pm

hummmmm

Slow the flow

What a novel idea :D

Thank-you Greg -- I reference that web site a lot, but your far better versed in its assets.

Would you offer some incite to Catskills issue also?

Problems Maintaining Water temperture.
Sting
 
Other Heating: BurnHAM=NG-gas

Re: Monoflow Continuous Circulation System

PostBy: Rick 386 On: Tue Dec 29, 2009 2:11 pm

Oh Stinger (You figment of the internet),

As soon as I have time, I'll be posting a full blown report with pics of the conversion that we just did in our Masonic Lodge heating system. I still have to get all of the pertinent details from the plumber so that I know what was done. We converted from a steam heat 1 zone building to a brandy new Peerless gas fired hydronic system. It utilizes the latest controls and supplies that varying water temp and varying flow thingy you mentioned in this thread.

This thing is cool to watch operate. There are 2 seperate burners - 1 @ 50-100K and the other that will fire up to 1,000,000K as needed.

I even learned all about the delta T as the control in pic 3 will display it.

Some teaser pics here:

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Rick
Rick 386
 
Stoker Coal Boiler: AA 260 heating both sides of twin farmhouse
Hot Air Coal Stoker Stove: LL Hyfire II w/ coaltrol in garage
Coal Size/Type: Pea in AA 260, Rice in LL Hyfire II
Other Heating: Gas fired infared at work

Re: Monoflow Continuous Circulation System

PostBy: brckwlt On: Tue Dec 29, 2009 3:05 pm

gregolma wrote:I hate to chime in so late, but I just finished reading the thread.

First of all, ...



Maybe im ignorant, but Why would it matter if i did what u mentioned and had the flow chocked so it flowed very slow ... because if im pumping 180 degree water very slowly to my rads wont it heat the same way 180 degree water pumped a lot faster does? and isnt there more chance for heat loss in the heat pipe if the water is moving slower through out the basement and house then if it is moving really fast? Another point would be when it is not really cold if i run the water continuously like u mentioned i would have to lower the water temp a lot, and that might mess with my DHW coming from the boiler.

Im not trying to argue with you, but i have no knowledge of plumbing, especially when it comes to this old stuff. just trying to understand ...
brckwlt
 
Stove/Furnace Make: Axeman-Anderson
Stove/Furnace Model: Rebuilt 1953 AA-130


Re: Monoflow Continuous Circulation System

PostBy: Rob R. On: Tue Dec 29, 2009 3:08 pm

gregolma wrote:I hate to chime in so late, but I just finished reading the thread.

First of all, this is not a monoflo system. It predates monoflo by decades. Dan Holohan of heatinghelp.com has some info on this situation in this article:

http://www.heatinghelp.com/article/17/Hot-Water/72/Gravity-Hot-Water-Heating
This link is broken, either the page no longer exists or there is some other issue like a typo.


Here is a fitting: Image


I thought the same thing when I started reading through this thread, but when he posted a picture of the main and a radiator supply/return it showed the supply and return going to separate tee's several feet apart.

View: New PagePopup


Have you see single pipe gravity systems setup this way? It would be nice to see what the fittings look like, but I can understand not wanting to mess around with the old insulation.

A friend of mine has a big 3 story house with a converted gravity system, like yours it has a combination of 6" and 5" piping. It runs with a very small circulator, a boiler bypass, and 1" piping connecting the natural gas boiler to the old iron mains.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Monoflow Continuous Circulation System

PostBy: gregolma On: Tue Dec 29, 2009 3:21 pm

Monoflows use fittings that essentially scoop the water out and redirect its flow. Here is a section of Holohans article that explains the system.
http://www.heatinghelp.com/article/17/Hot-Water/72/Gravity-Hot-Water-Heating
This link is broken, either the page no longer exists or there is some other issue like a typo.


The old one pipe gravity uses gravity and the fact that hot water rises to effect circulation. [Q: Were there other types of gravity systems?
A: Yes. If the original owner of the home went first-class, he would have installed an overhead gravity system such as this one.
Overhead_Gravity


Q: How does the overhead system differ from the upfeed system?
A: In the overhead system, water goes first to the attic (or to a main suspended from the top floor ceiling) and then feeds down to the radiators. Because this "express riser" is very large, it offers less frictional resistance to the water. As a result, the hot water moves more quickly from the boiler to the radiators than it would in the upfeed system.

Another plus is the way the cooler water pulls the hot water through the radiators as it falls down the return risers. This force counteracts the effects of friction and makes the radiators heat faster. As a result, an overhead system generally costs less to operate.

Q: Is this type of system easier to vent?
A: Yes, much easier. In fact, because of the way the radiators are connected to the mains, you don't need radiator air vents with this system. All the system air vents automatically through the attic tank. It doesn't take long to fill this system either, and you don't have to worry about spilling water all over the floor while venting, as you do with the upfeed system.

Q: How did they pipe the radiators into the mains on this system?
A: They always used top and bottom connections. They could enter the top on one side of the radiator and leave through the bottom on the opposite side, or they could enter and leave through the same side. This second method saved a riser which made for a less-expensive installation.

Q: Didn't they need special fittings to make this work?
A: Yes. They had to divert water through the radiator. To do this, they used a special type of tee. Here's a picture of one.
Image

Q: What did they call this tee?
A: They called it an "O-S" fitting after its inventor, Oliver Slemmer of Cincinnati, Ohio. It was a beautifully simple device.

Q: Is this similar to a "Monoflo" tee?
A: It is, but the O-S preceded the Monoflo by many years. During the 1930s, the Bell & Gossett Company introduced their "Monoflo" tee (the name is a trademark). It went on to play a big part in American house heating during the years before World War II.

Q: Do these special tees "tell" the water where to go?
A: In a sense, they do. They create a path of least resistance for the water and direct it toward the radiator.

Q: Is there any other way of directing the water in this type of system?
A: There are a number of ways, and all of them are critical to the system's operation.

Q: Why is this?
A: Because the pipes in a gravity system are very large and contain a lot of cold water on start-up. Not all of that water is going to get hot at the same time. And since hot water is lighter than cold water, it has a tendency to shoot directly up to the top-floor radiators - just like a hot-air balloon. That's its path of least resistance.

Q: So the top floors tend to heat more quickly than the bottom floors in a gravity system?
A: Yes, and that leads to system imbalance.

Q: How did the old-timers get around this problem?
A: They sometimes added orifice plates to the top-floor radiator hand valves. Here's what one looks like.
Plates

Q: What exactly is an orifice plate?
A: It's a round piece of metal with a small hole drilled through its center. You could make one yourself out of sheet metal; most of the old-timers made their own.

Q: How did the orifice plate direct the water?
A: By increasing the resistance through the radiator it was assigned to. If water found it difficult to enter, say, a top-floor radiator because of the orifice plate, it would go to a radiator on a lower floor instead. In this sense, the orifice plate was similar to the "O-S" and "Monoflo" fitting. The big difference, however, was that instead of directing the water into the radiator it was assigned to, an orifice plate directed the water away from that radiator.

Q: What other methods did the old-timers use to make the water go where it was supposed to go?
A: More often than not, they'd pipe the job in such a way as to avoid the problem in the first place. Here, take another look at this upfeed system.
Upfeed_System

We have three radiators - two on the second floor, one on the first. The hot water's tendency is to race up to the second floor. But look closely at the way the fitter makes his lateral take-offs from the supply main. Notice how the hot water supply to radiator #1 comes off the side of the main. The fitter did it this way because on start-up, the hottest water will be at the top of the supply main.

Image

That hottest water wants to go to radiator #1 but it can't get there right away because the water near the bottom of the horizontal main is colder than the water near the top of the horizontal main. That colder (and heavier) water is crowding the hotter water out of the way and driving it toward radiator #3, which just happens to be on the first floor.

Q: So you can tell from the basement where the risers are going?
A: Yes! They usually fed upper-floor radiators from the side of the main and first floor radiators from the top. That way, the system went into more of a natural balance.

Q: Did they do similar things with their vertical risers?
A: Yes, they did. Frequently, they'd supply a second-floor radiator from the top of the riser and a third-floor radiator from the side of that same riser.

In this case, the second-floor radiator is the lower of the two. That's why it gets the water from the top of the riser.

Q: How about the horizontal mains? Did the old-timers use the same size all the way around the building?
A: Not usually. It was customary to reduce the size of the supply main as it worked its way around the building, but if the fitter reduced the pipe too quickly, flow would stop because there would be too much overall resistance.

Q: What rules did they follow?
A: Generally, they wanted the internal traverse area of the main to meet or exceed the internal traverse area of all the attached radiator hand valves. If the main was too small (or if someone added radiators to an existing main) some radiators wouldn't heat well. The competent fitters sat and calculated every job they worked on. They knew no two were quite the same.

Q: What's internal traverse area?
A: Look down the round end of the pipe. The interior circle at the open end represents the internal traverse area. By using mathematics, you can figure out how many square inches of space there is inside that circle.

Q: Can you give me some examples?
A: Sure! Here's a list of common size pipe used in gravity systems.

Pipe Size Internal Traverse Area
(in Square Inches) Pipe Size Internal Traverse Area
(in Square Inches)
1" 0.86 3-1/2" 9.89
1-1/4" 1.5 4" 12.73
1-1/2" 2.04 5" 19.99
2" 3.36 6" 28.89
2-1/2" 4.78 8" 51.15
3" 7.39

Q: How about the supply and return mains. Do they have to be kept close together?
A: Yes, Ideally, the return main should parallel the supply main within a distance of no more than 8-1/2 inches. It should drop only when it reaches the boiler room.

Q: How did the old-timers bring their returns from their radiators back into their mains?
A: They followed this rule: Returns from first-floor radiators have to enter on the side of the return main because they leave from the top of the supply. This is important because the return from one radiator could block the return from another if the temperatures coming back from the two radiators are slightly different, which they almost always will be.

Q: Were there any special fittings for the mains?
A: They used a number of them. Here are two examples of the more common ones. This is called a Eureka Fitting.

This one was known as the Phelps Single Main Tee.

Notice how the hot water leaves from the top of the fitting while the cold water flows back into the side. Those old-timers were clever, weren't they?
Last edited by gregolma on Tue Dec 29, 2009 3:28 pm, edited 2 times in total.
gregolma
 
Stove/Furnace Make: Axeman Anderson
Stove/Furnace Model: 1980 Anthratube 130

Re: Monoflow Continuous Circulation System

PostBy: WNY On: Tue Dec 29, 2009 3:22 pm

Be careful COPYING text from other sites that might be copyrighted (Right Richard?) , a link good though.
WNY
 
Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
Coal Size/Type: Rice
Stove/Furnace Make: Keystoker, LL & CoalTrol
Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon

Re: Monoflow Continuous Circulation System

PostBy: gregolma On: Tue Dec 29, 2009 3:31 pm

brckwlt wrote:
gregolma wrote:I hate to chime in so late, but I just finished reading the thread.

First of all, ...



Maybe im ignorant, but Why would it matter if i did what u mentioned and had the flow chocked so it flowed very slow ... because if im pumping 180 degree water very slowly to my rads wont it heat the same way 180 degree water pumped a lot faster does? and isnt there more chance for heat loss in the heat pipe if the water is moving slower through out the basement and house then if it is moving really fast? Another point would be when it is not really cold if i run the water continuously like u mentioned i would have to lower the water temp a lot, and that might mess with my DHW coming from the boiler.

Im not trying to argue with you, but i have no knowledge of plumbing, especially when it comes to this old stuff. just trying to understand ...


Slower flow allows more heat to escape from the water. Hotter water will make the single pipe system more effective. The water in constant circulation will only rise when your boiler pumps hotter water into it.
gregolma
 
Stove/Furnace Make: Axeman Anderson
Stove/Furnace Model: 1980 Anthratube 130

Re: Monoflow Continuous Circulation System

PostBy: gregolma On: Tue Dec 29, 2009 4:08 pm

WNY wrote:Be careful COPYING text from other sites that might be copyrighted (Right Richard?) , a link good though.


I think that I used it properly and acknowledged its source.
gregolma
 
Stove/Furnace Make: Axeman Anderson
Stove/Furnace Model: 1980 Anthratube 130

Re: Monoflow Continuous Circulation System

PostBy: brckwlt On: Tue Dec 29, 2009 5:06 pm

gregolma wrote:
brckwlt wrote:
gregolma wrote:I hate to chime in so late, but I just finished reading the thread.

First of all, ...



Maybe im ignorant, but Why would it matter if i did what u mentioned and had the flow chocked so it flowed very slow ... because if im pumping 180 degree water very slowly to my rads wont it heat the same way 180 degree water pumped a lot faster does? and isnt there more chance for heat loss in the heat pipe if the water is moving slower through out the basement and house then if it is moving really fast? Another point would be when it is not really cold if i run the water continuously like u mentioned i would have to lower the water temp a lot, and that might mess with my DHW coming from the boiler.

Im not trying to argue with you, but i have no knowledge of plumbing, especially when it comes to this old stuff. just trying to understand ...


Slower flow allows more heat to escape from the water. Hotter water will make the single pipe system more effective. The water in constant circulation will only rise when your boiler pumps hotter water into it.



so for now since i dont have money to buy fancy new fittings, valves, pipe etc... could i simply just choke the flow of the water?

but am i wrong in assuming that slower water flow will have more heat loss in non heating areas such as the basement since it will take a long time pump the water around my house till it reaches the boiler again?

and if choking is the way to go like sting mentioned before, should i put my taco 007 pump back on and take of the taco 0011 pump i replaced it with?

EDIT:

gregolma ... this is from the link u supplied

Q: Why did they call it upfeed?
A: Because the water fed up from the bottom (the boiler) to the top (the highest radiator).

It does not work like this is my house. In my setup the radiators that branch off the loop first get all of the hot water and they are on the first floor. It takes longer for the hot water to heat the rads at the end of the loop. But when the boiler has been pumping hot water for a long time all of the radiators are equally hot, well as least as far as i can tell they are. The heat is pretty even throughout the house when boiler runs for a long time.

also my piping is nothing like in those diagrams on the website. on the single loop in the basement it will branch off to a first floor rad and only that rad then back down into the loop. it is like that for 9 rads on the first floor. The second and third floor might be more like diagram but there are a ton of places where it branches off down stairs. i would say 65-70 percent of the rads have their own individual supply and returns to the loop in the basement and dont share with any other rads.
brckwlt
 
Stove/Furnace Make: Axeman-Anderson
Stove/Furnace Model: Rebuilt 1953 AA-130

Re: Monoflow Continuous Circulation System

PostBy: gregolma On: Wed Dec 30, 2009 9:33 am

I'm sure that they all have individual supplies and returns. That's the way the system works. I seem to remember reading that pumping too fast gets all the heat to the first floor on that type of system. Remember flow will take the path of least resistance.

Read this as well:
http://www.heatinghelp.com/article/17/Hot-Water/74/Diverter-Tee-Hot-Water-Heating
This link is broken, either the page no longer exists or there is some other issue like a typo.
gregolma
 
Stove/Furnace Make: Axeman Anderson
Stove/Furnace Model: 1980 Anthratube 130

Re: Monoflow Continuous Circulation System

PostBy: brckwlt On: Wed Dec 30, 2009 9:58 am

yesterday i reduced the flow about to about 20% and now the 2nd and third floor are as hot as the devils lair.

should i put my smaller pump back on and take off the big pump?


will read your link when i get a chance to today. thank you
brckwlt
 
Stove/Furnace Make: Axeman-Anderson
Stove/Furnace Model: Rebuilt 1953 AA-130

Re: Monoflow Continuous Circulation System

PostBy: gregolma On: Wed Dec 30, 2009 10:08 am

What I found when I was experimenting with pump sizes was that the bigger the pump and higher the flow the more air ended up in the radiators. I picked up a bunch of old B&G pumps at a flea market for a pittance and switched them in and out starting with the biggest (2") and ending up with the relatively tiny NRF 22. I forget which pump stopped the air from ending up on the second floor, but I think it was the B&G 100. This pump has about twice the flow of the NRF 22.

I was engaging in some discussions on heatinghelp and out that came the concept that you needed to try to replicate the gentle flow of gravity as closely as possible to keep the balance in the system as well as increase the heat loss through the radiators.

If you put a smaller, lower flow (because smaller size doesn't always mean less gpm) pump on you will also notice that the return is colder. That's what you want.

Converting gravity systems is easy, but requires some thought.
gregolma
 
Stove/Furnace Make: Axeman Anderson
Stove/Furnace Model: 1980 Anthratube 130

Re: Monoflow Continuous Circulation System

PostBy: Sting On: Wed Dec 30, 2009 10:55 am

gregolma wrote:What I found when I was experimenting with pump sizes was that the bigger the pump and higher the flow the more air ended up in the radiators.



Yes -- there lays another problem with over sizing the pump. Walked onto a big job in a church one day - The pumps were horrendously over sizing - Air was constant problem - some vigual-anti had installed an air scoop in the system that was about the size of a queen bed - it was a disaster of remuddeling.

We simply changed out the two main B&G circ pumps to the correct size Taco units and the problem disappeared. Those big BG's were actually sucking air past their ceramic seals and injecting it into the circulating fluid because they were pulling that hard. :shock: Then we went in and fixed the air controls to the outlying zones - possibly the original problem that was to be corrected by over sizing the pumps - but --- well

that's what you get from the lowest bidder!
Sting
 
Other Heating: BurnHAM=NG-gas

Re: Monoflow Continuous Circulation System

PostBy: brckwlt On: Sun Mar 28, 2010 6:09 pm

i had the problem that sting mentioned above. I bought a taco 0011 f4 and all it make my rads make all sorts of noise, it was so bad in the bedroom some nights it was hard to sleep, so after about a week i took out the 0011 f4 and out my taco 007 f5 back in. No more noise now :D and a lot of wasted money on the bigger pump :x :oops: :mad:
brckwlt
 
Stove/Furnace Make: Axeman-Anderson
Stove/Furnace Model: Rebuilt 1953 AA-130

Re: Monoflow Continuous Circulation System

PostBy: kstills On: Fri Oct 28, 2011 9:49 am

Sting wrote:
brckwlt wrote:
Poconoeagle wrote:i see!!! :D sounds like ya gotta go choke a valve or two and speriment till you can circulate consistantly and maintain a narrower temp defferential between the in and out 8-)


But im not sure what valves im chocking, the radiator valves?



one question at a time

this one

Do ALL the radiator valves in the house still open and close -- turn easily so you can limit the amount of energy drawn from the house loop?
IF YES -- then close them all and the thermostat will call the circulator to action and the house loop will be charges with energy and constantly circulate -- then when the boiler is at idle fire, the circulator is still pumping and the house begins to cool -- ONE at a time -- CRACK open the radiator valve ( about an 1/8 turn) on each COLD radiator waiting -- and this will be the hard part -- about 15 minutes before going to the next one. When they are all open just a crack each should begin to "feel" warm. Now WAIT and see if that is enough radiation to keep the house comfortable -- Likely it will not so now it becomes a search and destroy mission -- crank the radiator valve in what appears to be the most lived in space another 1/8 turn and WAIT an hour to see if that's enough -- and on and on and on --

You just balanced your system

or

And I like this one better -- but I want you to wrap you head around the paragraph above before we continue....

if there is a valve on either side of the main house loop circulator -- TURN IT CLOSED and open it just a crack -- now your globally limiting the boiler energy out put to the house loop that feeds each radiation source in the house - and your doing it equally thru the system. WAIT an hour and if the house is still cool and if the circulator is still pumping and IF the boiler is at idle fire -- crack (that valve or valves) open just a slight little bit more and WAIT again and keep that up until the system is pumping all night long and the house is comfortable. You may encounter an area or room that is warmer than another -- twist the RADIATOR valve (in that room or area) closed and do the dance detailed above on it to balance that area -- IF you do this at more than one radiator you MAY need to close the circulator valve -- remember the one we started with in this paragraph??? because why??? the TOTAL system energy use is being reduced by your individual radiator balancing and thus --- you need to reduce the TOTAL energy input as a whole into the house loop. --

once you have accomplished balancing your main loop and balancing you area radiation as described in paragraph two -- as the out door temperature get colder you will have to open the circulator valve just a smidge bit more to introduce more energy to carry the load and you will have to close it when the weather warms. This was the boiler tenders duty 100 years ago when out door reset controls were more expensive than hiring a guy full time for the boiler room.

You can do this and it don't cost NUTTIN. It just takes a lot of time to get it right at first -- then it takes a little time every day to keep it on track and when your comfortable with it you will be able to anticipate what valve you need to set where for the weather coming in tomorrow.

It no different than the knowledge of the old dead steam train engine operator that drove his traction motor by the fell and the sound of it. He learned by driving it - what position a valve or lever had to be in for the grade and the terrain of the tracks he was piloting his equipment. There were no ECM controls -- ti was a human -- and the had of ONE human that moved miles of freight with one locomotive. Your hand can heat your house too.

once you get this -- and if you get sick of it -- lets look at automatic outdoor reset or delta t pumping. But as I began -- OK not 80 posts ago but some time ago -- lets crawl lets walk and lets run in sequence -- or lets read some books to learn what we are doing so we can help ourselves and not depend of some dumb duck on the otter side of the public internet that cannot see in your basement.



Ok, I'm resurrecting this thread because I'm probably in a similar situation atm.

Given the advice you gave here for a monoflow system, would it work equally well with a two pipe system that was originally a gravity feed system when it was installed?

I'm trying to imagine why not, but it would seem that throttling the output off the boiler and balancing the radiators would be just as effective in either case.
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line