Old House, Single-pipe hydronic with diverter tees

otishertz

Mid-Coast Maine



Planning to add 320 sq ft to a 1200 sq ft dual-zone boiler heated, mostly

insulated home.



New Yorker boiler, Becket Model AFG 0.75 - 1.5 gph burner,

Triangle fin "New Jersey" Hot water maker, two Taco 007 circulators, 1 1/4"

single-pipe loop with ONE four-way diverter tee for each of four cast iron radiators in the OLD house part.



3/4" copper loop with 8-foot fin/tube BB and 10-foot cast iron BB for the

newer 240 sq ft section. (Loop is about 60 feet long)



Proposed addition is 320 sq ft with 75 sq ft of

window. Older addition and new addition will be over insulated, unheated crawl space..



 For the proposed addition,

Question 1) should I add a length of BB to the

¾” copper loop in series with the existing baseboards ?

Question 2) should I add that baseboard with

venturi-type diverter tees?

Question 3) assuming 500BTU/foot about how many

feet of fin-tube would work for the 320 sq foot bed/bathroom

Question 4) should I consider adding antifreeze to the boiler water?

kcopp

It may be....

a bit overkill but I wouls just add a separate zone. Messing w/ an existing diverter tee set up is asking for trouble. Run a 1/2" line to the addition and you will have better control and less headaches. Insulate the crawlspace and the piping well and you should not need the antifreeze.

Ironman

Pics?

How about some pics of what's already in the boiler room? I don't know what a "four-way" diverter Tee is.



You really need to do a heat loss calculation to determine how much additional radiation is needed and to size the piping, circ, etc.



I would not add antifreeze unless there's a possibility of freezing - something that wouldn't happen under normal circumstances. By that, I mean a normal installation with normal useage. Glycol reduces the heat carrying capacity of the water it's mixed in. If it is warranted, only hydronic glycol should be used, not automotive antifreeze.



And I agree that a separate loop is probably better than messing with the existing diverter Tees.

otishertz

reply re four-way diverter tees

Hello Ironman,

this is the only clear pic I have at the moment. will be glad to make more..

The Tee has two 1 1/4" ports, a 1" wye off to the side and a 1" Tee out the top.

This particular one is the first one in the loop right after the air scoop, so I have to assume the angled wye is the return from the radiator. I guess it's like a Taco twin diverter tee.

otishertz

reply #2 re four way diverter valves

ok have to re-type this because I forgot to add a post title.

icesailor

Splits:

That "Wye" fitting is just to split the two zones. You have two circulators and two zones. Or as I see it.

I may be wrong, and I'm not beating up on you but you sound like a homeowner DIY'er and that is all well and good. You might need professional hands on help. You have complications that can bite you. I can't see all the connections but it is important how you connect a new zone back into your system. You can have issues.

I'm not the only one who doesn't know what a "4-way tee" is. With a "One Pipe" System. I know what a "One Pipe" system is supposed to be. Not everyone calls it that when it is a proper name for a type of piping. If you are adding on, you need to look at whatever is there and working as a complete and finished unit, You need to connect anything as a completely separate unit. Water doesn't care where it goes. You can inadvertently allow it to go somewhere that it will go, when you don't want it to go there.

Ironman

Better pics?

Icesailor has over fifty years experience in this trade and I have over forty, but neither of us knows what a "four way" Tee is. Your pic is indicating some form of wye fitting but it's not at a good angle. Could you get a better pic perpendicular (side) angle?



Also some pics of the diverter Tees in the system?



I can see there are multiple leaks on the system. They will be the death of your boiler if not corrected. You should give immediate attention to them.

otishertz

Old House single-pipe hydronic with diverter tees

Hello Ironman and Icesailor, thanks for your replies.

Sorry about the lack of pictures.. When I get back to the house I'll get better ones.

for the time being I've made a crude drawing of the "4-way tee-wyes" or diverter tees. below.

I just called it that cause it has four holes. The two plumbers in my family had never seen them either.. I think they date back to 1935 or so.

They do use four-way or cross tees for pipe racks- black pipe, steel, stainless, etc, also in (sched. 20?) PVC for furniture, tubular framing, sprinkler systems, etc

There are four of these buggers in the main loop, one for each radiator. I have to assume they have some kind of baffle in them like Bell & Gossett diverter tees. B & G cast iron/brass tees have two 1 1/4 or 1 1/2 openings, a baffle and two either 1/2" or 3/4" ports on one side.



In the old house, there's a regular tee (just before the air scoop & expansion tank with a gate valve to feed the second heat loop.. THAT's the loop that feeds the leaky (flange gasket) circulator.

AND yes indeed I need to fix that before heating season. I can only guess what was used instead of the two flange gaskets I found on a shelf nearby.

Mark Eatherton

Looks like a Eureka fitting...

http://www.heatinghelp.com/files/articles/1204/366.pdf



ME

kcopp

Again...

put in a separate zone. That way you will not have problems. 

Ironman

Indeed...but

I've never seen one (even in a book) that was wyed like that one.



The presence of circulators, which were obviously added later, makes me wonder if it is the eureka fitting. It seems to me that they would not interact well with that type of system. Your thoughts?

otishertz

reply to kcopp, ironman, Mark E, re diverter tees.

Eureka! Except they don't look like that and they function well.. All due respect to Leroy S. Bunker's efforts, based on what I've read in Dan Holohan's hydronics opus, the Eureka Diverter tee would need to have more of a baffle in it to work well, to create the pressure differential ( to force the hot water thru the more resistant radiator/pipes than straight thru the tee).



And, thanks to all, I'm going the add-another-zone route. Since there are 2 circulators on there now, I'll have to choose between creating a manifold and zone valves in the main loop or adding another circulator.  I'm thinking zone valves would be the way to go.

Mark Eatherton

Agreed...

The fitting was designed to work strictly with gravity. When adding a pump to the mix, it mixes literally. Probably still puts out some heat, but not the same as with gravity.



If you had to add a circulator, the smallest one you could find is probably too big.



It could also be derivative of the Eureka, kinda like a cross between a Eureka and a Monoflo or scoop tee…



To the OP, they compensated for flow pressure drop by having excessively large pipes to accommodate gravity flow. It was never intended as a forced flow fitting, and having seen them in action with my infrared imaging camera, their stratification is VERY good and consistent.



What slays me is the fact that the two fluid streams (hot versus less hot) flow in opposite directions to teach other. Those deadmen were something else.



The system I saw and documented was installed in 1906 in a huge red brick mansion in Denver Colorado. First one pipe gravity system I'd ever encountered. It sits at the corner of 13th and Pearl if memory serves me correctly. It was still completely original. The owners wanted me to "modify" it by adding pumps etc. I walked away, shaking my head. I'm sure some poor sucker got taken in and now "owns" the job...



ME

otishertz

Eureka diverter tee

To bastardize a phrase-  One man's can of worms is another man's goldmine! ( or headache) Knowing when to step aside is key.

icesailor

What am I missing?

What am I missing?



That looks like a ROTM 1 1/4 Black Malleable wye put in backwards to the flow. The 1 1/4" Copper Supply from the boiler goes into a copper tee of some function with a valve to go somewhere. Then into a 1 1/4" Taco standard cast Iron Flow Check and into a standard Taco air scoop. Then, comes the backward wye. Two circulators on the return. But the Wye is after the first flow check. unless that connection before the flow check goes to the other zone. It might have the unusual diverter tees in it. But, where I can't see any  pipes coming off the top, is it just a rube install? A practice eye may need to be cast upon it.



Or more extensive photos.



Two Taco Zone Valves (to keep it in the family) connected to the smaller zone, kick some grass on it and be gone. Its not a church. Yet.

otishertz

Rube install-not the first pass, but after that? Ruby 4 sure.

> ironman.. I will post better pics. there may even be some lettering embossed on the diverter. (The other 3 are wrapped in fiberglass+tape but all set up likewise)

And I'm sure ol' Rube helped out on some of the other fixtures in the house. A mix of

good & bad.. I'm taking them on one at a time- (a 20-foot long 1 1/2" pvc for a washer, dishwasher, disposer, kitchen & vanity with a 1" vent - for example)

Thanks again.. you got me scouring thru a couple hundred pix for a chance shot of the heat.

icesailor

Ship Work:

That now looks like one of those nautical fittings. A "Oh Ship. **** is that?" fitting.

It must be a cast iron fitting because they can't make a Malleable fitting Tee like that, and from the last picture, it looks like something is rising vertically off the top.

You need to find someone interested in historical piping. Whomever used that fitting there like that and piped it like it appears, is long passed and has joined that gang of wrench twisters in the sky. For a historical reference, it is invaluable.

Mark Eatherton

How old??

How old is the dwelling this system is connected to? Date of birth?



ME

icesailor

Old Houses:

ME:

Judging on what appears to be Asbestos Insulation on one line coming off the supply main. and the fact that the "new" boiler was all replaced with copper, are you considering that maybe the replacement boiler installer connected the return to the supply? The only time I have ever seen Wye's in heating systems, they were almost always on the return, and a flow entered the wye/branch part. the other flow came through the end. The opposite of flow in a waste wye.

That's one that needs a carefully experienced eye to be cast upon it. You have far more experience dealing with those Oh Ship fittings and odd flow designs.

I'm having a Flashback. Thinking about having to accurately draw that out to understand it. My neck is getting hot and my head is starting to ache.

Ironman

Flow

Ice,

If that IS some form of a Eureka fitting, then the warmer water would flow out of the top to the branch circuit and return the cooler water at a lower point on the side. That is, under gravity flow.



The wye seems to be what's confusing, but it's only aiding the return flow into the Eureka fitting.



Again, think in terms of gravity flow with warmer and cooler water in stratification within the pipe. That's the only way that kind of fitting could work. That's why pumping the system defeats its purpose.

icesailor

Gravity Flow:

Its not gravity flow now. Its pumped. That's why I think that someone replaced the boiler and converted it to a pumped gravity system without understanding how it was supposed to work. I'll bet that there are issues with the system.

That's all. Its hard to DX a system from an odd photo.

otishertz

1845(?) 4 room cape

Circa 1850, but the original heat was a coal kitchen stove, then single-pipe

hot water + column radiators circa 1910 when they wired the town. yep. knob + tube.

There was asbestos on the main loop, 99% removed and fiberglass wrapped.

The one un-wrapped fitting feeds a 2nd floor radiator thru 30 feet of 3/4" iron and 10 elbows.

the 3/4" street ell out the top of the fitting runs over 2 feet to a 10 foot rise, over 2-feet, thru the floor thru a 4-column radiator, a flow restrictor valve (half-turn gate/cylinder with a 1/2" hole and 1/16" hole in the closed position) then all the way back to the same fitting (to the wye). I was surprised I didn't see a return loop, then I noticed the odd diverters with the feeds

out the top and the returns thru the wye.  It seems to work pretty well... all four rads warm in

a few minutes. Also, the main loop may've been covered, but where it's exposed it looks

fairly new, considering the sometimes wet basement. There was an old rusty circulator

 pump in the garage- a little larger than a football, ancient-looking with big ventilation slots.

Based on the long 3/4" runs to the upstairs radiators, I'd guess it was pumped hot water on the previous boiler, too. Who knows, anyway. While the the current boiler seems installed up to mfg specs, there are quite a few other things done cheap and easy.



When you say "holy ship" fittings.. (what I say when I bang my head on the low pipes)

the town has been in the ship-building industry for 100+ years.. maybe there are a few

odd sourced bits. Definitely different from what I saw working in other regions.

icesailor

Fun:

That's what makes the job fun. Seeing and figuring out how these old systems work.

What interests me is the direction that the wye fitting is in. It is correct for water flowing from the boiler and through the run of the tee. Its the Wye part that is the question. If a direction of flow runs through the "run" of the tee, and another flow elters through the branch of the wye, it is more correct thab it it came in through the "bull of a tee. Because the flowing water through the wye gets restricted by the wall of water flowing through the run. It is the correct way to connect exhaust vents where two appliances are connected to a single flue pipe. I've actually found places where entering with a tee didn't allow the appliance that vented into the "Bull" of the tee to properly vent when the main appliance was running. A Wye solved the problem.

If you race small sailboats for fun and frustration, you come to realize how little wind energy it takes to move a boat through the water. And how just the right amount of something, gives you a competitive edge over your competition.

Moving air and moving water are the same. Just a different medium.



Sailboat Racing: Endless hours of tedious boredom. Interspersed with moments of stark terror.

otishertz

diverters

icesailor,

  small sailboats.. Frosties? Those look amazing. My cousins race them around the Merrimack in the cold. Smallest I've used is a Sunfish. (ok, maybe a sailboard or two)

Something very appealing about a 6-foot sailboat.

otishertz

diverter flow and the wye and the bull

>Iceman,

   In terms of flow direction the wye entering in the same direction would be like traffic merging onto a highway. There will be some turbulence and resistance caused by the merge.. Continuing that analogy, the upright (bull) tee would get some of the water traffic only because for some of the water it would be the path of least resistance.. so some of the water traffic would go up to the radiator and be helped along by the reduced pressure induced at the other end of the loop; at the wye merge, AFTER the constricted area...

I'm guessing that slow flow thru an iron radiator would be best for heat transfer, then cooler denser water would be more likely to drop back into the main system's heated traffic.

Maybe it wouldn't need a baffle in there after all, but if it were feasible to cast a baffle into the diverter it seems like the right thing to do. Unfortunately I don't plan to take one of them out.

icesailor

Conjecture:

That's conjecture. Its the balance in the zone with the larger sixed piped circulator. How do they make the pressure equal on both sides of a split loop on the primary zone? The circulator is on the return, pushing through the boiler. The main flow is through the boiler, through the air scoop and past the wye. There will be an element of suction as the water rushes by like the exhaust of a chimney flue pipe venting two appliances with a wye fitting. There is a positive force on both sides. In your case, although the pressure is still positive (Delta T) on the return, it will be  considerably less on the side with the Wye in that direction. Unless there is something that I can't see. The tee on the supply with the Asbestos insulation going through the wall must be the other zone that comes back to the rusty circulator with the 3/4" copper.SO, that isn't part of the flow.

But like I always say to myself. If it worked for years and works now, don't futz with it. Spend a moment and try to figure out how it works. And learn something.

icesailor

Frosties:

Frosties suck for big and old guys like myself. If I still lived in the North, and I wanted to build another boat, it wouldn't be a Frostie, it would be another Iceboat. Which I don't need.

I have a need for speed. Sunfish are one of the most uncomfortable things one can ever sail. No place to hook your feet for that smokin' upwind planning in ideal conditions. Sailing a Sunfish is like riding around on that old fat tire'd 2 wheeler with the Donald Duck head and the big wide handlebars with the friction coaster brakes. Sailing a Laser is like riding my last generation hybrid mountain bike. Fat tires but no un-sprung rear and the 25 speed de-railers.

But DN Iceboats. The most fun you will ever have with your clothes on. Like stepping up to my son's 2013 Honda 250cc Dirt Bike that he races Motocross all over the North East with. THAT gets your attention. Given a choice, if there is sailable ice and racing his dirt bike? He goes sailing. If its windy, and it is warm enough he beats his Laser around. Like I did.

Mark Eatherton

Antique...

As I thought, one pipe radiant, was definitely designed without forced flow.



These fittings do sound like a variation of the Eureka fitting Near the turn of the century, there was a LOT of innovation going on as systems were making the transition from steam to the much safer hot water systems.



ME

otishertz

BETTER PICTURES of a diverter tee

>Icesailor, Ironman, Mark E.,

finally.

TACOTROL

  FITTING

 1 1/2 X 1

 PAT. PEND.



with a little RH  embossed on the upright leg (radiator feed)

sorry for the delay and confusion!

Ironman

Tacotrol

Here's a link to info on it from right here on HeatingHelp:



http://www.heatinghelp.com/files/articles/1593/File0001.pdf

icesailor

WOW:

WOW.

That design must be older than the old dead guys. Taco in New York. They were in Rhode Island while the old dead guys were alive.

Clever how it works. An awfully expensive fitting to manufacture.