fin tube/ CIBB series loop

ralman

If the BTU output rating of fin tube is 610 per foot and Cast iron baseboard output is 620 per foot why do I keep reading that I should not use the cast iron baseboard on a series loop? If 67' of fin tube can be used on a single 3/4 loop, why not 67' of cast iron baseboard?

ScottMP

The big difference

is Mass, the cooper fin tubing has very little. The CI BB has alot of it and it will suck the heat out of a loop faster. Shorter runs and pipe design is much more important with CI so as to maintane that 620 per foot. I actually use 580.

With CI if your not carfull you can get 140/120 water goping thru your baseboard and you'll be lucky to get 200 a foot.

Scott

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J.C.A._3

The ends....

The end of the runs on CIBB will be cooler at the end of the heating cycle or the beginning will be hotter, depending on where the thermostat is located...and the CIBB holds heat FAR longer than fin-tube, and will lead to uneven heating over a large area.

If you pipe it with venturi tees, the heating will be more evenly distributed during the cycle leading to lower temperature deviations.

Does that help? Chris

Unknown

Ross,

CIBB or ,any CI radiation should not be looped because of its tendency to hold the heat longer. If you have say 3 rooms governed by 1 stat, the rooms without will likely become severely over/underheated.

Dave

ralman

Its the ratings.

What I mean is if a fin tube series loop was designed and met the requirements for heat loss of that zone, then the exact same CIBB zone should perform roughly the same since their ratings are so close.

ralman

Dave

I have one thermostat for the whole house now, basement and main floor on monoflo split loop. For example, I have laid out a loop design that puts 63' of baseboard through 5 rooms. I converted the published ratings for CIBB to remove the IBR 15% heating factor. I calculated the temp drop from baseboard to baseboard and figured my output ratings accordingly. Output capacity is greater than heat loss of each room. So it should overheat. The rating tables of CIBB and fin tube are so close. I can't see how there would be any difference between two identical zones of CIBB and fin tube.

ralman

I wasn't figuring 620.

I was just using that 620/610 from the two charts for the posted question. To get my actual numbers I had subtracted out the 15% heating factor from the chart numbers for my zone calculations and the output is even lower. 539 at 4 GPM and 513 at 1 GPM and 180 degree water.

Unknown

You mean,

you have a monoflo tee for each rad coming off the split main? If so you should be OK, just be sure to add a valve to each rad so you can tweak your temp.
I thought you were going in & out of each rad without returning to the "main",,that`s how I interpret a loop.
Or did I miss your meaning?

Dave

J.C.A._3

Like Scott said....

MASS ! Cibb weighs a whole lot more per foot than fin-tube...therefore holding the heat MUCHO longer than some "steel cased, copper piped, aluminum finned" easily demolished by small bangs... units.
Like Taco says...Do it ONCE, do it right. Chris

ralman

I have a monoflo tee split loop improperly piped 50 years ago.

I want to get rid of the monoflo altogether and convert to 3 zones, basement, main living area and bedrooms. I have no experience, I have the modern hydronic heating book. What I have doesn't work well at all. I can hold my bare hand on any baseboard indefinitely after the boiler is 45 minutes into a cycle. I may be able to put together the 3 separate series loop zones and my calculations lead me to believe it will work. A 20 degree delta tee should be the same regardless of the type of heat emitter is what I am thinking. I would prefer the homerun piping arrangement but the "how to" is over my head. Local heating companies do not use pex al pex and it is not available for sale in my area. 7 companies have stated my system is fine and nothing needs to be done. But MAMA ain't happy. The baseray installation manual states that series loop is an acceptable method of piping. So, I crunch the numbers, a 4.6 GPM flow rate on 85' of 3/4 pipe, 30 ells, 3 ball valves and 63 feet of baseboard at 180, grundfos speed 1 gives me a 15 degree DT.

Unknown

Well Ross,

you`re right , I see it in the BaseRay installation manual, but this goes against everything I was ever taught on CI radiator installation practices!
Will it work?, sure,,will you be comfortable?,,I doubt-it!
The reasons why have already been stated.

Dave

ralman

I am not comfortable now.

I appreciate your experience. The manual does not go into detail on how many feet of CIBB can be placed in series. I have spent the day removing radiator angle valves and enlarging the holes where the pipes go through the floor. The original installer 50 years ago undersized the riser floor holes. Each riser that touched the wood subfloor and oak wood flooring is rusted and falling apart. Some of the risers have to be tapped through the wood that is how small the hole is. I have been lucky with the weather so far.

Unknown

It does tell ya Ross,

on Pg. 7. Are we speaking of the same installation manual?
Burnham BaseRay 9A.

Dave

ralman

Yes, that is the same manual.

It does explain it, how to calculate. but I do not understand how to relate it to a system that is in place. Looks like I could get 30,000 BTUH with 175 feet total loop length, 210 water temp at 1GPM. My baseboard lengths are already determined as I do not wish to replace them. They are oversized in every room except the bathrooms. So, I am trying to work with what I have. I do not desire a 210 design water temp, I was working with a 180 design temp.

Unknown

Wow, tough call

using existing installed rads previously mono-flo, then changing to loop, against my better judgment, but be sure of your math!

Dave

ralman

LOL

It is ironic that all this hinges on math calculations, which I can't do very well. At any rate I could not grasp the table on page 7. The explanation of using table A to determine whether a 3/4 inch or 1 inch circulator would be adequate is confusing. This is what I get from the table. 210 design water temp at 1 GPM gives 770 BTUH per foot of CIBB, divided by a 40000 BTUH zone equals 52 feet of CIBB and 48 feet of equivalent length of piping. Not very much piping and fittings in 48 equivalent feet.

Unknown

You`re funny Ross, LOL

we seem to have made a "schlamazzle" out of this thread, Email me and I`ll try to help further, if I can!

Dave

martin

monoflow tee

Mono flow systems work great on cibb systems. Your problem with the old system was probably a hump or something in the feeder pipes to the rads. the feed pipes need upward grade and then a bleeder on the rad. Use reverse return and all rads will be real close to same temp..HOT

Unknown

PLUMBARIS

How do you incorporate monoflo and/or 2 pipe RR systems without separate zones?

Dave

ralman

I could not attach my diagram. it is in microsoft word.

I received a lot of help from, Mark Eatherton, Ken Secor, Brad White, Dave and others who looked at my diagram last year. The problem was noted with the CIBB being supplied on one side of the split and returning on the other side of the split. Also, two of the CIBB are connected beginning to end, short circuiting the main loop. Monoflow Tees were 6 inches apart to feed and return a downfeed CIBB with 30 feet of pipe and 9 ells; just could not get any air out of that baseboard so it must be no flow(LOL). I have everything torn apart sitting in my driveway right now. Surprisingly, the inside of the pipes are very clean, not much residue at all. The biggest problem is where the vents were located behind inside corners and leaked causing a rusty deterioration. Also, the riser holes are way too small; the risers deteriorated where the metal pipes touched the wood.

martin

Dave

I might have misspoken this is what the wholesaler called it. But basically you bring all your feeds off on one side of your mono loop and all your returns come in after on other side of loop. Not sure if proper term was reverse return.I thought the idea was to estabilish 3 zones for comfort.

Unknown

PLUMBARIS

That`s NOT even mono-flo, That sounds like 2 pipe,,,hope you don`t listen to that guy very often!
Yes diverter tees flow up to the rad(from the main), but the return from this rad enters the same main. (Only 1 Pipe Main)
Dave

Unknown

Hey Ross,

I`m sorry for all the anguish you`re going through, you have sound advice from the "best in the biz", I only tried to help, as you asked, (or I assumed).

Dave

martin

CIBB

We don't see much CIBB out here in Midwest usually fin tube.
I do own a triplex with baseray in a series loop, about 30' on one and 40 on another loop. Been in for about 40 years ,you can feel a dif in rad temp but system works and heats fine.
but i hate to see monoflows get a bad rap because of install

ralman

Hey don't get me wrong, I appreciate the help.

I was just trying to explain to PLUMBARIS that I had more extensive problems with the piping layout than he would have known from todays post. We all had looked at my diagrams a long time ago and had a lot of discussion about the piping arrangement that I had. The diagram would refresh memories of last years post but I could not get it to attach. Makes no difference now, everything is in the driveway. I will not put the monoflo system back in. You have been a good friend and answered many questions for me last year. I thank you for that.

Unknown

PLUMBARIS

mono-flows are a great system, but alot of math(I have one), the old guys used to over-engineer alot when fuel cost didn`t enter the equation, so just add a valve at the end of the rad to tweak-it, is what most did.

Dave

Unknown

Thanks Ross,

anything I can do to help, just let me know!

Dave

ralman

Well, I am the curious type and I have hundreds of questions.

But we all neeed our rest. I have errands in the morning and then I am going to finish the riser project I started today. 3 baseboards left. I have thought about the mass topic Scott and Chris mentioned all day. It will keep me up all night.

bovide_4

Just a thought: you have gone this far - is it out of the question to do a home-run system?

ralman

That would be good.

But I can't figure how to do the manifolds and manage the flow.

ralman

That would be good.

But I can't figure how to do the manifolds and manage the flow.