Radiator piping - balanced flow

JohnNY

I'm piping a large 4-level home with full radiant floor, and fin-tube supplemental heating. The spec calls for 2-tier Vulcan elements but I don't like the drawing provided by the engineer showing one element piped straight through and the other element set on two tees and two elbows, like a bypass arrangement.
Long story short, I'm piping these all up like the one in the picture. It's basically a simple reverse return and ensures equal flow through each element.

Guess what? Engineer hates it and is asking me to justify my method.
Same amount of fittings. No extra cost.

Do you see a downside to this piping arrangement? I'm at a loss.

SWEI

Smart and well done. Can the engineer justify his method?

icesailor

"" Do you see a downside to this piping arrangement? I'm at a loss. ""

Without seeing what he drew and how you piped it, as you describe it, it is wrong to have the bypass go through an element, unless it is his intention to have the floor heat on one thermostat and the top part/element to add to the load if needed while the one acting as a by-pass is always on.

IMO, the water through the by-pass will be the same low temperature as the floor heat, and the added section with the zone valve will add very little because of the low temperature of the circuit. Unless the water through the fin tube is from another hotter source, it won't help much.

I've seen that on applications where an air handler was controlling the air temperature but they used that type of heating to control the individual spaces. The hot water ran continuously through the by-pass but when there was a heat call, the zone valve opened up. One application I saw used Danfoss Mechanical Zone Valves.

Like I said, I can't see the rest of the piping, but if there was a tee BEFORE the zone valve, and connected back to the other side of the elements, it would be a true by-pass. Perhaps, that was his intent.

I don't know what the intent was, unless I covered it in my comment.

Gordy

Truth be known he probably does not understand the benefits of your method, but does not want to admit his lack of knowledge. He in turn criticises your method forcing you to explain the benefits of your piping. The engineer walks away learning something with out admitting his lack of knowledge at least in his eyes. I know a few people like that they make you feel like you did something wrong even though you know your right. The grand scheme is making you explain yourself so they learn, and not put themselves out there as less than superior to you.

Just an assumption though.

icesailor

"" Just an assumption though ""

My assumption though is that by his learning from the installer, he avoids making the second mistake he ever made in his life.

Because many "engineers" are a lot smarter than everyone else. Especially smarter than the ones that do the actual installations and repairs.

Gordy

A good engineer realizes the connection of a competent field person, and embraces that connection. No matter what aspect of construction .

JohnNY

@icesailor‌
I know what you're saying but that's not this condition. These are two separate, parallel systems at two controlled temperatures from a single heat source (boiler).

RobG

Any mechanical engineer that does not understand the benefit of reverse return piping needs to go back to school! What is there to not understand about it? Could you imagine trying to explain PONC to him?

Rob

icesailor

JohnNY said:

@icesailor‌
I know what you're saying but that's not this condition. These are two separate, parallel systems at two controlled temperatures from a single heat source (boiler).

I think you answered the point I was trying to make for you that is being missed.

You said that these are two separate parallel systems. Two different temperatures. A low for the floor and a higher for the auxiliary heated fin tube? That's how it should be. Then, if the fin tube part is either series looped, direct returned or parallel Reverse Returned, the flow should always be flowing through the loop and the zone valve will control the flow through what is actually the by-pass loop. The loop with the elements.

Now, if he is planning that the water always be flowing hot through a loop that he considers the by-pass loop (it isn't IMO) and the zone valve controls hot water through the other element, he is trying to balance a herd of angles on the head of a pin. SOmehow, he thinks that he can use the floor as an emitter with the one element as the extra to make it up. And if it doesn't quite, then the other element comes on. Well, like they say. If wishes were horses, all beggar's would ride.
That's what they make 3 way Zone Valves for. Did he ever consider them? That's what they are for.

Paul48

Maybe I'm not understanding, and I apologize if I'm wrong. He thinks that if I apply 10000 btus to a single emitter, then halve that, I get 20000 btus? I hope he hasn't figured that into heat-loss.

JohnNY

Forget about the radiant .

What's shown is a 2-pipe hydronic system. The zone valve disallows/allows flow through the fin-tube circuit.

Flow through the 2-tier fin-tube meets design load calculations for the given space, which would not be met using a single tier, if desired flow rate is met.

It's really quite simple.

Paul48

Sorry John....You'll have to explain it in simple terms for the engineer. Keep in mind, he has spent a fortune learning how to make a peanut into a phonograph needle. Your layout creates a backpressure and forces even flow through both elements. Simple as that. Try to use as few words as possible. "Never wise-up an idiot, or he'll leave you behind". He'll be writing a paper on it, and explaining it to you next week.

JohnNY

That's hysterical, Paul.

DanHolohan

John, the way you did it is the way I would do it. You've eliminated the path of least resistance for the flow and put the unit into balance. He can call me on my cell if he'd like. I'd be happy to chat with him.

JohnNY

Quite a generous offer.
The ball is in his court now and I'm anxious to know his next move. You know, it's never a good thing to challenge the engineer on a project. Everyone's got to play nice together and work toward one goal in the Client's best interests, but some amount of butting heads is often inevitable.
You may be hearing from me.

Best to all in your growing family, Grandpa Dan,
John

DanHolohan

John, you are such a grown-up. It's refreshing.

JohnNY

And being accused of that? A first time for everything!

icesailor

JohnNY said:

Forget about the radiant .

What's shown is a 2-pipe hydronic system. The zone valve disallows/allows flow through the fin-tube circuit.

Flow through the 2-tier fin-tube meets design load calculations for the given space, which would not be met using a single tier, if desired flow rate is met.

It's really quite simple.

I've never said that what you want to do isn't correct. Your original point question of the discussion was that the engineer had a fit because you didn't pipe it like he wanted it. All I personally wanted to do was answer your question. Which can't be answered unless the way he drew the design was known.

I'm no expert. No Siggy am I, I am not. If you had just posted the picture and asked what's wrong with it, I would have said "Nothing, why?". But you explained that some engineer lost his fleet of ships because you didn't pipe it the way he had designed.

I said that I had seen two situations where it was piped in a similar way. It is an unusual way to do something. I just wanted to know and understand what his objections to what you did were.

That's all.

JohnNY

I hear you, icesailor. No explanation needed, my friend.

Bob Bona_4

Clever. Tweaking a design to perfection!

icesailor

Bob Bona said:

Clever. Tweaking a design to perfection!

Which usually doesn't work out as intended.

Bob Bona_4

But will in John's case

icesailor

Bob Bona said:

But will in John's case

It really helps to answer a question when the whole picture is presented. I'm just interested in what the engineer designed that he is so convinced is better than what Johnny piped. We all know that it would work. There's more to the story.

That's all.

I know a lot of people don't read the whole book. I always do. I might miss something. The good ones, I read two or more times.

Learning is like a Pyramid. Lots to learn at the bottom. The farther up you go, the harder it is to find the pearls. You never know where you will find the one that adds to the knowledge. I'd just like to see what the engineer's thinking is about. Remember, a stopped clock is correct, twice a day.

RobG

Did the engineer actually notice the difference or did you make the mistake of trying to educate him?

JohnNY

He presented the question "You're feeding from the top AND the bottom?"

icesailor

JohnNY said:

He presented the question "You're feeding from the top AND the bottom?"

If he asked that question, he doesn't know what he is doing.

Hot water will flow in through one end and cold water will flow out of the other end until it gets hot. End of discussion.

Most of us can look at something and see how the fluid will pass through it. I doubt that anyone here will tell you that it won't work if there is adequate flow through the elements.

That old comment about getting 6 of one and half a dozen of the other comes to mind. A bigger concern to me is how accurate is his home made design for the emitter and how much heat will it give off. The inner sides MUST be very close to the edge of the fin tube or else the air will just pass by and not collect a lot of heat. You need a chimney effect of forcing the air through the fin spaces to get efficiency.

I've built things like that before. They will work if properly constructed. They won't if they are not.

Is this guy actually an architect? Or is he a "Designer". Does he have a AIA stamp with his name signed through it on the bottom of the drawings?

In some States, you can call yourself a "Architectural Designer" and not be a licensed, registered architect. In other States (like New Jersey), you can not even use the word, or any word that denotes "Architect" in your business. Unless there is someone in the firm that is and signs off on the work.

Gordy

Presenting the question in disguise that seeks an answer.

That's how it starts

RobG

How about doing an RFI and adding a circuit setter to each element to balance flow? What a moron!

SWEI

Death by change order -- it's killed more than a few projects I've worked on.

Rich_49

He presented the question "You're feeding from the top AND the bottom?"

Yeah , just like this , http://www.smithsenvironmental.com/HE_Submittal.pdf

icesailor

Rich said:

He presented the question "You're feeding from the top AND the bottom?"

Yeah , just like this , http://www.smithsenvironmental.com/HE_Submittal.pdf

And Smiths Environmental wants you to feed the supply to the top of that element and out the bottom. So the hot water is being lost at the top and traveling down. Not hot into the bottom and giving off heat to the cooler water heading out to the top.

A good example for anyone to find and see is a large fan foil cabinet heater like some form of Modine or Air Therm with a multi-speed fan. They are supposed to be fed hot at the top. With no fan, the whole coil should be hot. On low speed, it should be how at the return outlet. If the actual flow through the coil isn't high enough, on high speed, the bottom of the coil can be cold.

Rich_49

Ice, **** are you talking about ? Read the document in it's entirety . There are SEVERAL options for piping which would include feeding BOTH top and bottom on one side and letting them cool to the other in parallel . You know , kinda like Jonny configured his . Please read everything attached by me before posting a nonsensical reply in the future . It's frustrating .

JohnNY

Rich, have you not learned by now to tune out the people who post to every. single. thing. on this site?
Just words on top of words on top of words.

I'm an avid supporter and follower of HeatingHelp.com going back to when it was called danholohan.com.
According to the statistics, I've been a member since August 2003 and I've got a little over 1,300 posts. That's a lot. It really is.

Icesailor has been a member since 2010 and has over 4,800 posts.

Yes. Seriously.

Paul_11

John,
I hope you are well.
Since it is sat and you are still talking about this, I assume you have not spoken to the engineer.
I would love to hear how you work this out with him/her because we can all learn from this situation as we all face it from time to time.

This is obviously not a physics question, because You have it piped right, but it is a political one as he/she is supposed to know what he/she is doing and doesn't.

We all have to be patient when dealing with owners, architects, and engineers.

Usually it is the owners who approach me to install their heating systems.

If they contact me first, then I do the engineering in house, and that is what I love to do.

When the owner hires another engineer first, most of the time, their plans go into the garbage, or I won't stand behind the work.

At the end of the day, we must have the owners best interests at heart.

if we have to choose between the owner and the engineer, I think the ethical thing to do is choose the owner.

However, we need to try and not embarrass the engineer in the process.

Keep us posted on how this goes. We are all listening.

JohnNY

Hey, Paul. Nice to hear from you. I did hear back from the engineer and it was a very dry "radiator installation approved" as a side note to another RFI.
Thanks for checking in.

And yes. I ***know*** you've been through these, too.

RobG

John, I meant to ask earlier but how is the convection supposed to occur in that rad? Is it going to be a custom cover, open at the bottom and slotted at the top face? What is the control strategy as well, does it come on with the radiant floor?

Rob

JohnNY

These are custom enclosures that I've only seen drawings of, Rob G. I'll post a pic when I see it in action. It's supposed to get cold here soon, I'm told.
It's controlled as second stage perimeter heating through a Crestron panel. Stage one is the floor, of course.