Questions??? (GrandPAH)

[Deleted User]

I look at the primary as the point of no pressure change connection. So, that can be either the distribution loop, or the source loop. Regardless, any connections pumping away from the primary would be secondary to the primary, which is where the PONPC is connected, which can be either!

Capeesh?

But, in the letters of other, WTHDIK, IJAHWHGRTP :-)

Let me know if I've cornfused you Dave, and I'll try and clarify with a drawing.

Today is the day (weekend?) I start pumping sunshine where it has never EVER been before... (remember the wells in my back yard:-)

ME

Dave Yates (PAH)

a hydronics quiz

1: Which loop is the Primary Loop: the one with the heat source or the one following next that may be the only remaining loop.

2: What should we call the second loop following after the one containing the heat source?

3: Is there an industry standard here or are the two terms interchandable?



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ScottMP

I allways

understood that it was Primary Secondary. The Primary being the one with the heat source.

??

Scott

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[Deleted User]

OOOppps...

..

Dave Yates (PAH)

that's

crystal clear - sort of - depends on your starting reference point.

Imagine though, that you're a mfgr rep with an audience of neophites where hydronics, much less modcons, is concerned. You tell them that in this industry, almost everyone else calls this the primary loop (pointing to a projected drawing with red lazer). We choose to call it the secondary loop. No mention of PONPC.

Yours is the technically correct interp, but maybe a bit much to absorb at first glance until PONPC has been disected and assimilated.

Did you get my e-mail last week?



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[Deleted User]

message received...

Still trying to formulate a decent response in my still somewhat groggy head:-)

BTW, blood tests confirmed my suspicions. Recent elevated exposure to LP. Doc wants to retest in 6 weeks to make sure the levels are dropping and that I am not re-exposing myself on a regular basis.

Thanks to all for their thoughts, concerns, prayers and calls. I'm doing very well, thank you.

ME

Steamhead (in transit)

The way I'd explain it

is that the primary loop connects all the secondary loops together, and all the system water eventually runs thru it. But I see how this can confuse people, since the boiler may be part of the primary loop (if there is only one boiler, as on the small jobs we've done in P/S) or it may be on its own secondary loop (this method may be used with one or more boilers).

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Dave Yates (PAH)

well........

perhaps we should term the heat sourc(es) as the feeder loop(s).

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Weezbo

great take

you got the hole drilling done without hitting oil evidently well,..no problem did you check for gold? gold would be good

ah well, solar ..maybe ...is the next best thing *~/:)

[Deleted User]

Technically speaking...

There can be secondary inputs, as well as secondary outputs.

In some cases, the actual primary loop is just that, a loop to nowhere but itself. It could have secondary (multiple,and varying fuel sources) dumping heat into the loops, and multiple (different temperatures/flow rate requirements) secondary outputs.

So, me thinks it best that which ever loop the expansion tanks and main air seperator are connected to should be considered the primary, and all other loops pumping away from this primary loop would be secondary loops, with the ability to either put heat into or take heat out of the primary loop.

And you are correct Dave, there really are no industry "standards" spelling it out. I guess we'll just have to take the bull by the horns and make it so.

And so it is, and so it be.

NOw, how do we spread the "word" to the industry? I know the cream of the crop of the industry comes here, from boiler makers to boiler installers. We've got a start on it. We just have to spread the word, and when we see a manufacturer doing something that doesn't make sense, bring it to their attention and let them know what makes sense.

So, whats new...:-)

ME

Brad White_134

Primary-Secondary. PS I love you

My understanding has been that primary refers to the heat source or highest temperature and secondary being the system (radiation) loop. Sub-mixing from the secondary such as a radiant zone would be tertiary. (I tend to stop there.) But the concept is founded in the direction of heat flow, from warmer to cooler.

Often when writing a technical report such as a design statement for a schematic design (presented to generally lay-persons not necessarily technical) I will define the terms up-front and use the terms "boiler loop" and "radiation loop" to distinguish them.

May or may not be "correct" or have universal agreement; it is just what I do and understand. It makes sense to me anyway...

My $0.02

Brad

brucewo1b

Gee Brad

NO wonder we can't understand engineereeze, I was taught that the primary loop was always the loop with expansion/compression tank and water feed.

BTW how did the pickle get in the jar?

Brad White_134

I was always taught

that the primary loop would be the boiler -and that is where the air separator and hence expansion tank would go- so there is some truth to that. The boiler also has the safety relief valve, LWCO and high limit, reinforcing primacy

The pickle trick- It was grown inside the jar. When asked if that is how it was done, they lied and said "no".

And we are on a full-name basis now, are we, Bruce? Too many Bruces? No my friend, only one Bruce I trust before the others....

Primarily Yours,

Brad

brucewo1b

Primary Reasoning

I was told that it was the loop with expansion tank and waterfeed is that if you have two boilers they would then be secondaries along with the zones being secondary. Make sense??

You know how it is curiousity killed the cat, and I might be short lived on that account

[Deleted User]

But, what if....

there are more than one heat sources. I.E., when I do my systems up at XanaX Ranch, there will be an LP Mod-Con, a pellet fired boiler, a G.S.H.P., a Hydrogen Fuel Cell generator and Solar THermal, plus my earth linked storage system. How many primaries in that picture?

None of those individual heat sources will have the PONPC attached to it exclusively. Each heat source will be connected to a short loop primary with their own individual secondary branches.

I have no problem with what you are doing Brad, because you spell out your interpretation. THe problem lies within the industry (boiler and ancilliary equipment manufacturers). THere is no standard there, so they pretty much call it the way they see it, which is not always correct.

If there is a single boiler, and it has the PONPC and the primary air control system attached, then it COULD be the primary. But in the case of my ranch, it WOULDN'T be the primary.

Get my drift?

ME

Joannie_11

Loops

This is why I always call them "Boiler Loop" and "System Loop" and sometimes "Zone Loops."

hot_rod

Loop with PONPC would be my vote

I also do systems with multiple inputs, wood, hydronic, sometimes solar. My best example is the circular primary loop I built at my shop.

Check out Siggy's August 06 colume in PM mag. It explains delta P through a system and some options for locating and referencing the PONPC on mod con installs with indirects piped to them.

The PONPC is actually "referenced" through the indirect coil when the boiler switches to SH loads.

hot rod

Ken_40

Don't think so...

But am not THAT sure either...

Let's define one only, the "primary" rendering all others as secondary.

The PRIMARY LOOP is the pipe-manifold which is COMMON (connected to) to all others.

In the case of two, distinct, PRIMARY LOOPS (as in a high AND low temp array) it's simple. There are two (or more) PRIMARY LOOPS.

I don't believe the PONPC, the boiler itself, or circ. location is part of the requirement to define either!