Gorgeous Hydronic Piping – But Beware the Butterfly Effect

So the stream from the system is coming from proper and left to mix into the vertical 3” pipe, flowing down, or from the ceiling to the ground. The following two full dimension tees are a part of the first/secondary connection, permitting the system loop (major) and boiler loop (secondary) to have stream charges that don’t have an effect on one another.

I used to be taught a few years in the past that the principle loop was the first and the department loop was the secondary. Made sense to me, however most boiler producers modified that round once they launched the idea with mod-cons.

These days, I say system loop and boiler loop when referring to major/secondary piping, low loss headers, or hydraulic separators. All three piping methods have 4 connections: boiler provide, boiler return, system provide and system return.

The Child is Rising Up

I used to be educating a category the opposite evening, the Child was there. You keep in mind the Child, the man I used to be coaching years in the past. Properly he interrupted me whereas I used to be explaining major/secondary piping to the category. Possibly I used to be between factors, however it undoubtedly stunned me as a result of he’s normally fairly quiet.

He went as much as the whiteboard and drew a major/secondary connection achieved fallacious, on objective. He had it configured like many installers have tried over time, with the department connections of the tees piped collectively. It makes a pleasant sq. on paper, however isn’t the best way it’s alleged to be.

He defined that the right manner is with the frequent connection between the tees to be on the run of the tees, not the branches. He then drew a major/secondary connection for a mod-con boiler the fitting manner. A tear got here to my eye; the Child is rising up.

Much less Than Good

This job was piped appropriately, major/secondary connections will be in a horizontal or vertical orientation. The tees are shut sufficient and full dimension. Then there’s a discount from 3” to 1-1/2” on the boiler loop, which isn’t precisely right, however he known as sooner or later to say his becoming provider couldn’t furnish the fitting stuff and will he do it like that.

Generally I permit lower than excellent/right piping as a result of the distinction doesn’t have a lot impact on efficiency. On this case, the smaller than superb pipe dimension creates extra water strain drop within the frequent boiler loop piping, when each boilers are working. This improve is definitely dealt with by the boiler loop pumps, which have further capability. They could run on the excessive pace as a substitute of the medium pace.

The installer took nice care to make the connections on the boiler loops the identical distance, what I name the butterfly look, since butterfly wings are typically equivalent. On this case, with the piping working horizontally, he branched the return piping up whereas branching the provision piping down.

It appears nice, however creates an impact—a butterfly impact. Because it goes up increased than the return connection on the boiler, it has to return down. Each time a horizontal pipe goes up vertically and goes again down vertically, air can get trapped on the excessive level. When sufficient air will get trapped, circulation stops.

Troubleshooting

That’s precisely what occurred after we began up the boilers. The burners got here on, the water within the warmth exchanger bought super-hot and the boiler went into a tough lockout. I had them test the wiring for the boiler loop pump, since this is a sign that we didn’t have water stream via the boiler and discovered that they have been wired incorrectly.

With this boiler producer, the boiler loop pump is wired otherwise relying if it’s a business or residential boiler. He will need to have had his residential pondering cap on when he wired it. After it was re-wired, it did the identical factor. It was the air within the return line.

We have been capable of purge the air out by closing the valves on the boiler provide traces and opening the boiler drains, one boiler at a time. It labored a few occasions however reappeared a few occasions earlier than we determined to go to lunch. Air was getting back from the system and getting trapped in these excessive factors on the boiler return traces.

At lunch, it was determined so as to add handbook vents to these excessive factors to bleed the air out, after leaving the system pumps on for the weekend to get extra air out via the in-line air separator.

That is the seventy second column I’ve written for CONTRACTOR. After they known as me six years in the past, I stated I’d attempt to do that for 3 years. I generally assume that I’ll run out of informative matters, however then one of many subsequent web site visits has that picture op that I can ramble on about.