one pipe steam remodel, lots to look for, Pat Linhardt

Patrick Linhardt, \"Linhardt's Field Guide to Ste

Hi Frank,

No, they were just there to "move" the radiator. The boiler installation was done by a local company years ago that must have been thinking of furnaces when sizing.

I agree that it would be nice if people did the right thing, it would save so much energy. Maybe our dependence on oil could be reduced if more attention was paid to home heating, a 24/7 operation for 6 months of the year.

Their idea of system balance is odd, use no vent on the short run, and one OK vent on the long run. Definitely would work better with your proposal. Mo venting - mo better.

Best regards, Pat

Patrick Linhardt, \"Linhardt's Field Guide to Ste

one pipe steam remodel, lots to look for

I got a call from a service tech that sounded innocent enough. He was asking about main air vents on a one pipe system and I was happy to answer his questions. He's a good tech that wants to do the right thing. I like those kinds of guys.

He sounded a little unsure about some things, so I asked him if he wanted me to take a look at the job. Since I love to look at steam systems, we set up a time.

We went straight to the basement, and that's when the story got more complicated. He pointed to some new pipe that was stone cold. It was feeding a radiator that they moved for a room addition. They took it out of the kitchen where it stood for 80 years to put into a new family room on the other side of the wall.

They came off the original 1-1/2" horizontal runout where it used to turn up. They put on a 1-1/2" x 1-1/4" reducer to horizontally extend the pipe out to the new radiator location. All we could see in the basement was about 4 feet of new pipe before it disappeared into the stone foundation wall. It was hot to the reducer and then turned to ice before entering the wall.

Since the original call was about the vent, he showed me the two end of steam main vents located conveniently right at the boiler. Both were 50+ years to a day, and curiously didn't make a whisper of a sound during a steam cycle.

The size of the boiler also caught my eye, one of the smallest in the line. Now this wasn't a big house, but it appeared to be more house than that boiler could support.

So, I had a few things to sort out to determine why the supply pipe was cold.

1) was the boiler big enough? without enough steam volume, it can't fill the system.

2) what size pipe should have been used on the re-pipe to the new radiator location? to figure that out, you have to know how far it goes, and what size radiator it feeds.

3) what size working air vents need to be at the end of the steam mains? without main vents, all the air has to pass through the radiator vents, which can cause un-even heating.

I went out to my car to get the answers. Using the table on page 163 of the field guide, we calculated the radiation load. The result was what I suspected, over 500 square feet of radiation connected to a 325 square foot rated boiler. No problem said the homeowner, "We don't use all the radiators on the second floor, I'll just shut a few off". We re-figured the load and came close to the rating. Question 1 resolved.

Using page 161 of the field guide, we see that the 42 square foot family room radiator would use a 1-1/4" radiator valve, but since the runout was well over 6 feet, it needed the next size up. This is one detail of one pipe that often gets overlooked. When the horizontal runout from the main is over 6 feet long, a larger pipe size is required, since steam is flowing in one direction while condensate is flowing in the other. The pitch of the pipe is important for that same reason.

This is where this job failed miserably. The runout ended up being about 16 feet long, through an unheated crawl space, with no insulation, and the wrong pitch. The installation crew did a lousy job to say the least. No wonder the pipe was ice cold in the basement. The runout was the wrong size, the wrong pitch, and not insulated.

Using page 85 of the field guide, we checked the vent size. The main feeding the front of the house and most of the radiation was only 35 feet of 2". The main feeding the back of the house, and the cold radiator, was over 80 feet of 2" pipe. So, one main steam vent would do for either.

But we did a bit more free lance trobleshooting on the venting situation. There was a 100 sq. ft. radiator in the living room where the t-stat was located with an adjustable air vent set for maximum air flow. The family room radiator had a non-adjustable vent. I suggested that we swap the vents. This would speed the air venting of our cold radiator, and slow the venting of our hot radiator while increasing the run time of the boiler.

I offered my suggestions/observations to the tech who was going to run them by his boss. He called back in a few days to say it was working fine now. I had to know how.

They decided to insulate the runout and gave it as much pitch as was possible under the circumstances, but left it at 1-1/4". They put on one Hoffman #75 on the long main, but left the original non-functioning vent (plug) on the short main.

He said the family room radiator was working just fine now, but the living room radiator was a little cold with the non-adjustable vent, so they changed that out to a Hoffman 1A set about 2. I said call me next time before the install crew runs any more pipe.

Steamhead (in transit)

Sad to think

of how much better the entire system could be working, if they'd listened to EVERYTHING you told them. I think you'll be back at that job before long when they see the fuel bills.

The boiler sizing and main venting are the two big problems. The Hoffman would be just right for the short main. I would have vented the long one with two Gorton #2 vents.

Did the same company install the undersized boiler?

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Anthony Menafro

Linhardt

Thank God for Mr. Linhadrt and the Field Guide to Steam Heating. I can't say enough good things about the book and the ease of use with it. I'm happy to say that I talked two of my coworkers who are interested in truely learning about steam heating and steam systems into purchasing the Field Guide. They have looked my book over and can't wait for their's to be delivered. Thanks again Mr. Linhardt.

Anthony Menafro

Patrick Linhardt, \"Linhardt's Field Guide to Ste

many thanks

Hi Anthony,

Thank you for the kind words and the ringing endorsement. I'm glad to hear you have some co-workers who want to learn. There is a wealth of info at the Library section of this site. Enjoy.

Best regards, Pat

Boiler Guy

A classic case

of NOT acknowleging one component as part of a "whole system".