One-Pipe Steam - Bet You Thought It Was Dead!
The call came in on a day when a no-mercy wind whipped out of the northwest, as it often does during a New York City winter. No heat.
Since the ancient but newly renovated apartment building was still under warranty, the folks down at New York City's Department of Housing Preservation and Development passed the call on to the installing heating contractor. He immediately sent a man out to get the burner started.
There was a problem, though. The burner was no longer attached to the boiler. In fact, the burner wasn't even in the building. Now as you know, one of the first rules of troubleshooting states that If It Ain't There, You Can't Fix It, so the serviceman began scratching his head, wondering what to do next.
Within a few minutes, his answer appeared at the boiler room door in the form of what appeared to be a basket of dirty laundry with legs. It spoke:
"Yo! Your boiler needs one of them things, man. Yeah! I know where you can get one of them things. I seen a guy selling them round the corner, ya unnerstan'? Gimme forty bucks I'll go getcha one right away."
Welcome To The Big Apple: New York City has an enormous homeless problem. Look around. You'll see people stacked like cord wood in the parks and doorways. The City also has one of America's largest stocks of abandoned buildings. These blown-out, windowless shells are peopleless. Nobody wants them.
Most people blame the latter problem on rent-control laws. You see, as operating costs rose over the past few decades, many landlords abandoned their buildings rather than take a financial loss. The City picked up those buildings, one at a time, when the landlords didn't pay their taxes.
The City calls this "in rem" housing which is a legal term meaning, loosely, that when it comes to paying your taxes -if you snooze, you lose. These buildings which pockmock the South Bronx and the poor sections of Brooklyn and Queens are the mongrel dogs of New York City architecture.
A few years ago, much of the "in rem" housing visible from New York's major highways was decorated with hand-painted plywood window coverings. Each window had a gaily colored set of curtains. Some had flower pots. The paintings looked like bright pennies on a dead man's eyes.
In 1984, a group of city agency people began looking at both the "in rem" housing problem and the homeless problem. They came up with an idea: Why not fix up these old buildings and create housing for the homeless as well as for low-income people.
They started a "patch and get out" pilot program. Their plan was to do as much as possible with very limited funds. Unfortunately, most of the buildings had deteriorated to a point where there were few places to stick the "patches." Before long, the agency people realized that it was actually less expensive to gut these buildings, right down to the floors and walls, and begin anew.
Look at this situation from the City's perspective: During the early '80s, people on government assistance (mostly women with small children) were being housed in single-room occupancy hotels at a cost of about $35,000 per year, per family. The cost of renovating one of the abandoned buildings was about $65,000 per unit. Gut rehab made good sense; the payback period was less than two years,
Then, a few timely court decisions stating that a single room occupancy hotel was no place to raise kids made up everyone's mind. The people were out on the streets. Gut rehab was the way to go.
Since then, about 160 buildings have either been finished, are under construction, or out to bid. These buildings are big - four, five and six stories tall. Some hold as many as 60 apartments.
And all but the last 15 buildings (now out to bid) have one-pipe steam systems,
That's right! One-pipe steam.
I'll bet you thought it was dead.
Resurrection Of Steam Heat: New York City didn't decide on steam because the pipes were already there, Remember, this was floor-to-walls gut rehab; there were no pipes,
No, the adoption of this supposedly dead technology was a very deliberate choice, Pretty interesting, eh? Especially when you consider that the vast majority of people who understand steam heat nowadays are dead.
Why did the City decide to resurrect steam at a point in heating history when black-box technology and personal-size boilers are taking over? Well, there were a number of very good reasons.
First, steam once heated these buildings, The architects and engineers figured that if steam worked once, it should work again.
Makes sense, doesn't it?
Second, when the heat goes off (in other words, the next time the burner gets stolen) the pipes won't freeze because in a steam system, most of the pipes hold no water.
Next, if a pipe breaks in a steam system, there's very little damage. You don't have to call Jacques Cousteau, as you often must when a pipe in a hot water system breaks.
Steam systems are also easier to design and balance than hot water systems. (When properly done, this is always true.) And steam travels a lot faster than hot water -up to 60 mph! Hot water, at best, moves at less than three miles per hour.
As an efficient delivery system for Btus, you can't beat steam. A pound of this hot stuff will typically deliver about 980 Btus to the radiator, a pound of hot water, on the other hand, usually carries a mere 20 Btus.
Steam systems are as rugged as Mosler safes; that's why there are still so many of them after all these years. The parts to which the tenants have access won't break as easily as the parts of a hot water system will. Why, give the folks steam and they can bang on the pipes to make the heat come up - as they did in the old days!
But most important (and this was the deciding factor), there's nothing worth stealing in a steam system. There's no copper, just worthless steel.
"A contractor can look at a truckload of copper tubing and see a truckload of copper tubing," says Dennis Belie, Project Development Coordinator at New York City's Department of Housing, Preservation and Development (HPD). "But to a drug addict that's not a truckload of copper, that's a jewelry store!
"When we tried hot water heat, the only way we could keep the copper in the building beyond the first sunset was to paint it black as soon as it arrived on the jobsite. Once it was black, the locals thought it was steel."
Belie also told me that before the tenants move in, the general contractors usually weld a 3" wide steel bar across the middle of the front and rear door frames.
"That's the only way they can keep the refrigerators from taking a nocturnal stroll," he said.
Can you see how one-pipe steam begins to make sense? The City did. But the next problem they faced was finding people who remembered how to design and install the stuff.
"Most of the early problems were caused by rookie engineers who had no knowledge of steam heat," says Dennis Douglas, a Supervising Mechanical Engineer at the New York City Housing Authority. “For instance, a lot of the early plans and specs had steam traps going into places where steam traps had no place being.” On a gravity-return system, misplaced traps can cause water to back up into the steam pipes. That can (and did!) create water hammer and low-water problems in the boiler.
“There was also a problem with coordination,” Douglas continues. “Main air vents were left off the job or installed in the wrong places. And since venting is everything when it comes to one-pipe steam distribution, major problems popped up when we turned the jobs on.”
But perhaps the strangest thing that happened on many of these jobs was that the design engineers left the major decision of what size the pipes should be up to the installing contractor. In fact, one of the first things that strikes you when you look at the plans for these projects is the highlighted statement at the bottom of each page. It states, “Pipe sizes shown are for informational purposes only.”
That leaves the total responsibility for successful results (defined by the City as quiet pipes, even heat and no water spillage from the vents) to the installing contractor. On these jobs, he wears all the hats.
Don’t Believe Your Eyes: Ronnie Guterman and Tom Burke own and operate Parkset Plumbing & Heating Co., Inc. in Brooklyn, NY. They’ve been involved in 10 of these buildings so far. Each has had its own peculiarities.
“We couldn’t work with the plans the City gave us at first,” says Guterman. “The pipe sizes were all wrong. Common sense told you the systems wouldn’t work. The risers and returns were too small, the mains were too large. In one case, they were draining the end of a 3” main down into a ¾” pipe. You could just imagine the water splashing back. God help anybody who put the system in the way it was drawn.”
“We left the pipe sizing as an open end,” says HPD Dennis Belic, “because the contractor had to deal with the real-world geometry of the old building. We didn’t know what he was going to find out there. Giving the contractors the freedom to modify made sense. In fact, it gave them an opportunity to save money on the job if they could downsize pipes and still give us the results we were looking for. They would, of course, coordinate any changes with us.”
Having the freedom to size the pipes offered opportunity to some, and peril to others. For instance, one contractor increased 1-1/4” and 1-1/2” risers to 2” and still saved money. He could do this because he’d gotten a quantity discount on the 2” pipe and fittings from his local plumbing supplier.
That job worked out well because in a one-pipe steam system, steam velocity is crucial. If the risers are undersized, condensate won't be able to fall back down against the up-rush of steam. This leads to water hammer, spitting air vents and low-water problems in the boiler. Oversizing the risers to get the right price on the material probably saved this contractor a lot of problems. Had he gotten the same good deal on 1" pipe, well, that would have been a sadder story.
I asked Tom Burke if it was difficult finding men who could put a one-pipe steam job together.
"We put together a team of eight guys. This was our Steam Team. We trained them in proper pitch, how to run takeoffs and riser drips from mains. We drilled into them the importance of the differences in heights between the horizontal pipes and the boiler water line. These guys worked together on every job, and every job worked. We weren't looking at these jobs as a hit-and-run proposition. We took tremendous pride in each one. We wanted them to work."
Guterman agreed that the right men and the right attitude was the key to success, but there's no substitute for experience when it comes to steam.
"The biggest problem we had on those jobs was surging. You can't imagine how much oil was in this system on start-up! We used tri-sodium phosphate and let it cook in the boiler for at least six hours. Then we skimmed it off through a port we set up at the water line. We also wasted all the condensate for two days after start-up. That took a few extra valves on the return, but it was worth the cost. A lot of guys neglect details like cleaning when they work on a steam system. We don't. That's one of the main reasons why our jobs work so well."
Thoroughly cleaning a steam system after installation is common sense, but that doesn't mean it's common practice. HPD's Dennis Belic confirms this. "Most of the contractors we worked with tried to cure surging by throwing chemicals at the job and walking away. That doesn't work. You have to take your time and do it right."
Having had such a positive experience, Ronnie Guterman and Tom Burke have become fans of steam heat. "There are a lot of contractor benefits to it," says Guterman. "First, there's less pipe than there is in a hot water system. There's also less mechanical equipment to break down. I mean, as far as maintenance goes, all I have to be concerned about is the burner and the low-water cutoff. And since we're using the new probe-type low-water cutoffs, I don't have to be concerned with somebody forgetting to blow the unit down."
Burke adds, "We didn't have any air or balancing problems on the steam jobs. With hot water, we would have spent days bleeding and balancing. And the steel cabinet convectors we used are tough enough for the people living in these places. With baseboard radiation, we were always fixing the fins and replacing the end caps that took a walk before we could finish the job.
"And you have to remember that during the summer, the kids stand and bounce on the baseboard when they hang out the windows to yell to their friends. On one job, we spent two weeks fixing leaks the kids had caused. We don't have those problems with steam." "But the best part," says Guterman, "is there's nothing worth stealing. We don't even lock these buildings up at night. What's the point? There's nothing in there worth ripping off. The pipes are steel, so are the fittings and convectors. We just lock our tools in the site trailer and leave the building wide open. We've never had a problem."
System Of The Future? But in spite of all these benefits, New York City has decided to kill the "Steam Dream." The jobs now out to bid call for hot water heat.
"The reason we changed our mind was a very human one," says Dennis Belic of HPD. "To convince local community groups that the Special Initiative Program for the Homeless was a benefit to their neighborhood, we had to give the groups the basements. We set up offices for them, rooms for day-care centers, laundromats, meeting rooms. That left us with a physical problem -how do you properly pitch steam pipes without having ugly soffits -and without decapitating tenants. Most of these basements don't have much headroom to begin with. Once you start building down there, you're limited to what you an do.
"Many of the contractors involved in these jobs weren't as successful as Parkset," he continues. "We had a lot of banging and leaking air vents. The lack of height in the basement also meant that we couldn't run many of the jobs on gravity return. We also had to bury a lot of the steel pipe. And that's not good at sites where there's a lot of ground water. Some of those buried returns only lasted six months."
Dennis Douglas of the NYC Housing Authority says there continues to be engineering problems with steam.
"It's difficult for people who have never had experience with one-pipe steam systems to design them. Training has helped a great deal." (Last spring, the City hired me to conduct both steam and hot water seminars for their engineers.) "But you have to know what you need to know before you can learn it. That's where the experience comes in.
"And now that we've gained both the knowledge and the experience, there's a core of people here who are willing to continue working with one-pipe steam. But for the near term, we'll be working with hot water."
Douglas admits that balancing, air binding and oversizing (mostly of circulators) continues to be a problem with the hot water jobs now being done, however. "And we still have to deal with the static height problem. It takes 30 psig to get water up to the top of some of these buildings. That puts us into a higher-pressure boiler in most cases."
The hot water jobs the City is now installing have steel risers and copper runouts to the baseboard radiation. They paint the copper black and separate the two metals with dielectric couplings to prevent corrosion.
Not long ago, in one of these buildings, a bit of black paint rubbed off a piece of copper. It wasn't much, just enough to let the glimmer of copper shine through. Just enough to catch the eye of some poor unfortunate who, that day needed a few bucks.
Would somebody please call Jacques Cousteau? He's needed in the South Bronx.