My Arctic Vacation
I like to take my vacation in places where most folks don't go: Africa, Guatemala, and this June, the Arctic Ocean.
I was thinking about you plumbing and mechanical folks the whole time, because I saw things that you would've loved. How about 800 miles of 48-inch diameter, 1/2-inch-thick pipe - that's 19,000 truckloads - with 108,000 welds holding it together! It's the Alaska Pipeline. More than half of it is above ground; that means you can see it, touch it, and feel the heat.
The heat, more than the pipe, made me think of you. It was the principle of heat transfer that brought you to mind - the rule that heat moves to cool.
That principle is what makes hydronic heating work. The heat of the burner moves to the cooler water. The heat of the water then moves to the cooler living space air. Giving up its heat, the water cools. The cool water goes back to the boiler and picks up heat again from the burner. And on and on.
The word “arctic” makes us think of cold - extreme cold. You'd expect the main interest up there would be getting heat. But as it turns out, too much heat is more of a problem, whether in buildings or the pipeline. Much effort goes into getting rid of heat.
The place where I actually touched the Arctic Ocean was Prudhoe Bay, on the northern coast of Alaska. I got there by way of 358 miles of gravel road, driving north for two days from Fairbanks. The mountain and tundra scenery was gorgeous. The temperature was unseasonably cool in the high 30s, the wind wicked, and the port-a-potties few. In all those miles between Fairbanks and Prudhoe Bay, there were probably no more than 20 other vehicles, and even fewer buildings. Most of them were pump stations for the pipeline. Five of those pump stations had refrigerated foundations.
Prudhoe Bay exists because of the oil fields that feed the Alaska Pipeline, which takes oil 800 miles across Alaska south to the port of Valdez. No one permanently lives at Prudhoe Bay. There are no private homes or schools or kids or pets. People go there only to work. In the winter, 1,500 people work there, drilling oil or supporting the operations. In the summer, the number of people drops to 1,000, doing maintenance to prepare for the winter work.
The only thing to do there is work or sleep. Folks work 12-hour days, seven days a week. Work may be days or nights, but it doesn't matter, because it's always dark in the winter. You thought you had it bad! But once a person gets a job, he or she keeps it until retirement. Why? Because it pays extremely well, and to balance out all those weeks of work, there are the weeks off, when they go home for, depending upon the job and the company, three to six weeks at a time.
Down The Pipeline
The reason drilling can be done only in the winter is that the ground - called permafrost - has to be frozen if it's going to support anything. When thawed, it's a marsh, so anything of weight sinks. There, -40 degrees F is good weather for work.
Because the permafrost needs to be kept frozen, and because buildings and pipelines generate heat, refrigeration is critically important in the Arctic. Who would've thought! But no matter where you are, heat moves to cool, and heat moving into the permafrost causes it to become muck. Besides building refrigerated foundations, a large part of the pipeline is also cooled.
It's evident how a building would generate heat, but a pipeline? In Prudhoe Bay, oil comes from an average depth of 9,000 ft., down where things are hot. Since heat moves to cool, especially if the temperature is 40 below, that heat wants to move. But there are two reasons for slowing that movement way down. First, as you now know, the permafrost must stay frozen. Second, the oil has to stay warm in order to flow the length of the 800-mile pipeline.
Where the ground isn't critically sensitive to heat, the pipeline runs underground. But for more than half of the pipeline, the permafrost will thaw, even with insulated pipe. So for 420 miles, the pipeline runs above ground.
Even with elevated pipe, transferring heat to the ground is still a problem. The 48-inch-diameter pipeline is supported by 18-inch-diameter H-shaped steel supports. Of the 78,000 vertical supports that extend into the ground, 61,000 are fitted to dissipate heat above ground to keep the permafrost below the pipeline frozen.
This heat transfer is just like hydronic fin-tube heating - the tops of the supports are fitted with finned aluminum radiators to dissipate heat. The supports in the ground are filled with ammonia refrigerant - the same technology that was used in old-fashioned refrigerators. The refrigerant is vaporized by the oil's heat. The refrigerant rises, carrying the heat with it. Above ground, the heat in the refrigerant moves by way of the aluminum radiators to the much cooler outside air. I'll say it's cooler - a range of 40 degrees F below in the winter to 40 degrees F above in the summer. Because heat moves to cool, heat can be removed from the ground whenever its temperature is greater than the temperature of the air.
This is the same heat transfer principle as modern air conditioning and refrigeration, but it doesn't require electricity.
Back in the employee housing where I stayed, there was some heat transfer going on as well. The housing was a dormitory: two single beds per room, toilets and showers down the hall, and very, very warm. The outside temperature was somewhere in the 40s, but inside was like any overheated institutional building. It was hot in the hallways, and it was hot in the sleeping rooms. You could open the window (an all-too-typical method of heating control everywhere), but if you wanted to block out the endless daylight in order to sleep at night, you had to close the window shade, which stopped the airflow from outside.
The problem was that no one had told the miles of hydronic fin-tube baseboard that it wasn't winter any more. All of the radiator valves - in full view in the hallways if you knew what you were looking for - were set at three out of five, and some were set at five. No wonder it was hot in there. There probably wasn't any boiler temperature reset, either.
So, I want to report that I did my hydronic-controls-person good deed for the summertime workers at Prudhoe Bay. I turned off many radiator valves that night before I went to sleep. In the morning, I overheard several comments that the temperature in the building sure was a lot better.
The definition of the Arctic Circle is the point where there is complete light part of the year, and complete dark the other part of the year. I found it delightful to wake up at 3 a.m. and see full daylight. Yet during the opposite part of the year, there's complete darkness. Coping skills? Two of our tour guides had a solution I certainly hadn't thought of: They work half the year in the Arctic (North Pole), which is light during our summer. And for our winter, they work in Antarctica (South Pole), where it's summer.
I know a plumber who escapes our winter by working November through March in Antarctica, where it's continually light and about 40 degrees F.
So, as the days get shorter this fall, and you think about escaping to Florida or Arizona, check out the Web site www.rayjobs.com. When the page comes up, click on “featured opportunities” from the list on the left, and then choose “polar services.” Your winter getaway spot for endless sun might be Antarctica. I hear they hire plumbers.