Apprenticeship Week #1

  When I last reported in my final Walkabout diary, Coming to Rest, I indicated that I’d been doing some fund raising for farmerchuck’s business, Hilltown Alternative Energy. I’ve agreed to stay on here and do an apprenticeship with Chuck, learning the distributed heating business.

  This first week has been a lot of shuffling around getting things lined up and learning a bit about the boilers themselves.

   The main product line is from Central Boiler.  Farmerchuck runs a Classic 7260 – their largest system, with a 72" x 60" firebox and dual hot water feeds. The reservoir in this one holds nearly eight hundred gallons or sixty four hundred pounds of water and it’s set to run at 185 degrees. A BTU is the energy required to raise a pound of water one degree and the house heat exchanger can take energy out down to 140 degrees, so this is a storehouse of 45 x 6400 = 288,000 BTUs. Farmerchuck’s big, draft Revolutionary War era farm house takes a lot to heat in the winter, but the 7260 does just fine keeping it, another house on the property, the dairy, and the creamery warm.

 The buildings are scattered around the farm and given the number and layout the dual feed 7260 was the right machine to use. Here we see the outputs. The taller pipes are where the hot water is taken from the system, the shorter ones are the return paths. The water circulates continuously via a device called a cartridge pump. The feed line on the left has a Taco cartridge pump in line while none is seen on the right – that one has its pump inside the farmhouse itself. I think the rule here is that the pump goes at the lowest point in the circuit. The farmhouse is downhill from the boiler and the pump goes there, while the one seen in this photo pushes water up to the dairy and creamery.

 Here is a little closer view of the cartridge pump. The name is derived from the pump’s layout. The stuff on the right side can be unbolted from the part that interfaces directly to the plumbing, allowing for quick, easy replacement of the moving parts.

 Here is one of the places the hot water ends up – a heat exchanger in the house. The heat is baseboard and this plate style exchanger passes energy from the boiler’s water reservoir to the water in circulation in the house. Some wise guy will ask "Why was this necessary?" Strictly speaking it wasn’t – this was one of Chuck’s earlier projects and he wanted to play with heat exchangers, so he put one in this location.

 Here is the other destination – a mixer. You feed hot and cold water into this, turn the manual knob, and pick the temperature you want. There is a little thermostat inside the controls the amount of hot water passed, thusly setting the temperature.

 The cartridge pumps wear out, the circuit boards for controlling the system can go bad, and the solenoid that controls the damper on the fire door, which determines the fire temperature, can sometimes fail. This one stuck open, resulting in swift, hot fires, and chilly morning showers for the customer until we showed up and replaced it. Those three are 75% of the troubleshooting on these systems ... the rest is a weird mishmash of thermodynamics issues, air in the water loops, and cleaning up on poorly conceived modifications done to operating systems.

  I’m not having a great deal of trouble absorbing the details on this, but I have the advantage of having been a "network plumber" for the last decade; I’m used to thinking in terms of things providing or using resources on a distributed network. Oh, and I have the advantage of having started in engineering before switching to computer science, so I had thirty credits of math, physics, chemistry, and statistics way back when.

  I’ve started and erased this three times, grasping for a nice, tidy way to sum up what I’ve learned. I guess what I can say is this: Damn, we sure do need an illustrator!

 I’m not kidding a bit there – we’re at a point where we’ve got a lot of good writers, two solid editors, but Etch-a-Sketch for Dummies would improve our graphics tenfold. I noodle a bit with Visio but it’s been all network stuff, nb41 can whip out simple, effective line diagrams, but we need someone who can do a nice job. I keep hoping someone with a technical illustration background will get fascinated with this stuff, but we’re at the point where we pretty much need to hire it done, as it’s constraining us.

   OK, this seems short, but it’s a good stopping point. Next week I think we’ll talk about business infrastructure.