Construction Report: Burning the Midnight Oil

This is real dedication to meeting the construction schedule:Richard making a heating manifold

Here is Richard at work on the piping layout for the radiant heating grid that will lie beneath the floor of the workshop. How nice it will be to stand on warm concrete through winter evenings! To be able to work in socks instead of mukluks! Do you know how cold my feet get? (Richard does.) But before such pleasant work times, must come the building times. At midnight last night we looked down upon our work and smiled. All the pipes were connected and glued, all the loops of the grid lay beneath the reinforcing wire that will support the concrete floor, all the pipe was tied to the grid with little zippies every 3 feet. We were unable to stand up and walk normally, but the grid was finished, and in time for the inspector to look at it in daylight. Magnificent, isn’t it?

Piping grid for workshop floor

Lest you wonder why we were doing this in the dark, let me elaborate. The mechanical inspection had been ordered in concert with the concrete-pouring schedule in the confidence that it wouldn’t take all that long to make up the loops of CPVC pipe and set them in place. And while that was true who could know that, first, the supply line would have to be dug out of its bed of gravel and sand and foundation work two feet deep and replaced because of, let us say, specification errors? Who could know it would take a statewide search to find correct reducing tees and couplings? And who knew they would arrive in the early evening of the day before the inspection? Who even imagined?

So here we were, happily sharing the night with the hoot owls and coyotes, and Yellowcat who carefully supervised the whole matter.

Published in: Uncategorized on September 21, 2007 at 11:50 am  Comments (8)  

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8 CommentsLeave a comment

  1. Impressive!! I assume the inspection went well….

  2. Let us say it was… challenging. But we prevailed.

  3. I have a much reduced opinion of the inspectors hereabouts than I had going in. Mike O’s neck of the woods (Portland), by comparison, and presumably under his influence, is receptive to unusual but sound ideas. This county is trying its best to ruin the quality of life for existing residents and to establish cheap developments that will be sprawling slums in 20 years – much like what happened in Southern California around the time we were students.

    In a word, I built that system twice, once in PVC because it is approved for non-potable warm water in systems not within the building envelope. My understanding from more than one architect that the building envelope begins at the surface of a poured concrete slab. When that was not approved, and with express guidance of the planninig department, we built it again using CPVC which the code expressly states is good for hyponic heating systems. (Unfortunately, nominal 1.5″ CPVC is the size of nominal 1.25″ PVC! So our experiment in terms of comparing the conventional hyponic system with the “Yarnell/Moore radiant grid” is flawed.) Not only that, as Susan has told you, rounding up the fittings to do the job required overnighting some of them to the job site. Not a conservative way to build.

    But it’s in, the slab is poured (making the building seem that much smaller) and the shell will be erected in two or three days beginning on Monday. Finally.

  4. you refer to “nominal measurements.” As limited as my ideal government is, standardization of measurements is a critical government function, whether it be in the weight of gold in money, or the number on a hatband, or the significance of numbers on a speedometer, or internal diameter of a pipe.

    Richard should be aware that a clever person has invented knee pads for working situations such as the one photographed here.

  5. I suspect they produce slightly different sizes so that contractors don’t mix the two kinds of pipe. CPVC is more robust and approved for potable hot water. They also color the stuff differently and color code the cement. But, on balance, I’d say you go too far suggesting that the number on a hat band is anything more than a measurement of the radius of the head, that numbers on the speedometer indicate speed in mph or kph (although the government did try to get us to change to the metric system, for once a wise try, if unsuccessful); and that the ID and OD of pipe is an industry convention just as so many other commonly used construction materials.

    As to gold in the coins: you bet that should be a government function – history instructs that that’s a wise choice.

  6. Congratulations! And Susan is right, it will all be worth it when you can stand on your slab in your stocking feet and it feels warm. I think our aging bodies really appreciate radiant heat.

    Portland’s receptivity to new building ideas is mostly due to Commissioner Randy Leonard. He has brought the building department into a new world of customer service. Our office is funding a position to identify and resolve code conflicts.

    Just curious, how come you preferred PVC over PEX?



  7. PEX has only a limited range of sizes and fittings. Our grid (refer to the picture) uses only one connection to the warm water source and a “reverse flow” pair of manifolds or headers. As you can see, each pair of 3/4″ tubes connects to a different manifold and the fluid in the manifolds flows in opposite directions. As a result, except for minor differences in the length of the loops (we avoided heating the slab under counters and cabinets, for example) the distance, and hence the friction loss, is nearly identical for each loop.

    It was not possible to connect the 3/4″ loops to 1.5″ or better, 2″ manifolds using PEX, or so I was told. I wanted to use PVC because they make 3/4″ flexible tubing that uses the same glue connections that the rigid stuff uses. It would have cut down immensely on the number of connections. Further, “1.5” CPVC has the ID of 1.25″ PVC. In addition, PVC and CPVC take no specialized tools to install the stuff – just a saw and a glue pot (“Applicator in the cap.”)

    When Boeing designed the solar arrays at our NYC Co-op, I suggested that they would stagnate progressively each the panels as they got farther from the supply and return, which in their setup was at the same end of a 10 or 11 panel row. The first three panels got most of the fluid, the rest sat there, heated up, and melted the plastic inserts that some idiot had decided were necessary. When I went back as Solar Service Co-op and re-plumbed the arrays to reverse the flow, all the panels got the same flow across them and the efficiency improved remarkably. Boeing’s way we were lucky to get 15% of the hot water demand (based on year over year fuel consumption); SSC’s way, we improved to somewhat more than 45%. The Yarnell/Moore Hyponic Grid works on the same principle.

    Monty is going to bring an infrared thermometer over and we’re going to hook up a temporary warm water source to test just how uniform the heat pattern is. I’ll report the result.

  8. Impressive job you did! Nothing like having a warm floor. I think you probably have an easier time getting materials than we do in Belize. When we built our steel frame house in 2001, we would often go into a hardware store and ask for something that you could easily get in the U.S. That would elicit a look of “what planet are you from?” Such is life in the third world. Our floors are naturally warm, though.

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