HYDRONICS | HEATING HELP | CONTINUED FROM PAGE 40
both boilers,” I said. “I know,” the homeowner said. “The salesman
mentioned that it’s an old house, so it never hurts to have a little bit extra.” “Oh,” I said. So I did what the salesman should have done, which
was a heat-loss calculation. That’s the only way we were ever going to find out the actual heat loss of the house. Anything else is just guessing. And here’s what we learned: The total load for the
house on the coldest day of the year was 375,000 Btu/h. That other boiler was a standby. Why was it firing all the time? My guess is that a service tech turned them both on one day and they stayed turned on. The abnormal became the normal. Happens all the time. The homeowner decided to fire the oil company,
which didn’t surprise me. “They're seeing my house as a vending machine,” he said. I made him a sketch of how I'd like to see all the main gravity lines tied together into a primary loop.
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would have suggested those. Condensing boilers love those old, high-volume systems. He had this installed by a gas contractor, and I followed
up with him during the following winter. Most of the time, he ran just one of his new, relatively tiny, boilers, which is better than running a single 1,300,000 Btu/h boiler. Right? The homeowner was happy. So what cost the oil company that account and the contract for the new boilers? I think it was laziness. The
“Stop by a local supply house and ask them if they have in stock four, eight-inch-screwed by two-inch sweat reducers,” I said. “And don’t take no for an answer. They’ll try to jerk you around because you’re a homeowner. They’ve got them back there somewhere. They just won’t want to look for you.” Just kidding. So with the supply-and-return gravity mains connected
This place had horizontal mains made from eight-inch, screwed pipe. You ever see eight-inch screwed pipe? Trust me; it’s bigger than eight inches. There was once a day in America when someone lifted those bulky hunks of iron and caught a thread. Who was that guy? How big were his arms? What sort of wrenches did he own? Where the heck did he stand? I figured it was either Popeye or Bluto.
(with flanges and copper tubing, not reducers), I sketched how to use two boilers, with a combined load of 375,000 Btu/h, on secondary circuits. I included a couple of bypass lines so the flue gases wouldn’t condense. This story goes back to before we had condensing boilers; otherwise, I
salesman didn’t want to take the time to do what a professional should always do when replacing a hot-water boiler, that being a proper heat-loss calculation. The salesman must have thought that if he went to the trouble to do the calculations and then didn’t get the job, he would have wasted his time. But you can see where that got him. Thing is, I’ve been telling this story at seminars for
M1 HI-125 Primary Loop Module
HI-Series M1 Module shown with transition adapter and M2 secondary component modules systematically installed.
M2 Pumping Modules: Injection, standard and 3 way mixing
US Patent #6345770 and multiple patents pending.
Precision Hydronic Products Division of JL industries, inc. 6807 NE 79th Court Ste E - Portland, OR 97218 Phone: (503) 445-4188 - FAX: (503) 445-4187 ©2009
www.phpinc.us
Cold Water in
DHW anti-scald tempering valve
Concept drawing only, details may be omitted for clarity. M1 modules are available in different configurations than shown.
M1 HI-125 Primary Loop Module Installation
about 20 years now, and contractors still come to me during the breaks to argue with me. They can’t afford to do heat- loss calculations on every job. It takes too much time. They’ll go by the label on the old boiler. I was making them feel guilty. I have no idea what they’re up against. I’ll mention that a
L G ®
Ball Valve
Indirect Water Tank Boiler Patent Pending Components We do not export labor. Made in the USA. Rev 12/10
proper heat-loss calculation will nearly always give you a smaller boiler than one you size by the Label Method, and that smaller boilers mean better prices and more closed sales. They’ll argue with me about this too. It takes too long to do. They don’t have the time. “So how’s business?”
I’ll ask. “It sucks,” they’ll say. So I think I’ll just
keep telling about Redflash.;
e Circle 28 on reader reply card
N
Supply Return
For Exp. Tank
Ind. WH Supply Ind. WH Return
For Fill Water
phc march 2011
www.phcnews.com
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