Heating Help

We have one of those racy Cuisinart coffee makers that grind the beans for you scant seconds before you’re ready to use them. Somebody did a study on this and found out that this is what gives you the best results. The Cuisinart produces more decibels than all of NASCAR when it revs up, but that’s helps wake my sweet wife, so it's all good.

I followed what I thought were all of the procedures in my groggy state and I hit the GO button. Then I dragged my sorry self outside to get the newspapers. A few minutes later, I checked on the coffee, only to find that I had forgotten to put the beans in the Cuisinart. That left me with a pot of hot water, which wasn’t going to do either The Lovely Marianne or me much good.

So I mumbled a bit and started over again. I dumped the hot water down the drain, refilled the pot with cold water (always use cold water), added the beans, changed the now-wet filter, and poured the frigid water directly onto the red-hot heating coils deep within the bowels of my overpriced Cuisinart. It didn’t like it.

WUUUFFF! The steam flashed from the opening and hit me smack in the face. And this proves beyond a shadow of a doubt that even a supposedly knowledgeable person (at least when it comes to such things as steam heating) can still be an idiot.

So I'm standing there, wondering if I still have a coffeemaker, how I'm going to explain this to the hamster in the bed upstairs, and what to do next. But I'm also thinking about how cool that was (sick, right?), and how, had that been a dry-firing boiler instead of a Cuisinart, I probably woulnd't be writing to you today.

Heating lessons are everywhere.

Don't believe me? Here. I was on a plane, flying out west, and I was in a window seat on the left side of the plane. The flight attendant announced that they were going to show a movie, and she asked us all to lower our shades so that the sunlight (which was really booming through my side of the plane that day) wouldn’t wash out the movie. Being a cooperative guy, pulled the shade, turned on my reading light, and went back to my book.

A while later I began to notice that the window shade was getting really warm. I could feel it radiating onto my bare arm. I touched it and sure enough it was hot. So I put my book down and pushed the call button for the flight attendant. She came over in a jiffy.

"What would you like?" she said.

"I noticed that my window shade is getting very warm," I said. "Would you like to feel it?"

"Oh, that's perfectly normal, sir," she said. "Nothing to be concerned about. It's just the sun beating down on the other side."

"I know," I said. "Do you realize how very like a staple-up radiant heating system this is?" I smiled at her.

"I beg your pardon?"

"Well, it's like this. The sunlight can pass through the outer plastic window, but once it strikes the other side of the shade the sunlight converts to radiant energy. Radiant energy has a different wavelength than sunlight, so it can't get back out through the plastic. It's sort of like a check valve. Or a roach motel." I smiled. She didn’t.

"Sir?"

"It heats the air in the enclosed space, much like radiant tubing will heat the air within a closed joist bay. The heated air moves by convection, touching the other side of the shade, or the underside of the floor, in the case of staple-up, and then the heat moves by conduction through the shade, or the floor, and finally by radiation into the cabin. Or the room. See?" I touched the shade again. “Pretty neat, isn't it?"

"That's very interesting, sir. I'll be sure to tell the pilot."

I'm not sure if she did, though.

You ever do stuff like that? I do stuff like that all the time.

I was getting the car's oil changed at one of those quickie lube joints. As part of the deal they wash the windows and check the air in the tires. I like to watch these guys when they work. You can learn a lot about heating by watching them. For instance, when the mechanic was putting the air in the right rear tire I asked him how the compressor knows when the tire is full. He looked at me as through I was someone who might pour cold water into a hot Cuisinart.

"It knows the tires full when there's backpressure," he said.

"I think you mean equal pressure, don't you?" I said.

"Yeah, whatever."

"Did you realize that that's the same principle that makes two-pipe, reverse return hydronic heating systems work?" I asked. "The third pipe creates a condition where the water sees no path of least resistance. It flows evenly and balances nicely. Also, this principle is what often makes low flow appear to be an air problems, particularly at the top of a heating system. The further away from the circulator the water gets, the more likely it is that there will be two points where the pressure is reaching equilibrium. And where there is no pressure differential, there can be no flow. And no flow, means no heat."

"Would you mind sitting in the waiting area, sir."

"It's all about the delta-P," I said.

"Out there, okay. In the waiting area."

"Okay."

So many lessons, so little time.

The Lovely Marianne asked me to pick up a half-pound of sliced turkey at the deli counter the other day. I took a number and waited my turn. The clerk finally got to me and I asked for the turkey. He started slicing and when he was done he tossed it up on the counter and said, “Anything else?”

"Yes," I said, “have you ever noticed that you feel cooler when you’re standing near the meat case than you do when you’re over there by the slicing machine?"

"Huh?"

"I mean like where you are right now. Feel the coolness?"

"Uh, sure. There's a meat case right here, mister. It's cold."

"Do you know why it's making you feel that way?"

"Duh. Because it's cold?"

"Actually, it's because of the mean radiant temperature. It's pulling the heat away from your body and that's what makes you feel cold. Did you know that your body is a radiator? I could explain it to you if you’d like."

"Number ninety! Who's got number ninety? Next!"

Some folks just don’t want to learn about heating. Which is a shame because it's everywhere.

Go figure.