How does a thermocouple have enough power to operate a gas valve?

Interesting. I thought that sounded like quite a lot. A quarter of a 1 bar fire? Half the output of a big halogen flood? Found a web site that says a tea-light is about 50 watts (4 grams per hour), so I guess it's probably about right.

Reply to
newshound
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Common sense tells us it can't be. A quarter of a 1 bar fire would make the water in the boiler pretty warm! Now remember that at this point the pump isn't running, so that heat can't easily move to the radiators. The boiler would get piping hot pretty quickly. My medium sized gas boiler is rated 4-12kW (depending on the gas pressure setting), which would mean it's still using up to a 16th of the gas when turned off! That would be truly absurd. The only thing as stupidly inefficient as that is a Sky satellite TV box which uses precisely the same 38W when in standby as when switched on!

Reply to
Bruce Farquhar

Oh I don't know. In the dim and distant past, my boiler which had a pilot light was floor standing and about 0.6 x 0.6 x 1 metre high. Giving it a surface area of about 2.4 square metres. Much bigger than a modern boiler I know, but modern boilers don't have them. So, taking a convective heat transfer coefficient of 10 W/m^2K the surface temperature rise to dissipate 250 watts if it does not go anywhere else is about ten degrees C. Warm to the touch but not huge. And I bet 90% of the energy used to go out of the flue.

In the mid 70's I had a multipoint gas water heater which, IIRC, was 22 kW. The exposed surface was probably only half that of the boiler in the calculation, but that had a fairly lively pilot light and the casing was always perceptibly warm to the touch.

Reply to
newshound

I once calculated my gas usage for the pilot light to be £10 a month (at 3.5p a kWh) on my 12kW boiler, as it was the only thing running over the summer. That's a ridiculous cost, no wonder they use electric ignition now. Not sure why they didn't always do that - gas cookers have had spark ignition for at least 40 years, if not more. Even if they didn't have a spark that could operate millions of times, it could always light a pilot and extinguish it if not in use for a certain amount of time.

Reply to
Bruce Farquhar

He didn't say to power the spacecraft he said 'for power'.

Bill

Reply to
Bill Wright

So it moves by magic then?

Reply to
Bruce Farquhar

Very few spacecraft are electrically powered.

Reply to
Max Demian

Whatever they're powered by should be able to give off some electricity, like a petrol car does. You don't have to fill the battery do you?

Reply to
Bruce Farquhar

Its no good arguing with the Kernel, he is a troll and a comedian, but not really interested in any discussion about facts. Brian

Reply to
Brian Gaff

So they don't have any manoeuvring thrusters?

Reply to
Bruce Farquhar

He's not even a real Colon or a real vet. Well, he is a colon, I suppose.

- -

" I don't even have the heart to tell him I've never infested Arizona."

- Klaun Shittinb'ricks (1940 - ), acknowledging that he lied from the very beginning, A jew scam, as expected

" My real name's McGill. The jew thing I just do for the homeboys. They all want a pipe hitting member of the tribe, so to speak."

- Saul Goodman (Bob Odenkirk). "Better Call Saul" (2015)

"Die Juden sind unser Unglück!"

- Heinrich von Treitschke (1834 - 1896)

"But vhere vill ve be able to vatch gay jews taking black c*ck up ze ass?"

- Klaun Shittinb'ricks (1940 - ), bemoaning the depletion of jews in Hollyvood and the effect on his viewing preferences Message-ID:

Reply to
jew pedo

They could do, and very effectively.

Reply to
Bruce Farquhar

Could also just have solar panels.

Reply to
Bruce Farquhar

Your choice of words continues to amuse me.

Reply to
Bruce Farquhar

A few of those could power a house.

Reply to
Fred Johnson

[slaps self on face]
Reply to
Kristy Ogilvie

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