how quickly can a furnace raise house temp 20F?

[BobK207]

Mark may or may not reply to your inquiry but he is correct....that whole concept that

"by upping the flow of water to the point that it passes through too quickly to absorb the heat."

is bogus / wrong......some people in this news group are confusing heat (energy ) with temperature of flow.

I'll pose this question.....If you touch something hot (ie burn your finger) do you dribble water across it drop by drop to remove the heat or put it under the faucet with a gushing flow?

Does the quickly flowing water "pass over your finger too quickly" to cool it off? I say no..... I want a gushing flow.

Yes the gushing flow removes the heat quickly BUT the gushing flow has its temperature increased only slightly so someone feeling the flow after it goes over my finger would say "the flow passed too quickly to absorb the heat" ....but my burned finger says otherwise.

It's quite happy that all the heat has been removed.

My qualifications..... I'm an ME :)

To comment on the furnace discussion.......yes, faster air flow through the furnace will probably increase heat transfer from the furnace heat exchanger to the air flow BUT the temperature rise of the air across the heat exchanger might to too low, such that the exiting air is too cold (temperature wise) for instantaneous comfort.

Yes, eventually the house will reach the desired temp but during the heating process....air that is too cold for occupant comfort has been blown throughout the house. Not to mention the wind chill of low temperature air. :)

cheers Bob

cheers Bob

[makolber]

I don't know for sure what "they" were saying.

I'm saying as you increase the air flow through the furnace, the "element" will be cooler, the air out of the furnace will be cooler, and MORE heat energy will go into the house and the house will be WARMER.

Looks like we agree after all.

Mark

[Zootal]

Yah - that was kinda my point from the beginning :)

[clare]

OK - I'll answer you. It is not "flowing through too fast to absorb the heat"hat causes the problem. It is the unrestricted flow does not force/allow full circulation, so some of the coolant does NOT flow fast enough (it stagnates in certain cooling passages on certain engines) so although the rad temperature is cold, CERTAIN parts of the engine DO overheat. You get local boiling, and the vapour pockets do not get scavenged out

- so you get larger pockets - which causes the local overheating to get worse. So the engine overheats, causing valve problems (the "pockets" around the exhaust valves are one point where this has been an issue in the past) and detonation.

One example was the circa 1969? Olds 350 Rocket. If you towed a trailer it tended to overheat a bit unless you advanced the timing (late hot and lean school of emission control) - meaning Super gas was MANDATORY. Guys used to pull the 'stat, figuring that would help cool the engine. With the stat pulled you were GUARANTEED to get detonation, timing advanced or not - and even on premium. The rad didn't boil over any more (usually) but the engine was still suffering from overheating.

That's just one example that I can remember right off the top - there were many more.

Not confusing the two at all. Just going from years of experience, and knowlege of how engines actually function.

Your theory doesn't hold water.

I'm ME too!!!! Oh, you said AN ME. Well, I'm a certified automotive technician as well as a computer technician. No iron ring - but but lots of varied experience.

I think you got it right there. The house MIGHT heat up just as fast, over-all but the perceived heat would be a lot less - a "cold draft" instead of a "bit of heat". Could be the same number of BTUs or KCalories or whatever unit you want to use.