When is Tube Gear 100% superior to modern SS gear?

> thermal conduction of air (or gas) is like a high resistance

Except when the space is large enough for convention to develop.

If the air-space is large, convection will carry a lot of cold down and around.

If the air-space is thin, no convection, but the thin space is lower resistance.

So there is some optimum space.

Vacuum of course kills convection transfer; but estimate the force of air-pressure. A window-like window will collapse. Bottles ("Thermos") do better but arn't windows. A lattice of spacers between the panes would support air-pressure, but also greatly increase direct loss through solid, and muss the view.

Good 3-pane is maybe twice as good as good 2-pane, so it is efficient of material.

I'm looking at some medium-good double-glass doors and windows here. I think loss through the wood/vinyl sash is a large part of loss through the glass, and loss through the door's non-glass parts is absurd. That's not even noticing that the door's factory weather stipping does NOT survive the average installation. Yes the sheet says install plumb and square, but obviously they don't expect that to happen because they left large gaps. The rubber may work in the factory on a table, but not in the house.

PRR said:

> thermal conduction of air (or gas) is like a high resistance

Except when the space is large enough for convention to develop.

Click to expand...

Yup, I ignored radiation and convection as being insignificant. Conduction of air can be significant in forced air cooling (like fans inside power amps blowing against heat sinks, or my in wall heat pump.

Radiation wrt clear glass is probably minimal.

If the air-space is large, convection will carry a lot of cold down and around.

If the air-space is thin, no convection, but the thin space is lower resistance.

So there is some optimum space.

Click to expand...

Not up on the fluid dynamics aspect of this but even slowly moving air is much more effective at moving heat, than static air.

Perhaps non-parallel glass panes could disrupt the natural convective circulation or shift the stable width slightly further apart. If the bottom of the interior air chamber was narrower than the top, the warm less dense air above might find equilibrium at a net wider spacing. OR NOT just a specualtion. 

Vacuum of course kills convection transfer;

Click to expand...

and conduction via air molecules.

but estimate the force of air-pressure. A window-like window will collapse. Bottles ("Thermos") do better but arn't windows. A lattice of spacers between the panes would support air-pressure, but also greatly increase direct loss through solid, and muss the view.

Click to expand...

yup, vacuum was just a hypothetical, not practical for typical consumer applications.

Good 3-pane is maybe twice as good as good 2-pane, so it is efficient of material.

Click to expand...

Not unlike curtains that trap air between curtain and window to serve as another buffer layer of insulation.

I'm looking at some medium-good double-glass doors and windows here. I think loss through the wood/vinyl sash is a large part of loss through the glass, and loss through the door's non-glass parts is absurd. That's not even noticing that the door's factory weather stipping does NOT survive the average installation. Yes the sheet says install plumb and square, but obviously they don't expect that to happen because they left large gaps. The rubber may work in the factory on a table, but not in the house.

Click to expand...

It seems there is huge room for improvement with reducing heat transfer to/from our living spaces. We could heat/cool our homes for a fraction of what we spend now. But that is the beauty of the invisible hand of free markets... as energy costs rise, we will adjust our behavior to reduce our pocketbook pain...

JR

> the beauty of the invisible hand of free markets...

Yes. I'm thinking my steel door has no insulation. I could drill it and use squirt-foam to fill it. But pondering the $ of BTU through a 3x7 panel versus the $ for canned foam, the payback may be years. OTOH as energy costs rise it could come down to one year. OTOH much of the at-factory cost of foam is energy (direct, or the fuel value of the petro-stock used for poly and gas). So the payback may always be years.

Which all leads to the question, "should I re-fi the house with a loan built in, and replace all the leaky 1930's windows with something far less leaky?".  I really like all the rippled glass, and the fact that even though every single painter has made sure they can't be opened, they are still drafty as hell. 

PRR said:

> the beauty of the invisible hand of free markets...

Yes. I'm thinking my steel door has no insulation. I could drill it and use squirt-foam to fill it. But pondering the $ of BTU through a 3x7 panel versus the $ for canned foam, the payback may be years. OTOH as energy costs rise it could come down to one year. OTOH much of the at-factory cost of foam is energy (direct, or the fuel value of the petro-stock used for poly and gas). So the payback may always be years.

Click to expand...

That spray foam for filling cracks is pretty cheap, only a couple bucks a spray can... I used up a bunch when I sealed off the air gaps around my in wall unit.

The heat transfer in a hollow steel door is probably dominated by the direct conduction path around the edges,, You'd need a sandwich so the outside and inside of the steel door don't really touch. You might do better with some sheet styrofoam applied to the inside of the door.. even a 1/2" would be better than a large cold metal surface. 

JR

emrr said:

Which all leads to the question, "should I re-fi the house with a loan built in, and replace all the leaky 1930's windows with something far less leaky?".  I really like all the rippled glass, and the fact that even though every single painter has made sure they can't be opened, they are still drafty as hell.

Click to expand...

I'm too cheap for that so I use redneck storm windows... Sheets of plastic stapled up...

I recall years ago my step father found some cute clear plexiglass interior windows to seal up leaky windows. I don't recall the details and haven't seen them for sale lately, but IIRC they were very clear with nice molding to create an air tight press fit inside window frames. They sealed off any drafts and added an air buffer between inside of cold windows and warm room air, so pretty effective.

JR

A 1/16" gap around a door with a circumference of say 144" is equal to about a 3"x3" hole. Stuff the hole with weather stripping?

Cheers,
jb

I have a love for tubes that defy words and as such I can do wonderful things with them. Locally I'm in hiding from people who want custom stuff.  If I knew how to do PCB I think I would be rich. Somebody should offer that service to us.

I grew up in Buffalo in an old drafty house. My father got plexiglass that attached to the window frame using magnetic strips. I think it worked well. Easy to install and way less money than new windows. Especially in an old house with non standard windows.

analag said:

I have a love for tubes that defy words and as such I can do wonderful things with them. Locally I'm in hiding from people who want custom stuff.  If I knew how to do PCB I think I would be rich. Somebody should offer that service to us.

Click to expand...

If you are really trying to hide, you might be less noticed by not using inflammatory words in thread titles, and then bumping that thread when nobody posts to it for over a week.  :  I would say something over there, but I am waiting for that thread to die off on its own.
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FWIW a solid state class A amplifier could also serve as an effective room heater...

JR

JohnRoberts said:

analag said:

I have a love for tubes that defy words and as such I can do wonderful things with them. Locally I'm in hiding from people who want custom stuff.  If I knew how to do PCB I think I would be rich. Somebody should offer that service to us.

Click to expand...

If you are really trying to hide, you might be less noticed by not using inflammatory words in thread titles, and then bumping that thread when nobody posts to it for over a week.  :  I would say something over there, but I am waiting for that thread to die off on its own.
-----
FWIW a solid state class A amplifier could also serve as an effective room heater...

JR

Click to expand...

I am a free thinker, man. I question even the movement of electrons and even you if it comes to it. Peace bro.  Not everybody subscribe to the old traditional brainwash, boss.

analag said:

JohnRoberts said:

analag said:

I have a love for tubes that defy words and as such I can do wonderful things with them. Locally I'm in hiding from people who want custom stuff.  If I knew how to do PCB I think I would be rich. Somebody should offer that service to us.

Click to expand...

If you are really trying to hide, you might be less noticed by not using inflammatory words in thread titles, and then bumping that thread when nobody posts to it for over a week.  :  I would say something over there, but I am waiting for that thread to die off on its own.
-----
FWIW a solid state class A amplifier could also serve as an effective room heater...

JR

Click to expand...

I am a free thinker, man. I question even the movement of electrons and even you if it comes to it. Peace bro.  Not everybody subscribe to the old traditional brainwash, boss.

Click to expand...

What happened when Columbus told the the old gnarly tooths the world was round...hmmm?

analag said:

analag said:

I am a free thinker, man. I question even the movement of electrons and even you if it comes to it. Peace bro.  Not everybody subscribe to the old traditional brainwash, boss.

Click to expand...

What happened when Columbus told the the old gnarly tooths the world was round...hmmm?

Click to expand...

analag dammit now look what you've done. even the pope is resigning!

analag said:

I am a free thinker, man. I question even the movement of electrons and even you if it comes to it. Peace bro.  Not everybody subscribe to the old traditional brainwash, boss.

Click to expand...

What happened when Columbus told the the old gnarly tooths the world was round...hmmm?
[/quote]

Who told them it was flat?  Knowledge is good.

JR

Actually nobody told them it was flat. The real argument was about how big the earth was. Columbus said about 18,000 miles circumference, so the Indies would be relatively easy to reach by sailing west. The old farts said the world was more like 25,000 miles around, and it turns out they were right. Lucky for Columbuds, there was something in the way.

Peace,
Paul