Dude, I wasn't trying to start an argument...
1. 'Air' is everywhere on planet Earth, there is no escaping it.
If you did escape it, you would die.
If you discount air being everywhere we are going to be, then results are going to be skewed.
2. 'Air' is a very low viscosity fluid.
Most components of 'Air' can be compressed into liquid state.
We are just lucky the force of gravity doesn't compress our 'Air' into liquid,
And we are lucky the sun heats the air to keep vapor/gas.
3. ANY heat on planet Earth heats the air,
It's what drives the atmosphere and water cycle.
Any air warmer than ambient rises because it is less dense per volume, warm air pools at the top of closed areas, like room or coolers,
Cooler air than ambient sinks because it's more dense than the ambient temperature.
4. Energy radiated as heat IMMEDIATELY encounters air/moisture/dust particles, things with mass, and warms that mass, the mass absorbing the energy and expanding, becoming less dense in the air column and rises in the ambient air column.
5. The warmer than ambient air rises, that's the movement, which creates both a low pressure cell under the rising heat 'Bubble' or column, and the ambient air pressure forces ambient air into that low pressure cell.
Something has to MOVE FIRST...
6. Closed cell insulation has 'Air' (or other gasses) suspended in it, since that trapped air can't MOVE, the ambient (colder) air can't move in because the warm air didn't move.
Two objects can't occupy the same space at the same time, keep warmer than ambient from migrating up and out, there isn't any room for ambient air to move into place.
7. Energy has to be in the light spectrum to move through a vacuum.
Vacuum coffee mugs prove that, a vacuum space, no 'Air' in the gap between walls, keeps your coffee hot without an 'Insulation' material.
With no air in space, you can easily have a 300° temp change from being in sun, to being shaded by a planet.
The ambient temperature is say, -150°, while solar radiation in the light spectrum will strike the space traveler and raise suit exterior to +150°.
8. Light spectrum energy is just that, light.
When it strikes a surface it changes frequancy from that contact, loosing energy in the process, why a room with a lot of windows heats up in direct daylight.
The surface the light strikes is heated, becoming thermal mass.
9. I use this as 'Passive Solar', 15' of windows at its peak facing south/south east.
In the summer, high sun, I shade the windows with a growing/green vine cover from above.
In the winter the vines die back, low sun gets directly into the home, strikes walls & floor, changes frequancy and sheds heat inside the home when it's needed.
10. Before HVAC, porches and tall windows did the same thing,
Porch shades high sun in summer, low sun got directly into the home.
Instead of heavy drapes to keep heat in, or out, I use triple pane gas charged windows...
Automatically let's low summer sun in, and once it changes frequancy and sheds the biggest part of it's energy, traps that heat inside.
'Low E' coatings on windows reflects high sun, lets low sun in.
I want more sun in winter, so I use green cover instead of 'Low E' coatings.
It's a little more work cleaning up leaves and pulling dead vines back once a year, but it's more efficient when you want passive solar energy.
Nothing COMMON absorbs high summer sun like growing green leaves...
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I'm just going by the laws of radiation, motion & thermodynamics.
Insulation slows the migration of energy as heat from equalizing with the ambient atmosphere,
Mostly air tight lids help slow that migration, like on coolers.
There is a reason we stuff more insulation into ceilings than floors, because heat rises in our atmosphere.
If you can keep the heat from rising, ambient cooler air can't come in from below...
It's also why I suggest an inverted box sitting on the bottom insulation board, the inverted box allowing you to easily seal up all cracks/escape routes for warmer air and still allowing easy access to batteries, simply lift the box off instead of trying to reseal a lid everytime you do maintenance on batteries.
