Affordable, double-paned, earthbag window solution

So I have this idea. After the slides below, I'll show some action pictures.  There's a lot of detail in these slides and the text looks small at forum resolution. If you'd like higher resolution images of the slides, check out the online gallery. I recommend running it as a slideshow to get the right effect.


















Ok, whew!  Now that we've got the dull bit out of the way, let's go shopping!

Here we go, a whirlwind tour of the thrift shop kitchen aisle!  Here is a perfectly good ADEW pane.  Know why?  The knob is cracked and grody, so it's probably a dollar off.  Just gimme the glass, baby! And of course the washers. They are hidden gold.




A nice specimen of an ADEW pane in the wild. Also, no vent hole.  Some of them don't have the vent holes.  A+!  Unless the vent hole is a feature, in which case, B+!



These are interesting.  Thicker, and usually with patterns.  Not the best window in the world, and there's no stainless steel rim.  But these things are sturdy.  Would they be good for cold climates?



Don't worry, that will clean up real nice.  But no hidden treasure in this one.  No silicone washer that protects the hole.  Just means you'll have to fashion one another way.



Oddly shaped knobs are ok, cause we're pitching it anyway.



Oh what a sweet screwhead!  Stainless, big... this will be a breeze to disassemble.  That silver washer sure looks promising, too.



This one has a corroded screw that has been stripped.  Might be some challenging screwdriver antics ahead.



Some of the lids are oval.  That raises interesting possibilities about slanted cuts on pipes fitting odd wall joins.



IMPOSTER LID! IMPOSTER!  Don't get this one.  For one thing it has two offset holes instead of one central hole.  For the second thing, those are probably rivets.  Good luck getting them out without messing up the glass.



A typical assortment of lids in a bin.



Typical assortment part II.



The scrap yard yielded me these three pipes to play with.  The one on the left is to test oval shaped lids to see if there is room for interesting angle hijinks.  I do not think it will work but why not try?  

The others are exactly the sort of thing I think you should use.  Steel pipe.  But I suppose aluminum or PVC would be ok too.



For this example I used a stainless steel pool filter cover, just because I had it and it was approximately right.  It has flanges on it that steel pipes don't, and it's only 16" high, but the idea is the same.



So all the things are together now.  except that this one doesn't have gaskets because I'm still tinkering.



It's your house.  You can be as fabulous as you want to be.



I haven't cleaned these panes at all and there's some condensation inside because it is unsealed.  Even so, it's pretty see-thru!


For higher res versions of these photos you can visit the other online gallery!

The metal tube seems very like it would conduct alot of heat and the lids don"t seem air tight

S Bengi wrote:The metal tube seems very like it would conduct alot of heat and the lids don"t seem air tight

The metal will conduct heat for sure. Is that good or bad? You could also use pvc pipe which should conduct much less.

I'm pretty sure that between the gaskets and washers you could get this as airtight as most windows. I'll think about how to test that. Sound maybe?

With metal that thin, I would think the heat would be pulled off almost immediately by the mass of the walls.  I can't see it being enough to have much, if any, effect on room temp.  As you said, making them airtight shouldn't be an issue.  I think it's a very cool idea.

Thats my take as well as you can see from the insulation slide.  :)  

I'm going to build a test ADEW then we'll find out!

This is a cool idea!  Are you building an earthbag structure?

Your idea reminds me of these: https://www.solatube.com/residential

So the general idea is very do-able. The solar tubes are highly tweaked versions on what you're talking about ... enhanced solar capture, highly reflective tubes to transmit as much light as possible and then a diffuser panel on the inside.

Some thoughts:

install the tube at a slight angle to the inside, add a weep hole so any moisture can drain away. Moisture caught in between will result in condensation on the glass, mold inside, etc.

Use foil tape to seal the seam in the tube.

Cooking glass is tough, but I have no idea what its light transmission properties are.  One of the expense of modern glazing are coatings that control the emissivity - locking in heat and blocking it from the outside.  These are kind of miraculous.  Will it matter for your idea?  I don't know if it will matter giving the mass of the structure and the relatively small glazing area.

Julia Winter wrote:This is a cool idea!  Are you building an earthbag structure?

I sure hope so!  I'm trying to navigate city code issues right now.  It's a process, and I'm kind of taking a break from it, but I feel the momentum coming back.

Eliot Mason wrote:Your idea reminds me of these: https://www.solatube.com/residential

Great link!  

install the tube at a slight angle to the inside, add a weep hole so any moisture can drain away. Moisture caught in between will result in condensation on the glass, mold inside, etc.

I definitely agree that trapped moisture could be a problem.  My current design uses a couple of pounds of rice in each window as a dessicant to absorb any moisture.  I'm not saying that's gonna work, but it's my current design.  According to studies I've read, they use uncooked rice as dessicants to keep expensive scientific equipment dry.  I'm testing it out, stay tuned. :)

Use foil tape to seal the seam in the tube.

Foil tape is great but I'm not sure which seam you mean.  The tube has no seam, it's one piece.  Each pane will be fitted against a gasket and those will be compressed by a tension rod through the center.  Like a large, weak clamp.  This way the windows can be opened or taken out.  I'll have something to show soon which I hope makes it clearer.

Cooking glass is tough, but I have no idea what its light transmission properties are.  One of the expense of modern glazing are coatings that control the emissivity - locking in heat and blocking it from the outside.  These are kind of miraculous.  Will it matter for your idea?  I don't know if it will matter giving the mass of the structure and the relatively small glazing area.

I have no idea either but those are great things to think about, thanks.  I'll look into it!  I do know there are films you can apply but I don't think that would work very well on a dome.  

Rob Lineberger wrote:Foil tape is great but I'm not sure which seam you mean.  The tube has no seam, it's one piece.

Doh!  you caught me responding without completely inspecting your post! (had to get to dinner ...)  Using a solid tube makes a lot of sense, I was assuming you were using standard HVAC tube that snaps together.  Your clever scavenging avoids that altogether, and is a much better material for gaskets too.

I like the idea of gaskets instead of sealing with silicon... easy to get into and clean/replace your dessicant.  With rice, you'll want to use it to pull the water out of the air, but not leave it there!  Rice + Water = Something growing.

One last thing ... woodworkers use a fair number of brass or stainless knurled nuts on jigs and on some finished pieces.  What's that?! https://www.leevalley.com/en-us/shop/hardware/knobs/cabinet/102406-veritas-stainless-steel-knurled-insert-knobs  I've got a bunch of brass ones somewhere.  These are generally nice because unlike a standard nut you can just use your fingers to turn it.   The point is, pay attention to the thread on your threaded rod and you have a lot of options. I'd think 1/4-20 would be optimal, and then you can use a little block of wood or a branch or something with these https://www.leevalley.com/en-us/shop/hardware/fasteners/quick-connect-hardware/44236-1-4-20-quick-connect-plain-insert-nuts to make a very inexpensive and neat cover.

Don't enjoy all this by yourself!  Please share your progress - I think there is a potential application of these as skylights and in other thick-walled buildings.

Great idea,  presented well.
I wonder if you could create a stable vacuum between the two lids for exceptional insulation value.
Items inside the window could one manipulated without opening it via magnets.

Eliot Mason wrote:

Doh!  you caught me responding without completely inspecting your post! (had to get to dinner ...)  Using a solid tube makes a lot of sense, I was assuming you were using standard HVAC tube that snaps together.  Your clever scavenging avoids that altogether, and is a much better material for gaskets too.

I like the idea of gaskets instead of sealing with silicon... easy to get into and clean/replace your dessicant.  With rice, you'll want to use it to pull the water out of the air, but not leave it there!  Rice + Water = Something growing.

One last thing ... woodworkers use a fair number of brass or stainless knurled nuts on jigs and on some finished pieces.  What's that?! https://www.leevalley.com/en-us/shop/hardware/knobs/cabinet/102406-veritas-stainless-steel-knurled-insert-knobs  I've got a bunch of brass ones somewhere.  These are generally nice because unlike a standard nut you can just use your fingers to turn it.   The point is, pay attention to the thread on your threaded rod and you have a lot of options. I'd think 1/4-20 would be optimal, and then you can use a little block of wood or a branch or something with these https://www.leevalley.com/en-us/shop/hardware/fasteners/quick-connect-hardware/44236-1-4-20-quick-connect-plain-insert-nuts to make a very inexpensive and neat cover.

Don't enjoy all this by yourself!  Please share your progress - I think there is a potential application of these as skylights and in other thick-walled buildings.

Haha, no problem.  WHAT?  You didn't read my 18 pages in 8 point font??

Yeah I like the gasket too.  Regarding rice and water, I am on the rice toxicity bandwagon waving a banner around.  However, those little draft cozies go years without issue.  So I'm wondering, given the small amount of vapor involved, if a bunch of rice would be ok without molding.  I could also use a commercial dessicant and avoid this altogether.

I love the knurled nut idea, I'll look at that.

BTW I'm not opposed to using standard duct.  It would be nice to find some sort of inexpensive, readily available item like that.

William Bronson wrote:Great idea,  presented well.
I wonder if you could create a stable vacuum between the two lids for exceptional insulation value.
Items inside the window could one manipulated without opening it via magnets.

I'd love to get a vacuum in there.  I've thought about it but I'm not sure I have what it takes yet. :)  

You could be right about the earthbag walls sucking up the heat/cold, but it occurs to me that if you use a small section of your pipe near the outside edge of the wall, then use just a small amount of same diameter plastic pipe for about an inch and then the rest of the way the metal pipe, and seal the connections with silicon, you would have what's referred to as a "thermal break"? This might stop some of the cold/heat going either way?

Over all this seems like a great option for some locations. Turning the idea into a home-made solar tube is interesting also - there are sometimes places that really need just a little natural light for safety or so that you don't have to switch on a light every time you go through the area.

I will agree that these just won't do for emergency egress, so that still must be planned for. Even if your house is made of dirt which can't burn, most houses are filled with things that even if they resist burning, can create toxic smoke very quickly. I just don't know why proper, functional window shutters went out of style when they make so much sense for storm, excessive cold or excessive heat protection. My sisters have roll up shutters on many of their windows. They're not as pretty as wooden ones, but they sure help their heating and cooling bills and make their houses more comfortable and the windows are large enough to climb out of.

I also feel that many windows are actually *much* larger than they need to be. A well-designed smaller window in the right spot can be just as enchanting as sliding glass doors and yet far more efficient, but that's sort of off-topic.

I like the idea of a vacuum or using fancy noble gases to fill the void ... but is it worth it?  The SolaTube that I linked to is just a sealed space, and they are designed to go up through an attic and have a large portion of the tube exposed to the cold air therein.  Because the air is trapped in the tube and sealed from the conditioned space you just have the interior glass as a thermal bridge ... and thus "not much" thermal exchange area.  So for uber-performance ... yes, vacuums and such are better but its not like these are giant air openings or a huge thermal bridge.

But for low-cost?  maintainable?

Yeah, no.

Here's what I've found in the fancy sealed windows.  First, their thermal performance is dependent on the vacuum/fancy gas mix staying put.  And that's dependent on the seals.  And the seals seem to be reliable for 10, maybe 15 years.  Trying to recreate a seal like that probably requires special gaskets or sealant.   I'd also think that you'd need some special tubing to keep from collapsing - remember a true vacuum will place about 15 psi on the wall and I'm no expert here, but your basic HVAC piping is NOT going to handle that.

So if I had a good vacuum pump, the right sealants, a scrap source of heavy tube then I'd be willing to consider that route.

Jay Angler wrote:

You could be right about the earthbag walls sucking up the heat/cold, but it occurs to me that if you use a small section of your pipe near the outside edge of the wall, then use just a small amount of same diameter plastic pipe for about an inch and then the rest of the way the metal pipe, and seal the connections with silicon, you would have what's referred to as a "thermal break"? This might stop some of the cold/heat going either way?

Over all this seems like a great option for some locations. Turning the idea into a home-made solar tube is interesting also - there are sometimes places that really need just a little natural light for safety or so that you don't have to switch on a light every time you go through the area.

I will agree that these just won't do for emergency egress, so that still must be planned for. Even if your house is made of dirt which can't burn, most houses are filled with things that even if they resist burning, can create toxic smoke very quickly. I just don't know why proper, functional window shutters went out of style when they make so much sense for storm, excessive cold or excessive heat protection. My sisters have roll up shutters on many of their windows. They're not as pretty as wooden ones, but they sure help their heating and cooling bills and make their houses more comfortable and the windows are large enough to climb out of.

I also feel that many windows are actually *much* larger than they need to be. A well-designed smaller window in the right spot can be just as enchanting as sliding glass doors and yet far more efficient, but that's sort of off-topic.

I love the idea of a thermal break!

I didn't explicitly think of it as a light routing mechanism, but definitely feel like you could put them almost anywhere you have 6" of free space.  I'm guessing the by far easiest to source and at least cost will be 6" pot lids on 6" PVC,  So yeah.  6" windows along the vanity in the bathroom.  A window under the kitchen counters.  A window, or swoop of them, up the stairs.  Anywhere it is traditionally difficult to place windows?  Now it isn't.

Your last point was also my last point: aesthetics.  There's such a great opportunity here to curate the space, like an art gallery director would.  Build light.  establish beams or diffusions.  rows or patterns of small windows.  I love thinking about it.

I'm sorry, I didn't read all the details, but I just want to pitch in my two cents. I have extensive experience of smart guys around me insisting they've found a way to make a genuinely airtight homemade double glazed window. Yup, nope. After a year, or at most two, the moisture inside will have caught dust, so that even if the moisture dries out, the glass is hazy. Then the little bugs get in. Then sometimes the bigger wasps, or my phobia, a huntsman spider, get in. Yuck. Nope.

Even commercially premade evacuated double glazing seems to usually go hazy after some time.

My purpose for windows is threefold.
1) Windows need to be clear so I can enjoy the view and see what's happening outside. If I can't clean the window, it is an irritant every day, forever.
2) Windows need to let in light. I don't like using artificial lights in the daytime. Irks me. Every day.
3) At least one window in each room needs to be openable. Not every day, but several times a year, and when it's important, it's often urgent.

Because of number 1, I've gone off double glazing and moved toward operating my woolen curtains every morning and evening instead. In my two-year old rammed earth house, we put double glazing only on the east and west windows. The south, where my best view and solar gain is, I kept single. The downstairs of the house, I attach a greenhouse for the winter, so that increases solar gain hugely, and reduces heat loss at night slightly. Upstairs where it's single glazed large windows, I operate woolen curtains every morning and evening. My upstairs bedroom doesn't really stay quite warm enough, so I tack up a clear plastic layer for the coldest month or two of winter over part of the window, leaving one large pane single for the view and visibility. But that's only January and February.

About humidity,  don't think rice will do much. It only holds as much moisture as it's going to hold, and then it has to dry out before it can take moisture again. Earthen walls are pretty great at moderating moisture, but condensation due to temperature differentials is pretty insistent.

This is great.  I am going to work these points in as I make the test model.  Thanks!

Rebecca Norman wrote:

After a year, or at most two, the moisture inside will have caught dust, so that even if the moisture dries out, the glass is hazy. Then the little bugs get in.  

This is why I like Rob's concept - with the threaded rod I can open it up, clean it out, put fresh rice down, and if I do so on the lowest humidity day I can, it might be good for some time. We've got two south windows in our second-hand home which have done exactly what Rebecca describes - they've got hazy stuff on the inside of a sealed double-pained window and there's nothing I can do about it.
There's a lot of pressure about "maintenance free" housing. This is a myth - most of the maintenance is just being delayed and replaced with "expensive replacements" and the convincing arguments out there for this get all the press. There's only one place I've read about how traditional wooden framed, single-glazed windows with properly fitted storm windows for the winter have merit - with good reasons such as "longevity"  being key. But then people actually have to set aside some time to put the storm windows up in the winter and take them down in the spring, and have a safe, dedicated space to store the storm windows in, and they have to be smaller instead of uninterrupted feet upon feet of glass, to make those storm windows a manageable weight.
So I will watch Rob's experiment with interest and see where it goes. It's cheap enough that if it doesn't work, he's not out much. Rob, is there some place you could put a mock up and pack earth around it and just leave it for months, checking on it ever so often? It would be sad if you tried this on an actual important building only to discover flaws you hadn't predicted?

Hey Jay, I just got my earthbags and I'm making a mockup. I have all of the materials now so it should come together fast.  Then it's a matter of waiting to see what happens.  I was thinking of spritzing water in there to simulate moisture gain.  

Stained glass would have some really fun potential here. I don't know much about it, but I know I saw something about a solar glass melter somewhere in the forums. So could one melt down glass, add a strain, and then create a cool stained glass frame?

Rob, what a great idea and nice presentation!

One way to create a thermal break would be to use telescoping tubes, which also allows for adjusting to the finished wall thickness without cutting, and like your pool filter part the flanges could already be formed beforehand.
Now here’s another possibly heretical idea regarding the orphaned glass lids... if they are paired with their pot, that pot is a short tube with a flamge just the right size, if only the bottom was cut away!

Rob, and everyone else.  What fantastic ideas!!!
I wish you luck with getting your earthbag home approved.
I have "scavenged" for most of my life.  We just moved and built a new home in the country here in Montana.   When we moved the wife wanted me to get rid of all my "scavenged" stuff.  I did not.  I have used 80% of the stuff already, saving us hundreds, if not thousands of dollars!

Looking forward to learning more from you all.

I love this idea - and just in time for me to incorporate into my upcoming build! Thanks ever so much!! Now to get the county on board with it . . .

To be honest, I plan to try out earthbag building on a root cellar-type building first. If it doesn't work out well (I can't seem to find anyone nearby who knows anything about it) there won't be a lot of investment but if it does work - yeah! Maybe a little one of these modified to be a vent would work out.

I wonder, also, if these might be a legit solar oven if installed wisely. Good thoughts and a wonderful presentation. I read every word of it!

I love this idea!  I have a suggestion that might help.  If you allow the "gasket" between the pipe and the lid on one side to dry before you put the lid on, you can remove one end of the window clean out any moisture.  I view this as a real improvement over double paned glass, which if it gets moisture in there, you can't get at.  I would recommend opening the outside end on a very cold day (hopefully below 10 degrees F or -12 C).  The colder it is, the less water vapor the air can hold.  At about 10 degrees, there just isn't much water left (I think that's why snow flakes get smaller the colder it gets).  That way the air you introduce will be very dry.  Another alternative is to put some CO2 in it.  Rice could also work and if it starts to get moldy or something, pull it out and replace it.

Random thoughts here...

Is it inconceivable to create a vacuum? Perhaps a modified shop vac, or home sealer (the kind used on Mason Jars or used with plastic bags) could be employed?

The top of injectable medicine vials are "self sealing" perhaps they could be deployed over the screw holes and adhesive used to permanently attach?

Conversely, two identical sized lids could be permanently attached, to create a "fish eye" type window that could be sealed and then attached to tube at the outside, the tube could then be left open, or have an opening on the inside as no tube length vacuum would be required. The use of a dessicant like a rice bag could still be deployed, but it would be easily accessible, and changing it would NOT affect the vacuum.

Alternatively, one lid could be affixed to a flat piece of glass with a waterproof/airtight flange, gasket or adhesive...either could be vacuumed sealed with a bit of work, ideally with the attachment used to vacuum seal mason jars. The theory being the smaller space being more simple to create, and maintain a vacuum.

As one with a conventional Sun Tube, the highly reflective, mirror finish might be desirable to recreate as closely as possible.

IF the double paned method is employed, the sanctity of the tube becomes moot, and the tube could be fitted with a powered light source for nighttime.

The installation of a very small, high efficiency, long life bulb within the tube would allow for double duty, as the highly reflective surface would theoretically multiply the light thrown by the bulb. Perhaps the tiny "fairy lights" used for outdoor garden lighting, with a solar panel (or plug in rechargeable, or straight plug in) could be punched onto the tube (that based on above methods using the double paned method, now is an "open" tube), and affixed to the punched holes so they are permanently installed, super simple, cheap and provide illumination day or night.

I would look into the actual tubes used for the commercially available version. Investing in a similar, highly mirrored interior, MAY be worth the extra, be it a paint or prefinished tube may be an expense worth considering.

LOVE your idea! Just make sure any adhesives or gaskets used can handle the elements and be UV/temperature stable, intended for outdoor use and exposure to the elements. It would be a shame to go to all this effort to have the seals fail after just one season. This MAY be why the commercial sun tubes have a plastic/acrylic dome over them...

It's great to see someone present their ideas with this much detail.  Great ideas combined with good pics and illustrations.  Thanks for sharing.  

I'm impressed and inspired by the care and quality the responses y'all have given me. Some themes have arisen.

Mockup:
I've had an ADEW put together and laying outside in the yard for a few months.  That was just to see if the materials themselves will hold up to sun, storm, and temperature fluctuations. So far so good.  Now I've made a crate. I need to situate one side of the window exposed to the outdoors and one side exposed to the indoors as if it were in a real earthbag home.  The only way I can do that is to replace one of the existing windows in my home with this test ADEW.  It is the right size to fit into my existing window frame once I remove the window.  Then I can create a mini-earthbag wall inside it, thereby creating what I hope is a realistic test of the window.

Improvements:
There have been many great suggestions for improvements, which I do think will help make this better.  After a lot of thought I've decided to test the window as described in the slides.  Not because I neccessarily think it will be superior, but because that's what was described and we need a baseline. Also because one of the strengths of the original design is accomplishability.  I'm certain that's a word.

Air
For the purposes of this demo I'm going to proceed as though it's possible to get an airtight seal.  Given the discussion I no longer think that is realistic, but that was the original plan so let's see.  

I am quite intrigued by William's vacuum idea.  It has potential for the harder-to-reach, "permanent" placements.  Foe the demo I'm going with openable windows.

Water:
The original design assumes vapor will be in the airspace.  What I didn't state very clearly is that I don't expect a bunch of vapor to keep coming in, so I expect the rice to stay fairly dry and not breed Bacillus cereus.  I'm thinking of it more like one of those heatable neck pillows or one of those cozy draft blockers for under the door. Y'all are thinking of it more like mushy leftovers that are going to turn some blue-green color as the bacteria blossoms into a sentient being and invades the house.  One of us is right.  Let's find out who.

Reflectivity:
Several of you emphasized the importance of reflectivity in the tube to maximize light transmission.  I hadn't thought all the way about that aside from "pretty colors!" If it's anything like photography there's two possibilities:  Paint the inside of the tube gloss white, or cut reflective bubble wrap and line the inside with that.  I have both handy.  I'll try the white paint becuase it's probably the most accessible.

Gasket:
Oh dear.  I waved my hands around in the air and mumbled "gasket, silicone, blah blah blah" and you called me on it. I didn't consider UV exposure (thanks for that pointer Lorinne), although aquariums are sealed with silicone so it has to have some resistance. It definitely has moisture resistance.  So I am going to proceed with it.  But I've also been looking for easily obtainable alternatives. The most promising options I've sourced are closed-cell-foam sheets and yoga mats.  Are this good choices? *shrug* Obviously this needs more research and care.

Opening:
You can definitely open an ADEW.  All you have to do is get one person to stand outside, and you stand inside, and one of you unscrews their end. (Eliot, I like your idea of using threaded inserts into wood to make custom filials.) The other person catches, and then you have a huge hole in your wall.  

So maybe there should be a more elegant way?

The only thing that comes to mind is a large ring around the perimeter of the pane, like in a porthole, that could be anchored into the outer wall.  This is essentially a permanent outer pane. Then the inner pane could be hinged and you could open and close it at will.  This is for the "I wanna clean it" or "I wanna use it to store things" crowd.  If you want to actually open the window, the original design is clunky but it will work.  

Kenneth, telescoping tubes is an intriguing possibility!  

Rob Lineberger wrote:

I need to situate one side of the window exposed to the outdoors and one side exposed to the indoors as if it were in a real earthbag home.  The only way I can do that is to replace one of the existing windows in my home with this test ADEW.  It is the right size to fit into my existing window frame once I remove the window.  Then I can create a mini-earthbag wall inside it, thereby creating what I hope is a realistic test of the window.

Just make sure you aren't testing the quality of the original wall which was *not* built to support a dirt-filled box! I'm sure you'll find a way to support the box safely, but please "spread the load" as my engineering son would say.

And also wrote:

The only thing that comes to mind is a large ring around the perimeter of the pane, like in a porthole, that could be anchored into the outer wall.  This is essentially a permanent outer pane. Then the inner pane could be hinged and you could open and close it at will.

How wide are earth-bag walls? I'm more familiar with cob or straw bale, and if this idea were to be used there, I would definitely want to be able to remove that outside piece of glass as trying to reach through the tunnel to clean the far end would be "difficult". We're not talking a typical window here that's at least 2 ft by 3 ft (I've met few house windows smaller than that). We are seriously talking porthole size as that's the typical size of a pot lid, so reaching the far end could be challenging if you aren't an orangutan - and maybe even if you are! If this idea works and it's done right, this may need minimal cleaning and rarely give trouble, but we've had a few impressive storms with driving rain so if it were me, I would find ways to keep my options open. Certainly having the far side of the window supported by clips such as are use for hanging light shades from ceiling fixtures make a lot of sense, as then one could remove the inside glass without needing a helper outside.

I appreciate the warning.   This crate will be sitting on the ground.   I'm fairly certain I won't be able to lift it once its full.  

Lol at orangutan arms.   The wall i intend to build in my hyperadobe house is 24" or so.  Most are shallower.   Say 18".  Im intrigued by the clip idea!

Rob, what happened?! Don't leave us hanging like a non-tubular window...

great concept

I bet you could make that act like a kaleidoscope pretty easily...