making the best of electric heat

One additional thought (which may have already been mentioned up thread - I really should read the entire thing before butting in!):

Igor Kuznetsov shows an auxiliary electric heating element in some of his double bell masonry heaters.  As I read it, he implies that this is a "common knowledge" arrangement.  Usually, the heating element is shown at or near the bottom of the lower bell of his double bell heaters.  This element can be thermostatically controlled, and used for standby heat when the occupants are away and unable to fire the masonry heater.  The standby setting can be lower than would be comfortable when occupied, but still keep pipes from freezing, or can be maintained at the comfort setting (if someone needs to go to town overnight or a weekend, but wants a warm house when they return).  Historically, Russia had lots of cheap electricity from nuke plants, so this arrangement seem to have been, if not common, at least not unprecedented.

As an aside, I would think it should be possible to use another auxiliary heat source (perhaps a gas burner) to do the same thing.  Though the exhaust gases and/or condensation would need to be managed, this should be much more efficient than trying to maintain a warm air temperature with a gas forced air furnace, for instance.  Sosnin and Bukharkin show a number of such arrangements in their 1990 publication "Бытовые печи, камины и водонагревател" (Household stoves, fireplaces and water heaters), which appear to mostly involve poking a gas burner or two into the firebox of a solid fuel masonry heater.  I haven't yet muddled through the text properly to understand the subtleties (my Russian is atrocious), but the illustrations are quite clear.

Back to the electric-only heating, it should be possible to make a light double bell heater (light enough to not require substantial floor reinforcement - something small like Kuznetsov's OIK-14, which I have recently mentioned elsewhere on these forums in other threads; the OIK-14 weighs about 800 pounds by my best estimate), which uses an electric heater or heating element (e.g. electric oven element) to warm up the brick mass, after which the warm bricks can continue to radiate unheated for a number of hours.  The OIK-14 has about 3.3 square meters of exterior surface area, and if fired twice per day (as is typical in colder weather) would be rated at about 1600 watts continuous.  This isn't enough to heat most houses in wintry weather, but could keep some smaller portion of a house livable.  An electric heater or heating element could also be used to periodically heat a bench or low bed made of bricks or soapstone, on which the occupants could perch or sleep.  To reiterate, this is unmoored to any direct personal experience, but I do know that the Russian application of electric standby heat to masonry heaters is well attested.

Kevin Olson wrote:Recently, Midea and one other brand have come out with mini splits which can be inserted into an appropriately sized single hung window.  They will both heat and cool, and require no (or very minimal) modifications.

We have a small (8,000 or 10,000 BTU, I forget which; it's the medium sized model) Midea window AC unit, which we run a few nights per summer, installed in the smallest of our bedroom windows, with a cloth shower curtain on a spring tension curtain rod across our bedroom doorway.  This arrangement means that the AC unit really only needs to cool our bedroom, give or take a bit of leakage at the curtain.  A good night's sleep can make all the difference in hot, steamy weather.  Ours has a variable speed compressor, and all sorts of modes and settings, some of which are more energy efficient than the basic "cool" mode.  The evaporator is on the interior of the sash, and the condenser is outside.  Both heat exchangers have fans, and are connected via tubing which passes under the slightly raised sash through a small flat connecting housing.  A folding metal bracket supports the overhung weight of the exterior portion.  There are some foam blocks which provide a customizable seal at the sides of the unit.

If the Midea mini splits are anything like the quality of the AC unit we have (and the ancient but still very functional dehumidifier we have, also Midea manufactured, though with some private label marketing badge on the front), the mini splits will be long lived.  I haven't actually seen one in person, but it seems they could really be helpful for someone who absolutely cannot modify their residential accommodations.

In the case of our AC unit, I did screw in two very small screws for the folding support bracket, one at each side of the frame, but these aren't strictly necessary, though it does seem like good insurance against the bracket slipping out of position.  Otherwise, it is a no modifications install.  I believe the mini splits are set up the same, but the heat pump setting does require a higher performance refrigeration circuit than the AC only version, since it's an air source heat pump.  It would also suffer from the same weaknesses as any other air source heat pump; that is, when the outdoor temperature drops, the heat pump will need to work harder, and therefor will be less efficient, to provide the same heating as when the exterior temps are less cold.

Don't take this as a recommendation.  As I said, I don't have direct experience with the mini splits, just with the Midea AC unit and dehumidifier.  Take this as a "might be worth investigating".

These mini splits are also uncheap (roughly 10X the cost of the AC units, as I recall), so that might factor into how desirable a solution this might be.
Well, is my face RED (my neck is always red)!  I just checked, and it isn't Midea who has the window mini split after all!  It's Gradient, and they may not even have a consumer-ready product, yet.

I am leaving this post up as a monument to my everlasting shame, for not having checked before posting, but rather just going on my memory.
Some people's kids!

NOT the 1st nor last, to do that!!
But, keeping the info up, helps—folks can research them.
I actually found a Midea unit like the Gradient, but Neither are for sale yet.  Either costs DEARLY (4 digits)—gradient is most proud.
You weren’t whistlin’ Dixie, how costly these are.
But hey—try looking up “PTAC heat pumps”.  Most are mounted thru-wall, below windows.   The PTAC industry has been around a long time. MIGHT find units less costly.

Where I was grew up, enclosed porches were common on the older houses. Many were unheated. Others were heated just enough to keep things that would be damaged by it from freezing.  That porch buffer made a big difference in heating our old farmhouse home heated by nothing but a wood furnace in the basement.

Jay Angler wrote:

Timothy Norton wrote: One of the best things we can do is make it difficult for it to slip away and you can do that by closing interior doors.

Pearl Sutton started an excellent thread expanding on this concept: https://permies.com/t/187318/Adding-Heating-Zones-House

Installing interior drapes where there aren't doors to close is inexpensive and quick. This also allows some air movement which is important in damp climates like mine where there is danger of closed rooms going moldy!

Last winter I was in a poorly insulated/air sealed single-wide mobile home heated only with space heaters (in north Texas, it didn't get all that cold compared to some); here's what worked for me to stay warm and keep electric bills down, thanks to this thread and others on permies for inspiration:

-Thermostats set around 45 deg (F)
-Lots of clothing layers
-Heated pad under the top layer of my dogs bed to keep her warm
-Electric blanket to preheat the bed, along with extra blankets/comforter
-Multiple low watt heat sources for the couch/desk:
    -Heating pad between my back and the back of the couch
    -Heated throw blanket
    -Reptile heat "bulb" in reading lamp to warm hands and face
-Hot drinks to wrap my fingers around (hot water sourced from electric kettle)
-Place space heaters appropriately (and turn up only when needed) to blow heat on me when getting out of shower, changing clothes, etc.
-Reptile heat "bulb" in clamp-on reflector fixture above work bench to keep fingers warm

To change subjects:

Chi Monger wrote:
HEATPUMP MINISPLITS:
…
But for refrigerant?…
…Yes, they all (we entertained several contractors giving free estimates) …basically said it WILL leak (must have annual maintenance, incl. check refrigerant levels—of course that is another income-stream to the companies greedy for more profits).  

As an HVAC repair technician, it is not normal for a properly installed AC or heat pump system to leak refrigerant; anyone telling you that is trying to charge you for service calls, etc: income-stream like you said. Over time it is not uncommon for leaks to begin, especially with the higher working pressures of R-410 and the thinner tubing construction to save material cost, but leaks are not inevitable, and certainly not normal!

I'd forgotten, but I lived in a single-wide when farming. Though I didn't own it, I hit the suppliers and bought enough insulation to insulate the entire underside of the floor.  I used MIG welding wire I'd picked up at a garage sale and the nails with the big plastic washers to hold it in place.

It was a lot of work, BUT, before I insulated the floor, you had to wear shoes walking on it. After, it was very comfortable to walk on. It was well worth the few hundred I paid. Even though electric is cheaper here than every where else in the U.S., it was a very worthwhile project for the comfort it brought during the few years I lived in the trailer.

So, yet again, YEAH, INSULATE, INSULATE, INSULATE. Even if it isn't your place, and if you're going to be there a while.

If anyone is interested in heat pumps and DIY projects, the deep end of the pool may be the "Homemade Heat Pump Manifesto" thread on the EcoRenovator forums:
https://ecorenovator.org/forum/showthread.php?t=484

Even if you are just trying to make a home brew CoolBot or something, there is a lot of info on hacking used refrigeration units (old window AC units, especially) to do other things with them.

This thread runs to almost 200 pages, at 10 posts per page.  Some is chaff, some is wheat.  I read through from start to finish a few years ago, over the course of a week or more of evenings, when I was trying to figure out how feasible it would be for me to do a ground source heat pump on the cheap.  Where I am, I'd need a bunch of fairly deep boreholes, or I'd need to be well into the water table.  Where I was living at the time, bedrock was fairly close to the surface, and I didn't want to try to drill basalt, even if the Chinese were drilling deep salt wells in Sichuan Province with bamboo cable tool rigs almost 1000 years ago, so I let it lie fallow.

But, I'm throwing this out there, in case someone is interested, has more time than money, and doesn't mind (or even enjoys) some mechanical experimentation and recreational refrigeration engineering.

Kelly Craig wrote:Where I was grew up, enclosed porches were common on the older houses. Many were unheated. Others were heated just enough to keep things that would be damaged by it from freezing.  That porch buffer made a big difference in heating our old farmhouse home heated by nothing but a wood furnace in the basement.

I keep lobbying to enclose two of our exterior porches with plastic (6 mil poly drop cloth, or 10 mil DuraScrim).  Wiggle wire and channels would work to retain the edges.  I could even do a double layer, and blow them, to improve the durability of the plastic in strong winds at cold ambient temperatures.  I have a pair of low pressure blowers which I scavenged fair-and-square to use as greenhouse skin blowers, ready and waiting to go.  I think it would make a world of difference, since both porches have southern aspects (one just about due South, the other Southwesterly).  Fewer convective losses, more trapped solar gain.  I could skirt them both with insulation board (again, just for the winter).  I think we could use them as propagation rooms, once the weather starts to warm up and the sun is a bit higher.  My wife, on the other hand, is not interested in that aesthetic.  I agree it would look a bit redneck, but would be willing to have everyone's suspicions confirmed about about the exact shade of the tint of my neck if it meant we'd be warmer, for less energy use, and get an early season start for our plants.  She, however, has differing priorities.  I might be able to convince her of the scheme if I am willing to upgrade to the fancier roll-up clear plastic curtains which many of the swanky houses on Mackinac Island have on exhibit on their expansive porches, though that wouldn't be as airtight...

Yeah, Kevin, my dream home would have a wrap around deck using old sliding glass doors. In the summer, they could all be open in the summer and, in the winter, not so much.

It'd be fun to glass etch them, just because I can.  As I pointed out to wifey, it would look nice, and could all be done for a few hundred dollars (sand and contact paper is all you need). It would cost a fortune to have someone do it, but, as long as the projector bulb doesn't burn out, I gots me some talent and could do mountains, elk and whatever tickles fancies.

If a person wanted to get creative, some of the sliders could be framed to roll out of the way, to open the space even more.

If worse came to worse, I could save the five sliders I'm removing (two down, three to go) and just lay them sideways on the short walls/openings, as if windows (either way, I'd be wise to beef up the 4x6 supports below, just because glass is heavier than people think.

Kelly Craig wrote:...either way, I'd be wise to beef up the 4x6 supports below, just because glass is heavier than people think.

This is very true!  Particularly sliding glass doors. Any "glass" that's at a height where it can get kicked, is made substantially thicker than regular window glass.

Kelly Craig wrote:Yeah, Kevin, my dream home would have a wrap around deck using old sliding glass doors. In the summer, they could all be open in the summer and, in the winter, not so much.

It'd be fun to glass etch them, just because I can.  As I pointed out to wifey, it would look nice, and could all be done for a few hundred dollars (sand and contact paper is all you need). It would cost a fortune to have someone do it, but, as long as the projector bulb doesn't burn out, I gots me some talent and could do mountains, elk and whatever tickles fancies.

If a person wanted to get creative, some of the sliders could be framed to roll out of the way, to open the space even more.

If worse came to worse, I could save the five sliders I'm removing (two down, three to go) and just lay them sideways on the short walls/openings, as if windows (either way, I'd be wise to beef up the 4x6 supports below, just because glass is heavier than people think.

I've worked twice for one of the local glaziers.  We etched glass with a cheapo gravity fed sand blaster and contact paper masks.  I always just laid out the patterns to scale using a square grid, sketching it out freehand from the original.  French curves or a flexible rule with weights ("ducks"), like you'd use for lofting boat parts, helps to make fair curves.  I'm not the most artistic guy, but it did work.  When happy with the pattern, cut and peel away the areas to be frosted, using an X-acto/craft knife.  The compressor was a bit anemic for the purpose.  I had to wait every few minutes for it to catch up, but it worked.  A bigger tank would have helped.  One of the local churches still has etching which I did on their main doors  (which I always feel compelled to point out to my wife when we go there for a visitation or funeral!).

I've thought about pitching to her using twin wall polycarbonate, with a piano hinge in the middle of each vertical panel, like some of the airport hangar doors.  The doubled-up twin wall could lay flat against the ceiling (maybe held up there with turn buttons?) when open.  The polycarbonate would be tough and clear (at least for a few years), and would have some R-value while still reducing convective losses.  I'd probably need to mock up a demo for her to see.

Our house (and the whole neighborhood) is oriented at about 45 degrees to the compass points (I think it actually 38 degrees and change) because everything was laid out parallel and perpendicular to the lake shore, back when this area was platted.  I know that square to compass, with minimal glazing on the north side and reduced glazing on the east and west ends and carefully planned glazing on the south side would maximize solar gain in winter while rejecting excess gain in summer at my northern latitude.  But, I have to say that there is something psychologically refreshing to having direct sunshine through every window in the house at some point during the course of the day, except for a couple of weeks around the winter solstice, when the sun comes up and goes down far to the south.  Until we owned this house, we've always lived in houses that were square to the compass points.

You're not even kidding about how heavy glass can be.  Most of the thermal units we installed weren't much over 200 pounds, bare glass, but that was plenty heavy enough when working off a swing stage or scaffolding several bricks high to set them in the curtain wall frames.  Even with glass cups to get a handle at just the right height for good biomechanics, it was still nerve-wracking.  Only clamshelled edges of a few, but it's a workout setting them, for sure.

Interestingly, I used one of those anemic compressors, but since I shot the main parts at only 45 PSI and the shading at half that, it was never an issue.

I used to go through Exacto blades like they were going out of style, until I figured out resharpening them would get me back to go and the sharpened tips lasted far longer.

Too, you could use a small soldering iron to do the long, flowing cuts.

Well, Kelly, that's much more fancier than anything I ever did.  If my opinion counts for anything, she should turn you loose!

Kevin

Kelly Craig wrote:Yeah, Kevin, my dream home would have a wrap around deck using old sliding glass doors. In the summer, they could all be open in the summer and, in the winter, not so much.

It'd be fun to glass etch them, just because I can.  As I pointed out to wifey, it would look nice, and could all be done for a few hundred dollars (sand and contact paper is all you need). It would cost a fortune to have someone do it, but, as long as the projector bulb doesn't burn out, I gots me some talent and could do mountains, elk and whatever tickles fancies.

If a person wanted to get creative, some of the sliders could be framed to roll out of the way, to open the space even more.

If worse came to worse, I could save the five sliders I'm removing (two down, three to go) and just lay them sideways on the short walls/openings, as if windows (either way, I'd be wise to beef up the 4x6 supports below, just because glass is heavier than people think.

ETCHING slider door glass?!? NOOOooooo😱
Slider doors are at minimum, tempered glass.  
Once glass is tempered, which affects the exterior layers of the glass, anything used to etch, be it a vibratory tool, sand or acid, could cause it to shatter—either while etching, or some time after it’s mounted when wind, or a bird, hits it.  
But at least it’d shatter in small pieces…🤷‍♀️
👉🏼A better alternative might be etched-looking window cling film—lotsa choices from online venues. Less choices from big box hardware store.  
OR—can get creative & make real stained glass suncatcher panels, or fake them using stained glass paints on Plexiglas panels.  Even less costly, is make coathanger wire frames, glue on colored tissue paper, then varnish that on both sides—I made a huge flower like that, for an old boyfriend to hang over his pool table (circa 1960s).  Kids can have fun making those!  The varnish sticks the paper onto the wire & turns the tissue translucent.  Can use India ink & pen, or a fine marker after varnish dries, to give finer details.

We collected a number of slider door glass pieces, from folks replacing them—most were dual-pane sliders with broken seals.
 I removed the rubber seals, making separate panes.  
We had to build-out a roof extension across the back of our place, to protect the old walls.  Could only go out 10’, to avoid co earring the septic tank too much.
Bonus:  that is a microclimate helping passively reduce heating & cooling costs in the house.
(Now I want one across the front of the house!!)
That back area faces is south—but, it failed to give solar gain the right way, when the wall & its fenestrations were exposed.  

We made a short wall facing the yard, with enuf space + buffer space.  
For our needs (durability), I used metal roof panels as the exterior covering.  
Eventually, the lower wall framing can get insulated.
We scavenged the 4x4 posts on foundation blocks.
Those get beefed-up by cladding them with 2x6 PT planks (which help hold the glass in)…our posts for that part, have 7’ wide openings.  The 3rd section is a bit wider, the way things worked out.
There’s a 2x6 PT sill btwn the posts, supported by 2x4 studs…just like regular walls, just short.
There are 2x4 angles to roof from posts, to prevent racking.  
I used off-the-rack metal flashing to cover the sills, & caulked the edges to prevent water getting to the wood.
The slider glass will get mounted horizontally in the openings, sitting on the sill flashing, buffered w/a silicone seal strip; one pane will sit to the outside edge of the posts, in each of 2 large openings….
I think there’s enuf glass, a 2nd pane can mount towards the inside of the posts, to form a wide airspace btwn the 2 panes—a 3”+ airspace btwn single pane glass, insulates much better than average dual-pane windows—zero condensate btwn the glass, or on the interior side—ever. (We’ve done that on 4 big windows—pairs of recycled single-pane slider windows)

It kinda is “non-conforming”…but, I don’t care—this tactic of wide airspace btwn old single-pane windows, has proven very effective at lowering our electric heat bill.   The 1st month we finished the 4 front windows like that, was a cold November—those 4 windows suddenly saved about $100 off our worst cold month utility bill, in the Olympia, WA area.  (The old house windows, & the recycled ones to match, had been nearly falling out of their aluminum frames—cleaned, recaulked, work well).

Maybe folks who recycle materials are weird by some uppity metrics—but, I sure get a huge kick out of outfoxing the overpriced industries & utilities!!  Thankfully, our HOA has been cool with it…it’s old & simple rules (so far), as long as it blends-in fairly well.

Chi Monger wrote:

ETCHING slider door glass?!? NOOOooooo😱
Slider doors are at minimum, tempered glass.  
Once glass is tempered, which affects the exterior layers of the glass, anything used to etch, be it a vibratory tool, sand or acid, could cause it to shatter—either while etching, or some time after it’s mounted when wind, or a bird, hits it.  
But at least it’d shatter in small pieces…🤷‍♀️

Hmmm.  Thinking about it, tempered is pretty touchy (hence my fretting over clamshelling thermal units), but I am certain that the glass in the doors which I etched for the church would have been tempered glass , by code.  They are still intact, a good 20 years later.  Maybe someone has been looking out for them...

Chi Monger wrote:
We collected a number of slider door glass pieces, from folks replacing them—most were dual-pane sliders with broken seals.
 I removed the rubber seals, making separate panes.  
We had to build-out a roof extension across the back of our place, to protect the old walls.  Could only go out 10’, to avoid co earring the septic tank too much.
Bonus:  that is a microclimate helping passively reduce heating & cooling costs in the house.
(Now I want one across the front of the house!!)
That back area faces is south—but, it failed to give solar gain the right way, when the wall & its fenestrations were exposed.  

We made a short wall facing the yard, with enuf space + buffer space.  
For our needs (durability), I used metal roof panels as the exterior covering.  
Eventually, the lower wall framing can get insulated.
We scavenged the 4x4 posts on foundation blocks.
Those get beefed-up by cladding them with 2x6 PT planks (which help hold the glass in)…our posts for that part, have 7’ wide openings.  The 3rd section is a bit wider, the way things worked out.
There’s a 2x6 PT sill btwn the posts, supported by 2x4 studs…just like regular walls, just short.
There are 2x4 angles to roof from posts, to prevent racking.  
I used off-the-rack metal flashing to cover the sills, & caulked the edges to prevent water getting to the wood.
The slider glass will get mounted horizontally in the openings, sitting on the sill flashing, buffered w/a silicone seal strip; one pane will sit to the outside edge of the posts, in each of 2 large openings….
I think there’s enuf glass, a 2nd pane can mount towards the inside of the posts, to form a wide airspace btwn the 2 panes—a 3”+ airspace btwn single pane glass, insulates much better than average dual-pane windows—zero condensate btwn the glass, or on the interior side—ever. (We’ve done that on 4 big windows—pairs of recycled single-pane slider windows)

On her YouTube channel, Kristen Dirksen has profiled several houses (at least two, but maybe more) over the past few years, built inside greenhouses, either entirely enclosed (one within a dome) or partially (i.e. two of the exterior walls of the house formed part of the exterior of the glazed enclosure).  The two I distinctly remember were in Scandinavia - as I recall, both in Norway.  It sounds like you are well on your way to retrofitting that to your house, which is far ahead of my own plotting and scheming.

Greenhouses work by reducing convective losses (no matter the common usage of "greenhouse effect"); if the gap between panes is large enough, convective cells can set up between the panes, which will enhance heat transfer across the gap.  There is a point beyond which increasing the gap will be counter productive, but I don't know what that is for "air".

Attempting to maximize the resistance to heat transfer across the gap between panes bit Andersen a while ago.  They tried using argon gas to fill thermal pane units, because argon has better thermal performance than dry nitrogen or other common gasses one might use (Ken Kern just used air).  It was a good idea but their seals weren't up to the task (at least, the early ones weren't) and the argon would try to equalize the partial pressures between inside the thermal unit (high partial pressure, basically pure argon) and the surrounding atmosphere (low partial pressure, very little argon).  Argon being noble and monatomic, it's tricky to contain (not helium tricky, but tricky, nonetheless), and the argon managed to eventually mostly escape by diffusing through the seals.  This pulled a partial vacuum between the panes, and the surrounding atmospheric pressure would squeeze the panes toward each other.  Sometimes one or the other pane cracked, equalizing the pressure, sometime the panes just "kissed" in the middle, resulting in condensation circles.  I spent several cold days (preferably below -10F and clear) doing field fixes - drill through the seal to allow in ambient air, then set a sealing blind rivet in silicone to cork up the hole.  Doing the job on a cold day helped to ensure minimal moisture would get into the thermal pane when the air was sucked in.

Chuckle.  The U.S. Navy uses glass etch on equipment that incorporates tempered glass.  I worked on a lot of it and used the glass that would have been tossed, had I not rescued it.  The rule was, no deeper than 50/1,000 of an inch.  

One day, we had to do a clean up and had about fifteen of the glass tops for Mark 19 Plotters. Rather than just toss them in the dumpster, we were told to break them up, to save room. As noted, they were all etched. Many of them took several hard hits from ballpein hammers, because they all but refused to break.

At fifty one thousands of an inch, you can drag your finger nail across the glass and feel the line break, but it's not deep enough to trigger the stress factor needed to cause the glass to turn into rubble.

I've done many a tempered glass auto window and slider. None of them disintegrated. Even when, as was done to shock newbies, we slammed them with a hammer. So too it went with rock hits on vehicle windows.

The bucking horse I posted was a rear pickup window. Here are a couple of the tables I did, which were tempered glass, for the obvious safety reasons.

Side note, I was also around tempered glass that shattered into a pile of rubble just in the course of moving it.

On a totally different tack, but within the scope of the topic of saving energy costs in a house you can’t modify, I lived in a house for a year that was originally a fishing cabin, added on to over the years a whole wall of picture windows facing north (northern hemisphere)….

As we all know, plumbing needs to be protected from freezing.  This house had plumbing all over everywhere, I think the owners were people who heated the whole house to 70 F… there was a kerosene burner, a disconnected propane forced air furnace and 2 wood stoves.  Much of the plumbing was in exterior walls!   A crazy set up.

Luckily I got a hint I wasn’t doing enough to keep the pipes from freezing… there was no water in the kitchen sink one morning, but the frost had not broken any pipes.

There was a time delay on both the clothes washer and the dishwasher.  I kept my eye on the weather forecasts and when the really bitter nights were predicted, I would set the washers to run at 3 am and then 4 am.  It got me through the winter without breaking any pipes, or thousands spent on fossil fuels.

I was comfortable with the savings.😊, kept myself warm by the upstairs wood stove.

Kevin Olson wrote:

Chi Monger wrote:

ETCHING slider door glass?!? NOOOooooo😱
Slider doors are at minimum, tempered glass. ……🤷‍♀️

Hmmm.  Thinking about it, tempered is pretty touchy (hence my fretting over clamshelling thermal units), but I am certain that the glass in the doors which I etched for the church would have been tempered glass , by code.  They are still intact, a good 20 years later.  Maybe someone has been looking out for them...

On her YouTube channel, Kristen Dirksen has profiled several houses (at least two, but maybe more) over the past few years, built inside greenhouses, either entirely enclosed (one within a dome) or partially (i.e. two of the exterior walls of the house formed part of the exterior of the glazed enclosure).  …..

Greenhouses work by reducing convective losses (no matter the common usage of "greenhouse effect"); if the gap between panes is large enough, convective cells can set up between the panes, which will enhance heat transfer across the gap.  There is a point beyond which increasing the gap will be counter productive, but I don't know what that is for "air".

Attempting to maximize the resistance to heat transfer across the gap between panes bit Andersen a while ago.  They tried using argon gas to fill thermal pane units, because argon has better thermal performance than dry nitrogen or other common gasses one might use (Ken Kern just used air).  It was a good idea but their seals weren't up to the task (at least, the early ones weren't) and the argon would try to equalize the partial pressures between inside the thermal unit (high partial pressure, basically pure argon) and the surrounding atmosphere (low partial pressure, very little argon).  Argon being noble and monatomic, it's tricky to contain (not helium tricky, but tricky, nonetheless), and the argon managed to eventually mostly escape by diffusing through the seals.  This pulled a partial vacuum between the panes, and the surrounding atmospheric pressure would squeeze the panes toward each other.  Sometimes one or the other pane cracked, equalizing the pressure, sometime the panes just "kissed" in the middle, resulting in condensation circles.  I spent several cold days (preferably below -10F and clear) doing field fixes - drill through the seal to allow in ambient air, then set a sealing blind rivet in silicone to cork up the hole.  Doing the job on a cold day helped to ensure minimal moisture would get into the thermal pane when the air was sucked in.

I’d only been informed by some folks over many years, cautioning against etching tempered glass….but hey…new info!
One of my brothers etched a glass dish with face of Carl Malden—it was kind of a joke—it was for his iguana, which had a very Carl Malden grin😁

I had seen the greenhoused houses!  Thot it was a very good idea.  Tho, wouldn't any climate that can reach 90+*F., cook the household…requiring more cooling??  (Unless they also use geothermal…to keep costs down)

Did not know that about argon—thanks—Good to know!  Anderson still sells argon in their windows….when their windows are new, the resistance to heat transfer is pretty epic—a 200w heat lamp on one side of their window, did not heat the interior side of the one shown—compared with the single-pane slider window the same lamp could blister the flesh of one’s fingers.

& that is more reason to go low-tech! (Aside from their extremely high prices)

Idk about diminishing returns on wider airspace’s btwn panes….it seems it must not be too much loss of efficiency, if a house can be put into a greenhouse enclosure & work enuf to warrant the cost??  I know that good seals when windows are closed, help prevent condensate btwn ours;  but the one with a window AC in it, still doesn’t get much condensate.
(Twin wall has some great non-standard uses!)

If diminished efficacy happened btwn panes at a certain dimension, wouldn’t that cause condensation on one of the panes—likely the outer one?

Our “fake-it” remedy on one large, single pane aluminium frame window, was to mount a 2x2 frame covered with polycarbonate panels on the outside of that, & use 3 panels of twin wall, overlapping slightly, on the inside.  
That window used to leak rain fairly badly.   It’s protected from that now; the inside has had only scant condensate since it got its protection.   Only a small amount of condensate forms on the inner surface of the polycarbonate.  
It’ll have to do, til I can find the right contractor to help remodel that window…but for the past several years, can only find ones who do simple remove/replace—& only if I buy their windows, or, only if replace multiple units.
Industries are doing crazy things to prevent folks helping themselves, & making folks buy yet more stuff. But that’s a whole ‘nut her conversation!

Did you mean, you took apart the windows in order to get at their seals??  BRRRR!  That’s an epic job!  Good on you!!  Most folks just trash ‘em, & buy new ones.

I wonder, how might windows fare, if instead of air btwn glass panes, that space was filled with polycarbonate? (Because temps go thru plastic slower than glass). I wonder if the plastic could be close equivalent to air/gas filled, especially if there’s the film included btwn the glass & plastic?   It’d make a mess of recycling the windows, but, they’d be more resistant to breaking, & moisture couldn't get btwn to fog/grow mold…?

Kelly Craig wrote:Chuckle.  The U.S. Navy uses glass etch on equipment that incorporates tempered glass.  I worked on a lot of it and used the glass that would have been tossed, had I not rescued it.  The rule was, no deeper than 50/1,000 of an inch.  

One day, we had to do a clean up and had about fifteen of the glass tops for Mark 19 Plotters. Rather than just toss them in the dumpster, we were told to break them up, to save room. As noted, they were all etched. Many of them took several hard hits from ballpein hammers, because they all but refused to break.

At fifty one thousands of an inch, you can drag your finger nail across the glass and feel the line break, but it's not deep enough to trigger the stress factor needed to cause the glass to turn into rubble.

I've done many a tempered glass auto window and slider. None of them disintegrated. Even when, as was done to shock newbies, we slammed them with a hammer. So too it went with rock hits on vehicle windows.

The bucking horse I posted was a rear pickup window. Here are a couple of the tables I did, which were tempered glass, for the obvious safety reasons.

Side note, I was also around tempered glass that shattered into a pile of rubble just in the course of moving it.

Come to think of it, MAYbe, it depends on the kind of tempering done, as well as the thickness of the glass—& maybe if it’s made of different elements??  
Just recalled a day we spent at a dump, finding parts needed.  We found a front windshield from a vehicle, & nearby, a steering column.  One guy grabbed that column, climbed on a pile a few feet higher than that windshield, & commenced to drive the pointy end down at the middle of that glass—repeatedly.  
The column must have weighed at least 40#, & he was putting very strong efforts to heaving it down at the glass…..but not.a.single.scratch.  
We picked it up & frisby’d it into/onto other hard objects, flatwise, edgewise—still not chipped, scratched, cracked or broken.  
Us mere mortals admitted defeat, gave up 🤷‍♀️ & walked away.  
That was in the mid-1970s.  
I think bullet-proof glass was invented over 100 years ago…but, this piece didn’t look thick enuf to be that.  I’d never seen such a break-resistant windshield, before or since!
Compare that, with the recycled slider doors I’d stacked on a work table outside:  a panicked deer jumped out of one of the raised beds, onto the glass , which shattered dramatically…or, today's windshields that crack at the impact of flying bit of gravel…
Of course, window glass is thinner than that old windshield.  

Chi Monger wrote:
I had seen the greenhoused houses!  Thot it was a very good idea.  Tho, wouldn't any climate that can reach 90+*F., cook the household…requiring more cooling??  (Unless they also use geothermal…to keep costs down)

I don't recall, just now, about the house in the dome greenhouse, but I'm pretty sure the other one had operable windows near the peak to "burp" out an excess heat.  No attempt to annualize those gains!

Chi Monger wrote:
Did not know that about argon—thanks—Good to know!  Anderson still sells argon in their windows….when their windows are new, the resistance to heat transfer is pretty epic—a 200w heat lamp on one side of their window, did not heat the interior side of the one shown—compared with the single-pane slider window the same lamp could blister the flesh of one’s fingers.

& that is more reason to go low-tech! (Aside from their extremely high prices)

I believe Andersen got the seals squared away on the later iterations.  I don't know what they did differently, just that a lot of thermal units were repaired or replaced.

But, speaking of low tech, I'm pretty sure it was Ken Kern who advocated for DIY double panes windows, with plain old air between them.  I'll see if I can track down the reference, but I seem to recall that he said you could either pour in a little desiccant before you shut it up, or leave small vents to ambient.

Chi Monger wrote:
Idk about diminishing returns on wider airspace’s btwn panes….it seems it must not be too much loss of efficiency, if a house can be put into a greenhouse enclosure & work enuf to warrant the cost??  I know that good seals when windows are closed, help prevent condensate btwn ours;  but the one with a window AC in it, still doesn’t get much condensate.
(Twin wall has some great non-standard uses!)

If diminished efficacy happened btwn panes at a certain dimension, wouldn’t that cause condensation on one of the panes—likely the outer one?

In the extreme, the double pane unit becomes a single pane greenhouse (i.e. as a thought experiment, take a double pane thermal unit, and keep growing the gap - 2", 6", 12", 5 feet, 20 feet; see what I mean?).  Part of why thermal pane units "work" is that the gap between panes is small enough that there's too much "drag" for convective cells to efficiently set up in that space.  So, conduction and radiation are the only other ways of transferring heat.  Gasses aren't very good conductors, and glass is pretty much opaque to near infrared (the wavelengths associated with the radiant energy given off due to ambient temperatures), so more of the heat stays in (at least, compared to single pane glass).  If, however, the gas between the panes can easily set up convective circulation cells (sink on the chilly side, rise on the warm side), then substantially more heat will be transferred (it behaves a lot more like single pane).  A bigger gap between panes will facilitate the development of such convective circulation, all else being equal (which it probably isn't, in the real world).

Chi Monger wrote:
Did you mean, you took apart the windows in order to get at their seals??  BRRRR!  That’s an epic job!  Good on you!!  Most folks just trash ‘em, & buy new ones.

If I recall correctly, Andersen gave a choice of replacement under warranty, but the homeowner covered the labor, or Andersen paid for the repair, but that was the end of the warranty.  Not quite Hobson's choice, but...

No, it was a lot simpler than that.  Andersen provided a little plastic drill jig that slipped over the edge of the sash.  The (brass?  I forget, now) drill bushing positioned the drill bit correctly to pass through the edge seal and between the glass panes.  It was pretty quick (bzzzz, wooosh, squirt, pop - maybe not quite that quick, but a minute or two, if you were good and the work area was reasonably clear) and idiot-proof, even if you were hanging out the second or third story, working on a crank-out operable window.  The biggest hazard was dropping your cordless drill.  I'd guess doing the repair on a non-operable window (i.e. a big fixed picture window) wouldn't have been as painless, but I never had to deal with one of those that I recall.  The alternative to the drill jig was to carefully measure both sides to locate each pane of glass on the edge of the sash, then drill in the middle of those.  Also not rocket surgery.

A friend still has most of a house worth which need to be repaired (they were replaced, but he kept the removed leakers, because he, like me, can't bear to throw away stuff that might still be useful; actually, he may be even worse - better? - than me about that!).

Chi Monger wrote:
I wonder, how might windows fare, if instead of air btwn glass panes, that space was filled with polycarbonate? (Because temps go thru plastic slower than glass). I wonder if the plastic could be close equivalent to air/gas filled, especially if there’s the film included btwn the glass & plastic?   It’d make a mess of recycling the windows, but, they’d be more resistant to breaking, & moisture couldn't get btwn to fog/grow mold…?

I'd guess that the thermal performance would be substantially lower with the polycarbonate "filling" than a gas between the panes.  Ideally, you'd have a vacuum between the panes (like the old thermos bottles) but Andersen has already established with the failed argon units, which effectively did make a vacuum between the panes, that the glass just isn't up to that task, mechanically.  A vacuum can't convect (nothing in there), can't conduct (still nothing in there), and the glass still blocks a lot of the NIR radiation.

On that problem of finding people to deal with issues in windows, I had to resort to the extremely local handyman, me, to get our windows swapped.

We had two choices, order custom windows, or buy standard sized ones (e.g., 3' x 4') and chisel and grind the framing made at or just under the standard opening size. It was a pain, but things like a Porter Cable siding sander, which uses aluminum discs with 24 - 40 grit carbide fused to them make the project quicker, though there is a whole lot of dust.

On the up side, the very moment I got the new windows in (replacing conductive aluminum framed beasts, that last forever) and sealed, I could feel a  very obvious difference in how much the sun heated the south facing room.

The down side of poly filled windows would be, it would be a less efficient insulator than dead air space. The sealed air or other gas would conduct heat less than the solid mass.

The importance of this can be seen in building techniques. Now days, rather than 2x4's on 16" centers, most "stick" buildings use 2x6's spaced at 24" centers.  One of the notable advantages is, less of what they call bridging, which is just a way of describing the problem of heat transferring through the wood, and which happens at a higher, faster rate than with well done insulation.

The insulation issue aside, boy would those be some tough windows though. Even if the outer glass was shattered, it would remain in place, like car windshields that are designed to take hits in ways that protect the occupants of the rig.