Category: Environment

Post #1901: Artificial Xmas Tree

 

Three key things I didn’t know about artificial Xmas trees:  Fluffing time, branch tip count, and storage.

I knew nothing about artificial Christmas trees.  So I started my research where I usually do, on Amazon.

When I started, I assumed you pulled the tree out of the box much like a magician pulling a rabbit out of a hat.  Reach in, give a tug, and out comes the tree, fully-formed.  The branches must “sproing” into place, or something.  And at the end of the season, you stuffed it back into the same box, the branches neatly folded back into rest position, and you were done.

Five minutes on Amazon, and I realized I had no clue how modern artificial Christmas trees actually worked.  The twin keys to my ignorance were frequent mentions of “fluffing time” and “branch tip count” on Amazon.  Use of these terms made choosing a tree kind of difficult, as I had no clue what either one of them was about.

Fluffing time:  The big branches of the tree do fold up and down against at the trunk, but all of the little branches are just stiff wire, with plastic “pine needles” embedded.  Turns out, all those little branches are packed flat against the main branch.  You have to bend each individual branchlet into place, by hand, one at a time, in a process termed “fluffing” the tree.

Branch tips:  And this is where the “branch tip” ratings come in.  A six-foot artificial tree might have anywhere from 1000 to 2500 “branch tips”.  Which more-or-less equates to that many little stiff pieces of wire that must be bent, by hand, into some approximation of a real tree.  More branch tips (per unit of tree volume) leads to a fuller-looking fake tree.  On Amazon, time and again, the manufacture would say something like “45 minute assembly time”, and the Amazon comments would say something along the line of two to three hours of “fluffing time”.

The upshot is that “fluffing” is the industry euphemism for spending hours of time bending little stiff wires covered in bristles, so that your myriad branch tips approximate the look of a real tree.  The near-universal advice on Amazon was to wear gloves and take your time.  In fact, many of the trees on Amazon come with a pair of gloves thrown in.  Presumably because you’ll need them.

And the third key thing?  Storage.   Because, although nobody say this explicitly, fluffing appears to be a one-way street.  I get the impression that nobody packs their tree down into anything like the original size.  As a result, you need somewhere to store your fully-fluffed tree — possibly in pieces, possibly slightly compressed — for the off season.

The upshot is that a new artificial tree requires several hours of “fluffing time”, wherein you take 1000’s of branch tips and bend them into shape.  After which you must store the tree in its fluffed condition.

 

Purpose and summary of this post

In our family, we’ve always gotten some type of real Christmas tree.

But this year I’m going artificial.  I think.

As usual, before I buy a consumer durable, I do my homework.  This post summarizes what I’ve learned so far.  Starting from a point of complete ignorance about artificial Christmas trees.

Briefly:

  • Artificial trees are overwhelmingly the U.S. norm, with roughly 85 percent of households with Christmas trees opting for an artificial tree.
  • Families with little kids tend to favor real trees, and tend to transition to fake trees as the kids age and the parents retire.
  • The main reason cited for buying an artificial tree is convenience, which I think dovetails with the use of artificial trees by age.
  • Artificial trees last about a decade, on average.  So the decision to go artificial kind of locks you into it for a while.
  • Environmental concerns for real-versus-fake trees are more-or-less a wash,
    • But the longer you keep the same fake tree, the better.
  • For a newly-purchased fake tree, “fluffing” the tree — bending thousands of wire branch tips into position — seems like a major pain.
  • Fluffing is a one-way street, so you need a place to store your fluffed tree in the off-season.
  • Trees with embedded lights don’t last as long as plain, unlit trees.
  • White trees tend to discolor over time, particularly if stored in non-climate-controlled areas.
  • The more “branch tips” per unit of tree volume, the fuller your tree should look.

The upshot is that I’m looking for a plain, un-lit, un-decorated green tree.  With a reasonable number of branch tips per unit of volume.  (Which, of course, I have worked out a formula for.)  And the first thing I’m going to do is scour the local thrift shops, because the thought of spending hours “fluffing” a tree is unappealing.

We’ll see where it goes from there.

Background:  Oceania had always been at war with Eastasia

My father, who shouldered most of the labor, once suggested buying an artificial tree. We called him out for the vulgar suggestion of convenience over tradition, and he never brought it up again.

Aryn Baker, in Time Magazine, December 2022.

I can relate to the quote above.  As the family member officially tasked with Getting The Tree, I’ve been lobbying for an artificial tree for years now.  The stopper has always been my family’s refusal to consider an artificial tree.

In particular, my wife was clearly and firmly against buying a fake tree.

Or so I thought.

Our Christmas tree traditions have been sledding downhill for decades.  Once upon a time, we’d make a big outing out of taking the kids to a cut-your-own-tree farm.  That lost its charm as the kids got bigger, so we went with the trees offered by a local charity.  We’d go to the lot, make a fuss over getting just the right tree, then overpay the local charity, all in the spirit of the season.  After a few years of that, we got to buying our tree so late that my only option was to shanghai whichever child was available for a last-minute run to pick up a tree at the local big box hardware store.

So we were already at the point of real-Christmas-tree-as-industrial-commodity.  Which it has been, all along, in reality.  But buying one in the garden section of Home Depot just hammered that home.

Deck the Halls and scan the barcode?  Not very Christmas-y.

But last year I hit rock bottom, with an exotic tree species, the brown pine.  On a whim, I picked up a little live tree, figuring to plant it after Christmas.  It had some species name on the label, but as it turns out, it was actually a member of the brown pine family.  This was only revealed a few months after putting it outside.

And so, in the spirit of the holidays, I once again asked my wife if she still objected to artificial Christmas trees.  And the answer was not merely that she had no strong objection, but that she’d never had any objection to artificial trees in the first place.

And just like that, I’m in the market for an artificial tree.

Environmental impact of artificial Xmas trees?

In a nutshell:  It’s no big deal either way.

First, If I’m an environmental sinner for buying a fake tree, I’ll surely have a lot of company in hell.  Households with real Christmas trees are a small minority.  In 2021, about three-quarters of American households displayed a Christmas tree, and of these, 84 percent have an artificial tree (reference).  That’s figure varies a bit from year to year, but is in the low 80 percents in all the surveys shown on the cite referenced above.

A different (yet seemingly credible) poll shows just 71% of surveyed adults (who were having a Christmas tree) planned on having an artificial tree (reference).  That’s a huge discrepancy (versus 84 percent, above), for a simple yes/no question.   The same article cites the association representing Christmas tree growers, which puts the number around 75 percent, but should be treated as a number from an advocacy organization.

So which estimate is more likely to be right, 71% artificial or 84% artificial?

Don’t be mislead by statistics about annual Christmas tree sales.  Based on the survey cited above, the median life of an artificial tree is about ten years.  Accordingly, each year’s sales of real trees top the sales of artificial trees.  But that’s only because the typical artificial tree user buys a new tree just once a decade.

That said, annual sales data, coupled with a typical 10-year lifetime, suggest the 84-percent-artificial estimate is correct.  In a typical year, about one-third of Christmas tree sales are artificial trees (reference).  With an average 10-year lifespan, in the steady state, that (via simple math) implies that about 83% of Christmas tree used in any given year are artificial trees.

The upshot is that real Christmas trees are not exactly a relic of the past, but they long-ago lost the bulk of the market to artificial trees.

Further, and without citation as to source, my decision to switch to an artificial tree late in life is typical, as is my reason for doing so.  As people age, and no longer have young children in the home, preferences shift toward an artificial tree.  And the most-cited reason for going with an artificial tree is convenience.  Both of which describe my situation.  And so, my family’s long downhill slide toward fake-tree heresy is apparently normal.  Young families with small kids more frequently opt for a real tree.  Retirees, less so.

Despite artificial trees being the clear winner in the Christmas tree war, there seems to be a robust and highly-opinionated debate over the environmental impact of real versus artificial Christmas trees.

Which I find just shy of hilarious, given the context.  Kind of like obsessing about the environmental impact of plastic straws, as you sit in your Hummer waiting your turn in the McDonald’s drive-through.

In any case, as I contemplate buying a bunch of gifts that my family doesn’t need, I find it hard to get exercised about the impact of the Christmas tree itself.  Virtually every material Christmas gift will have been made overseas and shipped here in single-use packaging.  Which I will then re-wrap using yet more single-use wrapping paper.  Because it’s Christmas, and that’s how we do things here.  In that context, the difference between a once-a-decade purchase eventually destined for the landfill (fake tree) and a yearly purchase of some custom-grown compost (real tree) is lost in rounding error.   It’s just too small to matter in the grand scheme of the season.

Even more than that, the choice between real and artificial is more-or-less a wash, for the average purchaser, in terms of overall environmental impact.  Depending on whom you listen to, for the typical user, if you keep your artificial tree for enough years, you’ll have about the same environmental impact as the equivalent string of real trees.  The break-even point is five years’ use of an artificial tree (see this seemingly-competent .pdf life-cycle analysis).  Some say ten.  This one says 7 to 20.  Pick a number.   Some wing it and say never, based on what amounts to moral or emotional or other (e.g., fear) considerations.  But of the serious life-cycle analyses of the issue, somewhere in that five-to-ten year span, your N-year use of a steel-and-plastic artificial tree will have about the same environmental impact as growing, shipping, and disposing of N real trees.

YMMV.

So, for once, I just don’t care enough about the environmental impact to bother to look into it.  It’s just too small to matter, in this context.

 

Narrowing it down

My only environmental takeaway is that the longer the artificial tree lasts, the better.  But this immediately gives me three guidelines as I start to sort out what’s available locally and on the internet.

Unlit.  You can buy fake trees that are just fake trees, or you can buy trees that have Christmas tree lights already embedded in the fake tree.  Data pretty clearly show that trees with embedded lights have a shorter lifetime than unlit trees.  I’m not sure whether that’s literally due to lights breaking and burning out, or whether the persons attracted to the convenience of a pre-lit tree are more likely to dispose of a tree sooner.  That said, the (sketchy) fake-tree longevity data argue for buying an un-lighted artificial tree.  Plus, I already own lights.  And putting the lights on the tree is part of the Christmas tradition.

Green.  You can buy fake trees in a variety of colors, including ones that mimic snow on the tree.  Heck, you can buy them with the ornaments already (permanently) attached.  My take on it is that anything other than green is going to get old pretty fast.  And that, literally, the white plastics on white trees tend to yellow over time, particularly if stored in areas that are not climate-controlled, such as an attic or garage.

Better quality.  One huge drawback to buying a fake tree is that it’s a commitment.  Once you buy one, you’re pretty much stuck with it for the next decade or so.  You can’t in good conscience try it one year, decide that you’d rather have a real tree, and toss it in the trash.

Given that, even though I’m not quite sure how to judge this, I think that purposefully shopping the low end of the market might be a mistake.  In theory, all these trees are made from steel wire and PVC plastic.  So I’m not that worried about having a cheap tree fall apart.  It’s more that if the tree doesn’t look really nice, I’m less likely to want to keep putting it up.

The upshot is that I want a better-quality, un-lit, green Christmas tree.

Step 1:  Hitting Amazon as prep for hitting the thrift shops.

At first glance, it’s hard to make sense of the pricing of artificial Christmas trees on Amazon.  The price per foot, for the same model of tree, rises steeply with the height of the tree.  Below, increasing the height by 66% (from 4.5′ to 7.5′) increased the cost per foot by 180% (from $13/foot to $36/foot).  By contrast, I think that real trees are priced more or less the same, per foot.  You’d expect an 8-footer to cost about twice as much as a 4-footer, or zero percent change in the price per foot.  So the pricing structure of these artificial trees seems grossly at odds with what I’m used to, for real trees.

But just a little analysis shows that this steep increase with tree height makes sense.  For a given manufacturer and model of tree, pricing is pretty much a case of “you get what you pay for”.  The reason that costs rise so steeply with tree height is that the total volume of the tree rises faster-than-linear with tree height.  And the manufacturers more-or-less have to fill the volume of the tree with something.

 

To a close approximation, for this “family” of trees (same model, same manufacturer):

  1. The cost is about 7 cents per branch tip, more or less.
  2. The density of branch tips per cubic foot is roughly the same for all but the smallest tree.
  3. The actual height/width ratio falls as the height of the tree rises.

I think this, along with a look at a few similar trees, tells me roughly what I need to know as I go looking for a tree in my local thrift shops.

Mostly, there’s no free lunch.  The pricing of these trees seems to be almost entirely a function of the volume of materials used.  Count the branch tips, multiply by a few cents per branch tip, and that’ll be the price.

In addition, it appears that manufacturers of a given model of tree shoot for some more-or-less uniform density of branch tips per unit of tree volume.  Turning that on its head, for a given desired density of branch tips per unit of volume, I should be able to select any size of tree, and still be able to meet that goal.

So, with Amazon as the baseline, I think I ought to be able to look at trees and tree prices, across thrift shops, and make some sort of informed judgment.

Post #1900: The USDA released a new map of U.S. plant hardiness zones this week …

 

Source:  Maps are from USDA.  I added the line marking the boundary between hardiness zones 5 and 6.

… and nobody cared.

Which is a good thing.  I think.  On balance.

On the one hand, it’s good that they released it.  That’s my take on it, knowing the controversial history of the USDA hardiness zone map.

On the face of it, the red lines on the map above simply mark a data-defined boundary. Below that line is the area where winter temperatures should be expected to stay above -10F.  That’s based on the 30 years of local weather data, prior to the map date.  As the U.S. winter nighttime temperatures have warmed, those lines are moving north about 5 miles per year, in Missouri.  And, as I understand it, at roughly that rate, averaged across the entire U.S.

Back to the here-and-now, if you look at the illustration above and immediately say, hey, what happened to the circa-2002 map?  Why did they skip a decade?  Then you get an interesting story.

The answer is, Republican administration.  The Bush Jr. administration just somehow couldn’t quite seem to get around to allowing the public to see the updated version of that map.  The widely-held presumption is that they withheld the information precisely because it showed what I’ve highlighted above:  the USDA hardiness zones are migrating north.  That’s easily-grasped evidence of the early impact of global warming on the U.S.  And so that information was suppressed.

(This, despite the nonsensical CYA language that the USDA insists on including in the footnotes to the description of the map methodology.  They seem to say that “climate change” requires 50 years of data, and since each individual map only covers 30 years, you can’t infer that this is the impact of climate change.  Despite the fact that the underlying span of data across the full set of maps is now more than 50 years.)

On the other hand, I think those changes ought to get more press coverage.  This isn’t natural variation.  This is a clear and understandable signal of global warming’s initial effects.   And as slow as these changes are, relative to a human lifetime, there’s nothing on the horizon to suggest that they are going to stop any time soon.  Five miles a year doesn’t sound like much, until you realize that the U.S. is only 1000 miles north to south, and that things will move a lot faster once global warming really gets rolling.  And that it’s fairly hard to grow corn and wheat in a sagebrush and cactus desert.

So, even though I’m still in Zone 7, I think this deserves more press than it has gotten.  And I think that the Bush-administration suppression of the circa-2002 map needs to be remembered, right alongside the temperature data.

What are we talking about?

Source:  USDA.  I removed some details from the map (e.g., degrees C scale) to make it clearer.  Thus, I must say that: a)  the map is not the official USDA Plant Hardiness Zone Map, and (b) the USDA-ARS and OSU logos are eliminated.  If you want to see the full official map, follow the link.

The map above shows the coldest wintertime temperatures in each year, averaged across 30 years of data.  The 2023 map literally uses weather data from 1991 to 2020.

The map provides guidance as to what perennial plants can usually be expected to survive the winter, unprotected, in each location. 

That’s guidance, not certainty.  As the owner of a lime tree, I am acutely aware that citrus trees will typically die back to the ground if they go below about 28F.  Plausibly, you need to live somewhere near Zone 10 or higher (e.g., Florida) before you can expect your citrus trees to survive reliably, out-of-doors, unprotected.  Even so, the occasional freeze will hit Florida, so significant frost damage to Florida citrus groves seems to occur every few decades or so (reference).

More generally, if you ever buy a perennial plant from an on-line nursery, they’ll let you know the hardiness zones in which the plant is expected to survive.  Or they’ll give you information such as “hardy down to 0F”, and leave it up to you to know what USDA hardiness zone you live in.

It’s not hard to get your hands on the underlying data from which these maps were created, for example, via NOAA.  I’ve plotted the annual wintertime lows before, for the weather station at Dulles Airport.  Here’s 60 years of wintertime lows, as recorded at Dulles.

The obvious upward trend that you see above is pretty much the norm for most of the U.S.  So it’s no surprise that the revised USDA map shows those plant hardiness zones creeping northward.

In fact, my location (Vienna VA) graduated from Zone 7A (expected annual low of 0F to 5F) to Zone 7B (5F to 10F).  I was firmly in the middle of 7A, now I’m barely at the edge of 7B.  That’s reasonably consistent with the increase in wintertime minimums shown in the Dulles data above.

Footnote:  Hardiness zone creep exaggerates average warming

One final footnote is that, due to the nature of C02-driven global warming, the northward creep of the hardiness zones exaggerates average warming.

The reason for this is simple:  The largest impact of global warming is on nighttime temperatures.  (E.g., via Scientific American).  And on winter temperatures (E.g., via Axios).  By inference, the biggest impact of all should be on nighttime winter temperatures.  And, typically, the annual low temperature in an area is set during the course of some winter night.

If nothing else, knowing this is a quick way to dismiss denialist arguments that, somehow, the observed warming on earth is due to changes in the sun.  (That, despite direct satellite measurement of solar irradiance, dating back to the 1970s, showing no such thing.)  The fact is, the warming is more pronounced at night, and in the winter, both times of limited sunshine.  Heuristically, if enhanced atmospheric C02 is a blanket, that blanket matters more when it’s cold and dark.

Conclusion

The real lesson here isn’t the map, per se.  Anyone who cared to analyze the publicly-available weather data — as I did above — would already have a strong expectation that the official USDA climate zones would continue to move northward, in this most recent update of the USDA map.

Really, the big lesson here is the missing circa 2002 map.  There was a time when Republicans so thoroughly insisted in keeping their heads in the sand, on global warming, that they found excuses not to update this map.

Has that changed?  Are Republicans on board now, with the idea that global warming is real?   I doubt it, but there’s no way to know.  The last two iterations are both dated to periods with Democrats in control of the administrative branch of government.  So, as to whether or not a Republican administration would allow this to be updated on a once-a-decade schedule, I guess we just won’t know until we see it.  Or not.

Post #1899: Composting shed, testing

My tumbling composter doesn’t work in the winter. Which is ironic, given that it was made in Canada.  But it’s a common problem.  Winter composting is a problem for anyone who tries to compost small amounts of material outdoors, in a cold climate.  Composting stops as the temperatures drop.

So I made a little insulated shed, to fit around the composter. 

The upshot is that, so far, it seems to keep the compost around 16F warmer than it would otherwise be, without the shed.  On average.

I’m not sure that’s going to do the job. Continue reading Post #1899: Composting shed, testing

Post #1897: Re-using political yard signs. Composting shed, Part 2

 

In honor of election day, I’m re-using a bunch of political yard signs to build a small outdoor shed.  The Coroplast used for high-end campaign signs is far too good to be tossed out just because somebody lost an election.

I’ve decided on the following method of construction:

  • Coroplast campaign yard signs
  • Stapled to furring strips

It’s every bit as complex as it sounds. Continue reading Post #1897: Re-using political yard signs. Composting shed, Part 2

Post #1896: On re-using political yard signs: Composting shed, part 1.

 

Today is the day when a whole lot of campaign signs go straight into the dumpster.  Along with the political aspirations of half the recent candidates,

Which is a pity, really.  (The signs, I mean.)  The best of those signs are made to last a long time.  We really ought to do better than treating them as a single-use disposable.

So I suggest that the first Wednesday following the first Monday in November be declared Campaign Sign Recycling Day.  In keeping with that, today is a good day for me to make something useful out of some dead political yard signs.

This post is the theory.  Next post is the actual assembly.

We’re talking Coroplast.

Source:  Coroplast, Inc.

Campaign yard signs come in several varieties.

Cheap campaign yard signs aren’t re-usable in any obvious way.  Some are coated cardboard, on some sort of stick.  Some are a printed plastic sleeve that fits over a three-sided wire frame.  For both of those, the metal frames (if any) can be recycled.  But the signs themselves aren’t good for much.  Far as I can tell, once they’ve served their purpose, they’re trash.

By contrast, high-end campaign yard signs are Coroplast(r).  That is, corrugated plastic sheets — two sheets of plastic bound together with thin plastic channels.  As pictured above.  Effectively, they are built like corrugated cardboard, but plastic.

These sheets — typically made from polypropylene — have a surprising amount of structural integrity.  Much like corrugated cardboard, they are quite resistant to bending or folding across the corrugations.  This means you could  use a single thickness of Coroplast to build light-duty objects, and multiple thicknesses to build heavy duty objects.

These also stand up well to being used outside.  The ones forming the sides of my oldest raised beds now have more than five years of cumulative outdoor exposure (first as yard signs, then as raised bed sides.)  Only this year did they begin to show brittleness from all that sunshine and weather.  (And if I’d cared to keep them painted, I probably could have avoided that, as most of the damage is from exposure to the UV in sunlight.)

Fastenating

I’d say that the biggest downside is that these can’t be glued together.  (Or, at least, not well, or not easily, using conventional glues).  The underlying material (typically, polypropylene) just doesn’t stick to much.  And the ink coating — the printed message — further complicates things.

Near as I can tell, most people who make DIY projects with Coroplast sheet opt for some sort of mechanical fastening.  That can be as simple as cutting slots and tabs, so that sheets fit together.  Than can include melting sheets together, in places, to form a sort of plastic rivet.  Or can include using actual metal fasteners (bolts, washers, nuts) to hold the plastic parts together.  Or staple or nail them into a wood backing.

(The big exception being model airplane enthusiasts, for whom gluing coroplast is the only practical option.  That said, after having read one or two sites discussing that use, I’m convinced that gluing up Coroplast is not something that you’re likely to get right the first time.)

There are chemical methods that might, in theory, hold these sheets together.  Some are specialized glues specifically designed for this sort of application.  All of those appear to cost an arm and a leg, at least for the quantities that would be needed to build (e.g.) a piece of furniture.  And then there’s solvent-welding the polypropylene (PP).  That is, finding a solvent that will dissolve PP, dissolving some pieces of PP in that solvent, and then using that as if it were glue.  I strongly suspect that either approach — specialized glue, or DIY solvent-welding — requires a nice clean PP surface, involving a lot of complicated surface preparation, and that the ink firmly bonded to the typical campaign sign would interfere with that.

Dare I say this?  Even duct tape is iffy.  The same factors that make it hard for glue to stick, make it hard for tapes to stick.  And surface preparation for taping is not easy (e.g., lightly torching the PP surface).  All told, taping or gluing this stuff seems like a lot of work, on the off chance that you can get something to stick firmly.

The upshot is that I’m going with mechanical fastening only.

Never in small amounts

I find most plans for upcycling or recycling of materials to be of little value.  Most involve using small amounts of materials.  Most involve creating something for which there is a very limited demand.  The results tend to be more of a novelty than a way to divert significant amounts of material from the landfill.

Contrast that with using campaign signs for the sides of raised garden beds.  That used up a lot of material, slowed down the inevitable progress toward the landfill by years, and avoided consuming considerable amounts of virgin materials.

In this case, I have a stack of roughly 35 campaign yard signs, or about 100 square feet of Coroplast sheet.  Pre-cut into neat 2′ x 1.5′ pieces.  So I’m looking for a project that will use up just about that amount of material, and give me something useful in return.

Revisiting cardboard furniture

Source:  Google search

In Post #887, I did up a quick summary of the various construction methods used to create corrugated cardboard furniture.  I’d guess that just about anything you could build as corrugated cardboard furniture could also be built out of Coroplast.

So if you are stuck for ideas, you can look up cardboard furniture plans.  As long as they don’t depend critically on glue, they ought to work with Coroplast.

As I see it, the main approaches to creating weight-bearing structures for cardboard furniture are:

Simple stacked sheets.

Source:  Homedit.com

Folded beams

Source:  Time, inc.

Structural grids (with or without surfacing materials):

Source:  Planet Paper

Totes

Source:  Storage Techniques for Art, Science, and History

It seems worth mentioning that a lot of lightweight commercial bins and totes are made from folded and fastened sheets of Coroplast.  It’s such a common use that there’s even a market for used Coroplast bins and totes.

You can find lots of different plans on the internet for constructing Coroplast totes, bins, boxes, and so on.  They all boil down to folding a sheet into a box shape, and then somehow fastening it together at the corners.  In the example pictured above, the author constructs a sort of “rivet” out of hot glue, and uses that to fasten the corners mechanically (reference).

Here, I’m shooting for something larger, to use up more Coroplast signs.

From dead campaign signs to structural integrated panels.

Source:  Builder Bill

I’m going to turn my pile of used Coroplast into some structural integrated panels or SIPs.  In this case, the SIPs will be flat, rectangular wooden frames, faced with coroplast sheets, and filled with … probably scraps of insulating foam board.

Like a hollow-core door, if you’ve ever dealt with the insides of one of those.  The entire frame around the rim is solid wood, and so has enough strength to hold fasteners and hinges.  But the broad flat surfaces are just thin, rigid sheets backed by some hollow, honeycomb-like structure.

As long as those rigid face sheets stay firmly in place, the entire unit ends up being quite strong, given the light weight.  Far more than you might reasonably expect.  This is why (e.g.) you can easily use a hollow-core door as a table-top, even though the individual face veneers are far too flimsy for that use.

I think this takes good advantage of the strengths and weaknesses of Coroplast.  And it allows me to connect the Coroplast to the structure using a (hardware) staple gun, which is about as fast and as lazy as it gets.  But all the connections subject to high point loads — the sort of connector that would pull out of a thin plastic sheet — can be made through the solid wood edges.

And it’s generic.  I’m going to use this to build a little knock-down insulated shed for my composter.  But nothing would stop you from (e.g.) building furniture this way.  Bookshelves.  A larger shed.  A lightweight travel trailer.  Anything that can be made from rigid flat panels can be made this way, within the strength limitations of the materials.

 

From structural integrated panels to winter composter cover.

At this point, putting the composter cover together is just a matter of connecting the panels made in just above.

Ideally, I’d like to have “knock down” construction — something that can be easily disassembled and re-assembled without tools.  (That way, I can store it away easily during the off-season).  But in the end, this is only going to take four long screws to hold it together.  So I’m just going to screw it together.

How this actually goes together is going to depend on what scraps of lumber I build it out of.

Conclusion

In this post, I figured out how I’m going to use up a lot of 1.5′ x 2′ Coroplast campaign signs.  My proposed method is to build a bunch of “structural panels” out of those signs.  That is, thin wood frames faced front and back with Coroplast sheets.  And then use those rigid panels to build a structure.

This approach:

  • Uses up a lot of signs.
  • Doesn’t require gluing the Coroplast sheets to anything
  • Uses (hardware) staples as the main fastener
  • Avoids putting high point loads on the plastic sheets themselves, by placing all the “structural” fasteners into wood.
  • Is flexible — just make the panels different sizes.

All I have to do now is to make that happen.

I’m now going to test that, by building a winter cover for my composter, using that “structural panel” method.  Assuming all goes well, the construction of that should be documented in my next post.

Post #1893: Winter, firewood, soot, Canada

 

 

Normally, about this time of year, I’d start burning my way through two cords of wood, over the course of the winter.

This year, I’m not.

It’s complicated.

Soot uncertainty.

I went through the biggest global environmental problem in heating with wood back in Post G22-058.

In a nutshell, when I burn firewood for heat, the C02 that goes up my chimney came out of the air an average ten years ago.  For that reason, firewood is very close to a carbon-neutral fuel, when viewed over (say) a decade of time.  Over that time period, atmospheric C02 is neither increased nor decreased by the process of growing wood, then burning that wood.

As opposed to say, burning natural gas.  Typically, that was produced some time in the last half-a-billion years or so, and trapped underground.  The C02 from that source definitely adds to the current level of atmospheric C02.

But along with wood burning comes soot.  And even though that soot resides in the atmosphere for just a brief period (typically, two weeks), soot is incredibly effective at capturing the heat from the sun.  Dispersing a microscopic black powder through the atmosphere allows the atmosphere to absorb more light energy?  Who would have guessed that?

Source:  Myhre, G., D. Shindell, F.-M. Bréon, W. Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza,
T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013: Anthropogenic and Natural Radiative Forcing. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United
Kingdom and New York, NY, USA.

Back in 1995, nobody quite knew what the net effect of soot was.  Even through 2014, estimates were uncertain enough that the confidence interval around the point estimate included zero.

That said, you have to go with the most recent evidence.  Based on the 2014 5th report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), I estimated that the warming effect of the soot from my wood stove was just about large enough to offset any benefit from wood burning.  That’s the gist of in Post G22-058.

And that’s why I skipped the firewood purchase this year.

The IPCC sixth summary report was released in its entirety earlier this year.  So it’s worth taking a peek at that, as the estimate for black carbon involved a lot of uncertainty.

(First, though I have to note how different the public debate is now, for the IPCC 6th report, compared to nine years ago, for the 5th report.  For the IPCC 5th report, climate-change denialists went over it with a fine-toothed comb and found an actual substantive error, in a sentence, in a section of the technical portion of the report.  This had to do with the rate of melting of Himalayan glaciers. And, as is their habit, the climate-denial industry then proceeded to play the game of This Changes Everything,  So Believe Nothing You Have Heard.  For the sixth report, by contrast, the release was uneventful, and nobody tried to fabricate some made-up stink about it.  It’s almost as if everyone with sense now realizes that climate change is real, man-made, and causing problems.  And so there is little value in trying to generate new disinformation, because those who still deny that climate change is a real threat are more-than-satisfied with continuing to believe disinformation that was debunked decades ago.)

Interestingly, they’ve revised their estimate of the warming impact of soot way downward, compared to the 2014 report.  (Though still within the 95% confidence interval of the 2014 report).

The best estimates of ... attributed to ... black carbon is substantially reduced. The magnitude of uncertainty in the ... due to black carbon emissions has also been reduced relative to AR5. (Section TS.3.1)

Source:  Page 42, IPCC, 2021: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2391 pp. doi:10.1017/9781009157896.

And, in fact, it looks like the estimate of the warming impact of soot is back about where it was in 1995.  Which is about when I decided it would minimize my global warming footprint if I burned wood for (at least some of) my home heating.

Source:  Page 92, reference cited just above.

Without getting further into the details, at face value, the upshot of this most recent change is that heating your house with wood, in a modern air-tight low-emissions wood stove, probably offers significant net benefit in terms of global warming footprint.  Based on this most recent estimate of the impact of the resulting soot.  Assuming I did my calculations correctly last year.

Local air pollution

This year’s air pollution alerts from Canadian forest fires have made me a lot more sensitive to the issue of air pollution from wood fires. In the past, I’ve just turned a blind eye to that, mostly because as far as I can tell, I’m the only person within blocks that actually burns wood for heat.

Air pollution from an isolated wood stove does not have the same public health implications as air pollution from Canadian forest fires.  That’s because you have to be in the exhaust plume from my stove to be affected by it.  By contrast, you were breathing Canadian soot no matter where you were, and no matter when.  It’s the difference between a brief exposure, walking past my house (say), and breathing it 24 hours a day.

So, really, it’s more a question of what I’m doing to the air that I and my neighbors breathe.  And for that, the key question is how particulates generated by my wood stove, at my property line (i.e., entering the public domain) compare to the particulate levels we saw during the Summer 2023 air pollution alerts?

I suspect that the only way to tell, with this one, is to measure it.  Which I will, the next time I light a fire in my stove.

For now, let me work through the basics, given that this stove is EPA rated to produce no more than 2 grams of soot per hour.  A good round number for “too much soot in the air” is, say, 100 micrograms per cubic meter for total particulates.  That would trigger an “unhealthy” reading for PM 2.5.  To get down to that level, an hour’s worth of soot from my stove would have to be diluted into … 20,000 cubic meters of air per hour.

Or about 333 cubic meters of air per minute.  In order to dilute the smoke from my wood stove down below the “hazardous” level for particulate matter.  That’s a cube of air roughly 18′ on a side.  That seems like a high-but-plausible rate of dilution.

There is also a sense that if you can smell wood smoke, you are breathing in pollutants.  And that may well be true — the smell must come from somewhere.  That said, a quick look at some scholarly papers suggests that there isn’t a tight correlation between the smell of smoke and the density of particulates in the air.  (As evidenced, I guess, by the Canadian forest fires, where there was no smell of wood smoke in the air, but particulate levels were high).

So, before I even lay my first fire of the season, and get out my recently-purchased air quality meter, I’m guessing that this is an open question.  I can surely smell wood smoke, at ground level, at least part of the time that I’m buring wood.  The next step is to measure it and see if I’m pushing unhealthy levels of particulates out into my adjacent neighborhood.

Post #1866: Winter composting, take 2, using an indirect solar air heater.

My roll-up solar air heater is putting out about 2200 watts of power, in the form of heated air, in the mid-day October sunshine, 37 degrees north latitude.

But absent some sort of magic, that’s not enough.  Not on its own, anyway.  To keep my composter working through the winter, I’d have to build an insulated box for it, and pipe the hot air into that box.

I’m not even sure that would work.  And even if it did work, I’m not sure it’s worth the effort.

Continue reading Post #1866: Winter composting, take 2, using an indirect solar air heater.

Post G23-066: A little fertilizer calculation, or why I #leavetheleaves.

 

It takes a surprisingly small depth of fall leaf litter to provide an adequate supply some key nutrients for your vegetable garden.  Leaves-as-fertilizer is just another reason to #leavetheleaves.

 

A time to plant garlic, and a time to refrain from planting garlic.

It may be difficult to believe, but some versions of the Bible actually omit that line from Ecclesiastes 3.1-11.

I’m getting ready to plant a 4′ x 8′ area with hard-neck garlic, for harvest next year.  Plant the cloves in the fall, once the soil is good and cold, and, with any luck, they’ll come up next spring and give you nice big heads of garlic by mid-summer.  I wouldn’t know, because, typically, I plant them too early, by contrast, and they’ll sprout now.  They may survive into next year, but I can tell you from experience, the result will be puny, unusable heads of garlic.

(Weird garlic fact:  If you plant bigger cloves, of a given variety, you’ll harvest  bigger heads of garlic.  I’ve seen this result replicated enough times that I’m fairly certain it’s true. E.g., Red Gardens stumbled across this effect, but you can find it in many scholarly sources as well.  This is arguably the only reason not to plant grocery-store garlic.  As it turns out, “culinary grade” garlic, found in the grocery store, has smaller cloves than the garlic reserved to become “garlic seed”.)

Two options for Nitrogen fertilizer

The lowest recommended fertilizer application I found, for commercial garlic growing, was from Cornell University.  Their most recent study said that that 50 pounds of nitrogen per acre would be sufficient, and that yields did not increase if you added more than that.  Essentially, you should expect your garlic to pull that much nitrogen out of the soil, so that’s what you need to replace.

I could supply this using 30-0-0- lawn fertilizer.  To be clear, I think that putting lawn fertilizer on your lawn is crazy and environmentally destructive.  But it’s a good source of nitrogen. I own a 10-pound bag of it.  I’ve owned that particular bag for maybe a couple of decades now.

To supply the complete nitrogen needs of by 4’x8′ garlic bed, I would need four level tablespoons of lawn fertilizer.  Like so:

If nothing else, this shows you why you shouldn’t just wing it, when it comes to concentrated chemical fertilizers.  You only need trace amounts.  That’s such a small quantity of material that it would be difficult to spread that evenly over the bed.

But, in fact, I’m going to supply this using fallen leaves.  Because a) why not, and b) the leaves serve as both mulch (before they decompose) and fertilizer (after they decompose).

How deeply must I bury that bed in fallen leaves, to supply all the nitrogen the garlic requires?  Take a guess:

  1. An impractically large layer (e.g. feet of depth).
  2. An inconveniently large layer (e.g., one foot of depth).
  3. A few inches of leaves.

The answer is C, a few inches.  In this exact calculation, the answer is that about half-an-inch of fallen leaves should be adequate. Surprise.  That’s based on leaf litter containing about 1% nitrogen by weight, as shown here.

To double-check that, I can start from an alternative data source. At a mean of 10 grams of nitrogen per kilogram of leaves, I would need about 1.5 kilograms, or maybe 3.5 pounds of leaves, to supply the required nitrogen.  Same as the calculation above.

Source:  American Journal of Horticultural Science.

Unlike the water-soluble lawn fertilizer, where excess will run off with the rainfall, it’s probably close to harmless to err on the upside with leaves.  Some sources suggest fertilizing at up to three times the rate recommended by Cornell.  And, to be sure, the actual N content of my particular leaves might be less than average.  And maybe there’s some catch here, such as the N in fallen leaves being less readily available than the N in commercial fertilizer.  So, in theory, if I wanted some insurance, I could pile (say) three inches of leaves on that garden bed let them rot over the winter.

The term of art for this — for letting a relatively thin layer of leaves rot over a large area — is sheet composting.  By calculation, I can easily supply the required nitrogen for my garlic by sheet composting my fallen tree leaves on that bed.

In fact, fall leaf litter contains so much nutrient, in total, that in well-watered climates, centralized leaf collection reduces nutrient runoff into the surrounding surface water.  So says the USGS, in this piece.  I count that as the sole potential environmental benefit of centralized leaf collection.

During the growing season, it’s better to compost the leaves first, then add that to the bed.  The act of breaking down the leaves temporarily draws nitrogen out of the very top layer of the soil (explained per this reference).  But by the time the garlic needs nitrogen in the spring and summer, that thin layer of leaves will have already broken down.

Like sulfur for garlic?

Finally, this year, I’m going to give my garlic a little sulfur.  If I can figure out how to do it.

It seems like a not-unreasonable thing to do.

First, sulfur is a key component of allicin, the chemical that makes garlic, garlic.  Some research suggests that sulfur-deficient soil results in garlic with less allicin, which I think has to mean, less garlic-y.  And, possibly, smaller bulbs, to boot.  I see no point in growing small, bland garlic bulbs.

For sure, garlic withdraws sulfur from the soil.  Whether or not the soil is actually deficient, it seems prudent to put the expected amount of the sulfur withdrawal into the soil head of time.

By my estimate, if all goes well, I’ll need to replace about a gram of sulfur per square foot of garlic bed.  Or, in this case, 32 grams of sulfur, just bit over an ounce of weight, in the 4’x8′ bed I’m planning to use. That’s assuming I get lots of garlic out of this patch, two 100-gram bulbs per square foot.  More realistically, this is an upper bound on what I need.

The hard number is that garlic is about 0.5 percent sulfur, by weight (this reference).  The naive assumption is that I can grow 6400 grams of garlic in 32 square feet of bed.  (Then 0.5% of 6400 = 32 grams).  That seems to ballpark with other published estimates.

Can I do this with Espoma Holly-Tone?  Maybe.

Source:  Espoma.com, used without permission.

Turns out, I own a big, almost-unused bag of Espoma Holly Tone.  Why, I cannot recall.

Which probably explains why the full bag is still here.  It’s a result of a reverse-Darwinism, survival-of-the-un-fittest process.  If the duds are allowed to linger, they eventually dominate fill your storage space, for the simple reason that they don’t get used.  Likely, whatever I bought this for, long ago, did not pan out.

Will it work here, to give me my 32 grams of sulfur?  Because I sure won’t mind using some of that up. To get 32 grams of sulfur, I need about a pound and a half of Espoma Holly Tone.

That seems like a lot, and that’s a problem.  If I do that, I add too much nitrogen.  The Espoma mix is 4% N.  When I do the math, that 1.5 pounds of Espoma H-T- provides 0.06 pounds of N, or about twice what the Cornell-derived estimate suggests that the garlic needs.

Given that I am going to cover this bed in fall leaves, I may have to buy something else for sulfur.  Looks like the Espoma H-T can provide enough sulfur, but it brings along too much N (etc.) that I’d rather provide by sheet-composting leaves.

Maybe a reduced amount is called for.  Maybe some different product entirely.  We’ll see.  There are still things about sulfur as a soil amendment that I clearly do not yet grasp.

Finally, I have to find a cheap test for soil sulfur, if such exists.  For now, I’m still feeling my way through the whole sulfur-for-garlic thing.

Conclusion.

Am I going to rake my leaves to the curb this year, for vacuum pickup by the Town of Vienna.  No.

Do I need to add chemical fertilizers to my spring garden?  No.

Are those flip sides of the same coin?  Yes.

Add sulfur to garlic bed?  Not clear yet.

Post #1863: Overthinking winter composting.

 

Yeah, no joke, that’s what this one is about.

After N pages of thinking it through, my solution is to toss two layers of clear plastic over my tumbling composter (below), and hope it buys me a few weeks.

As I have learned from Watch Wes Work, it’s only temporary, unless it works.

It’s a long and winding road, to end up with that.  But sometimes you have to assess the options, even if nothing new jumps out at you.

With my redneck double-glazing, the plastic surface of the composter reached about 110F, on a roughly 70F day.  There’s no way that’s going to get me through the winter.  But maybe it gives me some time to think about it.

Background

Source:  Amazon.

I use the composter shown above.

It has two weird features.

First, it’s made in Canada. 

Second, it doesn’t work in cold weather.  At all.

I guess that’s why they send them down here, eh?

Turns out , wintertime composting is a problem for anyone who composts small amounts of material, in a colder climate.  The heat given off by decomposition isn’t enough to keep the compost warm.  Composting grinds to a halt as temperatures fall.

My dad claimed that when he was a kid, dairy farmers in upstate New York would mound up cow manure around their barns for winter.  This was not for the aesthetics of it.  Instead, this was done to take advantage of the heat generated by large volumes of rotting manure.

In hindsight, that was a lot funnier the way my dad told it.

For two decades now, I’ve stopped composting kitchen scraps each fall, and resumed in the spring.  Today it occurred to me … instead of just putting up with it, I should … maybe look for a solution?

What a radical thought.

What’s that garbage worth to you?

Generically, the problem has two parts:  Get rid of your kitchen scraps responsibly, and produce desirable compost for the garden.

Here’s the thing:  I want the compost.  In my experience, compost is nature’s Miracle-Gro(r).  Or maybe vice-versa.  It’s good for what ails a plant, and then some.  It’s inexplicably helpful.  Gardening black magic.

Otherwise, merely disposing of kitchen scraps responsibly is not an issue for me.  I think.  Elsewhere in the U.S., those scraps might be landfilled, at which point their anaerobic decomposition would generate methane.  If vented to the atmosphere, that’s a bad thing.  By contrast, Fairfax County VA incinerates its garbage, generates electricity from that, recovers metals as possible, then landfills the ashes. Here, food waste in the household garbage is just more biomass fuel for the electrical grid.

There’s some minor benefit in recovering the plant nutrients in those kitchen scraps.  But not much.  You only need trace amounts of those in the garden, and until the world runs out, those nutrients are cheap.  At present, looks like 10-10-10 fertilizer (10% (by weight?) each of nitrogen, potassium, and phosphorus) runs about a dollar a pound, retail.  I’m finally getting to the bottom of the 10-pound bag of that stuff that I bought fifteen years ago. 

Should I fry in Hell for all eternity on account of that?  I’m thinking, probably not, but it’s debatable.  Conservation of mass says that N, P, and K went somewhere.  If not stored in the soil in my yard, or gone down the sewer pipes, they’ve run off to the Chesapeake.  But is that a large, medium, or small contribution of those nutrients, on a per-person-year basis?  No clue.

Plenty of ways to get rid of household kitchen waste

If it were just a matter of getting rid of kitchen waste, without putting it in the household garbage, I have numerous free and paid disposal options in my area.  Practically speaking, these would require me to store my kitchen scraps for a week at a time. But no longer than that.

Reportedly (my wife did the homework here): In Fairfax County, VA, I have at least these following locations for dropping off my kitchen compostables, for free.  This includes animal products and plate waste, items you would not typically compost at home.

  • The Fairfax County I-66 and I-95 transfer stations/landfills (documented, here).
  • plus all ten farmers’ markets run by Fairfax County (same document).
  • Selected Mom’s Organic Markets (Moms) (documented, here)
  • Whole Foods in Vienna (solely an internet rumor, not documented).

In addition, there’s the option of weekly composting home pickup for  $360/year.  Around here, one may subscribe to a privately-run once-a-week compost pickup service.  Apparently the dominant local service is highly recommended by its users.  It costs ~$30 a month for weekly composting service, and there is no mention of seasonal contracts, so I’m assuming it’s an annual contract.  They’ll even throw in a couple of 20 pound bags of compost, per year, if you ask for it.

The free drop-offs lack appeal for a few reasons.  One, for some reason, my wife isn’t keen on my routinely transporting buckets of decomposing garbage in her car.  Two, I’d be on the hook for making that trip weekly, without fail.   Three, these would require a dedicated car trip just for dumping the kitchen scraps, as I don’t routinely visit any of those places.

The energy required for my part of these options isn’t a big deal, but …  It’s about an 18-mile round trip to the I-66 transfer station.  That would use about the same amount of electricity as drying an extra load of laundry, a week, in the wintertime.  (Call it 3.5 KWH/week.)  Doing that for three wintertime months would generate around 40 pounds of additional C02 release. That 40 pounds is within rounding error on my household carbon footprint.  Not a big deal.

I do wonder about, and am clueless about, the fossil fuels required for the paid pickup option.  Near as I can tell, customers of that service are spread thin.  The service provider has a distinctive bin, and I’ve only noticed one household in my broad neighborhood that puts a bin like that on the curb.  That implies that there are a lot of truck-miles per pickup, but I have no clue just how many, or how large the carbon footprint of that is.

But mostly, where I live, the decisive factor is that putting kitchen scraps in the trash is more-or-less environmentally harmless.  As noted above, they end up as biomass for electrical generation.  They seem to have what economists term “free disposal”, environmentally.  You can convert them back to carbon at virtually zero net cost.  Spending any fossil fuels to get rid of those scraps seems like a losing proposition, from a carbon-footprint perspective.  Let alone the time, effort (and potential car-stink residual) of any of the free dropoffs.

Why go to a lot of trouble, or some trouble and expense, just to shoot yourself in the foot, environmentally?  Even if you’re only shooting yourself a little bit.  If my options are to haul it myself, pay someone to haul it separately, or just put it in the household garbage, it makes more sense to chuck it in the garbage.  At least in Fairfax County.  YMMV.

You know you’re a suburban gardener when …

Source:  Ace Hardware.  Not AI.

You find yourself buying shrink-wrapped shit.  That is, packages of manure.  Off the hardware store shelf.  And not for cheap, either.

I think that was near the low point of my organic-gardening phase.  In the distant past, I was a gardening purist and sought natural sources of nutrients for my garden. No Matter What.

Until one day, after transporting an entire 4’x8’x2′ utility trailer of horse bedding from the exurbs to my garden, I did the math and realized I could have bought the same amount of nitrogen for about $1*, in a nice, clean bag, at the hardware store.  With far less expenditure of fossil fuels for transport.  And far less effort.

* Calculated from data in this reference.  Typical used straw bedding weighs in at maybe 4 lbs/cubic foot, and is one-fourth horse manure.  Manure from a sedentary horse comes in around 7 pounds nitrogen per ton.  My trailer would have held ((4x8x2 cubic fee, * 4 lbs/cu ft.)*(.25% manure * 7 lbs nitrogen per ton for manure / 2000 lbs per ton) = ) about a quarter-pound of nitrogen.   Which is slightly less than you get in a pound of 30-0-0 lawn fertilizer.  Which costs about a buck at Home Depot.  You don’t believe me?  Read the N-P-K percentages on the shrink-wrapped manure, above.

Organic sources of garden nutrients are nice because they are typically slow-release and low-nutrient-density.  That makes it just about impossible to shock your plants with over-fertilization.  (Or goof-proof, said as one who has goofed.) These also add carbon if worked into the soil, which improves its tilth.  But the flip side of low nutrient density is inevitably a relatively high environmental cost in transportation energy.  Finally, I would guess there’s less likelihood the nutrients will be transported by rain runoff, rather than being used by your plants.

Despite that, I decided that it was smarter to use artificial fertilizers sparingly than it was to lug around tons of low-nutrient-density organic matter.  Hence the soil test kit comes out every spring.  And I limit my organic materials to those I can gather at home.  Including kitchen compost.

I’m all for organic sources of garden nutrients.  I just don’t want to haul them any significant distance.  Let alone dispose of the packaging.

A tempest in a compost tea pot?

Before I go to any significant cost to fix this problem, I need to have a quantitative handle on the benefit.  Just how much kitchen-waste compost do I typically produce, in the (roughly) nine months a year that the composter actually works.  And by inference, how much will I gain from an additional three months.

On the output side of the equation, I’d guess that my composter produces about a cubic foot of finished kitchen-scraps compost every three months.  I seem to empty one side of the composter about that often, and each emptying yields one and a half five-gallon buckets of compost.  (N.B. a cubic foot is about 7.5 gallons).  Working it in the other direction, that’s about a third of my estimated initial volume of kitchen waste, which seems about right. (I mix “brown” material 50/50 with the kitchen waste, so in theory, in three months, six cubic feet of total composter input ends up generating one cubic fit of finished compost, or just under an 85%) reduction in volume.  Not sure if that’s a reasonable figure or not.)

So that’s the question.  Where I live, there’s no particular environmental harm in chucking food scraps in the garbage.  The only real benefit of not doing that is the highly desirable compost.  So as I work through this problem, the issue boils down to how much effort should I go to, to obtain an extra cubic foot of high-quality kitchen-scrap compost, per year?

Stuff I’m not going to do.

Countertop electric composter. 

I recall this coming out as a new product just a few years ago.  Now there’s an entire industry segment for countertop electric composters.   These dry and grind your kitchen scraps, resulting in “shelf-stable” dehydrated material.

Looks like your typical countertop electric composter will:

  • cost about $350.
  • hold maybe three quarts of kitchen scraps maximum
  • dry and grind that in 6-10 hours
  • produce a dry, shelf-stable product.
  • reduce the volume by about 90%.
  • produce odors as they work.
  • Use about 0.8 KWH per quart of scraps.

That last one is my estimate.  The manufacturers say somewhere around that much electricity per batch.  But they must be counting on the machine to be only about a third full when run, typically.  (Calculation not shown.  It was boring.)

From the gardening perspective, the end product seems a bit weird to me, in that, well, it’s still food.  It’s not composted, as in rotted.  It’s dehydrated, ground food scraps.

Really, the only difference between this and a food dehydrator is that this dries your food (scraps) and grinds them up.

It’s as if someone mated a hair dryer and a garbage disposal.  I can’t help but think that the (stressed) moving parts predict a relatively short lifespan. 

If I had to work up a figure for my expected electrical use over the winter, for this device, I’d guess that I’d run this for three months (90 days), producing about two quarts of kitchen scraps per day.  If that then takes 1.5KWH per load, over the course of the winter season this would use 135 KWH.  In Virginia, that would result in about 90 pounds of additional C02 emissions per season, from the electrical generation.  (I can’t count on any reduction in landfill methane from not putting my scraps in the trash, because Fairfax County incinerates everything.  I think.)

Aside from the cost, the smell when operating, the potential for the results to attract vermin when used outside, the electricity consumed, and the likely short lifespan of the device, this seems like a pretty good option.

Ew.  Just ew.

One common nugget of internet wisdom is to freeze and store your winter garbage, and compost it later.

Another alternative is indoor worm composting.

Nope.

Groping toward a solution

First, all the internet gives me, for fixing my current composter, is lame advice.  Ooh, just move the composter to a sunnier spot.  That should help with daytime warmth.  Aah, what you need is some insulation, so the heat of decomposition isn’t lost.

Qualitatively, those make sense.  Yeah, you got it, I want my compost to be warmer.

Quantitatively, there’s not a chance either one will do the trick.  As a solar heater, my composter sucks.  That’s not what it was designed for.  It has a lot of mass, but little sun-absorbing surface area.  It doesn’t trap any hot air (it’s not glazed), it’s just black plastic sitting in the sun.  And did I mention it’s plastic, yet it relies on conduction of heat through the durable plastic walls into the composting material.  Separately, as a heat-retaining compost holder, it sucks.  For one thing, the container of compost is suspended, allowing cold air to contact the container from all sides and both ends, all the time.  And you literally can’t insulate the ends or the thing won’t spin.

Let me now discount some out-of-the-blue solution to this.  For example, it might be possible to purchase bacteria that operate efficiently at lower temperatures.  I’ve seen hints that such exist, but I haven’t really hit upon a product aimed at the home market.   Or, surely I could use electricity to warm the composter, but (see “free disposal” above) that surely increases my carbon footprint.   Let me ignore things of that nature.  One’s over my head, the other seems like outright stupidity.

And yet, the internet is kind-of right, because, practically speaking, it comes down to finding a cheap way to keep that composter warm.  Cheap, because my total reward from this is to reap a whole extra cubic foot of compost per year.

And so, first shot, I covered my composter, as I might cover a plant.   In effect, I mocked up a little greenhouse for it, where it stood.  Just like my tomatoes.

Maybe the bricks behind it provide thermal mass.  Maybe that’s where the composter sat and I didn’t want to try moving it when full.

Having looked at solar air heaters, I now know to classify this as a direct solar heater, and as such, probably low-powered.  So I don’t think this, by itself, will do it.  It’s still a lot of mass, and not a lot of surface.  (Plus, if it does, I’m going to kick myself for not having done this sooner.)

But, in my back pocket, I have the notion that it’s not hard to add an indirect solar air heater to that.  And once you go that route, you can, to a limited degree, pick your power to match your application.  So the obvious next step, if and when this fails, is to take the one I just built, mod as required, and see what temperature it can produce inside that composter “tent”.

But that’s as far as I go, today.  Maybe this will do the trick for the next few weeks.  As with my tomatoes, it’s a season-extender.  I doubt this is going to get me through the winter.

Post #1859: Why all bathroom fans suck. A corollary to Post #1843

 

Answer:  Because they’re small.  That’s it.  It’s just basic physics.  And there’s nothing that can be done about it.

Background

In Post #1843, I figured out and explained why ceiling fans are vastly more efficient that box fans.  Where efficiency is measured by cubic feet of air moved per minute, per watt of power used (CFM/watt).

The answer turned out to be remarkably simple:  To move the same volume of air, a smaller fan blade has to move that air much faster.  That’s just arithmetic.  (If the area swept by a 20″ box fan blade is one-seventh the area swept by a big ceiling fan, the box fan has to move the air seven times faster, to keep up with the volume moved by the ceiling fan.)

Moving air faster takes much more energy than moving it slowly.  Not due to the energy-wasting turbulence that might create ( though that can be a factor), but merely because it takes more pressure to move air faster, and overcoming that pressure takes more energy.

Roughly speaking, CFM/watt should scale inversely with the size of the fan.  Given identical designs and motors, a box fan that is one-seventh the size of a ceiling fan should take seven times the wattage to move the same amount of air.  Roughly.

That’s all laid out in Post #1843.

And now on to bath fans

Today the penny dropped, and I realized that this same phenomenon explains the poor performance of bathroom vent fans.  Seems like bath fans take forever to clear a bathroom.  And I include all bath fans, almost regardless of make or quality.  Where a box fan stuck in a window could clear the air in a bathroom in a couple of minutes, an in-ceiling bath fan might take half an hour.

At best, a bathroom vent fan might have 6″ blades, feeding a 6″ diameter duct.  (Although 4″ duct for bath fans is far more common).  Since the area of a circle goes as the square of the radius, the area swept by the blades of a 6″ bath fan would be about ( 3-squared / 10-squared = ) 9% of the area swept by the blades of a 20″ box fan.  And so, to move the same volume of air as a box fan, a hypothetical 6″ bath fan would require (1 / .09 =) 11 times the wattage.

Let me now put that to the test, via virtual shopping at Home Depot.

And, sure enough, the median bath fan from Home Depot moves about one-tenth as much air per watt, compared to a box fan.

Bottom line:  A bath fan that could clear a bathroom as fast as a box fan would draw ten times the wattage of the box fan.  If you could squeeze that much air, that fast, through the ducts, you’d need to have a 500-watt bath fan*, in order to clear a bathroom as fast as a box fan sitting in the window.  That, before we even consider whether or not you could move that much air through a small duct without undue losses due to turbulence.  That, before we consider how much noise that would make.

* That’s 2/3rds of a horsepower, more or less.  A big electric motor, in this application.

And so, the apparent poor performance of bathroom fans is not a figment of my imagination.  Bath fans move air quite slowly, compared to (e.g.) common box fans.  It’s not a design flaw, or an intentional choice.  It’s just physics.  The smaller the fan, the more power it takes to move a given amount of air.  And bath fans — typically restricted to 4″ ducts — can only move a tenth of the amount of air that box fans can move, per watt of power.