Author: chogan@directresearch.com

Post #2033: A rare double-attaboy today.

 

I wrote the following two comments (to other comments) on Jennifer Rubin’s opinion piece in today’s Washington Post.

In a first, two people thanked me for my comments.

Maybe I should buy a lottery ticket today.

So here’s something that’s topical, and near-zero marginal effort.  And so far, hasn’t managed to tick anybody off too much.

On the urban/rural Democrat/Republican divide.

Just think of the entire Republican platform as promising to return to the past. They want to pretend to live in a world where: Global warming doesn’t exist. American manufacturing dominates the (Post WWII) world. Women know their place. Non-whites, non-English-speakers are a small and quaint fraction of the population. Coal is king.

I’m sure you can fill in others.

And this jibes well with the core audience, which is rural America. Just look at the red-state blue-state map. Even within blue states, the rural areas are red.

And, at a guess, that’s because rural America has been going backwards, economically, for about the last half-century. In large part from the gutting of light industry in the U.S.

I don’t think anything could have stopped that. But if I were in their shoes, I think I’d listen to anybody who promised to turn back time. No matter how illogical and frankly racist that promise was.

So Trump exploits that. Remember how he was (e.g.) going to bring back American Coal, when talking to West Virginia miners? Even though every trend said that was nonsense.

Well, truth or fiction just doesn’t much matter if you’re poor, getting poorer, and see no way for your children to make a living where they grew up.

Not making excuses for it. I have yet to see any positive policy proposals from the Republican side for doing anything about … well, anything. Just trying to grasp the mindset.

In response to somebody who pointed to the massive increase in asylum-seekers allowed into the country …

Then, if America is still governed by the rule of law, change the law. But what we’ve seen this past year is that, at Trump’s order, the Republican party would have nothing to do with revising immigration law. Because this is too juicy an issue for Trump to use in his campaigning.

In 2022, about a quarter-million people requested asylum, of which Cuba was the most common country of origin. So, roughly speaking, with a population of about 330M, roughly 1 person in 1000 in the U.S. was a new 2022 asylum-seeker. That’s a lot, by historical standards, but hardly a crisis.

That ramped up so much in 2023 that Biden temporarily shut down asylum at the southern border, by executive action, this year. He can’t do that permanently. Not unless he’s a dictator.

But that, along with cooperation from Mexico, greatly reduced the number of people trying to immigrate at the southern border.

And what was the centerpiece of the immigration bill that Trump shot down? It was to expand the immigration courts, and so clear the asylum case backlog and get almost all of those people out of the country, as actual grants of asylum in any given year number in the low tens of thousands.

Instead of just exploiting the issue, it would be a breath of fresh air if Republicans would, like, you know, try to govern. Which starts with addressing a legal issue, by changing the law.

Post 2032: Replacing my heat pumps, part II: How efficient are my ground-source and mini-split heat pump options?

 

The key question for this post is about as simple as it gets: If I have two choices for heat pumps, which one will use less electricity?

In my case, one option is the replacement ground-source heat pump that has been recommended, at a base installed price of about $25K per heat pump.  The other option is to replace my dead ground-source heat pump with a modern air-source mini-split heat pump, at somewhere around half that cost (call it 60% after adjusting for likely difference in equipment life, in my particular case).

This is a stupidly hard question to answer well.  As I explain at length below.

But, after doing all the homework that I care to do, for my house and my climate (with mild winters and an efficient gas-fired secondary heating system), the answer is that either style of heat pump (air-source or ground-source) will use roughly the same amount of electricity.  Or near as I can tell, based on published data.

That’s not due to the underlying physics of the situation.  If it were only about the physics, ground-source would win hands-down.  Instead, that appears mainly due to faster technological improvement in air-source units over the past decade or so, compared to ground-source units.  This seems to have fully offset the “natural” advantage of ground-source.  In effect, my real-world choice is between air-source using the current generation of technology, and ground source using older technology.  (The model of ground-source heat pump I have been offered was first introduced in 2016.)  Or, at least, using a less-efficient design for the heat pump itself, disregarding which heat sink (air, ground) is used.  That’s what makes it a tie ballgame, as of now.

This leads me to conclude that replacing one of my dead heat pumps with (e.g.) a name-brand air-source mini-split system:

  • Is substantially cheaper, even accounting for likely shorter equipment life.
  • Incurs no significant loss of efficiency compared to my ground-source option.
  • As a bonus, bypasses my house’s barely-functional 1959-era ductwork.

Ground source systems still have some clear advantages.  All the equipment is indoors, and so likely lasts longer.  They work well even extremes of cold or hot weather.

But the fact is, there just ain’t that many of them, particularly in a relatively mild climate like Virginia.  Of the roughly 4 million annual residential heat pump installations per year (in 2022), maybe 50,000 (call it 2.5%) were ground-source units.  That has big implications for how rapidly the units reflect improved technology, and how much choice you have for who installs and services your unit.

Unless some unforeseen problem arises, I will replace one three-ton dead ground-source heat pump with a pair of 1.5-ton mini-split air-source heat pumps.

And I will not feel the least bit guilty about doing so.

I was going to give full and excruciating details but the overall accuracy of the conclusion does not warrant that.  Below, I sketch out enough to summarize how I arrived at the numbers above.

SEER, EER, HSPF, COP, and all that jazz.

The efficiency of a heat pump varies, based on the how big a temperature difference it is trying to pump against, and how close you are to the maximum capacity of the system.  The bigger the temperature difference, and the closer to maxed out, the less efficiently the heat pump runs.

This means that, despite what you read from many internet sources, you cannot simply convert one heat-pump efficiency measure to another with a simple conversion-of-units number.  Yes, you must do that first, because some of these measures mix BTU/Hs and watts, and others don’t.  But in addition, you also have to make some sort of adjustment for how stringent the test is.

It’s very much like EPA mileage.  The MPG the EPA gets depends on how the car is driven.  Typically, EPA city mileage is much worse than EPA highway mileage.  If you compare the city MPG of one car to the highway MPG of another, you’re making a mistake.  So it is, in spades, with SEER, EER, COP, and HSPF.

Now we get to the hard part:  Things are hazy.

If you Google SEER, say, you’ll see the same zero-details definition everywhere:  It’s the ratio of the cooling power produced (in BTU/H), to the electrical power supplied (in watts).  But as to, how, exactly, that’s measured, it’s hard to find any information at all.  E.g., is the energy used to run the water pumps included, what indoor and outdoor temperatures were used for the test, how were ducts, water pumps, etc. factored in, and so on.

  • The details of the tests are proprietary and reside behind an expensive paywall.
  • For the same measure, ground-source and air-source heat pumps use different methods.
  • Certain aspects of overall energy use — duct system back pressure, water pump electricity use, and resistance electrical heating for backup heat — are either ill-specified, or not stated as to impact.

Among the things that I’ve seen hints for, but no definitive answer, is how these tests treat the waste heat of the electric motors themselves.  I saw at least one credible-looking website showing that ground-source heat pumps add the value of this waste heat to their heating output, as if that heat would make it into your ductwork.  But air source heat pumps do not.  That’s consistent with where the compressor is located (inside for one, outside for the other).  But it boils down to an assumption that the waste heat of the compressor motor somehow warms the air in your ductwork, which clearly isn’t the case for the units in my basement now.  I have yet to find a clear answer on that, and it matters materially to the comparison.

So you need to take the table above with a grain of salt.  My interpretation is that if there is a difference in efficiency across the three units I looked at, it’s small.

Definitions

Each of these measures compares output heating or cooling power, to input electrical power used.

EER (energy efficiency ratio).  Cooling.  Measured at a steady 35C outdoor air temperature, 26C indoor air temperature, and 50% relative humidity (for the outdoor air?).  Heat/cool is measured in BTU/H, electricity is in watts.  I think the test calls for the unit to run full-blast when this is measured.

SEER (seasonal energy efficiency ratio).  Cooling.  Near as I can tell, this is set up to simulate the range of temperatures you would see in a “standard summer”, so to speak.  Heat/cooling power output is measured in BTU/H, electricity input is measured in watts.

COP (coefficient of performance):  Heating:  Generically, COP is simply watts of heat out, divided by watts of electricity used.  Heat pumps have different COP values depending on the temperature tested, and how hard they were running.  But the EPA-reported COP appears to be for one temperature, and I think its with the unit running full blast.  Heat/cooling power is measured in watts, electrical input power is measured in watts.

HSPF (heating seasonal performance factor).  Heating.  Like SEER, this tests the units over a range of temperatures designed to be a sort of “standard winter”.  I believe that, where the unit has a resistance-heating secondary heater, if that clicks on during the testing, the electricity used in secondary heating is counted toward the total.  Heating power is measured in BTU/H, electrical use in watts.

The -2 suffixed versions of these appear to include a more realistic measure of the back-pressure of typical home ducts.  Best I can tell, in the typical situation, you’d expect the (e.g.) SEER2 rating of an appliance to be 5% to 10% lower than the SEER rating.

Accounting for test stringency:  SEER to EER conversion, units-adjusted HSPF to COP conversion.  Here, I found some sketchy internet sources suggesting that where you have SEER and EER for the same unit, SEER is typically 85% of the EER value, due to the more stringent testing cycle.  So I used that to adjust these all to a common EER-style basis.

Conclusion so far

Again, take this table with a grain of salt. There’s a whole lot I don’t know about the details of how each test is applied to each type of machine.  And probably never will know, particularly for the details of testing ground source machines, where tests specifying outdoor air temperature are irrelevant.

That said, if you adjust for the difference in units-of-measurement (BTU/H versus watt), and assume that the tests that use a broad range of conditions (SEER, HSPF) tend to run about 85% of the equivalent tests that use a single set of conditions (EER, and COP as EPA reports it), then you get the comparison above.

Which, honestly, is just about what I came up with, back-of-the-envelope, when I first looked into this some years ago.  The super-high-SEER Japanese-made heat pumps that emerged a decade ago seemed to eclipse (my estimate of) my existing ground-source heat pump’s efficiency.  SEER 25? Maybe I mis-recall.  But I do recall being startled with how high the available SEER ratings got, for air-source units.

Bottom line, efficiency-wise it’s a tossup.  If I weight each units two numbers by local degree-day (3x heating a cooling), I get my estimated all-year efficiency values of 3.6, 3.5, and 4.0 for the three heat pumps examined, respectively.)

If your location experiences lot of time at extremely cold or hot temperatures, ground-source heat pumps still seem to offer some significant efficiency advantages over air-source.  And, for sure, because the equipment is all inside, ground-source is likely to last longer.

But in my case — with a relatively mild climate, efficient (gas-fired) backup heat, and so on — it’s six of one, half a dozen of the other.

Finally, this pretty strongly suggests that the current tax law is out-of-date.  The huge advantage given to ground-source heat pumps might have made sense in 2004.  It appears to make no sense in 2024.

Once upon a time, ground-source heat pumps were king.  But not any more.  And the law has yet to catch up with that.

Post 2031: Both of my heat pumps have died? This should be interesting.

 

 

My house is heated and cooled by two ground-source heat pumps, installed by the previous owner almost exactly 20 years ago.

Well, “was heated and cooled”.  One died last spring.  The other has one foot in the grave, with its most recent repair involving some burned wiring (never a good sign).  Both heat pumps need to be replaced. 

No-brainer, right? Just replace them.

Well …

The only firm in my area that specializes in ground-source heat pumps quoted me a price of $50,000 to replace my two three-ton (ground-source) heat pumps.  That’s for the basic model.  Bells, whistles, and line sets extra.  I’m guessing the final cost would end up around $60K.

 

At this point, the only thing I know for sure is that no matter what, this home repair is going to be about like buying a new car.  Or two.

Minus the fun.

Follow along for the next several posts, as I get a handle on what to do next.

Am I a heat-pump heretic?

I drive an EV.  Cripes, it’s a made-in-USA Chevy EV, for that matter.

I re-calculate my family’s carbon footprint every couple of years.

And I bought my house specifically because it had efficient ground-source heat pumps.

But the world continues to change.  And I’m not sure I’m going to be replacing those with new ground-source heat pumps.

And the fact that I would consider not doing that makes me something of a heretic.  But I’m still in the process of gathering my facts.

  1. Twenty years ago, ground-source was the undisputed king of heat pumps.
  2. In part, that’s because air source heat pumps of the time weren’t very good.
    1. They worked inefficiently when it was cold out.  To the point of essentially not working.  That caused use of “secondary heating”, meaning, typically expensive and inefficient resistance electric heating.  In winter, your fancy heat pump spent too much time operating as more-or-less a big dumb electric space heater.
    2. And they weren’t any great shakes, efficiency-wise, the rest of the time.
    3. Plus, they just kind of generally sucked.  Comfort-wise.  In the winter, they always seemed to blow air that was, upon careful measurement, slightly warmer than the existing room air.  Or, at least, that’s how I recall my Maryland apartment of the mid-1980s.
    4. Basically, they were air conditioners that, in this climate (Virginia), could also put out some heat, for some of the winter.
  3. My impression is that this changed about ten years ago.  At some point, cutting-edge air source heat pumps appeared to be — by my calculation — at least as efficient as my 2004-vintage ground source heat pumps.
  4. That’s because air-source technology improved rapidly, while the technology of ground-source units … lagged?
    1. Part of the improvement was in finding a way for air source heat pumps to function well even at low outdoor temperatures.
    2. That went hand-in-hand with greater efficiency of operation.  E.g., modern air-source units might now have variable-speed compressors, fans, and so on.
    3. But not much seems to have happened to ground source heat pumps.
    4. The slower rate of improvement in ground source heat pumps is a side-effect of the vastly lower volume of ground-source (about 0.5% of the home market) compared to air-source (the other 99.5%).
  5. As a result, ground-source heat pumps are no longer a slam-dunk winner, compared to traditional air-source heat pumps.

    1. As a matter of basic physics, they should be.
    2. But because they seem to be behind the curve in efficiency improvements, they aren’t.
    3. The upshot is kind of a temporary tie:  The rapid adoption of more efficient technology in the air-source sector has offset (or nearly offset) the inherent physics-based advantages of ground-source heat pumps.  For now.
  6. There is no point number 6.
  7. But the tax laws still grossly favor ground-source heat pumps over air-source.  And the subsidies are large.
    1. For ground source, the Feds pick up 30% of the installed cost, no limits.
    2. For air source, if it meets certain efficiency standards, the Feds pick up a maximum of $2000 (or 30% of the installed cost, whichever is less).
    3. And Virginia offers an incentive system for ground-source that is beyond weird, and must be described in a separate posting.  At first blush it appears ludicrously generous toward ground-source units.
    4. Separately, I’m not sure they were thinking about replacements of worn-out old systems when they wrote the law.  Effectively, what I’m doing is repairing my existing system, by replacing the worn-out heat pumps. But, legally, that’s treated identically to putting in a brand-new ground source heat pump system.
  8. So, something is not right here.
    1. Is the law outdated, and out-of-step with the current state of technology?
    2. Or is the law a closet buy-American plan, as these ground-source units seem to be U.S.-made?
    3. Or am I dead wrong about the near-equivalence of air-source versus ground-source efficiency in the modern world?
    4. Or, some thing even weirder — geothermal versus ground source discussion to be added at some point.
  9. Curveball:  My first floor would be ideal for a couple of “ductless mini-split” systems.  These are little air-source heat pumps, but instead of being designed to hook up to your ductwork, they simply blow air around like a room air conditioner.  You pass the refrigerant pipe and condensate drain through an exterior wall, between the inside air-distribution cabinet, to the outside compressor.
  10. So, why not replace one of the dead ground source heat pumps with two mini-split air source heat pumps, half the size.
    1. Near as I can tell, I’d pay only a modest or no efficiency penalty for doing that.
    2. And it looks like it would be quite a bit less expensive, even accounting for likely shorter equipment life of an air-source system.
    3. Plus, we’d possibly have a warm kitchen for the first time since we moved here, because we could bypass our near-useless 1959 first-floor ductwork.
    4. Plus, it’s lower risk — more like an appliance, and less like a fixture in the house.  If one of those dies, I can just toss it and more-or-less just plug in a new one.  Not quite as convenient as a fridge, but not hugely different.
  11. But … but … but … the very thought of replacing a ground-source heat pump with an air-source heat pump is … heresy.  Particularly given that the actual “ground” portion of the ground-source system — the mile of plastic “slinky” pipe buried in my back yard — still functions perfectly.

Conclusion

That’s as far as I can take it in this first post.  I need to pin down some facts to go any further.

I bought this house in large part because it had an efficient ground-source heat pump.

But the world has changed since I bought it.

The next post takes the two real-world heat pumps — one a ductless mini-split air source heat pump, one the ground-source heat pump for which I have been quoted an installed price — and tries to get an apples-to-apples comparison between them, in terms of efficiency.

That turns out to be stupidly hard to do.

That’ll be the next post:  SEER, SEER2, EER, EER2, COP, HSDF and all the rest of that alphabet soup.  And how on earth they measure that, for ground-source heat pumps.

Post G24-027: A review of my vegetable garden year.

This has been a year of disappointing yields.  I still have a bit of stuff growing, but I am more than ready to call it quits this year, here in Virginia zone 7.

When I boil it down, it looks like I should grow tomatoes, okra, beans, and winter squash.  And not much else.  So, tentatively, that’s the plan for next year.

Continue reading Post G24-027: A review of my vegetable garden year.

G24-026: Squash-off, round II: Tromboncino versus Butternut.

 

Tromboncino was an exceptionally productive winter squash in my garden this year, in Virginia zone 7.  Maybe a little too productive, if you get my drift.  It’s the kind of vine that doesn’t take no for an answer as it attempts to sprawl its way to garden domination.

In the end, two plants plus total neglect yielded about a dozen fruit, roughly 6 pounds each.  Area for area, this was more productive than butternut squash, this year, by a large margin.

But how does it taste?

OK.  Neither as colorful nor as flavorful as Waltham butternut.  But no off notes, either.  It’s a perfectly adequate winter squash for adding bulk to (say) a soup, without altering the taste.

Easy to grow, productive, and edible.  And an amusing shape.  What’s not to like?  I’ll be growing this again next year.

Details follow.

I did not set out to grow tromboncino as winter squash.

The back-story is in this post, below.  I grew both tromboncino and cucuzzi (guinea bean) to use the immature fruits as a substitute for summer squash. That, because I’m tired of fighting the squash vine borer.

As a substitute for summer squash, that was a failure.  More for cucuzzi, which to me had a distinctive “dirt” undertone, than for tromboncino.  But neither of them was good compared to the taste of normal (e.g., straightneck yellow) summer squash.

Post G24-023: Taste test of tromboncino, cucuzzi, and yellow summer squash.

So I killed the cucuzzi, but let the two tromboncino vines live.  They turned out to be the most productive winter squash I grew this year, by a large margin.

I won’t be buying winter squash any time soon.

How does it compare to butternut?

I took my smallest, seemingly-mature tromboncino fruit, and a small butternut, and had it it.

Tromboncino is clearly a relative of butternut squash. Same color.  It peels easily, like butternut, but it takes longer to peel, per edible pound, as the long, thin neck of the tromboncino has around about twice the peel area, per unit of volume, relative to the stockier butternut.

The flesh is a paler orange (right, below).

I ended up throwing away the seed-cavity end of the tromboncino.  This squash has a large, bulbous, thin-walled seed cavity.  I dug out some seeds, but decided that between peeling it and de-seeding it, I’m guessing I’d have gotten another half-pound of usable squash.  Didn’t seem worth the effort, so I chucked it.  I might reconsider that when I get around to cooking the larger ones.  Might also make “roasted pumpkin seeds” out of the bigger ones, depending on the volume of seeds.

Steamed or boiled, tromboncino is blander than butternut.  I get no “sweet potato” notes whatsoever.  Instead, there’s a faint aromatic after-taste that reminds me vaguely of steamed yellow summer squash.  In any event, tromboncino has a distinctively different taste from butternut, but not much of a taste.

In chicken-squash soup, both squashes are bland enough that they contribute bulk, but no noticeable flavor.  If I closed my eyes, I would not have known I was eating diced squash as opposed to somewhat-overcooked diced potato.

Bottom line

Assuming this keeps fairly well, I will definitely plant this again, owing to the high productivity and the toughness of the plant.  By eye, these two vines (allowed to sprawl) out-produced all the rest of my winter squash combined.

Better yet, once these were established, I did nothing other than kick them out of the way occasionally.  (The same can be said for butternut in my garden.  Nothing seems to bother it much.)

Compared to butternut, it’s paler, blander, and has an unusual hint of summer squash to it.  But that’s pretty subtle, and in a soup or stew, it serves merely as a bland filler.  Not necessarily a bad thing, for a winter squash.

See also:

Post G24-025: Squash-off, round 1: Waltham Butternut versus Georgia Candy Roaster.

Post 2028: Shortages in the rear-view mirror.

 

This is a list of prior posts relevant to the current spot shortages of toilet paper.  Just the stuff that seemed on-topic to me.

The first post predates the arrival of coronavirus here and starts with the first pre-pandemic whiff of panic buying (masks, Home Depot).  Most of the rest deal directly or tangentially with pandemic-related shortages.

I toss in a few other shortages, and end wit a post about bank runs.  Because everybody likes a good bank run.  Now and then.  But I have omitted any mention of the great canning lid shortage, which surely deserves a separate list for length considerations alone.

Each image should be a link.

 

Post #535: Answer: Milk, white bread, and kitty litter

Post #543: Genteel panic buying

 

Post #560: Real backpackers don’t use toilet paper: The arithmetic of panic shopping

This next one is the exposition of the economic theory, such as it is.  Call today’s TP shortage just another example of a self-reinforcing irrationality, a.k.a. “Who’s laughing now?”.

The argument is this:  If I’m rational and know where TP comes from, I see no need to stock up.  But thinking ahead, this means that if I do legitimately need to purchase TP in the short term, the stores may be out.  And guess who has toilet paper, in that situation?  (Answer:  All the dummies that panicked.  They have TP and I don’t.  Who’s laughing now, eh?  Rationally, then, I should participate in what I know to be irrational behavior.  Elbow-to-elbow with my fellow shoppers.

 

Post #563: We need a TP FDIC, or, hoarding is a self-fulfilling prophecy

Post #1719: A brief note on the 1980s Savings and Loan Crisis, or why sometimes It’s (not) a Wonderful Life.

Post #1720: The Systemic Risk Clause and the FDIC

Back to the pandemic.

Post #568: A wrap-up on grocery shopping, revised

Post #576: Shopping report CORRECTED

Post #724: Coin shortage

I had forgotten how badly the Trump administration fumbled the response to the pandemic.  Kind of glad now that I blogged about it at the time.

Post #816: We actually did have a rational, national plan for mask use?

Post #865: Getting ready for a hard winter, 5: Grocery story deja vu

Post #1568: COVID-19 trend to 8/10/2022, now 33 new cases per 100K per day

 

 

 

Post #2027: Toilet paper and self-fulfilling prophecies

 

It says something deeply, deeply weird about the soul of America, that people are panic-buying toilet paper in response to the East and Gulf Coast port strike.

I had a few responses to this, in no particular order.

First, guess I’m glad I haven’t worked my way through my pandemic stockpile yet.

Second, maybe I had better pick up some toilet paper at the store today.  Just in case.

I fully realize that toilet paper doesn’t move through these ports.  Almost all toilet paper used in the U.S. is produced domestically, call it 93% (reference Yahoo).   The rest that is consumed in the U.S. is produced in Canada and Mexico, and isn’t shipped by ocean-going freighter.

And yet, it’s a fallacy to say that toilet paper should be unaffected by the port strike.  If enough people are stupid and irrational about it, and the target of their stupidity is toilet paper, then toilet paper is very much affected by it.

Oddly, if you substitute “Springfield, OH” for “toilet paper” in the last sentence, it still makes perfect sense.

Anyway, the consequence being that if you need to buy TP, you’ll be every bit as much out of luck, even though a shortage is purely a result of irrationality, as if there some actual disruption of the toilet paper supply chain.

Some consumer items will likely go out of stock from this strike.  Bananas being the poster child for that.  But who would have guessed that TP remains the canary-in-the-coal mine for American anxiety.

Source: Clipart-library.com