Why boilers are still a great heating source My article for PM Magazine

RayWohlfarth

I wrote this article about a class I taught for a group of apprentices on boilers. They thought boilers were inefficient and not green. I showed them they were mistaken. Hope you enjoy it,
https://pmmag.com/articles/104830-ray-wohlfarth-why-boilers-are-still-a-great-heating-source

Ironman

So many in our trade (young and old) know so much that’s just not true.

Solid_Fuel_Man

Ahhhhh, heat pumps..... Everyone thinks they are the answer. Nothing like 400psi of R410a in a 1/2" copper tube running at 120F and cycled to -10F in that forged brass flair nut..... never will that all leak out! Lol

HomerJSmith

So many in our trade (young and old) know so much that’s just not true.

As Will Rogers said, I think, "It ain't what we know that gets us into trouble, it's what we know that just ain't true." or something to that effect.

flat_twin

Sounds like a great classroom discussion Ray.

RayWohlfarth

It just drives me crazy that we are fed a false narrative. Granted, I see boilers going y way of the horse drawn buggy but I still believe they are one of the best heating systems for comfort, longevity, and efficiency Thanks for the comments

Hot_water_fan

I like boilers, but those emissions and efficiency stats are misleading and are missing a lot of context. They apply if you’re talking resistance heat, not if you’re talking heat pumps. You’re also underselling the grid’s cleanliness. All of this information is publicly accessible on the EIA website. Not trying to argue, but revise or remove them so you don’t mislead students and readers. Otherwise great points! The case for boilers is strong.

Steamhead

From the article:

"According to the U.S. Energy Information Administration, 38% of electricity is generated with natural gas and 22% coal. Nuclear makes up 19%, and the rest, 20%, is generated by renewable sources such as wind, hydro and solar".

Add to that, the grid has its own inefficiencies. So, where power is generated from fossil fuels (60% according to the article, and this would depend on where you are), the entire process- from the fuel being burned to the power being used at the end point- is something like 30-35%.

I fail to see how, given the above, heat pumps are more "green" than boilers.

Hot_water_fan

@Steamhead

Here are the two links that answer this question. 

https://www.eia.gov/environment/emissions/co2_vol_mass.php

https://www.eia.gov/tools/faqs/faq.php?id=74&t=11

From there, it’s just multiplication. You have how much CO2 is in gas (the cleanest of the fossil fuels) as well as the CO2/kWh for the electricity side. Basically, the best a gas boiler can do is: 116.65 lbs CO2/MMBtu/ 95% efficiency ~ 123 lbs CO2 per MMBtu output. Given the average CO2/kWh from the link above, a heat pump with a COP > (.855 x 293 / 123) is cleaner. That’s a COP just over 2. The generation mix without the actual emissions attached is confusing! Why not just get the number that matters, CO2 lbs/kWh? As we burn more gas and less coal, we get lower emissions. When combined with heat pumps, we get even lower emissions. 

Otherwise, the article was great. Getting this right only helps the credibility. 

STEVEusaPA

Great article. Hey Ray, do you happen to know the brand name of that mixing manifold (hydrolink-looking part)?

Steamhead

Hot_water_fan said:

@Steamhead

Here are the two links that answer this question. 

https://www.eia.gov/environment/emissions/co2_vol_mass.php

https://www.eia.gov/tools/faqs/faq.php?id=74&t=11

From there, it’s just multiplication. You have how much CO2 is in gas (the cleanest of the fossil fuels) as well as the CO2/kWh for the electricity side. Basically, the best a gas boiler can do is: 116.65 lbs CO2/MMBtu/ 95% efficiency ~ 123 lbs CO2 per MMBtu output. Given the average CO2/kWh from the link above, a heat pump with a COP > (.855 x 293 / 123) is cleaner. That’s a COP just over 2. The generation mix without the actual emissions attached is confusing! Why not just get the number that matters, CO2 lbs/kWh? As we burn more gas and less coal, we get lower emissions. When combined with heat pumps, we get even lower emissions. 

Otherwise, the article was great. Getting this right only helps the credibility. 

Nowhere in those articles do I see the CO2 emission increases that inevitably come from grid inefficiencies.

Hot_water_fan

You’ll have to explain which inefficiencies you mean. This might be the problem - you may be underestimating how efficient the grid actually is. The ~ “33%” number is not accurate in regards to carbon emissions. The 33% number includes nuclear, which has a high heat rate along with coal, but obviously low carbon emissions. That’s why the CO2/kWh number is so much easier to use - it does all of the weighting for us. 

To be clear, I am ignoring all natural gas leakage in this as well. 

Steamhead

Hot_water_fan said:

You’ll have to explain which inefficiencies you mean. This might be the problem - you may be underestimating how efficient the grid actually is. The ~ “33%” number is not accurate in regards to carbon emissions. The 33% number includes nuclear, which has a high heat rate along with coal, but obviously low carbon emissions. That’s why the CO2/kWh number is so much easier to use - it does all of the weighting for us. 

To be clear, I am ignoring all natural gas leakage in this as well. 

What I mean is, since the grid is certainly NOT 100% efficient at transmitting power, how much extra power needs to be generated to overcome this, and how much does this increase carbon emissions? I've seen figures published pegging the grid's overall efficiency at 30-35%, but that includes the combustion process.

You might loosely compare this to a "pick-up factor" but it doesn't (theoretically) go away after the piping is heated.

Hot_water_fan

Oh we’re on the same page! You’re right of course. 5% of electricity never makes its way to the end user according to the EIA. The major losses come from the conversion, not the transmission. So we’d to divide by .95 to get the true emissions accounting for these losses. So if a gas distribution system with 0% leakage is 123 lbs CO2/MMBtu at 95% efficiency, a heat pump COP needs to exceed: (.855 x 293 /123) /.95 = 2.14. We know some gas leaks before it reaches the house (BGE seems to be digging up streets all over here), so my thumb is on the scale for gas here. The overall grid efficiency number is brought down by nuclear and doesn’t include the 20% hydro, wind, solar, etc. the CO2/kWh catches all of this. 

https://www.eia.gov/tools/faqs/faq.php?id=105&t=3

RayWohlfarth

@Hot_water_fan I have links in my articles to the stats I quoted because I knew it would ruffle some feathers. I used legitimate sources for my numbers. You are welcome to click on the links I believe I quoted EIA on one Thanks for the feedback My thinking is there are emissions whether at the house or the power plant

Hot_water_fan

The stats are all right and your links support the stats! The point is the context - we all know emissions occur in both situations. However, the stats do not support that boilers are cleaner - actually the opposite. Otherwise, great work. 

Steamhead

Not always. It would depend on what mix of energy sources was in use in a given area. For example- West Virginia, as most of us know, has mostly coal. Out in the Midwest there is a substantial number of wind turbines, and probably many more since the last time I was out that way. Where there is a lot of sun, one would expect more solar.

So the short answer, as usual, is "It depends".

Hot_water_fan

Of course it depends, it’ll be changing minute by minute all across the country. That’s not what the article said though. If the article uses averages, it should use the correct averages.  

Mad Dog_2

Ray...excellent article as usual.  My style...no nonsense, unvarnished facts.  The doubting Thomases will see....Mad Dog 

RayWohlfarth

Thanks @Mad Dog_2 I appreciate it

Dave Carpentier

Hot_water_fan said:

5% of electricity never makes its way to the end user according to the EIA. The major losses come from the conversion, not the transmission.

I was always under the impression that the transformer out on the pole across the street was about 60% efficient ? I would imagine the substation a few miles away drops something when converting from the 115k to the distribution levels too. The wires heat up some themselves, somewhat minimal due to the high-v and low amps, but it's a lot of wire out there.

RayWohlfarth

@STEVEusaPA You asked about the manifold. Sorry I missed it The picture is a stock one the fine people at BNP used. Not sure where it came from
@dave carpentier I was told that also but not sure of the actual amount

Steamhead

Dave Carpentier said:

Hot_water_fan said:

5% of electricity never makes its way to the end user according to the EIA. The major losses come from the conversion, not the transmission.

I was always under the impression that the transformer out on the pole across the street was about 60% efficient ? I would imagine the substation a few miles away drops something when converting from the 115k to the distribution levels too. The wires heat up some themselves, somewhat minimal due to the high-v and low amps, but it's a lot of wire out there.

ISTR the same, but haven't found anything on it.

Waher

Steamhead said:

Out in the Midwest there is a substantial number of wind turbines, and probably many more since the last time I was out that way. Where there is a lot of sun, one would expect more solar.

The typical methods utilized to mine rare earth metals to manufacture non-recyclable components in wind turbines and solar panels with relatively short service lives are less 'green' that extracting oil and natural gas. The refrigerant manufacturing process for heat pumps, and the miles of copper involved, also cut into the 'green' equation. Short of going to Thorium based nuclear reactions and vastly upgrading the electrical distribution grid (every NIMBY hates Nuclear and throws a fit at substations, high tension wires both above and below ground), I see the current ill conceived push towards electrification as deliberate sabotage of Western economies and standards of living.

The green crowd is almost entirely made up of fundamentally unserious people literally chasing cow farts and tilting at windmills while a small Bond Villain faction takes advantage of greenwash to empower and enrich themselves at everyone else's expense.

Larry Weingarten

Hi @RayWohlfarth , The stats at the end of your article are fun. To me they help make it clear that hydronics are more versatile than air-based systems, and in addition to boilers and heat pumps for generating heat, heat recover and solar thermal could chime in depending on the circumstances. Not many people argue about the greenness of these technologies. You're rattling some people's cages with this article, but it also makes it clear that we need to work from the same set of facts. Thanks!

Yours, Larry

Waher

Solar thermal for both hydronic purposes and air preheat is low hanging fruit. Use natural convection or a thermosiphon and there's a reduced to eliminated need for electric pumps/fans.

No one seems to pay much attention to wastewater heat recovery either. In urban areas there's a good amount of latent heat literally getting flushed down the drain that could be recovered compared to short life cycle solar panels.

Heat recovery could even be used to generate coolth with absorptions chillers. But nooooooo all the effort and PR goes towards inefficient electric generation with significant storage issues instead of focusing on taking advantage of thermodynamics for an energy source for thermal comfort control.

Mad Dog_2

Great points Waher...This reminds me of folks that are OBSESSED with insulating but ignore Boiler sizing, Venting, pressure, Dumb circulators...its Laughable...Mad Dog

RayWohlfarth

@Larry Weingarten I was hoping to get people thinking about it. I am all for being a good steward of the environment and I just dont believe we are ready to make that jump. Perhaps when we make 75-80% of electricity through green measures, we could consider it.
Thanks

Hot_water_fan

I was always under the impression that the transformer out on the pole across the street was about 60% efficient ? I would imagine the substation a few miles away drops something when converting from the 115k to the distribution levels too. The wires heat up some themselves, somewhat minimal due to the high-v and low amps, but it's a lot of wire out there.

Hm can you show evidence? I’m not an expert, but google says efficiency in the high 90s. Seems like 60% efficient transformers would be glowing they’d be so hot. 

Hot_water_fan

@Larry Weingarten I totally agree with you- this is a case for hydronics more than boilers themselves. Hydronics can of course utilize heat pumps and boilers at the same time, so it’s not even a binary. 

Hot_water_fan

@RayWohlfarth that’s a fair point. Even if the grid is cleaner than a boiler now, on average, it won’t be at all times or in all places. Not by a long shot. I appreciate you putting a percentage on what you consider green, as obviously we can “it depends” it all way the from 0.01% clean to 99.99% clean, which definitely isn’t productive. 

RayWohlfarth

@Hot_water_fan You hear about these rolling blackouts throughout the country now. Can you imagine if every car, stove, rooftop unit, and furnace was converted to electricity. The other concern I have is that there would be no competition. The customer service is bad now what it would be like for a monopoly?

Dave Carpentier

Hot_water_fan said:

Seems like 60% efficient transformers would be glowing they’d be so hot. 

Maybe not glowing, but warm..
"General-purpose dry-type transformers used for distribution within buildings come in three standard temperature rises: 80°C (176°F), 115°C (239°F), and 150°C (302°F)."

That being said.. check this
https://www.ecfr.gov/current/title-10/chapter-II/subchapter-D/part-431/subpart-K#431.196

Looks like since 2007 anyhow, they're up in the 97% range (at a typical 35% loading, i think it said).
The info I was given back in the late 80's by hydro guys, likely referring to non-new (ie, 1960s ?) transformers has been upgraded a bit.
Working on the telecom, a few feet below an aged humming transformer , where you could feel the heat (or was it casting a "Danger" vibe at me ?) sure seemed to fit the eff% back then. lol

I should try to capture the model off of the xformer outside my house with binocs , and look up the % directly. Its about 5 years old.

Hot_water_fan

@RayWohlfarth my utility is both gas and electric so nothing would change for me. They’re fine enough, they sell the gas at cost. Electricity is about $.13/kWh, delivered.

You can always keep the gas/oil appliance for backup if you want! I think the hybrid approach is perfect if you have something existing. 

ethicalpaul

RayWohlfarth said:

@Hot_water_fan You hear about these rolling blackouts throughout the country now. Can you imagine if every car, stove, rooftop unit, and furnace was converted to electricity. The other concern I have is that there would be no competition. The customer service is bad now what it would be like for a monopoly?

I hear people being panicked about them, but who has experienced one?

We don't imagine that everything is electric today because that's not how it works. How it works is that over time, more things are electric, and over time the grid is improved to handle it. Just like has happened for the last 100 years.

ChrisJ

Dave Carpentier said:

Hot_water_fan said:

Seems like 60% efficient transformers would be glowing they’d be so hot. 

Maybe not glowing, but warm..
"General-purpose dry-type transformers used for distribution within buildings come in three standard temperature rises: 80°C (176°F), 115°C (239°F), and 150°C (302°F)."

That being said.. check this
https://www.ecfr.gov/current/title-10/chapter-II/subchapter-D/part-431/subpart-K#431.196

Looks like since 2007 anyhow, they're up in the 97% range (at a typical 35% loading, i think it said).
The info I was given back in the late 80's by hydro guys, likely referring to non-new (ie, 1960s ?) transformers has been upgraded a bit.
Working on the telecom, a few feet below an aged humming transformer , where you could feel the heat (or was it casting a "Danger" vibe at me ?) sure seemed to fit the eff% back then. lol

I should try to capture the model off of the xformer outside my house with binocs , and look up the % directly. Its about 5 years old.

Pole pigs can apparently be 80-98% efficient with a light load. But best I can tell near full load drop to something like 50% efficiency.

My own house shares a 25KVA transformer with 4 others.

25KVA running 5 houses. My house alone can pull 24KVA without tripping the 100A breaker. That transformer at 100% of it's rating would give each of the 5 houses basically 20A @ 240V which to me sounds like a pretty typical load, doesn't it?

I'm betting most of the time that transformer is near it's 100% rating and often over it especially in the summer. So in that case the efficiency is in the toilet.

My understanding is this is common practice because the transformers are grossly underrated and can easily take the abuse. But........clearly that whole "80-90% efficiency" thing is baloney under such conditions.

My parents house on the other hand is in a rural area where each house ends up with it's own 10KVA transformer. Under those conditions efficiency is decent under normal conditions. However, 10KVA is rated for 42A @240V where's my parents house has a 200A service so can draw 48KVA. It looks like that specific setup will be over 90% efficient with a draw of 20A or less @ 240V.

So yes.
90+ Efficient but usually installed so they are much less in real use.

ChrisJ

ron said:

RayWohlfarth said:

I wrote this article...
"A boiler uses fossil fuels, and that affects the environment. A heat pump doesn't," another person says.

a gas or diesel powered automobile uses fossil fuels, and that affects the environment. An EV (electric vehicle) doesn't.

I think you should edit the title of the article from educating young minds to deprogramming young minds. I wonder how many boiler haters are renters and have no clue about real world cost and maintenance of such things.

You sure do hate renters eh?

Hot_water_fan

"A boiler uses fossil fuels, and that affects the environment. A heat pump doesn't," another person says.

We can all agree this is silly. People say dumb things sometimes!

hot_rod

NG takes some additional dirty energy, and piping loss to get to the end used also. Diesel and NG powered compressor stations, for example.

Look like NG compressor stations are turning to electricity.

Go figure, NG to generate electricity. Electricity used to spin motors to turn compressors to move NG thru the pipeline. How does that pencil out for use of NG? Efficiency losses all along the way.

ChrisJ

hot_rod said:

NG takes some additional dirty energy, and piping loss to get to the end used also. Diesel and NG powered compressor stations, for example.

Look like NG compressor stations are turning to electricity.

Go figure, NG to generate electricity. Electricity used to spin motors to turn compressors to move NG thru the pipeline. How does that pencil out for use of NG? Efficiency losses all along the way.

Well.
Name one fuel you can get to a power plant for free?
Coal obviously isn't free to mine, process, transport etc. Diesel etc the same...

Uranium lasts a while and doesn't take up much room but it's still not free to make, transport or store.

Out of all of the fuels I'd say natural gas has the best bet at being the cheapest to process, transport and store, especially offsite.

ratio

ethicalpaul said:

I hear people being panicked about them, but who has experienced one?

<raises hand> Although, technically, we were load shed to keep someone else's power on, but I feel like it's pertinent.

We don't imagine that everything is electric today because that's not how it works. How it works is that over time, more things are electric, and over time the grid is improved to handle it. Just like has happened for the last 100 years.

If the plans involved a century of planning, growing, getting better, etc., I (and I believe many others) would have a lot less to complain about.