The average US adult footprint is 30 tons. About half that is direct and half of that is indirect (government and corporations).

If you live in Montana, switching from electric heat to a rocket mass heater cuts your carbon footprint by 29 tons. That as much as parking 7 petroleum fueled cars. And reduces a lot of other pollutants.

Here is my four minute blurb at the energy conference yesterday

I wish that everybody knew about this form of heating and cooking - and about the building design that uses that heat from the summer to heat the home in winter. Residential heat in a cold climate is a major player in global issues - and I am struggling to get my message across.

Proof .... proof 2

EDIT - had to sleep. Back now. Wow, the reddit night shift can get dark....

Comments: 928 • Responses: 76  • Date: 

HCTriageQuestion480 karma

Why do climate activists target the lowest percentages of pollution instead of the largest?

Honest question.

AdmiralPoopbutt376 karma

Because if we all do a little, we can accomplish a very little.

TheBroWhoLifts23 karma

This is the best answer on this thread.

The average US family of four would need to not only stop emitting all carbon, but to actually draw down carbon from the atmosphere to stabilize the climate, that same family, if they had a magic machine that could draw literal carbon from the CO2 in the atmosphere, would need to produce a block of it weighing 980 lbs per week year in and year out for decades.

There is no solution to the climate collapse. The time to act has long passed. We're heading into the consequence phase now.

paulwheaton31 karma

I think there is a lot we can do.

I think it is possible to have much lower CO2 next year.

I think that the only ingredient missing is connecting the "how" to the people. Rocket mass heaters are one thing on a large list of things. The trick is getting the list to the masses.

TheBroWhoLifts54 karma

Ok I'll bite. What else is on the list other than a better way to burn twigs?

Sorry for the flippant tone, but these "one simple trick" concepts to solve colossal, intractable problems should always be met with skepticism. In this case, the skepticism should be aggressive because it's almost insulting.

There is zero evidence or indication that carbon emissions are on track to do anything other than continue their increase propelled by the momentum of continual industrial growth that capitalism requires. Short of drastic de-growth, which is not only not being talked about here or anywhere in any serious way because it is antithetical to the goals of industrial capital but also requires mass austerity compared to the modern comforts we're accustomed to, there are no systemic, effective proposals on the table.

No. The truth that no one wants to hear is that we would likely need to cut our population by drastic numbers and go back to living something like a 17th century agrarian lifestyle in order to even stand a chance at averting a catastrophe that is already probably unstoppable even if we did make those changes literally tomorrow. Not going to happen. This thread of full of hopium.

Before anyone jumps on the "quit being such a doomer!" bandwagon, one does not call the oncologist who tells a patient that they have late stage pancreatic cancer a "doomer." These are facts. There are no solutions. But good luck with your stove.

paulwheaton14 karma

things I advocate:

  • rocket mass heaters
  • solar food dehydrators
  • developing a richer life so a person doesn't feel like driving
  • gardening that is super easy
  • lawn care with less effort and zero chem
  • edible cleaners for the home
  • cooking with cast iron
  • the use of diatomaceous earth
  • plant trees (free seeds in a lot of fruit!)
  • for people with electric heat - the heat bubble
  • drying laundry on a clothes line or drying rack
  • go pooless

chakalakasp14 karma

The problem is that rocket mass heaters are like taking a leak in the ocean. Yes, you did something, but only you can tell because the ocean does not look or function any differently.

If you made a real list of things that would actually make a difference and got it to the masses, they would ignore it, because acting on it would be so disruptive both on an individual and society wide economic level that it would have no chance of adoption.

But in case you doubt me, feel free to forward this very pared down list to the masses and see how it goes:

  1. Stop producing and eating all meat. This directive lasts forever.
  2. Ban all coal and petroleum fired energy generation. Replace it with primarily nuclear power generation, with a side of wind and solar.
  3. Ban all concrete production.
  4. Forbid more than one child per family until the population is decreased by 75%.

Those would get humanity an appreciable way there, although it still probably would not be enough to prevent massive climate change. In order to do that, we would need to massively implement geoengineering technologies that do not exist and may not even be physically possible. A significant amount of the official planning going forward to reduce climate change relies on this magic technology that presumably one day we will invent because the math does not work out without it.

paulwheaton4 karma

While it is true that switching from the standard amercian diet to a vegan diet will cut 4.5 tons per year, getting that vegan food from an at-home garden will cut 10 tons per year! Therefore, I would like to encourage people to learn a bit about gardening.

ElonMaersk9 karma

I have helped with some casual at-home gardening. The amount of food a human eats is enormous. Zucchini is easy to grow, one of them has ~35 calories.

At 1KCalories/day (not enough to thrive on) you would need ~30 zucchini per person per day. For a year that's ~11,000 zucchini per person. Family of four and allowing some extra for some to go rotten or fail, you need 50,000 zucchini per year to keep up this barely-enough-calories-to-survive level of eating. If your plant takes a square foot of ground and produces ten zucchini, you need five thousand square feet of dedicated ground. ~450 square meters, maybe with 450 square meters of fertilizer to put on it. Make it 100,000 zucchinis per year to get the family to 2KCal/day, and hope none of them are doing physical jobs, and the family of four needs a square kilometer of zucchini farm with no room to walk through it.

Plus all the pickling and preserving and freezing equipment and effort to keep tens of thousands of zucchinis for the times of the year where they aren't growing. Plus all the grow beds and fertiliser and tools and equipment for everyone to do this. Plus most Americans don't have land, or are young or elderly or have day jobs or other responsibility.

If we really can't improve the situation by centralising and specialising, we must be doing things very wrong.


[Yes, yes, potatoes and lentils are more dense. Still, the scale and quantities are non-trivial].

paulwheaton7 karma

An apple has about 100 calories. One tree can put out more than a thousand apples. And I would encourage systems that make it so that tree needs zero care.

But if we want to talk about calories per acre, the king is sunchokes. 100 calories per cup. And they will wait in the ground for a year for you to harvest them. And they love being ignored.

A cup of black walnuts: 500 calories.

One egg: 75 calories. A few chickens can provide a thousand eggs per year.

1500 calories in a pound of grain. It grows great here without any help. In an afternoon I can fill a five gallon bucket. Maybe 35 pounds? That's 52,500 calories.

I'm gonna shoot for systems that crank out huge calories for very little effort.

paulwheaton12 karma

Exactly. What is the deal with the light bulbs? A clothes line will do ten times more than a box full of light bulbs.

Here is my ted talk touching on this a bit

slappindaface113 karma

While this is a fair point I think they were talking about the shift to personal responsibility vs corporate responsibilities in as far as 80% (or whatever the actual percent is, I'm spitballing) of all carbon emissions are from large polluting corporations.

While I agree that saving 29 tons of GHG is good, it pales in comparison to the output of a single coal powerplant. I dont mean to sound defeatist but that's a lot to overcome

paulwheaton-17 karma

to have a billion people do it - then we just need to make a billion people aware of it.

SwansonHOPS34 karma

Wouldn't the good that does still pale in comparison to the negative climate effects of massive corporations?

paulwheaton12 karma

If a billion people elected to not buy from those massive corporations, then they would dissolve in a day.

dos8s140 karma

You got any of them solutions for Texans who struggle to stay cool in the summer?

paulwheaton20 karma

First, the rocket mass heater, does help with cooling in the summer

Second, the building mentioned in the video ... we hit 104 this summer and it was 74 inside. The building was absorbing heat into an annual mass - which makes the living space much cooler in the summer.

emu9015 karma

Solar panels. Not only will they generate electricity, they also shade your roof since they sit above it and create a ventilated air gap.

paulwheaton3 karma

Yes! A twofer!

Maxwell_Jeeves96 karma

Where did you find out about this concept? As a mechanical engineer interested in HVAC, I have never heard of this.

paulwheaton101 karma

In 2008 a guy was visiting my house and explaining what he saw in oregon. The fire burns sideways. You are warm even though the window is open and you can see snow outside.

It sounded wacky. And after an hour or two I felt I needed to see it myself. So I went and saw it first hand. "Why doesn't everybody do this?" "We don't know - we tell everybody we can." I put the first videos up on youtube showing it.

I have now built lots of these. The exhaust is pretty much just steam. Look at the roof and you can see this little trickle of steam for all but the very beginning of the burn. The exhaust in my house is 140 degrees. I watch the sideways burn every fire - I'm used to it now.

Maxwell_Jeeves40 karma

Very cool, thanks for sharing. From an engineering standpoint this makes a lot of sense. Combustion can be very inefficient. Heat recovery has been used in industry for a very long time in the form of cogeneration, so not sure why people would doubt this would work. Instead of using waste heat to heat other processes, waste heat is going to a thermal mass or storage system for later use.

The fact that steam is leaving in the exhaust would suggest that there is still fugitive heat leaving the system, but creating a condensing system would probably not be cost effective when considering material costs and occupant needs being met. It would also require removing condensate. Would you agree?

paulwheaton42 karma

It is something we talk about.

I think there is mountains of room for further optimization.

The key is that we are doing all of this unpaid - just because it is important that somebody is doing it. But we could use more brains on this. We are, after all, trying to improve rocket mass heaters on many fronts - for first world countries and third world countries.

mashedpotatoes10124 karma

Holy shit, there's other people designing rocket mass heating systems out here? My dad builds them professionally, I'm currently studying chemistry, and have quite a bit of experience testing/working with docket mass heating systems. My home used to be heated by a rocket mass heater attached to a central heating systems! I'm not sure if you are familiar with Peter van Der Berg, bad his Rocket Batch Box, it has won some prizes for high efficiency I believe. I helped design a small part of that thing! (Preheat of secondary air by routing of the P-channel was my idea!)

Anyway, condensating wood stoves are extremely hard to design with any durability. As you said, rockets mostly output steam, but some volatile hydrocarbons and other junk is still in this steam. It's nearly nothing during the normal burn, but during startup.... it gets dirty. This means that the condensate gets polluted with all sord of nasty tar like acidic chemicals, which are really, really good at damaging internal structures, and are also combustible, which is of course an issue as you really don't want a fire in your chimney.

Some of the solutions we used are stainless steel chimneys with water drains. This works! However, it's nearly useless. If the rest of the stove isn't resistant to these chemicals (Wich it isn't, see below) , you can't condense there, which means that the heat extraction has to happen in the chimney, where storing any useful heat is hard, as the chimney needs to be well insulated for improved draft (Which is more important to high efficiency as the energy gain)

The only material that can withstand this stuff without being a fire hazard and operate at high heat I've found thus far is stainless steel or extremely expensive ceramic liner designed for steel furnace's.

One way we have figured out works somewhat is using a water-based heat storage, where you build a flame-pipe heat exchanger out of stainless steel. This way, only a small size area needs to be made out of the expensive stainless steel, as the heat exchanger and chimney are the only parts exposed to the condensate. The water van be stored in some sort of buffer vessel. A tank of 1000L of water is enough to store all the heat to heat a well insulated house all day and night, in the dutch climate drying winter, at least.

I'm super excited there's more people who like these stoves. Any idea where I could sign up to help spread the word and share all the data and designs I have?

paulwheaton22 karma

Peter has been to my place several times and appears in my youtube videos and movies. Peter is most famous for being "the numbers guy". His first 8 inch batch box system is still being used in our classroom.

Stainless has a melting point of 2800F. Peter and I have a famous exchange (in the movie) where we talk about how steel spalls at 1600F and melts at 2600F.

We have a forum for rocket mass heaters at - and peter is one of the moderators! I think there is a lot of information (Peter's and others) that would be great to infect more brains. It really makes a difference!

mashedpotatoes1016 karma

Cool! I might join then!

Also,i was talking about using stainless for the second chimney, if you use stainless for the riser it will indeed melt, as I can personally attest to 😅, however, if you are running you don't need to use stainless at the hot side as condensation is a non issue there, you could use any ceramic there. The stainless would be used posey cool down. In the flame tube exchanger, it is actively cooled with loads of water, so I don't see it's melting point being a problem here either.

Peter has much experience with casting RBB's out of castable refractory cement, has he recently stopped using it?

paulwheaton3 karma

I get the impression that nearly all of the rmh bigs are stepping away from castable refractory. It just doesn't do super great for the DIY folks.

On a related note, I recently had an excellent exchange with the liberator rocket mass heater guy. I don't want to say anything I'm not supposed to say .... uh ... stay tuned?

Maxwell_Jeeves8 karma

I want to do more research on this, but should I decide that I want to get involved, how would I do so? And what kind of help are you needing? How are you looking to improve?

Consider this tire kicking, so if you have higher priorities, don't feel the need to respond to this.

paulwheaton20 karma

Build some. Look at some. Contemplate the materials and efficiencies. How do we get the cost of materials down? If somebody is going to go into business selling rmh cores, can you come up with an effective design that has a materials cost of less than $100?

We are shooting for temperatures over 2000 degrees F - that really limits materials. Especially if you are trying to keep things cheap and environmentally friendly.

Level9TraumaCenter12 karma

We are shooting for temperatures over 2000 degrees F - that really limits materials. Especially if you are trying to keep things cheap and environmentally friendly.

Hopefully a materials scientist will chime in here, but two come to mind, if you've not already considered:

Sheetrock is comprised of calcium sulfate; the melting point of calcium sulfate is 2,660F. Its primary disadvantage would be whether there is any dimensional change as it reverts back to hydrate, which would happen if the heater were allowed to cool and ambient air was introduced.

Another is kitty litter, comprised of sodium bentonite: it melts above 1200C (about 2200F).

But I don't know about the dimensional stability or strength of these materials at such high temperatures; there may be better options. Maybe there's a refractory concrete that can be cobbled together in a cost-effective fashion.

paulwheaton8 karma

For the hottest parts, we tend to use fire brick. One I've been liking lately is firebrick surrounded by a lot of sand and wood ash. We have used ceramic fibers - they give excellent results, but are expensive and we would prefer something more natural.

The mass is easy - those temps rarely get over 300F.

mashedpotatoes1014 karma

Ceramic fibers are suprizingly environmentally friendly! Just make sure to cover them in a sealant of some sort. My favourite method of building rocket cores is by casting them out of a castable refractory, as this is an easy way to prefabricate cores and have exact sizes. For insulation, have you looked into vermiculite? It's a puffed up mineral used as a ground replacement when growing plants. It's also cheap, and entirely natural (it's made out of puffed up rocks). And, best of all, it's a superior insulator to sand/ash. I've had the stuff glowing red hot without problem! Vermiculite can also be added to castable refractory to increase its insulating properties. I've also been looking into designing a clay based porous castable, Wich would mean cheap and acute cast rocket cores. (so just using river clay and some other material to create bubbles that last)

paulwheaton2 karma

Vermiculite melts at 1500F and perlite melts at 1400F.

We have done a lot of experimenting with castable refractory and had mixed results.

MDCCCLV62 karma

He's been peddling this for a while. It's a very niche idea, and like many enthusiasts he acts like it's a secret invention that will change the world. It has issues and I don't think it's the amazing thing he says it is.

Notice he's essentially against renewable energy and solar.

paulwheaton33 karma

When I was a young fella I worked as a lowly librarian for the northwest power planning council. I got to read all the white papers, all the proposals ... all of the environmental disaster reports for every type of energy for four states. I got to hear the other people working there try to come up with solutions that don't have environmental disasters. This stuff is super duper hard.

The real solution ... the constant elephant in the room ... the butt of all uncomfortable jokes ... conservation. What if people just used less? "They won't." But ... "no" but ... "never."

Mmm-kay ... some people use about a tenth of the energy of average. What are their lives like?

What if a picture can be painted showing an even more luxuriant life with a tenth of the average? What if I could make a hundred little pictures that are a hundred little flavors, all using much less? What if I could make a list of suggestions where each suggestion shows something that can add luxury to your life and/or saves a lot of cash? Conservation without sacrifice? Conservation that adds luxury. What if?

I am "peddling" many things. Including "peddling."

Rocket mass heaters are purely renewable.

I am not against solar. I am for recipes for conservation.

bralyan95 karma

I read your book Paul, and really enjoyed it - we made some changes but I couldn't figure out how to incorporate a rocket mass heater into my house. Are there experts who can come out and set one up? I'm not handy.

There's some good tidbits here, and I have a family of 5 and was able to make some changes (growing more of our own food, reducing our climate control CO2 based impact, etc.)

Link to the book -

paulwheaton20 karma

Thanks for knowing about the "direct from author" stuff! Yay!

As for rocket mass heater builders, here is a list of a few

I'm so glad you enjoyed my book! I worked very hard on that! :)

vitaelol59 karma

Do you find it a little depressing seeing some people trying to dismiss that kind of simple,affordable and effective solution ?

I mean, what more do we need to do to convince people that there are some simple and accessible solutions that are out there like this one ? Do we need magic or what ? :D

paulwheaton29 karma

Yes. It is really mind blowing to see people complain about how the end is near, and then flush a quick and easy solution. And then go back to a world of panic that the end is near.

People protest against fracking, and heat their home with natural gas.

Here is my question to you: When somebody says "don't waste your time on this - instead write to your politicians" --- does that sound to you like a corporate troll saying "keep giving money to us and go complain in the rigged playing field!" ??

MJWood52 karma

What is a rocket mass heater and how can we get one?

paulwheaton42 karma

Right now, the best rocket mass heaters are DIY. But there are some quite good UL listed rocket mass heaters in the US under the brand "liberator" and in europe there is a brand called "gamera".

Mudpill11 karma

What are your thoughts on geothermal heaters and coolers?

paulwheaton35 karma

I have created a structure on my property called "a truly passive greenhouse". The numbers are just now starting to come in. It's working! The heat from the summer is stored in a geothermal mass - and heats the building through the winter.

TyPasta_45 karma

Your idea of using Rocket mass heaters as an example seems to be more useful for smaller residencies or cabins. Do you have a comparable solution for apartments or multi story households? I imagine having multiple rocket mass heaters would be a liability at some point.

paulwheaton26 karma

I have heard of a 4000 square foot house that has a single rocket mass heater - centrally located. I have heard that people were plenty warm, but i wonder if a faraway bedroom would be pretty cold.

I'm in a 1300 square foot home and I'm plenty warm all over the house.

elf_monster15 karma

I notice the pictures in the posts you linked are all from areas that receive a lot of sunlight & that don't get quite as cold as the northeastern US. Have you seen these systems producing sufficient heat to keep people who live in colder climates warm?

paulwheaton3 karma

I live in montana. This stuff keeps me plenty warm. Here's my bit about heating this 3 bedroom home with 0.60 cords of conifer wood

Aconceptthatworks39 karma

Why did you choose to educate individuals when it is corporate that do all the dirt? Isnt it easier to get a big company to reduce their output by 1% instead of 10.000 people?

paulwheaton19 karma

I think that trying to persuade politicians or corporate entities is a bit of a rigged playing field.

But I think a billion people could choose to not give money to icky companies and THAT would be some real progress.

Plus, I know of things that I can do. First hand stuff. And if I save a few thousand bucks and tell others - then they can save a few thousand bucks and they tell others. And then the pollution goes away. And the icky companies dry up and blow away.

This is my path.

Thinktank5833 karma

I’m checking out the rocket mass heater wiki page, and as a mechanical engineer my gut reaction is that it’s bs. Fossil fuels have a finite energy potential. There’s a BTU (thermal) cap on how much heat they can produce per unit, and 300 years of industrialization hasn’t been able to capture more than the upper limits of 49% or so.

Is there something about these stoves that isn’t listed that makes them more efficient?

Additionally, the biggest driver of carbon footprint for residential usage is air conditioning and cooling. I’m not sure how large an impact this would have on noticeably impacting our carbon footprint.

TL;DR - At first glance this sounds like hocus pocus.

paulwheaton8 karma

First, they burn slighty more efficiently than a conventional wood stove - when the conventional wood stove is operated by a pro seeking optimal efficiency. Most rocket mass heaters operate at 93% efficiency. Conventional wood stoves that are labeled as 75% efficient are allowed 16 points for the heat that goes up the chimney, so they really run at 59% efficiency. At best.

But most people operate those conventional wood stoves in ways that drag them down to 3% efficiency. They are attempting to do a "slow burn" through the night.

The rocket mass heater is built to do just the really hot and efficient burns - using the smoke and creosote as added fuels. And then some of the heat is stored in the mass to give off heat for the next few days when the fire is not burning.

The result is that a rocket mass heater will heat a home with one tenth the wood.

paulwheaton3 karma

Here is a bunch of experts brought together from all over the globe to address this concern

spatz201130 karma

If I build one of these things, and it only 'heats the person' I need to put one in every room I spend time in, correct? So one in my bathroom, one in the bedroom and one in the living area. I'm already in a 590 square foot apartment, where would I put these then?

paulwheaton22 karma

I have one in a 1300 square foot house. One is more than plenty. I think you might consider two when you get to, say, 2000 to 2500 square feet.

steve_yo16 karma

How do you avoid too hot in the living room too cold in the bedroom scenario? Can you set up some sort of duct system?

paulwheaton12 karma

For me it isn't much of a problem. But if the doors are closed it can get five degrees cooler in the far rooms - so i open the doors.

ConsulIncitatus22 karma

So you're selling rocket mass heaters, then?

paulwheaton16 karma

No. There is a UL listed manufacturer in the states called "liberator" if you are looking for one pre-made. And something similar in europe called "gamera."

I am in no way affiliated with either of these companies and make no money.

In fact, I advocate that people build these themselves.

Cultiststeve16 karma

If your direct impact is 15 tons how does a different heater reduce it by 29?

paulwheaton13 karma

15/30 tons is per american adult.

29 tons is per home.

Subsenix12 karma

How likely is it that a homeowner would be able to obtain insurance for their home with a Rocket Mass Heater inside?

paulwheaton11 karma

First, a lot of insurance companies and building codes are embracing rocket mass heaters.

On a related note: I hope that people will do with rocket mass heaters the same thing they did with marijuana - nobody touched it until the government and insurance companies said it was okay. It doesn't matter that it solves global problems and saves people thousands of dollars.

xchris_topher8 karma

Never heard of you or your work before, so I apologize for any ignorance - but do you also talk about how each individual's carbon footprint is heavily outweighed by that of corporations and third world countries?

Even if everyone heeded your advice and utilized your solutions, we'd still be up shits creek without much of a paddle.

paulwheaton12 karma

If a billion people, in a cold climate, switched to rocket mass heaters, it would have a massive positive effect.

coreynj24613 karma

I live on the east coast. How concerning is it that summer temperatures continue well into late October with some days near record temps. Will every summer go 6+ weeks overtime from now on?

paulwheaton7 karma

Looking into the future of what damage is coming is something I know nothing about. It does seem there are millions of people with a lot of opinions.

I offer recipes for solving global problems - including climate change. It seems this information is a bit more scarce.

Sub1ime142 karma

I've been planning to build an RMH in my home for a few years but haven't focused too hard on it due to concerns that I won't be able to readily obtain or keep home owners insurance. Could you provide some guidance or direction on how to navigate that? I currently heat with a traditional wood stove, whose intake damper I have automated via a custom solution using Arduino and a PID algorithm. I'd be open to talking with you to combine RMH tech with my automation to achieve even greater efficiency.

paulwheaton2 karma

Here is Chris McClellan and I talking about building codes and insurance for rocket mass heaters

Paulrik2 karma

Could this same technology be used to heat modern homes more efficiently with natural gas or oil?

paulwheaton1 karma

Hmmm .... I think so.

At the same time, those two things are unsequestering carbon. Wood is part of the natural carbon cycle. And if the wood used would have been involved in a wildfire or is part of wildfire prevention, it could even be considered a zero carbon heater.