If you live in an apartment, what good is a rocket mass heater

This just appeared as a question here on permies:

If you live in an apartment, what good is a rocket mass heater going to do if you cant produce the fuel to run it?

response #1

What good is a nuclear reactor going to do you if you don't happen to already have uranium in your pockets?

The reason I ask such an odd question is:  you have, somehow, learned what a nuclear reactor is.  And you have a vague idea of how it works.  You probably even know about the upsides and downsides.  Nearly every apartment dweller knows the basics even though they will not build one in their apartment.

I wish for people to also know about rocket mass heaters.  Including people that will never build one.  What are the upsides and what are the downsides.    

I wish for apartment dwellers to talk about rocket mass heaters more than they talk about nuclear reactors.  Maybe they will talk to some people that will actually build them.  Maybe they will someday move and build one.  Maybe their next home will have one!  


response #2

If the only impediment is fuel ...    Well, it is true - getting firewood into an apartment on the eighth floor in new york city has challenges.  Of course, there are some apartments that do have access to lots and lots of wood.  There is landscaping, complete with trees, at their apartment complex.  And rather than hauling that wood away to a dump, I suppose a few of those apartment dwellers could use that wood.  

In an apartment, you might be wholly surrounded by other apartments.  So even if you had zero heat, there is a good chance that your apartment will never get all that cold - because most of your walls are heated by the other apartments.  

When I first heard about rocket mass heaters, I met a guy that heated his home, all winter, with purely junk mail.  Today, there is a lot less junk mail, but there are amazon boxes.  

And what about that waxed carton that your milk/mylk/malk/drink came in?  That is awesome fuel.

Every apartment probably has a bunch of bins for recycling - what if there was one more labeled "burnables"?  

And if you are the only one on your floor doing this, maybe your neighbors will let you have their burnables?

Don't forget, you only need heat part of the year.  You could start saving burnables in the fall.



So it seems that without leaving the apartment, you have access to 100% of your fuel needs.



This is the moment where I expect the other party to clearly state "you are right.  I hereby concede this point."  But rather than doing that, they universally say something about codes, insurance, routing the exhaust ...    And I have answers for all of that too.  But I just need to savor this moment - once again I was presented with "impossible" and I painted a picture pointing out that the solutions are simple and obvious.

Bring on the next questions.  I'll step back and let others fill in the answers.

This thread and the other you quoted from reminds me of something I heard in a Twelve Step meeting:

‘A problem is not a problem, but an attitude. Without the attitude, it’s just a situation. The solution is to adjust the attitude.”

I always supposed then that in adjusting the attitude, you'll stop seeing things as problems, but just situations that can have solutions.

‘What’s my problem? I live in an apartment building, too many people close-in here for such a thing; no way I can put an RMH in my apartment!’

vs:

‘What’s my situation? I live in an apartment building; there are places to put things, there's already a laundry room, boiler room, etc; we can put an RMH  in the basement, and heat several floors! People can provide the fuel!’

you are right.  I hereby concede this point.

I live in tiny duplex style apartments. I would like to know how to route the exhaust without damaging the wall or ceiling. Board in window with hole?

Kim Avery wrote:I live in tiny duplex style apartments. I would like to know how to route the exhaust without damaging the wall or ceiling. Board in window with hole?

Kim, depending upon how discreet you'd like it to be, I wonder if it's worth disguising it as a dryer vent?  It might go unnoticed/ignored since dryer vents are commonly seen on the sides of buildings.

codes, insurance, routing the exhaust.

Also, the Town preference for having brick chimneys to "preserve the appearance"/cladding.

I actually think I know how I could do it here if need be, but I'm 95% done moving to a house.  Still, I'd love to know your current best answers to the "codes, insurance, and routing the exhaust" question.  A big block to actually "getting this through congress" was that the insurance wants something on a thermostat--the oil heat, currently--and replacing that with something that doesn't need a flue looked extremely expensive (cheapest possible heat pump? "15k").  So any better solutions would be awesome.

Weight of the mass is the big thing.  

Can it be on a wood floor? is a "glassblock" a superexpensive thing? are there workarounds?  

If it has to be just a Liberator, still answer to these questions would help move things forward.

For everyone's information, my landlord was actually pretty positive about the idea when I pitched it, as long as his insurance wouldn't be affected and as long as I could get it cleared with the Town.

Karee Freeland wrote:

Kim Avery wrote:I live in tiny duplex style apartments. I would like to know how to route the exhaust without damaging the wall or ceiling. Board in window with hole?

Kim, depending upon how discreet you'd like it to be, I wonder if it's worth disguising it as a dryer vent?  It might go unnoticed/ignored since dryer vents are commonly seen on the sides of buildings.

Wouldn't the dryer vent as an exhaust be subject to back pressure problems if the wind is blowing toward the wall it is protruding from? A dryer runs as a forced air exhaust system, and usually has a flap that acts as a check valve, and a RMH is kind of running that way part of the time, with the heat riser acting in place of a blower, but for the times it is not providing much force, back pressure could cause problems. Close the check valve for too long, and you have exhaust backing up through your system.  One of the reasons chimneys stick up above the roofline, is to remove the possibility of back pressure.

I imagine if your vent extended far enough from the wall, it could be out of the pressure zone created by wind against a wall, but then that adds to your tubing length. Maybe if you were at the corner of the building...

From all I hear, the dryer-vent approach doesn't work in most situations, but maybe there's ways I'm not aware of.  Anyone reading this thread, please check other resources before starting a dangerous fire, or maybe wait till Paul or someone else with experience with these has a chance to respond.  

L Cho wrote:

Karee Freeland wrote:

Kim Avery wrote:I live in tiny duplex style apartments. I would like to know how to route the exhaust without damaging the wall or ceiling. Board in window with hole?

Kim, depending upon how discreet you'd like it to be, I wonder if it's worth disguising it as a dryer vent?  It might go unnoticed/ignored since dryer vents are commonly seen on the sides of buildings.

Wouldn't the dryer vent as an exhaust be subject to back pressure problems if the wind is blowing toward the wall it is protruding from? A dryer runs as a forced air exhaust system, and usually has a flap that acts as a check valve, and a RMH is kind of running that way part of the time, with the heat riser acting in place of a blower, but for the times it is not providing much force, back pressure could cause problems. Close the check valve for too long, and you have exhaust backing up through your system.  One of the reasons chimneys stick up above the roofline, is to remove the possibility of back pressure.

I imagine if your vent extended far enough from the wall, it could be out of the pressure zone created by wind against a wall, but then that adds to your tubing length. Maybe if you were at the corner of the building...

Agreed.  I'm hoping anyone who has done enough research to build a RMH would know how to modify the dryer vent to make it safe, if it would even work in their situation at all.  Ianto Evans' design seemed to have factored in such things as wind direction, etc., before venting out a wall at all.  

If I lived in an apartment and I was considering a rocket mass heater, I think finding fuel would be the very last of my concerns.  As efficient as rocket mass heaters seem to be, I think you could supply a lot of your fuel from free paint stirring sticks from the nearest hardware store, or in the free scrap lumber bin at the same.  My first concern would be wondering if I would end up in my downstairs neighbor's apartment.

Erica and Ernie Wisner worked with Portland's code department to write up and test a RMH that was then approved by the city, and multiple other cities have followed that approval. Most departments have a variance exception, so a person can show where it's allowed in other cities and make a case. But you still need to safely vent the exhaust, and properly support the mass. Pebble style benches are lighter but are still pretty heavy, but compared to say a water bed, maybe they are light enough. With any floor or subfloor that can smolder you need to ventilate, which can be done by laying brick feet and then a fireproof platform. Stockpiling burnable material could be done in a garage or other location. I don't have personal experience with relying on mostly paper and cardboard, but it seems the more you use the more ash buildup could be an issue. But with a good vacuum filter it could be done. For individuals in an apartment, they could also focus on the "heat the person, not the space" method, lowering the overall apartment temp but use a heating bubble to reduce the cost/footprint of their heating.

I  would like to have some ideas and feedback on this idea, I would surely appreciate it, So I watched everything I could about rocket mass heats bought the videos and the book by Erica, and I think it is a great idea. But do to my disabilities bad knees and also neck from a rollover accident I had to move into a single level town house, unfortunately there's no wood burning allowed here, 15 years ago went through a full renewal energy school basic and advanced classes in pv then solar was about $10 dollars a watt for panels, took solar hot water and air heating also wind and water power.
So I'm always thinking about how I can incorporate this into my living space. How can I combine solar hot water or hot air to store the heat that it produces all day, using the idea s of a rocket mass heater to store the heat in a mass all day to be released at night. I've put this out there a couple times with no response about a Hybrid Rocket Mass Heater and solar combined by running hot air or hot water throughout the mass all day long. And also im thinking about building a thermal mass wall in my existing wall with hot water tubes running through it from a solar hot water panel or using a evacuated tube collector for a smaller footprint on the roof, if we are feeding 140 degree plus heat into a thermal mass all day long with a solar pump this would be a automatic heating system .

Absolutely you're on the right track with solar heated water being pumped through a mass. The pump could also be solar powered. (Our greenhouse and attic are both cooled by solar 12v fans, the ultimate perfect solution.) It may even work on sunny winter days, depending on your latitude. Evacuated tubes are even better, for their efficiency.
We cannot yet build an rmh due to the insurance issue (no codes here though, so just that one hurdle). But if/when we can, it will definitely have tubes for water to circulate within the mass. I recently spoke with someone who built an rmh in their 30x40 home and they cannot always get adequate heat to the extremities (bedrooms). The water coil would allow remote radiators.
I think you will see a huge increase in people installing RMHs once (if? Hopefully!) the insurance industry comes around. But that may not happen until there's consistent engineered plans and certified builders/installers, same as for woodstoves.
Our current mad scheme is to maybe build an RMH in an outside super insulated cement block building, similar to the outdoor boilers people buy. This would negate the insurance issue as it would be fireproof and not inside the dwelling. Coils in the mass would supply heated water to radiators inside. Downside is having to go out and feed the fire. Still working out the details...

Julie, have you seen these videos of rocket water heaters?

I have now! THANKS! All sorts of ideas for us to consider! A modified version of the walker boiler is sort of what we had decided we need, just a matter of working with pressure and circulation pump and expansion tank.

I'm not in an apartment but I am in a city. I can find plenty of wood. It's the heater, the building code, the burning code etc. that are stumbling blocks for me.
I'm in my 70's, and not very good with tools beyond knitting needles & vegetable knives. I am not going to take on learning all the new skills that will be needed. I need someone to build me one.
The house has an old chimney that is not in usable condition - this is earthquake country. It's inside the walls, and it's a two storey house, so having it repaired is far from trivial. If I hire a professional, they're going to want to do it to code, which probably means there's something above the roof that is going to be a problem. I know the exterior chimney was shortened below the legal height but I don't recall why.
So if the exterior chimney is too short or if it's a no-burn day for the air quality, all the smoke has to be totally invisible. Which I know is the desired effect anyway, but can I really count on it to work as planned?
I'm thinking about the Liberator, but for all the effort and expense of making it possible to burn wood, I want to at least see some flames!

Ellen Lewis wrote: The house has an old chimney that is not in usable condition

Ok, the chimney is not usable on it’s own, right? But you can, if the chimney is large enough to install a 6” insulated pipe inside, do that fairly inexpensively, or possibly a chimney liner.
I realize that doesn’t solve the rmh construction problem but it gets you a legal chimney for maybe $1000.

I understand the point on talking about a technology even when you are not going to use it, although it is much easier to talk about it when you install one in your appartment and people get curious.
Fuel might be available, space for storing it not so much. I've barely have enough space for a couple of weeks groceries.

I see only two ways a RMH can work in this situation:
- Central heating for an appartment block. There are already commercial gasification heaters which work on the same principle as RMH but cost 2000-3000€. Someone has to fuel these things daily, but the savings might make it worthy.
- A micro unit not bigger than a portable gas heater or an indoor pellet stove. I think pellet stoves can work in appartments because they have a vent to force exhaust through the wall, otherwise they would need too big a chimney. It would also need to be easily movable, so I can store it in summer and install just when needed. To provide the mass I think unpressured water could do, as the 'tank' can be emptied when no longer needed, but then we have to drive the steam somewhere. This must be combined with a steady supply of wood in small quantities. When you have a house, you can order a truck load of wood, but in an appartment you can't store that much, so we need to be able to get or purchase fuel every week or every other week.

For apartment dwellers, I’d guess at least 90% can only ever talk about it with others. Very few landlords are going to allow the sorts of things needed to have an RMH in your apartment, even it it were possible, which in most cases it won’t be due to weight and exhausting the smoke, plus the needed materials and skills.

Julie Reed wrote:Very few landlords are going to allow the sorts of things needed to have an RMH in your apartment, even it it were possible, which in most cases it won’t be due to weight and exhausting the smoke, plus the needed materials and skills.

The Liberator!

How much does the heater weigh?

The heater weighs 165 pounds without the pellet hopper. The pellet hopper and outside air intake adapter together weigh 36 pounds. When crated the heater with all accessories weighs 300 pounds.

What are the dimensions of the heater?

The Liberator Mass Heater measures 16" long x 24" wide x 36" tall (no pellet hopper) and 16" long x 24" wide x 44" tall (with pellet hopper).

https://rocketheater.com/faq-1/

If the apartment has a fireplace, why not put in a Liberator?

16x24x44" including the feeder... that's 41x61x112cm, roughly what a pellet stove measures!!
If the price is right (not much more expensive than that pellet stove) then I see this working for some people even in appartments.

First, I am very glad to see people attaching themselves to #1:  getting a rough idea of what a rocket mass heater is.  

Second, I think there is a way to get a rocket mass heater into every apartment situation, but each situation will require a fair bit of figuring out.  I've now had a few really long conversations with mud about the idea that somebody in an apartment could have a fold up rocket incinerator - which they run in the winter to get extra heat.  It won't be a perfect solution, but it could be a partial solution.  Something where the exhaust goes out the window - kinda like some of those window mounted pellet heaters.

Through all of this, the key is

Greetings from the UK!
We are now downsizing, bigtime.
Retired 22 years ago.
Spent 21 of those years helping our bewildered posse to move to Linux, and now have -no- (zero) friends/rellies relying on me to maintain their pox-infested proprietary PC software, mostly because their kids have adopted Linux and helped to retrain the parents.
The world cannot wait 20 years for a fuel fix - but the RMH is (I submit) ready for the world.  Packaging is crucial to public acceptance - and the 'branding' is important, especially nowadays.  The UK has a slew of dumb regulations, with at least one loophole, which does allow the 'portable gas heater' to be sold and used in the home.  Plenty for sale on line.
I'm an engineer, need belt and braces, so would arrange for an exhaust vent, of course. These gas heaters (and cookers, often) lack effective vents.  It's still legal!
Here one can get air vents with flap valves that prevent blowback. Not rocket science to build one. Disguising your vent(s) as a window-aperture air conditioner should be pretty easy - a scrap aircon window box, eg.
We kept four wood-burners fed throughout a frosty Aussie winter, and the main difficult was logging and humping the tonnes of firewood needed.
Having built endless test cores (house bricks, hollow blocks, some clay slip, pottery, pyrex) and tested them (with inexpensive analysers) I am fully convinced that the RMH is potentially a boon to all mankind.
For the UK, portable cores will probably be needed, but with (say) a vermiculite board core and a 'hardened' firebox it need not be heavy. And with the truly huge efficiency, there is just not that much lumber to lug!
Plus . . . the cleaner exhaust is environmentally sound.  
Finally, things that look similar to the familiar usually succeed better, so I think it worth 'converting' existing wood burners to Rocket combustion at the very least.   Flames are cheerful! Have yet to try the excellent Peterberg open batch boxen, but plan to try.  That could solve the technical problems, and I have a couple of wood burners to try out ideas in the New Year, after we have moved. <sigh>
The 'selling' of ideas is critical to success of those ideas. People can be so bone-headed! (Me too) So, instead of persuading a potential client that "Rocket Mass Heating" is what they want, how about "upgrading your wood stove to the best available eco standard" as the sales message?  Or other verbiage?

Thanks to all for their published research and hard work that makes these fabulous stoves possible.  Ben

Not sure how it is in the UK or other places, but one issue for renters in the United States is the lease, which would typically require landlord permission to install an alternative heating device. Meaning- you could get evicted for trying to make (what seems to you) an improvement. This circles back to that pesky problem of the RMH not being recognized as a UL listed device to keep codes and insurance happy. If you bought an electric space heater and plugged it in, the landlord isn’t going to care. To me, it seems like getting the landlords on board is going to be the first concern. Having been one, I’ve seen tenants try to get away with all sorts of craziness, and it’s a landlord’s constant worry.
Also, in many rentals, especially multi-unit buildings, heat is included in the rent, thus there’s no advantage to the tenant to mess with any form of alternative heating. So again, it’s the landlord who needs to be educated about the benefits of an RMH. Obviously cheaper heat would theoretically make for cheaper rent, so it benefits the tenant too, ultimately, but this leads to another issue.
The typical tenant rents for one of 3 reasons- they want to be a homeowner but can’t yet do so because they have financial or credit problems; they move frequently; or, perhaps most common, they don’t want the responsibility of maintaining a home. So there’s going to be a lot of tenants who have no desire to embrace the effort required to run an RMH, vs turning a dial or pushing a couple buttons (if in fact they even control the temperature). The tenants wanting to be homeowners are probably the easiest to convince.
So… a big part of this brainstorming process involves factors other than structural or venting.
I think focusing on new construction may be the easiest place to get a foot in the door. Shared walls of duplexes could be brick faced thermal mass, heated by an rmh located in its own mechanical room in the rear of the building. Maybe one tenant gets reduced rent in exchange for feeding the fire. Maybe neither tenant wants to be bothered so the landlord has to pay someone to do it. Most building owners would still want a back up ‘hands off’ heating system. These sort of logistics make this a tremendous undertaking. Ironically, it’s tough to get the world to embrace great ideas.

I don't see how you could have a RMH in an apartment.  Is there a way to have one without a "chimney"?
That and the "mass" are my 2 biggest problems.  Are there any lighter weight heat retention materials that could be used instead of heavy masses.  My RMH would have to be on a wood subfloor above a full basement.

John Walter wrote:I don't see how you could have a RMH in an apartment.  Is there a way to have one without a "chimney"?
That and the "mass" are my 2 biggest problems.  Are there any lighter weight heat retention materials that could be used instead of heavy masses.  My RMH would have to be on a wood subfloor above a full basement.

Hey John! I think you are taking this literally, and you ask good questions. But respectfully, I think the idea of the thread is to push back on silly/lazy objections rather than practical ones. Sort of like 'What good are goats if I live on Mars?" Cheers mate!

John Walter wrote:I don't see how you could have a RMH in an apartment.  Is there a way to have one without a "chimney"?
That and the "mass" are my 2 biggest problems.  Are there any lighter weight heat retention materials that could be used instead of heavy masses.  My RMH would have to be on a wood subfloor above a full basement.

Hello.
Here it is not uncommon to install pellet heaters in appartments, and they are required to install a chimney towards the wall. It may depend on the actual permissions required in your appartment, but technically it's doable. Without a chimney that would be pretty dangerous, I guess.

If you are not confident about your floor, then maybe you can find a way to store heat in distributed weights all around the room. If you can do plumbing, you can use water to distribute heat to a few radiators, each of them may have a brick layer which would store heat for slow releasing. Even better if you can pass hot water just under the floor, so you keep heat in the floor itself.

Pellet heaters have fans for intake and exhaust of fresh air and fumes. The fans (which we don't have in your usual rocket mass heater) and the complete combustion (which we do have in rmh) are what combine to make an exhaust through a wall possible, reason being the aforementioned wind pressure.

So if you would like this to work for a rmh, you'd have to install a fan.

Also, I would be concerned about the few times when the rmh isn't burning at it's optimal levels and is producing soot. When regular wood burning stoves are exhausted on the side of a house without going up above the roof (which is wrong but is still done now and then, sometimes with horrible consequenses eventually happening) you will see the wall becoming darker and darker over time as the fumes from the exhaust leave residues on the wall.

This will also happen during moments when the stove isn't properly burning, or simply every time we're lighting it anew before things get going properly.

It'll be a lot less buildup than with a regular woodstove of course, but it might be something worth keeping an eye on.

Didn't I react before on this thread? Can not find it.

I know what a RMH is, I have seen many photos of them and a few videos of people building a RMH. If I would live in a house of my own, I would want to have a RMH built (no, I don't think I can build it myself).

But I live in this rented apartment. The fact that it's rented, that it's owned by a housing company ... probably that's all the problem.

There is an old chimney, hidden behind board and wallpaper. It hasn't been used for decades, but it is still there. The floor is made of concrete, I think it's strong enough for a small RMH. There's public park nearby, I can probably find the wood (do some walks in the evening, not too visible collecting wood in the park).

But, as I said: there's a housing company. They have 'renovated' these apartment buildings. Many years ago they closed the chimneys, that were there for old-fashioned natural gas heaters. They provided every apartment with a central heating and a modern type heater. That heater heats both the central heating and the hot water for kitchen and shower. (still burning natural gas). It is in the mud-room and has a pipe through the back wall (no chimney). We pay the rent and that heater is included in it (not the gas and electricity we use).

The housing company would never allow a RMH in the apartment. Not even a conventional wood burning stove/oven is allowed. And I'm not able to buy a house or apartment. The money I inherited is less than half of what is needed to buy a house. And I can not get a mortgage (do not want it neither).

Am I right to think I'll never have a RMH, or am I wrong?