Why dont we all want rocket mass heaters?

[Seasoned Oak]

The biggest factor here is the RMH is heating only 1 Room to a not so warm 69 or lower . This is not a big deal. Various electric heaters in the other rooms which are colder. May as well make it total electric and change out the stylish barrel in the living room for a mini split. Skip the work gathering twigs altogether.

 

[Seasoned Oak]

So realistically speaking, a 1/2 reduction claim may have been believable assuming a very inefficient stove as baseline. But 5x that much, uh, no - everything else is definitely not remaining equal.

The difference is ,your house is warm.

 

[Squisher]

These sorts of temps being discussed are part of why I don't really see something like this catching on. For me a big part of the picture of wood heat is having a splendidly warm house. Were the whole thing becomes warm 75 in the far reaches of the home.

I would hate to heat with wood and be chilly still. That would be an awkward conversation with the missus too.

Wife, "we need a fire!"
Me, "it's already going" , or "we've already used our stick of wood for the day."

I don't foresee the above conversation ending well.

 

[RobbieB]

I like to wear long sleeve flannel shirts with a tee underneath. 72 is too warm for me, I like it around 68.

With a fire going it gets to 75-77 in a couple of hours and then the clothes need to come off. Which is why I have a stove, romance and ambiance -

 

[edyit]

if i'm going to keep it at any temp under 76 i might as well just run the oil burner. the wife being warm was one the biggest deciding factors in getting wood heat. we both grew up with it, when we moved in together she wasn't as keen on the idea of sitting in a 62F house in a sweater because fuel oil isn't exactly cheap in the adirondacks (or anywhere for that matter) so in came the stove and now the average temp is around 76-78 and i don't have to hear i'm cold or worry about the power going out

 

[georgepds]

I like to wear long sleeve flannel shirts with a tee underneath. 72 is too warm for me, I like it around 68.

With a fire going it gets to 75-77 in a couple of hours and then the clothes need to come off. Which is why I have a stove, romance and ambiance -

It's sort of like that in my house, but ,really, the view of me in my skivies just doesn't kindle romance anymore.....


Maybe I need a RMH

 

[OhioBurner©]

Yeah temperature is entirely personal. I shoot for upper 60's. Lately I've been reluctant to fire up both my stoves (usually needed below freezing) and since the temps have dropped the last couple days my house is down to about 60 throughout with the stove room being 68. Mid 70's I'd be wearing boxers. But then again most of the winter I am still barefoot outside. Cold doesn't bother me as much as several thousand dollar propane bill, but I do like at least 60's.

 

[peakbagger]

I generally could care less about the actual room temp as long as there is good radiant heat from the stove.

I hang out in front of campfires in the winter on occasion. It may be below zero but if I am standing in front of the fire I am plenty warm from the radiant heat.

I do miss the radiant heat aspect with my wood boiler which is in the basement. Heat from the boiler and the flue actually heat my insulated living room floor but the rest of the house is baseboard. On occasion when I get home after a few days to a cool house, I fire off the boiler and hang out in front of it until the house warms up. Same with my minisplit I find that I need to run a higher temp as I dont have any radiant heat.

 

[Seasoned Oak]

I d like to hear for others using a RMH that actually keep their entire house warm with just the wood. To get a more accurate comparison to a conventional wood stove. I do think there is more efficiencies that can be had from a wood stove but perhaps its a diminishing return thing as far as complication and expense of mfg. Just what would it take to go from 70 % to 90+ % with a wood stove ,I feel if it were that simple it would have already been widely done.

 

[FarmerDan]

Caught up with this whole thread, and started spelunking around the internet. In general, I think it's a pretty cool DIY-idea. It simultaneously makes sense that it's completely un-insurable AND it's a shame that this cool, low-tech heating solution has a lot of burdens in front of it.

One thing that's been a sticking point in all the articles/videos supporting the wonders of the RMH is the low, low wood use and how things appear to defy physics. Wood does have a maximum burning temperature (~1,000dF) and btu content, correct? I finally found a video that jives with my understanding of how wood heating, in general, words. These folks appear to give an good, open review of the RMH, they live in a pretty small home with an open floor plan and estimate that in the Boise, ID area they would use 2 cords over a 96 day period. Boise doesn't appear to have super aggressive winters. This estimate of wood use feels like a more reasonable amount of wood. What do you think? Of course, like we've discussed, hard comparisons are difficult to come by.

From my poking-around research,

• with the unique nature of each RMH build, comparisons appear to be difficult.
• mass appears to be the biggest key of these stoves stoves in particular. the rocket part, I'm not convinced
• masonry stoves are pretty awesome. most homes can't handle them without major renovations (like my drafty farm house built in the 1880s)
• mass (extracting maximum heat from combustion into living area), home insulation (keeping that heat inside), and square footage (less space, less btus required) of the home appear to be the biggest factors in reducing wood use

The video shows that the sitting areas surrounding the stove can get uncomfortably hot when firing. They hope to finish the exterior of the stove to make it look more aesthetically appealing. They disclose that it's a different type of wood-burning lifestyle. But, this style of wood burning appeals to their lifestyle. But overall appears to be a unique and affordable way of designing a wood-burning appliance for the home, if you're down to clown with these accompanying quirks.

As discussed here, insurance, permits, appearance and DIY-nature will be the huge barrier in before gaining a massive (hyuk hyuk) RMH following.

Thanks for the discussion, folks! If anyone sees one in action in southern Wisco, lemme know.

 

[jetsam]

There's a lot discussion but no actual people who heat with rocket stoves/mass heaters as far as I can tell.

"I want to heat my house with a rocket stove", yes.

"I currently heat my house with a rocket stove", no.

 

[bholler]

There's a lot discussion but no actual people who heat with rocket stoves/mass heaters as far as I can tell.

"I want to heat my house with a rocket stove", yes.

"I currently heat my house with a rocket stove", no.

Well there is paul wheaton. He heats his doublewide (that would take 6 cords with a regular stove lol) on .6 cords. Unfortunately he is so full of crap on everything else there is no reason to beleive that.

 

[begreen]

For all its benefit of even heat mostly due to mass, it doesn't seem to be worth the hassle. We have a few nicely built Russian Fireplaces in our area. They do a great job of even heating, but not much more as compared to a good woodstove with a lot of mass. They need to be fed twice a day - check, so does our stove. Cleaned out once a year - point to our stove which is an easier clean. Fire view - um no, not usually, though it's possible to design in. Ease of installation - many points to the wood stove over the masonry stove. Clean burn - about a wash if the masonry fireplace is well made. Fuel consumption - about the same, btus are btus, though some dispute this. Even heating - point to the masonry stove, but a stove with a lot of thermal mass will provide similar experience.

 

[Seasoned Oak]

Its almost impossible to compare one house to another. Just on the basis of air infiltration and insulation level alone. As someone who has been a real estate developer and owner of dozens of homes for 35 years each one is vastly different. Even well insulated homes that were not done correctly can skew the results. I went from using 161 Million BTUs a season to 69 Million in my own 3000SF old drafty 100+ yr old home. in the span of 15 yrs. The big 3 factors were adding some passive solar, plugging up air leakage and adding cellulose insulation and removing fiberglass insulation. Some of the reduction may have come from milder winters, but this winter which was brutal so far I'm still on track for no more than 70 million. I keep this castle at about 77-78 degree avg.

 

[Seasoned Oak]

Well there is paul wheaton. He heats his doublewide (that would take 6 cords with a regular stove lol) on .6 cords. Unfortunately he is so full of crap on everything else there is no reason to beleive that.

And if you read between the lines,he was only partially heating ONE room to the 60s. The other rooms with a combination of small electric heaters.

 

[illini81]

For all its benefit of even heat mostly due to mass, it doesn't seem to be worth the hassle. We have a few nicely built Russian Fireplaces in our area. They do a great job of even heating, but not much more as compared to a good woodstove with a lot of mass. They need to be fed twice a day - check, so does our stove. Cleaned out once a year - point to our stove which is an easier clean. Fire view - um no, not usually, though it's possible to design in. Ease of installation - many points to the wood stove over the masonry stove. Clean burn - about a wash if the masonry fireplace is well made. Fuel consumption - about the same, btus are btus, though some dispute this. Even heating - point to the masonry stove, but a stove with a lot of thermal mass will provide similar experience.

Another factor is the effect on the value of your home. A relatively small number of people are interested in heating their homes with wood. A practically infinitesimal number of people are going to be interested in heating their house with a rocket mass heater.

Thankfully, wood stoves can be removed without too much trouble, but good luck "undoing" a rocket mass heater. In general, my guess is that if you put one in, you're home value goes into the toilet. You may love it, but good luck finding someone to buy your house.

 

[Seasoned Oak]

Has anyone tried to place mass in the form of stone ,sand or any type of heat absorbing material around a regular wood stove in order to even out the normal heat swings of the typical burn cycle of a wood stove. Possibly like a fireplace surround. I may try this in a house im rehabbing to possibly move into. Im wondering if its worth the effort.

 

[begreen]

Essentially this is what the cast iron jacket does on steel stoves like the Jotul F45, 50, 55, Alderleas, etc.. Yes there are past threads on this topic, simplest I recall was someone building a cement block surround. Not sure how that worked out over the long term. Definitely not a nice look for the living room.

 

[Seasoned Oak]

Not sure how that worked out over the long term. Definitely not a nice look for the living room.

With mountain stone over it would look good. I was thinking cement block filled with sand and faced with stacked stone to make a large fireplace like structure that surrounds the stove but is not to close to the stove so i can access behind it. The underside above would taper up toward the front to keep air circulation moving. House is a very open floor plan.

 

[Nateums]

Wood combustion also produces CO, that alone is enough reason to not have a horizontal draft like in these things. You combine that with the claim that the flu temps are very low, you're going to have dangerously little draft.

The 'mass' part is equally ridiculous. There is likely more mass in the drywall in your house than from those mud benches. 10 yards of concrete (a truck load full to the gills) would give you an 800 sq ft 4" thick slab that most houses have in their basement - again, way way way more than the stucco stove has. Thermal mass/storage is overrated.

Put the pencil to the paper and do the math. None of these 'experts' that 'designed' this heater are professional engineers or are in any way qualified to tell you these heaters are safe. I would love to see an actual expert, by the legal definition, opine on the specifics of how dangerous this is.

At the risk of being even more confrontational I will also say that my impression of Paul Wheaton is that he is running a cult, in the literal sense, out in Montana.

 

[maple1]

Thermal mass/storage is overrated.

That part I don't think I would agree with, at least in the generalized sense. Storage and its benefits have been a game changer for me, coupled to our boiler.

 

[Nateums]

In the generalized sense, take the total mass within your thermal envelop and look what percentage goes to the rocket mass heater, or the soapstone on your stove.

 

[maple1]

Yes, but all that 'other' thermal mass can't store the heat as fast as my boiler can make it. Which defeats the purpose of the mass. Whereas the 700 gallons of water can ably do that, and also send it exactly where it needs to in a very controlled fashion.

We might be talking apples & oranges by having a boiler & storage in this conversation/thread.

 

[Nateums]

My main reason for responding is that there is a lot of misinformation out there about how dangerous these contraptions are.

The wikipedia article itself just references and links to sales materials. Paul Wheaton just keeps linking to his DVD in this thread. This is a blatant scam.

Adults should know better, but I shutter to think of these being installed in homes with kids in them.

 

[maple1]

My main reason for responding is that there is a lot of misinformation out there about how dangerous these contraptions are.

The wikipedia article itself just references and links to sales materials. Paul Wheaton just keeps linking to his DVD in this thread. This is a blatant scam.

Adults should know better, but I shutter to think of these being installed in homes with kids in them.

I don't think I see anything there to disagree with.