My masonry stove heating hot water to 500 gal tank under basement slab -- pics

[sailawayrb]

I am not going to argue the point here. Let's just say that if you go out and buy an air tight wood stove these days you will see efficiency in the 80 to 90 % range and not anything like the figures shown on the web site. The idea that an open fireplace is 75% efficient is ludicrous - even 10 to 15% efficiency is generous. Some of the other figures were valid 20 or more years ago but have no place in this discussion. Everything modern will have secondary burn zones (and/or catalytic converters) where gases are converted to heat. Sure you can see a reduction of wood used if you go from a box that used to be called a wood stove 20 years ago to a modern wood burning device but you would see similar gains whether the wood burning device is a modern air tight wood furnace or a masonry furnace.
The thing the masonry furnace is good at is storing heat - period. You can burn a load of wood at optimum firing rate without overheating the room. BTW, to get optimum efficiency you still need to control the air feed. Guess what will happen if you have hot coals and you have wide open air feed - you will heat the outside.

I'm not going to belabor the point any more either because I believe I am right, and I firmly believe that people should believe whatever makes them happy  

Our OR next door neighbor remodeled their home two years ago (because they now have 8 children) and they dumped their 5 year old super efficient super clean burning metal wood stove (that was installed when house was originally built 5 years ago and is required in Medford, OR area) for a new Tulikivi soapstone masonry heater.  They claim they now only burn 40% of the wood they previously burned.  If one researches masonry heaters, that's pretty typical and one of the reasons people are willing to shell out $10-$30K to have one.  The other big reason is that masonry heaters are more healthy and provide a more comfortable way of heating.

Here another "heart-warming" masonry heater story:

http://mainewoodheat.com/2008/09/rothschild-heater/

Bob B.

[sailawayrb]

you will heat the outside?

not in a russian, with its labrynth/maze of flue running back and forth through the thermal mass, let 'er rip!

by the time those burnt gasses make it to the stack there ain't much left.

at least that is my understanding of the process

bob g

Well, at least I believe you are are correct  

I believe the bio-mass heating description on this link confirms this as well:

http://www.sunnysolutions.us/products1.html

I attached PDF of one builder's planning guide that I believe has some worthwhile info too.

Bob B.

[sailawayrb]

I have seen this discussion a number of times about heating devices and efficiency. There is usually a lot of emotional attachment to claims and not nearly enough control on the statistical "facts" and the conditions under which they were collected. Often what seems to be a clenching argument can be easily explained and not overall conclusive at all.

One of the biggest waste of wood is failing to get decent utilization of a given woods volatiles component. With some wood varieties this can be as much as 80% of the inherent energy, on others much lower. The wood gas boys will be right up on this aspect. The masonry heaters burn and firing style scores high in this aspect. It is doable with a continuous burn device but takes more skill and attention.

As another poster with tongue in cheek has alluded, percentage efficiency is elusive game especially when not identified. Unless a continuous log of room temperature and stack temperature is recorded and the wood is identical and weighed, and the weather and heat loss is identical, any claims about wood usage are of questionable value. Hell most wood burners and wood sellers dont seem to know within 50% what is a cord.

The masonry heaters have a lot of good points and certainly lots of charm. I just dont think they are good bang for the buck and might be hard pressed to prove under controlled conditions that they are any more efficient than a skilfully fired epa iron stove being fed the same quality wood.

I believe this is very good perspective Crofter.  There are many ways to calculate efficiency, and unless it is done properly and the same way for the products being compared, the % numbers are meaningless.  I certainly don't believe any of the % numbers that the vendors claim.  I put more credence in the critical thinking capability of my engineering/science minded collegues and how many less cords of wood my friends and neighbors, who actually have masonry heaters, claim they now only burn.

I attached a PDF of a masonry heater BTU efficiency analysis I just found that meets my resonableness test for being well engineered and properly executed.  It concludes that the masonry heater tested is about 80% efficient in terms of the BTUs it extracts from the wood.  If you can harvest the wood gas BTUs (which can be as much as 70% of the total BTU energy available in wood) and you get nearly all the heat out of the exhaust and store it in the masonry before it goes up the chimney, you put more BTUs into the house for the same mass of wood than you could otherwise. I suspect that the best metal wood stove available today would do well to score 60-70% efficient under similar testing.

Perceived "bang for the buck" is an entirely different animal and discussion...and very subjective too...  If you have more buck, you can have your desired bang and feel completely happy about it.  Masonry heaters are crazy expensive if you pay to have someone build you one.  So is a lot of professional assistance...and being frugal to an excess and getting great enjoyment from using my mind/hands, this is why I have always done everything 100% myself (car engine repair, house electrical, house plumbing, house remodeling, house construction, house selling, house AE, etc.). Even if you totally screw something up the first time you do it, you can usually do it again one or two more times and still be ahead of the game $-wise...and also be more competent for the experience.  The only professionals that ever got my bucks are doctors and lawyers...and we are beginning to have a surplus of them in the family.

Bob B.

Edited to attach another PDF showing masonry heater test results from Austria.  In this case, efficiency is calculated from CO2 emissions.  They tested 34 masonry heaters.  Efficiency ranged from 73-94% with average being about 90%.

The US Department of Energy states that "Masonry heaters commonly reach a combustion efficiency of 90%."

http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm/mytopic=12570

The US Department of Energy states that "New catalytic stoves and inserts have advertised efficiencies of 70%–80%.
New advanced combustion stoves have advertised efficiencies of 60%–72%."

[mobile_bob]

this has become an interesting topic, indeed
thanks for the links to the various papers on these thermal mass heaters

i first became enamored with the russian design back in the early 70's while living in an old limestone hotel that i converted several rooms into
an apartment,, that damn place was so friggin cold and expensive that it left an indelible wrinkle in the old gray matter.

one winter i paid 200 bucks a month on natgas and 200 bucks on electricity, the forced air furnace never shut off for nearly 4 months and the temperature
never rose to over 55 degree's,, never not once!  and i was making all of 4.50 an hour!

i spent many a cold night researching alternate heat production, and came across the russian design used in some god aweful place like siberia without tree's
where all they had was small bundles of what we would call kindling to survive on,,  that design sure got my attention, although it could not be used in
that building, i was on the third floor and the basement was another 20ft to the concrete floor.

its funny how all these years later i can still remember how damn cold that winter was, and i can still see in my mind the construction of that russian fireplace.
enough so that i think i could probably reproduce it from memory if i had to,,,  however if i get to that point i will go look it up again just to make sure.

my problem now is knowing whether the concrete floor can support such a massive weight?  i suppose the best thing is to have a concrete saw cut
out an opening, dig down and poor a proper footing to start with.

then there is the matter of an uninsulated concrete floor...

bob g

[Geno]

At least 90% of my heat comes from wood. I have a modern cast iron wood stove with secondary combustion. It's in front of the fireplace and the stack goes up the fireplace flue. There is a fan behind it which makes a noticeable difference. My wood is plenty dry and I burn Oak, Maple and Beech. From the ground there is no visible smoke about 75% of the time. I would guess that's when near complete combustion is taking place. Guess what, if I go on the roof when there's no visible smoke I could almost cook hamburgers up there. It may be burning the wood completely but I sure aint getting all the heat into the house. There are ways to capture that heat but it doesn't work out in my situation.

By the way Marcus, I'm glad to hear the water loop to the fireplace is working. Beautiful job on the house and I'm happy to hear your getting settled in.

Thanks, Geno

(addition) When my stove was in the basement I had one of these on it and it worked very well.

[mbryner]

@sailawayrb:

Spent six days at our Evans Creek hide-a-way.

Hey, you should have said something.   We could have met.   I like people w/ interesting ideas!     (most everyone on this forum!)

Did Jackson county require you to use outside makeup air?

We're in Josephine Co., and they do require outside makeup air for new construction.   Our fresh air pipe ends up in the basement/garage, and they never said anything about it on final inspection.

Hey, we could all debate the merits of masonry stoves vs. regular woodstove ad nauseum, but it probably won't get anywhere.   Don't anyone get their feathers riled up! 

So Geno, why don't you use one of those heat recovery units on your current setup?   Wait, I'm going back and rereading and it's probably because the pipe is in the fireplace flue....

[sailawayrb]

@sailawayrb:

Spent six days at our Evans Creek hide-a-way.

Hey, you should have said something.   We could have met.   I like people w/ interesting ideas!     (most everyone on this forum!)

Did Jackson county require you to use outside makeup air?

We're in Josephine Co., and they do require outside makeup air for new construction.   Our fresh air pipe ends up in the basement/garage, and they never said anything about it on final inspection.

Hey, we could all debate the merits of masonry stoves vs. regular woodstove ad nauseum, but it probably won't get anywhere.   Don't anyone get their feathers riled up!  

Hey, I did tell you we would be down your way then...I even offered to bring you your new 6/1 rebuild parts from George  

We probably should exchange cell numbers sometime.  Then we could just connect when the opportunity prevails.

If you have to use outside makeup air, getting it from garage is about as good as it gets.  If you have to go outside, they say it's best to get it from windward side of house.

Well, MY feathers are certainly not riled up.  There is absolutely no question that I'm going with passive solar and masonry stove for heating, and hydro for power  

[mobile_bob]

HYRDO POWER, WHAT THE HELL ARE YOU THINKING!!

(kick snort)

only kidding!



seriously, if you are on hydro, how will you ever get your hands greasy again?
how will you get by without smelling diesel?

i guess you could splash some on for aftershave!

bob g

[sailawayrb]

Bob G.,

Yeah, I always thought diesel aftershave would be a big seller.  Most weekends that's my scent.  If the woman you are with doesn't get turned on by it, probably best to find another one  

No worries, the 6/1 will move to the new homestead.  It will just share a home with my other toys...opps, I mean my other essential power generation equipment and my beautiful, most efficient, and comfortable masonry heater...

Bob B.

[Crofter]

In all fairness the conclusions section of that PDf on proving the efficiency of a thermal mass heater does make some disclaimers about lack of control and gets off into the very subjective realm of "pattern language".

Speaking of which I believe I have read an article about computer checking an article using a list of tag words that appears to do a good job of spotting  agenda or bias. No one is free of their own subjectivity and it takes deliberate attention to keep it from slipping into supposedly scientific study, but when an operator is starting to nibble at your ears and nuzzle at your neck with "pattern language" it is well to question who this is supposed to be good for.

You could make a very large list of pros and cons for different types of heaters. How you weight the various criteria decides which best suits the situation.

[sailawayrb]

In all fairness the conclusions section of that PDf on proving the efficiency of a thermal mass heater does make some disclaimers about lack of control and gets off into the very subjective realm of "pattern language".

Speaking of which I believe I have read an article about computer checking an article using a list of tag words that appears to do a good job of spotting  agenda or bias. No one is free of their own subjectivity and it takes deliberate attention to keep it from slipping into supposedly scientific study, but when an operator is starting to nibble at your ears and nuzzle at your neck with "pattern language" it is well to question who this is supposed to be good for.

You could make a very large list of pros and cons for different types of heaters. How you weight the various criteria decides which best suits the situation.

Great perspective Crofter.  Once someone has a strong belief or agenda that they want to accomplish, there is little point in further debate to convince them otherwise.  Sort of like trying to convince some religious, racist, Republican that their beliefs might not be 100% correct.  About all one can do is to present the best available data on any given subject and allow critical thinking and time for the truth to become apparent.  People come to their own beliefs and as long as they can't force their beliefs on other people, I don't see any problem.

Bob B.

[Crofter]

Sailawayrb; You have it right about changing someone elses opinion; anyone who thinks that is easy has only to try changing some of his own to judge how hard it will be to get inside someone elses head, Lol 

I think the home that Marcus built is fabulous, I love the sight of natural wood and stonework and he has a lot of thermal mass working for him which does wonders at making daily temperature swings work to ones advantage. Once he gets some seasoned consistent wood for his heater he will get a handle on how well it is performing for him.

[sailawayrb]

Sailawayrb; You have it right about changing someone elses opinion; anyone who thinks that is easy has only to try changing some of his own to judge how hard it will be to get inside someone elses head, Lol  

I think the home that Marcus built is fabulous, I love the sight of natural wood and stonework and he has a lot of thermal mass working for him which does wonders at making daily temperature swings work to ones advantage. Once he gets some seasoned consistent wood for his heater he will get a handle on how well it is performing for him.

Agreed, Marcus did real good    

He has a great quote on his powerhouse.  I think he needs another one that perhaps captures the essence of this entire project.  Perhaps this one from Goethe:

"Whatever you dream you can do, begin it.  Boldness has genius, power, and magic in it."

I saw it carved into the stone of a masonry heater in Ken Matesz's new masonry heater book.

Bob B.

[mike90045]

So, how to keep the static water in the storage tank clean ?      All that copper will tend to be a fungicide.
The initial dose of bleach will dissipate in a couple of days when the tank is warm. 

At 100F, it will want to grow something.     Hot tub/Spa treatments of bromide might do bad things to the sealers. 

Perhaps silver ion stuff for spas will work well.    500 gall is a large tank to drain and clean by hand 2x a year.  Once gunk/bioslime gets established, it's hard to get rid of.

[mbryner]

Going up to 70 - 80C, I don't think anything can survive.

Jens, I think that is key.   My tank plateaued at about 120 F (almost 50 C).    Just perfect for growing gunk.   Except there's no sunlight.    Hadn't thought about copper being a fungicide.

I was also wondering about things in the garage getting steamy, but nothing is getting wet around the lid of the tank.   I'll have to check the water level every month or so initially, then maybe every 6 months.

Any of you have any suggestions of any agents besides bleach that would not damage the silicone liner?  I'll look into the silver ion suggestion.  Silicone is rather resistant to most chemicals.