How It Works: Masonry Heater

System Purpose.  Maximize wood as primary winter heat source.

How It Works Summary.  Wood energy efficiently converted to heat which is stored in masonry and slowly released into house via radiation and convection. 

System Cost.  $22,000 including masonry heater and costs associated with cutting, splitting and storing wood.   Since masonry heater is very reliable and splitting mauls are cheap, repair and replacement of chainsaw is main lifetime cost.   By spending money on a very efficient and effective heater we’ve reduced time and costs associated with wood:  moving, cutting, splitting, and storing.    The masonry construction virtually eliminates fire hazard, a serious and costly challenge for some wood burners.    Masonry heater also eliminates health risks and costs caused by ducting of heated air. 

System Components

Masonry Heater, the heart of our home, acts like a giant, super efficient fireplace.   Nine feet long, four feet wide, the heater’s exterior is lined with 8 inches of masonry:  firebrick inside, concrete block outside, all finished with beautiful  American Clay.  We light two fires a day December through February, and one fire a day otherwise.  To light a fire, cordwood is stacked in the 20”x20”x20” firebox, topped with kindling, and lit with a match.  Within 15 minutes, the fires burns from the top to the bottom,  igniting the entire stack.  Fed by a 4 inch pipe of outside air, the fire is now a raging inferno.   The smoke escapes via a contraflow system.  Smoke rises, then falls down the sides, slips under the bench, then rises and exhausts via the chimney.    Above the firebox,  the escaping smoke is momentarily trapped in a contraflow vortex and---like the catalytic converter in a car---reignites at a temperature of 1700F, converting smoke to heat while eliminating many pollutants.  Within 90 minutes, no matter how dense the wood, the entire flaming stack is reduced to glowing coals.    While a small amount of heat escapes out the firebox glass window, the vast majority is absorbed by the masonry and slowly released into the home.   As I type this, I can feel the gentle massage of radiant heat on the back of my neck.    Unlike homes with steel wood burners, the temperature inside our home varies only slightly, from a 73F peak 8 hours after lighting the fire to a low of 68F 24 hours later, just before lighting the next fire.   The 8 hours to reach peak is the time needed to conduct the heat through 8 inches of masonry.   The outside of the masonry becomes warm but never dangerously hot.    Laundry dries quickly when the drying rack is placed on the heated bench.  So too wet clothes.    The massive masonry heater requires deep footings and works best when centrally located in an open floor plan.   Even the most remote room in our home remains cozy warm all winter long.  Masonry heater does not work well during the shoulder seasons around winter.  The heater must be slowly broke-in each heating season, requiring several days to reach its full heating potential.  The combination of masonry heater  (for winter) and solar heating (for the shoulder season) is excellent. 

Cordwood---wood that is cut, split and well-dried---is stacked into masonry heater fire box and ignited with kindling.  Since the masonry stores the heat, fast-burning wood---like boxelder, willow and poplar--- works well in the masonry heater.   Denser wood like oak has the advantage of less wood needed.    A pound of dry wood, no matter the type, produces the same amount of heat.   

Chainsaw fells trees and cuts into logs ranging from 8 to 20 inches long.   Gas-guzzling, loud, hot, unreliable and notoriously dangerous, chainsaws are a necessary evil.  We do use handsaws for smaller logs and pruners to cuts kindling.  

Splitting Maul, swung by hand, splits the cut logs into cordwood.   If logs are mostly dry when split, then split cordwood can be immediately stacked in covered storage bin.  If logs are still green when split, then split cordwood is stacked in sun-exposed, one-layer thick windrows for one year before storing.    We do not use a gas-powered splitter for several reasons.  First, they do not save much overall time since the most time consuming step is moving the wood.  Second, they are expensive.  Third, we enjoy splitting wood by hand and so do many friends. 

Kindling is placed on top of the cord wood in firebox to ignite a top-down burn (fire burns from top to bottom so wood does not scorch and smoke).   Kindling---dry thin sticks---is everywhere:  falling off trees, the ends of sawed branches,  invasive shrubs like honeysuckle and buckthorn.    When collecting kindling take care to avoid sticking yourself in the eye. 

Wood Storage, the covered storage bin, needs to store enough cordwood and kindling for a winter.    We store kindling under the shed’s lean to.  We store cordwood in the containers which our steel roofing arrived, a total of 3 cords for a winter.    Prior to burning, a sixth of a cord is moved inside the attached garage to assure dryness and to make it easy to build a fire.

Trees, solar powered and eminently renewable, remain the unsung heroes of our heating system.  We harvest mostly dead and downed trees or those our neighbor cleared around his home.  Boxelder is our workhouse and the perfect tree for a masonry heater:  grows anywhere quickly,  sheds bark to dry well, easy to cut and split, burns great and since nobody likes it, we can always get plenty from our neighbors.   A single boxelder can be harvested many times via coppice and standard methods.    Since the masonry heater works best when burning hot and fast, we can use the entire tree, even the small branches and twigs.    Ash from the masonry heater is spread in a wide ring around trees and shrubs, inhibiting grass and feeding nutrients to the next generation of trees.

System Maintenance.  Wood heat is very labor intensive (see above).  I recommend it only to those who enjoy such or the health benefits from the steady activity.     By far the greatest amount of time is devoted to moving wood (retrieving, stacking to dry, storing, stacking in garage, carrying into house, stacking in firebox).   Creosote builds slowly inside the chimney since heater burns so efficiently. 

Report Card.   Warm Season = B.   Cold Season =  A.    (See blog post for details).

Biggest Challenge.  Leaving the home for many days in a row during very cold weather.   With our solar heating we do not fear freezing pipes.  But we will return to a cold home.  While we’re gone our “backup” is a friendly neighbor (who starts the fire).  This fits our value of community reliance rather than self reliance. 

Biggest success factor.  Adaptive process.   No matter the type of heater, burning wood is a learning experience.   Rather than over-thinking and investing in expensive splitters and wood sheds, our system has slowly evolved as we learn.   We not only save money, but it’s fun to creatively improve.

The Connection.    Imagine a cold winter night before a blazing wood fire, drink in hand.    Need I say more?   Yes actually because growing and harvesting trees pulls us out onto The Land and dreams us years and years into the future Land.  

The Secret Spot

Where in the whole mythic world does an epic adventure take place?   Between a farm house in Kansas and the city of Oz?  Between the comforts of Hobbiton and the horrors of Mount Doom?    Ordained by at least one brave boy, I hereby submit the following location:  Between Home the Land Built and The Secret Spot. 

‘Twas day two and the pressure was on; me that is.  My dear friend Heather had not only brought her two boys Riley 11 and Ryan 9, but a friend as well, Josh 11.  And intentionally or not, she brought some pressure with her.  This was Josh’s first sleep-over outside family.  I so wanted our Land experience, which Riley and Ryan had experienced many times, to go well for Josh. And we’d had a good day one.  Pulling down wild apples with the telescoping claw and basket of the apple picker.  Stripping, crushing and flinging the potpourri like seed of the prairie’s grey-headed coneflower.  Scouting potential sites to build a fort.  But that evening, as our stick-pierced hot dogs blackened over the fire, the pressure mounted yet again.   

 In spite of their conflicted mother, Riley and Ryan wanted to quit Boy Scouts.

“Where will you find such outdoor experiences?”  Heather asked.   “Such adventures?”

Both boys seemed to respond in unison.  “The Land!” 

As I gazed upon the fire-lit faces, I felt both honored and overwhelmed.   What would day two bring?

After the morning frost melted, we hiked through prairie---the autumn-blazed grasses far higher than the boy’s heads---to the place where all three boys decided to build their fort.  Linda and I had always called this southeast edge of the ridge the Secret Spot.  Here, where prairie meets pasture meets oak woodlands, an eminently visible old cedar hides the rock outcroppings beneath with well-extended lower arms.  We’d always meant to take better care of its secret, but other priorities called us away, much to liking of all the grasping buckthorn, raspberry and prickly ash.

But Riley, Ryan and Josh had a plan.  They lopped and pulled and sawed a clearing.   And soon, voila!  There was the Secret Spot I’d remembered, better actually.   

But they weren’t nearly done.  Rolling loose stones into a ring, they soon had a fire going.  And a grate.  And hotdogs.  

From the bottom of the old cedar to the very tip top, they sawed off the thin wood until all that remained was a ladder of strong limbs.  And climb the ladder they did.  To the very tip top.  And added a rope hoisted can for hauling knives.  And a tabletop where Linda and I can one day enjoy a treetop meal.   

Best of all, perhaps, they created a sign.  Cut into an old board with a knife, red-stained with the juice of wild grapes, the sign still greets me when I return, which is surprisingly often.  The call of the Secret Spot is hard to resist. 

That night, back at Home the Land Built, Heather asked each boy if they could share a one word impression of the day.  “I’ve got one,” Josh shouted. 

“Epic!”

I know Riley and Ryan shared amazing words too.  But what stuck with me, and will stick with me as long as I live, is that one word.  Until that moment, I’d never heard anyone so describe, with any sincerity, our joined experience.    Yes, Josh had already voiced that he’d remember the Land experience for the rest of his life.  “Better than any video game,” he assured us.   But now the journey from Home the Land Built to the Secret Spot resides alongside the mythic great. 

I never considered that I might be holding back my thoughts, my feeling for The Land.   Yet these three boys awoke something in me, something similar to yet far beyond Mud Mountain.  Mystical and magical as the Connection feels, perhaps there’s more.  Much more.  Perhaps I’ve only glimpsed the wonder.  Perhaps I have not yet begun to surrender myself to possibilities of the Land. 

I’m hiking to the Secret Spot.  Now.  And if you feel so moved, come, join me.  And definitely bring the children in your life and the child in you.  Here on the Land you never know what journey awaits.

Epic?

Is It Winter Yet Mom?

Mom!  Where you running to?

Away Bambi, fast as I can.

But mom, it was just a question.

I’m not running from you Bambi.  I’m running from him! 

I though you said he was nice.

Not when he bathes in fox pee and flings razor-tipped sticks at us. 

OK mom, but we’re like a mile away now.  Are you avoiding me?

Well, after that “Is It Spring Yet?” fiasco, can you blame me?

Yeah  but this is a totally different question.

Very well Bambi, what do you want to know?

Is it winter yet mom?

What kind of rut are you in?   Look around.  Leaves of yellow and red tumbling in the air.   Fields brimming with yummy corn.    Not to mention fox pee man pointing his razor at us.   If you think its winter, then maybe those supposed antler nubs are just your brains falling out.

But mom, he told me.

You talked to fox pee man!

Not him mom!  The nice man who planted all the tender trees for us to nibble.

What? You snuck into his house again?  Clump, clump, clump.

No mom.  He invited me in.

A complete stranger???!!!  I just can’t fourth stomach this.

We’ve been eating his yard all summer, mom.

You have a point there.  What did he do to you?

Nothing.  He just showed me to the dining table.

Ah!!!  He wanted a Bambi barbeque!

No mom.  He offered me a pint of Belgian ale, Auroch’s Horn.

At least the Auroch grew horns before he went extinct.

Nice Neolithic sarcasm mom.

Thanks Bambi.  It’s a mom’s job to run down their children so they don't have to.

The man just wanted to celebrate with someone.

Celebrate what?

The season’s first fire.

Yikes!  He started his barbie to grill Bambi.

Not the grill mom, the heater.

So that’s what this is all about.  Nice man starts his heater and you think its winter.  Oh deer me.

But this ain’t no ordinary heater.   He clinked my frothing mug, touched the ceremonial match to the kindling, and told me everything.  It’s a wood-burning masonry heater featuring contraflow, meaning the chimney is not directly above the firebox, forcing the heat to rise, then fall, then rise again .  The smoke, which normally escapes and pollutes, gets trapped above the firebox in the contraflow vortex and---like the catalytic converter in your car---reignites, driving 1700 degree heat into the surrounding 8 inches of concrete which, over the next 24 hours, slowly and evenly warms the home, much of it as sun-basking radiant heat.   Never a damper on this fire, its raging inferno reduces 30 pounds of oak to mere coals in one hour. 

I don’t have a car.

Way to obviate the point mom.

Don’t go using the “o” word with me, young man.

Great.  Now I suppose you won’t answer my question.

Alright Bambi, why oh why---when autumnal crispness fills the air---do you wonder if its winter yet?

Because he doesn’t start the heater until its cold out for good.  Due to the masonry’s high thermal mass, it takes days to heat up and days to cool off.  When warm days are expected to follow cold days---or if sunny days lie ahead---then nice man doesn’t start the heater.    And since he lit the season’s first fire today, he believes that cold and clouds are here to stay. 

I see Bambi.  You’re wondering if day after day of cold and clouds means winter?

That’s right mom.

And you’d like to know what season I think it is?

That’s right mom.

Did you know that if you play nice man’s words backwards you get a recipe?

For what mom?

For everything he had at the table:  beer, brats and Bambi.    Now do you finally know what season it is?

I’m not sure mom.

Hunting season.  Run Bambi run!

How It Works: Solar Heating

System Purpose.  Maximize sun as primary shoulder season (Apr and Oct) heat source and backup winter (Nov to Mar) heat source for home.

How It Works Summary.  Passive solar (windows) and solar hydronics (solar hot water) heat the air and concrete slab floor which then slowly releases its heat into home.    The combination works well since passive solar jump starts the heat in the morning, while solar hydronics continues drawing on excess solar hot water long into the evening. 

System Cost.  $4,000, including installation, to pump solar hot water into floor.  This excludes the cost of windows (which we had anyway), the solar hot water system (whose primary purpose is domestic hot water usage), and the concrete slab (we needed a floor anyway).

Shared System Components

Concrete Slab, heated both by passive solar and solar hydronics, slowly releases its heat via conduction (warming your feet), convection (warming the adjacent air) and radiation (heating you and all objects like direct sunlight).  Slab is insulated below to slow heat loss into underlying sand layer.   A day of sun can raise the slab from 70F to 78F.   During the shoulder season, when outside temperatures can fall to freezing, the heat stored in the slab from a couple sunny days keeps the house above 65F for several cloudy days.  During winter, when the wood-fired masonry heater is the primary heat source, the solar heating systems acts as a bonus.   On a bitter cold, yet sunny day, the stored heat in the slab allows us to open a window for extra fresh air and skip the morning fire.

Passive Solar System Components

South-facing windows convert sunlight into heat via the greenhouse effect (objects absorb solar energy and convert to heat whose wavelength is too long to escape through the glass).   South-facing windows are best for three reasons.    First, the sun spends most of its day in the south during the heating season.  Second, south facing windows take advantage of the most intense solar heating around noon.  Third, during the hot summer, sunlight can be effectively blocked from entering south-facing windows via an overhang.   Do not use low e glass for passive solar since they block the needed infrared light.  Passive solar is free heat, since it costs nothing to choose to orient windows south rather than north, east or west. 

Overhang blocks sunlight from entering windows during the high solar angle summer while allowing sunlight to slip beneath during the low solar-angle winter.    Our 2.5 foot overhang blocks all sunlight on the summer solstice.   On the spring and fall equinoxes, the sunlight reaches in 6 feet.  On the winter solstice, sunlight reaches in 19 feet, touching the far wall.    A warm September requires the addition of shade cloth to block unwanted sunlight.  While we used our roof and rain gutter as overhang, awnings could be used as well.

Solar Hydronics System Components

Solar Hot Water System (see How It Works:  Solar Hot Water for details).

In-floor Pump circulates water through a heat exchange element inside the 80 gallon solar hot water storage tank then out into pex tubing embedded within the 5” concrete slab.   Like any other in-floor pump, except our relies exclusively on “excess” solar hot water.

Programmable Thermostat turns In-floor pump on or off depending on the temperature of the water inside the solar hot water storage tank.  Since our solar hot water is primarily for domestic usage, the thermostat is set to only pull “excess” heat out of the tank.  We’ve discovered that “excess” is anything over 130F since even our well-insulated tank quickly loses its heat to the cellar at temperatures above 130F.  This excess temperature is only reached on sunny days. 

In-floor Pex Tubing, embedded like a winding plastic snake throughout the concrete slab, carries water whose heat is conducted into the slab.   As the slab absorbs the tubing’s heat, the water cools and is returned via the pump to be reheated by the solar hot water storage tank. 

System Maintenance.   Turn solar hydronics system on (via thermostat) at beginning of heating season and turn off at end. 

   

Report Card.   Winter = A.   Shoulder Season =  B.    (See Report Card for details).

Biggest Challenge.  The shoulder season house temperature can swing from a chilly 62F to a sweaty 80F.     We adapt to 62F with sweaters and blankets.  While we can keep the house below 80F by opening more windows, we often don’t.  On sunny days we allow the house to overheat so that the stored slab heat can keep the house warmer during the inevitable cloudy and cold days which follow.    We actually wanted (and designed) our house to experience the seasonal temperature fluctuations to feel more Land connected.

Biggest success factor.  Orienting most windows south.  Even the ancient Greeks practiced what we’ve largely forgotten.   In addition to the huge energy and cost savings, south facing windows maximize light during winter, brightening our sometimes darkened spirits.    And it costs us nothing to orient them south.  

  

The Connection.    What could be more Land connecting than sunlight streaming through a window, the bright patterns moving across the floor throughout the day?    And then there’s the absolute joy, the thrill, of experiencing  a beach-like 80F when its below zero outside.  

Best Question Never Asked

“I’ve never heard that question before!”  I said to Linda.  Stars, the bright early evening ones, seemed to illuminate the wall behind our chairs on the west porch.  Or maybe that was just our happy hour red wine.  “I don’t mean just from you,” I continued.    “I’ve never heard that question before from anyone in my entire life.”   And it was such a good question, a question so fundamental to the fate of humanity that I could hardly believe I’d never heard it. 

“I have no idea what the answer is, “ said Linda.  “I’m not sure there is one.  But maybe that’s just cynical me.” 

Well an answer was certainly stirring within me.   And while it incubated (I have a lot of introvert in me) I told Linda how lucky I feel.  “I wonder if it’s the Land, “ I said.  “Maybe your connection to the Land inspired such a uniquely visionary question?”

Whatever the cause, Linda’s visionary question was this:  “What is our purpose in this world?” 

By ‘our’ she meant not Linda and I, but humanity.  “What good are we really?”  This last rephrasing, she admitted, came from her cynical side because frankly she couldn’t see anything we’re doing that’s particularly good.   We’re good at taking from the world.  When someone asks ‘what is the purpose of bees?’ what they really mean is ‘in what way do bees serve humanity?’ Thus the answer must be ‘they pollinate much of our food’.  Ours is a dualistic, selfish, humanity-first approach, which ironically isn’t well-serving humanity either, except for making more of us.   

“There are many, many individuals doing their best,” she admitted.  And many individuals striving, best they can, toward their own purpose.  But she saw little evidence of any jointly shared binding purpose that moved the world forward to a better place.

Maybe it was the stars, maybe the wine, but for whatever reason I wasn’t feeling nearly so cynical.  Not only that, but long before Venus set, my introvert completed his incubation.   How arrogantly preposterous to believe I could answer her ‘meaning of life’ question.  Not matter!  I was ready to share.    But now as I type, the sun outshines the stars and there is no wine within reach.  So while I sit here and feel shy about my answer, perhaps you could ponder the question.  What would you say is the purpose of humanity?  What should or could humanity contribute to the betterment of the world?  And if you dare, leave your answer in the comment.

“Consciousness!”  I said.  “The world gifted us with a level of consciousness as never before.  So maybe humanity gives the world the gift of consciousness, the ability to ponder itself and its connection to the universe.”

“What good would that be?” said Linda.  “What good has our consciousness been?”  

“I’m not sure,” I replied.  “It could very well be that consciousness will be deemed yet another of the world’s experimental failures and soon terminated.  But perhaps not.  Perhaps the world will harvest an amazing reward one day.  My small mind can’t know what that reward might be.  But the earth is genius, in so many ways.  I just wonder what she could do if we helped her grow her consciousness?” 

We sipped.  We gazed at the stars gazing back at us.  A heady conversation?  Yes!  And that’s a good thing.  Maybe even an essential thing.

So why am I telling you all this?  After all, what I’d really like to do is have the conversation with you, not type it. 

What I’m really sharing is this.  The Land and Home the Land Built are changing us, shaping us into…into something quite different than what we were.   Linda just asked a question not only ask-able in our former life, but unthinkable.  And then, under the gaze of the universe, we allowed ourselves the luxury of actually engaging the question. 

Rah-dur!