Rocket Mass Cheater

Years ago we moved onto a tiny piece of land east of Kansas City, Missouri about 20 miles outside the suburbs. We’re in the middle of nothing, but surrounded by everything. It’s an odd dichotomy but suffice it to say it’s only a bit rural in these parts so we only hear the banjo music when there’s no moon, instead of every night… like where I grew up.

Right out the backdoor of our bedroom (2 feet from where I lay my weary head) is a sidewalk that goes out to the driveway in one direction and then off at a 90 degree angle, about 100 feet, to a concrete pad. On this pad is a Hardy Woodstove that, once upon a time, was used as a secondary furnace to heat the home.

Hardy Woodstoves, no longer being made, are a poorly engineered outdoor boiler system. The idea behind them is sound, but the actual heaters are less than efficient. 

The idea behind the heaters is thus; you have a fire chamber that is surrounded by a water tank. Water is pumped from the heater to the house where it goes to a furnace that is separate from the main furnace. They sit together kind of like buddies, taking up a decent footprint in our creepy 120 year old basement. The water line runs from the furnace over to the hot water heater, then runs back outside to go through the jacket, get heated up and then do it all over again.

Quick side story!

A few years after we moved out here we decided to get chickens. Seemed like the thing to do at the time. We bought a small starter coup for the chicks and then I proceeded to build them a permanent coop, a real home for them. A fine home indeed, I spent hours drafting out the perfect chicken coop. It had a screened in area, roosting area, nesting boxes, etc.

I mention this side story because we built this coop about five feet past the concrete pad where the heater is built.

So what else does this chicken coop have to do with this old heater?

Do you know what a derecho is? Until a few years ago I didn’t.

That’s when we got hit by 100+ mph winds, with gusts of up to  120 mph, for over 90 minutes. That’s basically the same thing as a category 2 hurricane right here in the middle of the country.

My wife of 25 years, who grew up on the beach, said it was more like a Cat 3, but I can only tell you what the news man said on that there radio.

Tornadoes sure, we see those all the time, but this was the craziest storm I’ve ever been in.

It happened, I kid you not, the day after we finished painting that coop I built. Keep in mind I’m not a handy guy and building an 8×12 building was a month long process that took up multiple evenings and weekends. It was a lot of work and we went out of our way to make sure we built it right.

At one point during this storm the lightning flashed as we looked out the back window. At the end of the sidewalk, right before the concrete pad, was a 70+ foot tall Maple Tree. Based on the rings it was here.. well a really long time, I didn’t actually count them.

Regardless, that beautiful, majestic tree had been blown over, right on top of our brand new chicken coop.

It was rather devastating. The storm outside was mad chaos, there was nothing we could do, except evacuate to the basement and hope for the best. That next hour, as the wind raged, was so long and the entire time we worried about the birds.

Flash forward to when the rain stopped and what do we find? The coop was damaged, but not nearly as bad as it could have been because that old Hardy Woodstove took the brunt of the trunk.

The concrete blocks below the coop exploded and part of the roof was smashed. Just about every nail and screw in the thing was bent and the walls were all Dr. Seuss, but only three boards were damaged so badly they had to be replaced.

Heck of a mess to clean up and the saga of me milling down that old maple tree into slabs for lumber is a story of its own and the chickens, who all made it out alive, are still in therapy for posttraumatic stress disorder.

But for now let’s go back to that Hardy Woodstove, which now has its outside steel shell crumpled and looks like some kind of new age art piece.

I want to use the infrastructure from the Hardy Woodstove and build my own outdoor boiler. I want to take apart what’s still there, scavenge it for parts like the steam valve, water pump, firebox, firedoor, stove pipe, ashbox, etc.

Then, after I go all Sanford and Son, I wanted to build a concrete “box” around the firebox/ashbox. I want to put it about 12 inches away, so there’s a big solid gap between them. In the open space I wanted to run copper water lines in a loose coil and then up over the firebox to a radiator that then goes to the other side before going back out to the house.

My thought was to fill the gap with sand and then lay 4-6 inches of sand on the top before capping it with blocks and then a small metal roof to cover the stove, the wood stack and the person loading.

I suspect covering the outside with ¾” insulated board and then metal paneling might be too much, but the backside needs to be somewhat open to access the electrical, the pump, valves, etc. So I still have some areas that I haven’t thought out completely, but that was my general idea.


You see, during my research I discovered Rocket Mass Heaters.

Now that I’ve seen and have a basic understanding of the Rocket Mass Heaters I’m rethinking how I want to rebuild the outside heater. I was going to heat up my “mass” of sand and concrete by putting a firebox in the middle of it.

But maybe that isn’t the best way of heating up a mass, perhaps I build a Rocket Mass style heater and use the bells to heat up the mass that in turns heats (warms?) the water.

My nearly 90 year old father, who installed many a furnace during his day, keeps pestering me about BTUs, but I keep reminding him we’re not British. Then I have to remind him I get my sense of humor from him and if he wants to do the math then knock himself out.

Although I suspect he may have a point, I have no clue what I’m doing.

Which is why I’ve written this long twisted tale explaining the situation before me.

Here I sit, pecking away at my keyboard, hoping someone smarter than me (so just about anyone) would take pity on me and share some of their wisdom on what they would do given the same situation.

Any advice would be greatly welcomed, but keep in mind that I’m fairly incompetent, stubborn and somewhat crippled up (a whole other long story that would leave my father saying, “Just rub some dirt in it, you’ll be fine” – shrug).

The man cut off half his thumb on one hand and I kid you not, it regrew, nail and all. His secret? Said he used duct tape and since it was only half gone there was no reason to bother the doctor. Rubbed some dirt in it too, so he said.

So recap: idiot in Missouri has a broken outdoor heater and needs guidance to prevent opening a fiery portal to doom.

In exchange: will send metaphorical warm fuzzies and buckets of appreciation.