Podcast 225 - Rocket Mass Heater Workshop Recap Part 1

That was an awesome podcast

Boy, that guy that pushed the "exhaust your heater into a greenhouse" must have been super obnoxious, because y'all covered that six ways from Sunday! It was interesting to hear you talk about this, because in an old hobby of mine (ornamental aquarium horticulture, or heavily planted tanks) many people use CO2 tanks, or yeast digesters, to enhance plant growth. (I never did--that was too fiddly, and if your system breaks down in any way you can wake up to dead fish.) If anybody wanted to spike the CO2 in their greenhouse, I'd advocate for fermentation or critters as a safer source of CO2.

Just FYI, room air has 21% oxygen most of the time.

Yeah, the guy was quite pushy about it, but it was also brought up at other time during the last day of the workshop. Some people thought that they could make it work. I think Paul, Ernie and Erica's point is that it can be done, but that it is inherently unsafe.

I just got an email:

Since a good, well-operated RMH exhausts very little smoke and almost purely steam and CO2, what about venting that into a greenhouse?  The research is in: plants love CO2. It’s basically home-scale carbon capture.  You may need to have a fork in the exhaust line, 1 exit tube going outside, and another going into the greenhouse.  Then you could have a CO detector by the greenhouse tube that automatically switches the exhaust to shoot outside when the smoke gets out of desired parameters.

It is in this podcast where Ernie, Erica and I thoroughly discuss this.  

To the three of us it seemed obvious that this was a bad idea.   A REALLY bad idea.  Awful idea.  Fuck, DO NOT DO IT!  And the guy asking ....  in hindsight, I don't understand why he was even asking.   He started off by asking me, I said "bad idea" and then said I was wrong, and then erica got involved and he said erica was wrong, and then ernie got involved and he said all three of us were wrong.  If you think you already have it all figured out, why do you ask?  

Before this guy, I am certain that E&E&I would not have made a podcast on the topic - it just seems so obvious.  There's oodles of other stuff to talk about.  But this guy was such a douchebag about it and for 45 minutes just railed at how stupid the three of us, the instructors, were ...   the very next moment we had (breakfast the next morning) we recorded a podcast.  

Oh sure, we think about things like "I think that problem will solve itself.   He'll be dead in a month."  Of course, it could turn out to be that others get killed or that rocket mass heaters get a bad name.   And then we started talking about how he was so sure he was right and he would not listen to any of the things we were saying.  To make matters worse, he seemed like a smart enough guy the moment before.  So we got to thinking that others might embrace this awful train of thought.


Over the years, this question has been put to me about eight more times, but I say "NO!" and the person asking the question says "Okay."  - and we're good.  


Still, I think if anybody is thinking of a rocket mass heater in a greenhouse, they might be tempted by this thought and they really need to listen to this podcast.

What's not mentioned in that podcast, and perhaps I missed it, is that CO2 enrichment only works when CO2 is the limiting factor in growth.  So, if you're firing your rocket mass heater once in the evening for a couple of hours in winter, and making sure the soot doesn't turn all your glass black, it's just not going to work since winter light is the limiting factor in growth.

Although carbon monixide will kill you, and other animals, because it binds tightly to haemoglobin, it doesn't affect plants who might thrive on it since they convert carbon monoxide to carbon dioxide.

Us greenhouse growers can help our selves, but think we can squeeze a little more growth out of our plant when we have low light in the winter. After getting a small dose of CO poisoning after my second RMH test fire that was venting into my wide open greenhouse(sides were open about 4 feet all the way around the greenhouse and most of the smoke I was breathing was from burn back), I am having second thoughts about trying to vent an exhaust into the greenhouse. I did purchase a couple CO2 and CO sensors. It will still be interesting to collect data on CO2 levels in the greenhouse and CO levels in the exhaust.

Not to mention that although CO2 is not nearly as dangerous as CO (it doesn't bind to Hgb and you breathe it in and out in every breath) you can still suffocate from CO2 displacing O2. If you're not paying attention, sleepy, or overexerting yourself you could easily pass out and suffocate in a CO2 enriched environment.

Also, you lose weight from exhaling carbon in the form of CO2 do your CO2 generator may make you gain weight, Just kidding but if it convinces people not to play with fire, no pun intended.

There's an old report about 4 seaman falling asleep and dying in the refrigeration hold of the ship after buckets of dry ice were put down to keep the fish cold.
There are still about 90 deaths per year still in the USA from CO2 asphixiation, and many of those are rescuers.
Someone told me about a young girl who lost consciousness in a boat as she was standing by the outboard motor in the open sea.  This was apparently due to carbon monoxide inhalation.
So, the moral of the story is, don't do this at home.  It should not work, and only introduces danger to your environment.