rocket bath?

Satamax Antone wrote:Russell, plan a bypass, to get the chimney warm, and get things moving. Just in case. Peter usually says, make the bypass at mid height in the bell.

Good idea bro I forgot bout a bypass lucky I still just have dry stacked brick lol. Some more pics below with comments sorry bout the darkness. Midnight here. Or I could lift the bath another 6 inches  then only bout three bricks high to top of riser

Hope this one shows the bell height better

We built this rocket stove and copper coil heat exchanger to fill these two tubs with hot water. This is our Mendocino county California hippie hot  tub deluxe. I did find a steel plate to put on top of the heat exchanger and that made the water get a lot hotter.  we hooked up a regular garden hose to one end of the copper coil and a hose on the end other end of the copper coils which fed the tubs with hot water we did have to be careful not to create steam it can be pretty dangerous I. Am thinking next time That i build something like this I'm going to use a heat exchanger that is in the loop back to the tub where we can create a thermosiphon and instead of continually feeding the water can be continually heating once the tubs are full.

Should thermosyphon set up like that too just need to put a couple balance pipes  between the baths to heat them both at once. One down low join the waste connections together for the cold return to the bottom of the coil. And the other balance pipe at opposite end bout 6 or 8 inches from the bottom. Once my bath is set up properly and running next project is one of these.

New inlet bell size I think she will work this time. Roof of bell will be 250mm above riser 500mm x 400mm rectangle height is 600mm down to a 500mm x 200mm opening tapering away from the rocket towards the bottom of the bath.

Hello I would like to share a hot tub we built in our garden.
We used earth and stones around the bathtub to keep in the heat
Check out the link ...
http://ademas.es/rocket-barbecue-hot-tub/

Awesome setup

Sweet I had never thought of doing this I now have my first cob and rocket heater project

I am also on the way for a rocket bath
3 points below

James Heap wrote:
1- the primary heat source ideally should be solar or better yet a compost hot water heater, like the one developed by Jean Pain. The rocket is there for a booster to maintain the desired temperature as this varies amongst people.

2- I felt the experience of bathing under the stars was a one up on inside (personal preference), so that was the whole point in the 'outside' bath.

3- Remember to find a bathing buddy, it saves water

1- I will try to have a system for heating water but mainly will rely on solar water.
My bath will be near the exhaust pipe and will benefit from heat as a bench.
My main idea is that I will look at the fire from the bath!
As I could not have the fire visible from the living room, I build the bath room where the fire is.

2- Having a fire outside JUST for a bath is very romantic and nice, but a lost of energy, as it  all goes away apart from the bath.
+ I want to bath in a warm room, it is more important for me than warm water from the RMH.

3- Thought about it as well.... but then what when you are alone... so I have found a design that allows me to use for 1 or 2 persons, and use the right quantity of wáter.

Actually, I want a bath just to be able to  take salt  bath, or epsom salt bath, for HEALTH REASONS.
Or else, sure that just the shower I have is enough for washing myself!

Also, I needed to think about where the water goes, because not all plants like salt, and so I will think about a piece of land just for salt loving plants!

This one is nice. I guess it's not exactly a rocket mass stove. I don't understand if the wood they use under the base of the pool will hold up long. Seems like if would burn or something. It's pretty though!

This isn't a rocket or cobb tub heater. But it might serve the purpose.You can skip to about min. 31:00

I’ve built several bush baths, Cowboy hot tubs, outdoor baths, or whatever thy are called. It always bothers me that I’m not stacking functions very well. Outdoor fires are so inefficient. I’d much prefer the tub was in a greenhouse so the latent heat goes towards something. In fact perhaps the tub could be the greenhouse heater and always ready to go as a bath. Cheers.

Jeremy Baker wrote:It always bothers me that I’m not stacking functions very well. Outdoor fires are so inefficient. I’d much prefer the tub was in a greenhouse so the latent heat goes towards something. In fact perhaps the tub could be the greenhouse heater and always ready to go as a bath. Cheers.

That is such a good idea.  Hmm.  The only part I'd miss would be being outside while in the water, but if I could use this to make the greenhouse more supportive of subtropical plants that would be a great tradeoff.  Also, I'm in the desert SW where it is rather windy.  It is nice to be out of the wind when sitting in the water.  Thanks for the idea! It's very timely for us, as we are building a home/shop with a greenhouse lean-to attached.  And there is enough room for a hot tub in it.  I was intending a rocket mass heater in there that could stabilize temp, but connecting it to water didn't even occur to me.  

I get the best ideas from people on Permies!  Thank you.

I'm intrigued by the idea, ever since I saw a Cowboy Hot Tub (Cowboy Hot Tub) and built a simple galvanized pipe coil that I would stick in a fire to heat water for camping or use to heat a 150 gallon rubber maid tub full of water.

How does the fire get air on these?  I can't figure it out from the pictures on their website!
Thanks,
Amy

I love this thread, because...I’ve had it in my head to use a rocket mass heater in 2 ways.  One of the ways is to heat our swimming pool or at least the attached spa.  Then I can throw a valve and with the loads of 2 inch pipe left by the previous owner, run it underground in a high tunnel to grow peppers and tomatoes in the winter here in AZ.  

I’m light on the knowledge of pressure, temperature etc to get into it just yet, but with the community help, maybe I can tackle it this Fall.  

We bought a barn in mid-Wales which we've since converted into our now-lovely home. An early requirement was a bath so we built a "bath house" down by the river. This was quite basic - a metal bath rescued from a skip, along with a second hand Woodburner with a back boiler. The output from the back boiler went into the bath overflow and the cold return came from the waste pipe. I extended the waste with a pipe long enough to be clipped above bath-top height, along with a section of flexible pipe. This enabled us to empty the bath when finished. The bath was filled, almost to the brim, before the fire was lit so that the back boiler was full.
I've modified it a bit since then, adding a copper hot-water cylinder and other mods to improve it. All very basic really.
It's certainly not a fancy rocket stove but it has served us well over the years - in fact we still use it regularly as it is so enjoyable to have a kind of sauna along with masses of hot water to soak in.

Did a bit of study on rocket fire concept and decided to make a fire bath as a first project.
I must of got the measurements right because it's super efficient (powered by sticks smaller branches - if you can't snap with hands or feet it's too big), flows the right way and burns clean I.e very little to no smoke. Basically propped the bath up on bricks and cobbed to seal around the base. Used dirt dug up from home mixed with extra clay and straw. I did add a wool based insulation around bricks before cob applied to help hold heat in the system. Plumbed a pipe from the plug to drain water away and added a hose for cold water input. Takes just under 1 hour to heat a bath with lid on. Mild climate Wellington NZ. Bath is cast iron and it's bottom forms the top of the heat chamber.

I have since used a slaked lime to the cob to protect from erosion which seems to have worked so far. The bath is now two years old and hasn't missed a beat. Love it.

Shane, that looks great!  So, do you run the fire with a lid over the water, and then you get in the tub?  Is the tub too hot to touch right over the fire (or where the fire was)? Do you have a wooden bottom inside the tub?

Julia Winter wrote:Shane, that looks great!  So, do you run the fire with a lid over the water, and then you get in the tub?  Is the tub too hot to touch right over the fire (or where the fire was)? Do you have a wooden bottom inside the tub?

Hi yes i heat up with lid on to help speed up heating. And yes the bottom of bath gets hot so I have a floating wooden slat frame that we sit on. Otherwise burn my bum!

One of the benefits of this is the cast iron stores heat and keeps bath warm for a long time without feeding fire too much. I can get out, put the lid on and it stays hot for ages. The side above fire generally only gets warm and not hot due to suction effect pulling fire and heat under the bath rather than vertical.

The chimney never gets too hot to touch. Only warm. But I would like to harness the heat from the top somehow.

I was thinking you could speed it up even more by adding a copper coil in the burn channel and setting up a recirculation system. But to be honest it's already within my acceptable time frames for heating.

We are moving soon so will leave the bath for the tenants and try and incorporate some new ideas, efficiencies in my v2.

One tip is if you make a system like this then you need to leave the bath water in when you are done. If you drain it immediately, it will get too hot and crack the enamel! (Lived experience!)


Any ideas welcome.

Perhaps this is helpful to anyone interested in rocket bath options.

My friend contacted me about building him a rocket boiler for an outside bath. We call boilers 'geysers' here in South Africa. A wood-fired geyser is known as a 'donkey'. Enter the rocket donkey!

His reason for not wanting a fire under a cast-iron bath is, according to him, that the bottom of the bath can get very hot, causing bathers to have to sit on submerged wooden planks. He did not want that.

His reason for not wanting a copper coil thermosyphon mechanism is, according to him, because spurts of hot water make the bathing experience tricky.

So I designed and built him this:



His rocket donkey won't have a burn-box lined with metal. I've made him a separate core and we'll brick it up.

You can get a sense of what is happening inside the drum via this pic. Note that the entirety of the outer drum will be lined with ceramic fibre blanket:



I'll post an update once the unit has been installed.

Howdy!

I said I'd post an update once I installed a "rocket donkey" at my friend's place.

The update is located here: rocket donkey

(insert donkey braying sound...)