Tiny house efficient wood heater ?

We are building a tiny-ish house (16x24). It’ll be crazy well insulated, so it shouldn’t take much to heat (super cold climate though). We don’t have a ton of space for the wood stove, and I don’t want to cook us out of the house, but I really want the efficiency of a rocketmass heater so we aren’t letting heat, creosote and all that junk just blow out the chimney. I think it would be amazing to be able to heat the house with just branches that fall off the trees on our property too! So sustainable!
My question is in the tiny house if we don’t want to dedicate a whole wall to a cob bench what are my options? I’ve been looking at making a small masonry style heater but it’s harder to find info about those, are they as efficient as rocketmass? I saw a batch box rocket with kind of a bell shape? Could I make something that tucks tidily into a corner that I could potentially still cook on top of?

Thank you!!

So far I know that your building is about 400sqft.
What the R value of your roof, wall floor.
How high is your ceiling, do you have a loft or 2nd floor?
Do you have a HRV or ERV? How airtight is your structure?

Have you thought about a radiant floor heating system, with a cost breakdown of $400 for 400ft of pex pipe, $300 for a circulating pump, you then connect it to your hotwater tank powered by solar/gas/heatpump/pellet/wood/etc.

Here is a link on ERV/HRV. https://en.wikipedia.org/wiki/Energy_recovery_ventilation
In short they are air intake devices that are used to bring in fresh air into houses with a super tight/insulated envelope with minimal air leakage. The incoming cold winter air is pre-heated by outgoing condition/heated indoor air. (ERV also help in the summer too, by cooling and dehumidifying the incoming air)

Do you live in hot Florida OR cold Maine it will a difference?
But here are a few stoves that might fit your request:
https://www.tinywoodstove.com/product-category/stoves/

S Bengi wrote:So far I know that your building is about 400sqft.
What the R value of your roof, wall floor.
How high is your ceiling, do you have a loft or 2nd floor?
Do you have a HRV or ERV? How airtight is your structure?

Have you thought about a radiant floor heating system, with a cost breakdown of $400 for 400ft of pex pipe, $300 for a circulating pump, you then connect it to your hotwater tank powered by solar/gas/heatpump/pellet/wood/etc.

We will have r 24 walls, r 49 roof, and cement slab floor (with insulation and vapor barrier).
Peak of the ceiling will be 15ft, there will be a double sleeping loft.
Plan on an hrv system with 2 vents and the building should really airtight, using sips and taping corners and windows.

I LOVE the idea of doing radiant floor heat. We plan to have a tankless hot water heater for showers etc. Would it work to set up a rocket mass or masonry heater system that heated the floors? Does there need to be a water holding tank or can you set that up with just a pump to circulate the water?

A tankless hot water heater is perfect for radiant floor heating. It does not need a tank.

Because I am not too sure which region of usa you live in and thus if you need 30BTU per sqft  or if you need 60BTU per sqft. I am going to go with an average of 45BTU/sqft
24ft x 16ft x 45BTU/sqft = 17,000BTU boiler/furnace or a 0.7gpm tankless hot water heater.

$100 Tankless Water Heater
$400 Pex Pipe 400ft of wire for a 400sqft house, and you only need 1loop
$300 Pump
$100 Thermostat/pump control
$10 Pressure Relief Valve
$10 Fill/Drain Valve
$10 Air Bleeder

It is possible to have a rocket stove heat recirculating water. They do have quite a few pellet boilers.

I highly recommend running the pex pipe in the floor, so that you can switch to in floor heating later even if you end up not using it now.

You could even charge up the slab during the daytime with the device below, if you get solar onsite or solar from the grid.
https://www.homedepot.com/p/ATMOR-3500-Watt-120V-0-5-GPM-Point-of-Use-Electric-Tankless-Water-Heater-Includes-Pressure-Relief-Device-1-Sink-Water-Heater-AT-35WH-HD/315389815

An efficient wood heater will not have this issue

so we aren’t letting heat, creosote and all that junk just blow out the chimney.

From minimize-creosote-buildup/


They are an authority on how to minimize creosote buildup and prevent chimney fires. Here are there top recommendations:

Only burn dry, seasoned firewood.
Freshly cut wood is packed with moisture that makes it difficult to burn and produces dense black smoke filled with combustion byproducts.
Allowing firewood to season, or dry out for at least six months, helps it to burn completely and produce less smoke.
Build hot, clean burning fires.
Stacking firewood with enough space between the logs for oxygen to circulate will produce a hotter, cleaner burning fire.
If you consistently build efficient fires like this, less creosote will build up in your chimney because your fires will produce less smoke.
Make sure the fire gets enough oxygen.
Open the damper in your fireplace before you light a fire to ensure it will get enough oxygen.
If your fireplace has glass doors, it is a good idea to leave them cracked open slightly so that air can circulate.
Reduce condensation by warming up a cold flue.
If your chimney isn’t well insulated, the flue can reach low temperatures. Lighting up your fireplace when the flue is cold will create more condensation and larger creosote deposits.
You can easily warm up the chimney by rolling newspaper up to make a torch, lighting it and holding it up in the chimney.
When you notice the smoke from the torch rising straight up, you’ll know that the flue is warm enough.
Schedule an annual chimney cleaning and inspection.
The NFPA recommends an annual chimney inspection and cleaning because they have found that it is the most effective way to reduce the risk of a chimney fire.
Professional chimney sweeps are trained to spot issues in your chimney that may pose a safety risk or increase creosote buildup.
We also have the tools and training to safely and efficiently remove creosote.

Rae, would something like either of these work for you:

https://permies.com/t/167690/Cubic-Mini-Wood-Stoves#1317157

https://permies.com/t/71576/tiny-house-rocket-mass-heater

This has served me and my tiny home very well for a few winters now: