Which is better thermal mass or stratification chamber

This may have been covered before. I'm new to this style of heating. My question is which is better  thermal mass bench with ducting or a stratification bench.  Looking to build in my basement to keep it warm

Hi Brian! Welcome to permies!

I'm not entirely sure a rocket mass heater in the basement is a good idea. I think more enjoyment would be had from it if the rocket mass heater was in the living room or an area that people frequently visit.
Trying to not go off topic from your question, but is there any particular reason why you would like to build a rocket mass heater in your basement?

Hi Dave thanks for the welcome. I'm located in northern Illinois and my thoughts are two fold. 1) heat rises so will warm the upstairs floor and 2) having a heat source to dry my winter work clothes

What is a stratification bench? Describe in as much detail as possible.
How high/tall would it be. What is the working liquid?
What is the projected min/bottom temp and the max/top temp.
What type of insulation do you have.

Are you trying take do DHW for showers from the the top of the stratification unit. And radiant (floor) heating from off the bottom.

A thermal mass bench might melt if it gets up to 2000F, but the liquid will steam and exploded at '200F' how will you plan for this. Will others operate this unit, are they skilled?

I think rocket ,mass heaters are more focused on conductive heat and radiative heat, instead of convective heat.

Yes, heat does rise. Though, I'm thinking there's got to be a better way of doing this than trying to use convection.

Would it be okay to let your clothes dry by laying them ontop of the rocket mass heater bench? Or hanging them inside the room?

How windy is it in Illinois? If it is windy enough, it might be possible to dry your clothes on a clothes line, even with it getting a little cold.

Brian Funk wrote:This may have been covered before. I'm new to this style of heating. My question is which is better  thermal mass bench with ducting or a stratification bench.  Looking to build in my basement to keep it warm

Hi Brian,  Here is a good explanation of the two types of heat capture.  Flues vs Bells
If you don't already have it, a lot of information can also be found in the book The Rocket Mass Heater Builder’s Guide by Erica and Ernie Wisner

My personal opinion is that bells ("stratification benches") make less friction in the exhaust path, and may give more heat exchange surface, than ducting, so may be more reliable and less tricky to get right. Both rely on thermal mass, no difference between them there.

If you want most to warm your basement and plan to spend a lot of time there, a basement RMH is fine (though there are possible issues with draft in a basement installation). A J-tube style core needs frequent tending while firing (every 20-40 minutes), so you need to spend an hour or two or more depending on weather and other factors down there. If this is doable for you, that would work; if not, you would likely be better off with a batch box core which needs to be started, loaded, and fires by itself for an hour.

Gerry Parent wrote:

Brian Funk wrote:This may have been covered before. I'm new to this style of heating. My question is which is better  thermal mass bench with ducting or a stratification bench.  Looking to build in my basement to keep it warm

Hi Brian,  Here is a good explanation of the two types of heat capture.  Flues vs Bells
If you don't already have it, a lot of information can also be found in the book The Rocket Mass Heater Builder’s Guide by Erica and Ernie Wisner

The link is broken. I think it was meant to direct to this site: Flues vs Bells

Thank you for spotting and making the correction Karlijn.