Fireplace designs for mass and efficiency

I am in the process of designing a new home with an architect.  He's not proficient in passive and low tech energy conservation but he's willing to work with me.  Currently we have a standard fireplace in the design but I want to have something more efficient, but not something like a rocket stove.  I have seen a design on here before for a fireplace built with multiple sections that hold the hottest of the air and only allow the coolest air to travel to the next chamber.  What are these called and where can I research the construction of these better?  Is a wood burning stove a better option than that?  What other options do I have if I want to burn wood and use it for heat as well as ambiance?  Thanks in advance!

That would be a masonry heater.

And a rocket mass heater is just a type of masonry heater. There are ways to build RMHs with visible flames, and infinite ways to make them "prettier" than a traditional RMH with barrel and bench. For starters, look at batchrocket.eu.

The concept of trapping the hottest air and letting the coolest escape from the bottom of the space is known as a "bell" or stratification chamber. It is highly efficient and easy to build, but cannot be used with an open fireplace, as that requires that a lot of heat goes up the chimney to avoid creosote condensation and chimney fires. You must have an extremely efficient firebox with complete combustion (like a J-tube or batch box) to use a bell system.

Mike Bettis wrote:I am in the process of designing a new home with an architect.  He's not proficient in passive and low tech energy conservation but he's willing to work with me.  Currently we have a standard fireplace in the design but I want to have something more efficient, but not something like a rocket stove.  I have seen a design on here before for a fireplace built with multiple sections that hold the hottest of the air and only allow the coolest air to travel to the next chamber.  What are these called and where can I research the construction of these better?  Is a wood burning stove a better option than that?  What other options do I have if I want to burn wood and use it for heat as well as ambiance?  Thanks in advance!

You can also build the mass into your home using elements like thicker drywall, solid counter surfaces, ceramics, and a thicker base slab with radiant tubing. Some go so far as to have rubble filled or cob constructed walls. by building it into the home you can save floorspace and shrink the footprint.  All of the above listed elements will slow down how fast your home cools down in the winter and heats up in the summer.
cheers,  
David Baillie

Mike Bettis wrote:I am in the process of designing a new home with an architect.  He's not proficient in passive and low tech energy conservation but he's willing to work with me.

What do you want the fireplace to look like?

Do you want it to look like a traditional fireplace or is mass more important?

There are some traditional Russian, German, and Swedish stoves that sound like what you are describing.

There are some threads here on the forum if you are interested.

Paul just released a new video showing the temps of the inside air, outside air, rmh and pipe exiting house.  I like the demonstration how heating the mass contributes to heating the room.

A note about mass and efficiency: mass does not in itself make a particular combustion core more efficient; it does -allow- a more efficient fire by permitting a very intense fire releasing a lot of heat for a short time and saving the heat generated to distribute over the day while the fire is out and the draft sealed up.