Glenn Herbert wrote:The effective length is not at issue; it is a matter of the actual amount of duct surface that can transfer heat. As short as 20' will not extract all the heat, but putting a couple of half-barrel bells in place of some duct will give more area. It will not affect the footprint of the bench at all.
Peter van den Berg wrote:for each 90 degrees elbow deduct 4'
Dax Robbe-Grillet wrote:The integrated kotatsu decreases the thermal mass by about 25%.
Peter van den Berg wrote:From the top of my head: an 8" system could drive a horizontal duct of 40', for each 90 degrees elbow deduct 4'.
Glenn Herbert wrote:Reviewing earlier posts, I want to reiterate that making an 8" system with only 24' or so of duct will not likely give up anywhere near as much of the heat to the bench as you could.
Dale Walker wrote:Your comment about the SS flue liner attached to your existing firebox, made me start to think about using a flexible duct for the run through the mass.
Dale Walker wrote:Also curious what you were planning to use for a mechanism to raise and lower you table?
Glenn Herbert wrote:A basement location with a good chimney may have enough draft to overcome more duct length/drag.
Erik Weaver wrote:A thought with regard to living with this....
You show a table. Do you really want to have to crawl over the ducting/bench to get to the table? Seems inconvenient to me. Why not change the routing of the ducts to allow people to walk directly to the table?