I had no idea that the "modern" fireplace had a "throat" design that is truly terrible!
Rumford
So what happened?
I have videos of my slanted back Rumford with the damper adjusted to 1-3/4" with no smoke.
It radiates more heat than the straight version and has room for a nice fire made with logs laid horizontally.We have just reduced the setting to 1-3/4'' and burned it for 30 hrs and not a trace of smoke.
This is just 79 sq.inches and 1/30th the FP opening of 50'' by 48''.
We are preparing a detailed video as there is no straight back Rumford we know of with this ratio.This is lean as they get.
This slant back Rumford fireplace has been burned avidly for 18 years and the face has never discolored due to smoke escaping. There is no better proof of proper function!
Being able to close the damper down from the normal 4-1/2'' to 5'' used on straight backs, negates the often used statement,"the longer throats of slanted versions let more heat out the chimney".
If a slanted rumford is constructed properly it cascades flames and heat towards the room and frugally exits the smoke through the long and narrow throat, which is located a mere 4 to 8 inches behind the face, heating the face right up practically to the ceiling.
The damper is self fabricated in the early 70's when I first read Vrest Orton's book, The Forgotten Art of Building a Good Fireplace. It is a shame Orton is being disrespected by those whom advocate the straight backs calling them "the true Rumford", and use misleading jargon like, "slanted backs have longer throats.. up to 1/3 larger which waste heat'', '' they can't have tipi fires which makes them prone to smoke, because the horizontal logs emit smoke out the ends then get cast forward and into the turbulence, then out into the room!" They choose to write history's closure to what Rumford was trying to accomplish in his attempt to slant fireboxes, just because he never did elucidate on his findings.They privilege themselves in saying he hired a potter to build a special throat / breast, but failed, then blow smoke at themselves for accomplishing this throat 200 years later, but in reality he never needed "back then" what they ''now make", If these people had any success in building smokeless Orton Slanted Fireplaces they would have the knowledge to realize it wasn't the throat / breast of Rumford's experimental slanted box-s that needed special skills, nor Harry D Potter and his magic!
Hats Off To Orton!
Francis Casini
In a footnote he said that particular fireplace seemed to be an especially good heater and he wasn't sure why. Perhaps it was the additional radiation off the slanted back wall. He never came back to the subject and there is no evidence that he ever built any other fireplaces with slanted firebacks. Yet this footnote was tantalizing, and many people took this exception to be the rule - the best of Rumford - usually getting the geometry of the slant wrong, as Orton does, and neglecting to round the breast.http://www.rumford.com/articleOrton.html
So Casini has been in "discussion" with the author of that website - that considers the Slanted Rumford to be just an anomaly.
I have seen many fireplaces said to be Rumfords which had slanted backs. While it's a common variation, it's not a Rumford.So that author considers the Slanted Rumford to be more prone to smoke but Casini proves otherwise!
I am interested in the orton fireplace but it seems the info is lacking unless you want to read buckley bashing it.Someone comments on youtube to Casini - now consider the Rumford figured how the secret of open fireplaces but this Slanted Rumford design is still being "bashed"!!
Strangely, most people today have never heard of Count Rumford, even though most fireplaces built between 1796 and 1850 are Rumford fireplaces. The mystery is that after the 1850’s, Rumford fireplaces were not built as often and by the 1900’s, most masons had forgotten or never learned how to build a proper fireplace anymore!
Sadly, the modern fireplace is a poor substitute for the simple effectiveness of a Rumford fireplace. How did we step backward in our knowledge of fireplace design so much? The answer may surprise you.
https://thecraftsmanblog.com/what-is-a-rumford-fireplace/
https://newengland.com/yankee-magazine/living/homes/fireplaces-best-rumfords/
Remember, this is still a fireplace and is not going to be very efficient at all.So that is the "Permies" view about fireplaces but obviously the Permies do not know about the Slanted Rumford!! Casini:
the slant into whole new category regarding efficient open burning fireplaces.
Jim Buckley himself now is a throat choke advocate!So apparently Casini has now convinced Buckley that the Slanted Rumford with the newly designed Casini damper is the real secret to efficient open fire places!!
Our latest accomplishment was proving throat size limits air flow lost up the chimney. Weve already attained small throat sizes up to a 1to 60 ratio in slanted Rumford's also called Ortons. This test model shows a 12-1/2" deep 36" straight back Rumford burning at a 1 to 41 throat ratio without needing our tweeking.http://www.rumford.com/tech12.html
However the deeper straightbacks cannot attain such small throats. The good news is that they do respond instantly when we apply our tech to them for a nearly 70% reduced throat area and equally less flow lost up the chimney. This very much will improve the epa testing that Straight Back Rumfords have previously tested to on behalf of Jim Buckley.
We now have both style Rumfords performing at very frugal rates formerly unheard-of. This applies to all fireplace styles, even those non Rumfords some call conventional fireplaces. i e. shorter.
It has paid off to delay our patent application to do this latest testing so as to certify that deeper straights can now burn like our slants, attaining efficiencies that have never been seen anywhere. We also certified with petot flow testers that the flow is absolutely in cadence with throat choking.
This is a video of the only Straight Back * depth size that will burn with such small throats "like our slanted styled fireplace" without our help, and its noteworthy that its only 12-1/2" deep.
So Casini notes in 2013:
On a foggy drizzly night with no air current, the perfect test for any fireplace, my 50'' Rumford Orton Fireplace uses my damper [first fabricated in West Port, CT in the early 70's] which helps to enable choking the 3-3/4'' throat to 1-3/4'' equaling a 1 to 30 throat area to fireplace opening area ratio! This means the area of the slant's throat actually can be far less [60%] than that of it's straight back cousin with it's shorter deeper "non-adjustable" damper which was up until now at the helm. The fixed throat Rumford design of 200 years ago was for the shorter rear positioned throats of Count Rumford's straight back fireplaces. A never talked about fact regarding a full length throat is that Counr Rumford'ssingle best heating fireplace was a little bedroom half slanted fireplace that used it's existing throat .This throat was a mere 4'' behind the brick face, hence ''full length". The Orton Slanted Rumford which evolved later due to the increased heat radiated off the rear wall, has been wrongly used by many whom assume that the fixed throat rule apply's to them also. This fixed throat rule was even suggested by Vrest Orton, the author of the book "The Forgotten Art of Building a Good Fireplace'' written some 45 years ago, and is still common practice in all slanted fireplaces as well as in straight back Rumfords .
It should be realized the 4'' deep throat was never ment to be placed upon a slanted firebox which has a full length throat. To do so and leave it unchoked has only resulted in years of turbulence and high heat loss lending to the demise of the slanted firebox, i.e.both Rumford and conventional styles. Human nature's ''dare not choke a leaky fireplace'' perhaps has had much the blame in no one studying the smoke currents while pushing the slanted firebox and the longer throat to it's limits which very well can lead to an overchoke, meaning going past the highest velocity and volume and still avoid leakage. This is now proven almost nightly in my Modified Orton and hopefully soon in many more fireplaces whom currently burn wide open throats via mass air volume and excessive heat loss! Seems like there's a fix to the fixed throat after all and it's not just hot air! I have noted a 5 degree drop in temperature in 1 hr going from my 1-3/4'' highly choked throat to it's 3-3/4'' fully open setting.So Casini was able to "reverse-engineer" the Slanted Rumford despite the wrong assumptions of previous research. Casini from 2014:
The prototype has been working beyond expectations for a few months, [now nearly 3 years].This 50'' Orton Rumford is pure bliss and has everyone in disbelief. With the throat at just 1-3/4'' and a 1:30 ratio it surely leads keeping warm house air from be sucked up the chimney. Such a fine example of utilizing the slanted wall to change some of the would be totally lost combined heat into radiant heat. This he made clear in the footnote of his fireplace essaySo someone writes up a Rumford article only to realize they don't REALLY understand Rumford!
I’ve been fooling with novel dampers for slants for 30 years and developed a reverse tilt lintel damper for the Orton Slanted Rumford which is very enabling.Frank Casini
It is public free to make by anyone and has been by engineers whom along with invented enabling technology burn their Ortons to throat /opening. Ratios as high as 1/55 in 36” boxes and 1/40 in larger 48” Boxes.
As you know the standard throat ratio for The True Rumford StraightBack by Superior Clay and Jim are 1:20 which is best case scenario in many situations.
It is common here in my CT. home to have my 50” Orton burning all winter ( weeks straight day and night) with a throat at 1/40 th the fireplace through
Just a1-1/4” x 47” long throat opening!
This past winter was a 7 cord season which heats my 3400 sf home while in the 20’s where as before with a 4” throat (all others out there do)
It literally froze the home all but if you stood in front of it, just as witnessed by many have complained about!
The difference is immense turning the open fireplace into near masonry heater thermal mass but with an radiant heat advantage!
The fuel consumption is also cut far back and in lockstep to the flow reduction.
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