From: Jim Buckley
Subjects: Architectural Graphic Standards on Rumford fireplaces
The attached pdf was sent to us by one of our architect customers. Frankly, the piece concerns us because it miss-represents the traditional Rumford and promotes a particular proprietary modern variation of a Rumford - a Moberg Rumford - without identification.
We would urge you to do the research and re-write the piece.
For the traditional Rumford you should at least be aware of Rumford's original essays which we have on line at http://www.rumford.com/chimneyfireplacesa.html and which have been reprinted a number of times and are available at good academic libraries. A quick glance at Rumford's illustrations at http://www.rumford.com/chimneyfireplacesp.html will confirm that what you show as a traditional Rumford misses the mark. What you show is an erroneous version promoted by Vrest Orton in 1969. See http://www.rumford.com/articleOrton.html
As for modern versions of Rumford fireplaces, I would hope that you would not just promote one proprietary and modified version. If you feel that you must cite modern Rumfords, you should identify them and depict several including ours at http://www.rumford.com/components.html and some of the variations linked from http://www.rumford.com/tech12.html
We are interested in historic and design accuracy. We maintain the most complete and accurate website on Rumford fireplaces and are forced to point out that the AGS piece is inaccurate. We would rather that you get it right and we can support and promote AGS.
In addition we don't mind if you feature proprietary designs, even those of our competitors, but we think you should identify them and include other proprietary designs so you are not suspected of favoritism.
If you want some help let me know. Please also let me know if and when you plan to re-write the part about Rumford fireplaces so I will know what to put on our website about AGS.
from: Eric Mustard
date: Tue, Sep 21, 2010
subject: sloped back
The Rumford fireplace drawings in Architectural Graphic Standards show a sloped back wall and your drawing shows a plumb back wall.
I would think the sloped back would put more heat into the room, similar to the angled sides. Do you feel the plumb back is preferable? If so, why?
What I "feel" I'll tell you later but I can say with certainty that the sloped back version is an adaptation and not what Rumford prescribed. See Rumford's essays published originally in 1796 and especially the plates.
Some fireplaces built in America 100 years ago did have sloping firebacks - or appeared to have. Maybe the backs sloped in order to bridge the top of a firebox because the rounded throat was not understood and neglected or the firebox was too deep. Or maybe the backs of some of these old fireplaces just appeared to be sloped because they had been worn away and patched so often.
Then in 1969 Vrest Orton wrote a little book entitled "The Forgotten Art of Building a Good Fireplace" which, among other errors, repeated the sloped fireback error. The fireplace he described in his Vermont home, he said was a Rumford but it had a sloping fireback and no rounded airfoil throat. Without skipping a beat Orton just ignored Rumford and went on to describe his variation, repeating a few more errors along the way, such as the air flowing down the back of the chimney. See our "book report" on Orton's book. Orton, the founder of the Vermont County Store sold a lot of copies of his book at a time when Rumford's essays were out of print and only available through a couple of academic libraries.
Architectural Graphic Standards a few years ago used Orton's incorrect book as its main source. I wrote to the AIA but they said the work had been contracted out and there was nothing they could do about it's accuracy. The most recent "American Graphic Standards" - is that the same organization? - features a proprietary Rumford variation, the Moberg Modern Rumford, which is mostly metal with an European made throat without mentioning the company by name and passing it off as generic. See http://www.rumford.com/graphicstandards.html Again I wrote to them and they didn't respond.
Okay, the plumb fireback is historically correct and what Rumford recommended, reiterated and emphasized. But you ask if I "feel the plumb back is preferable".
No one has bothered to build a sloped back open faced Rumford in a test lab and test it objectively for emissions and efficiency so my views are necessarily somewhat conjectural. Moberg did test his "Modern Rumford" variation for emissions but the results are proprietary and I think he only tested it with closed doors and only tested emissions - not efficiency. We tested our Superior Clay Rumford in the same lab with and without doors and attempted to also test for efficiency but with marginal success since the lab did not normally test for efficiency and the whole radiant efficiency vs. flue gas loss method was inconclusive. See http://www.rumford.com/tech9.html
If you slope the fireback maybe it does get hotter, but you also kick the smoke forward and the fireplace is more likely to smoke, especially if you also neglect to round the breast. To keep it from smoking you have to open up the throat to let more dilution air in to carry away the smoke or you lower the fireplace opening. Both strategies would limit the length of time the plume of smoke rising up the fireback is hot and burning with the result that the fireplace will be less clean-burning and less efficient. See the comparative diagrams and, for this discussion, I would say the sloped-back Orton is only a taller more temperamental version of the "modern fireplace" on the right. Moberg's and the American Graphic Standards' version, with a sloped back and a rounded throat, but with a bigger throat opening, is in between. So I think the original Rumford with a straight back and rounded breast is the standard and probably the most efficient and cleanest-burning solid fueled radiant heater ever developed. It's up to the innovators and pretenders to back up their claims if they think otherwise.
Thanks for asking.
Buckley Rumford Fireplaces
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