Mann

Buckley Rumford Fireplaces
Posts Standing: Gambier Island, BC
11/19/10

Henry Yorke Mann Architect
S-1, C-26, RR#3
Oliver BC V0H 1T0
250 498 4766, fax 250 498 0101
http://www.henryyorkemann.com
info@henryyorkemann.com
Hi Jeannie,
Thank you for your information the other day.
Re. Rumford fireplaces we have built, I have attached the granite fireplace from the small cabin we call "Totems", and a small fireplace we installed into a 8"x8" flue, we sized this fireplace by downsizing the dimensions (proportionately) for opening and throat etc.to fit and work properly with the 8"x8" flue. It works well.
Our current plan (on the Allard Residence) that I discussed with you is to use the existing 10" dia. flue - two story plus attic Height and to use the 36"x 32" Rumford.
Regards
Henry

Henry,
Firstly let me thank you for the great pictures. Both Rumfords (and the rooms they are in) are elegant.
Jeannie asked me to address your "plan (on the Allard Residence) that I discussed with you is to use the existing 10" dia. flue (two story plus attic Height and to use the 36"x 32" Rumford."
1) As we discussed, you know that round flues have to have a cross-sectional area at least one twelfth of the area of the fireplace opening. A 36" wide by 32" tall fireplace has an area of 1,152 sq.in. and needs a round flue with an area of at least 96 sq.in. to meet code. A ten inch diameter flue has an area of only 78.5 sq.in. so would not meet code. But a ten inch flue is at least one fifteenth of the fireplace opening area and the chimney is tall so I am confident that it can work if the workmanship is good and the ventilation system is balanced so that the indoor air pressure is not too negative.

2) More importantly, you need to be sure what kind of metal chimney it is. To vent a wood-fired stove or Rumford fireplace it has to be a double wall insulated "Class A" or "All Fuel" chimney tested to UL 103. If it was used originally to vent a zero clearance metal fireplace, it probably is an air cooled chimney tested only for that particular fireplace to UL 127 and would be unsafe to use for any other fireplace or stove.
If you have to replace the chimney, send me plans and maybe I can help.
Best,
Jim Buckley