Bowers

Buckley Rumford Fireplaces
Bowers Rumford
(A smoky fireplace evaluation*)
1/9/04

Bowers' hinged doors:
top hinge, bottom hinge and doors partly closed
Recommendations
Even though I think the main reason the fireplace is temperamental is becasue the box is so tall, the fireback slants forward and the throat is partially blocked, my recommendations are organized with the most simple and least expensive first. There are many factors which effect the draft of any fireplace and maybe we can adjust or over compensate the easy ones and avoid fixing the expensive ones that may actually be the problem.

Evaluation
The Bowers 36" Rumford fireplace is temperamental. It tends to smoke unless the fire is built just right, the combustion air vent is closed and a door or window near the fireplace is cracked open. The fireplace differs from the dimensions recommended in several ways.

The firebox is taller - 48" tall instead of 36"
The fireback is deeper and wider and the fireback slants forward
The non standard Vestal damper partially blocks the masonry throat opening

In addition the chimney is barely tall enough to meet the code minimum and is not as tall as most of the roof of the house.
Finally, the house is well-built and tight with no apparent provision for make-up ventilation air. The outside air ducted into the firebox is inadequate at best to replace the air needed by the fireplace as well as other appliances. See discussion at "combustion air"

Report Submitted on 1/9/04 by
Jim Buckley
Buckley Rumford Co.
1035 Monroe Street
Port Townsend, WA 98368
360 385 9974 (fax 360 385 1624)
http://www.rumford.com So, in order of easiest and least expensive:

Add two or three feet to the height of the chimney. This might be accomplished either by building the chimney taller or by adding a clay chimney pot, but try it first by setting a flue tile or two on top of the chimney to see how it works. Adding to the height of the chimney gets it above the top of the roof and away from turbulence and may be all that is required.
Stop after each "improvement" and see if the fireplace works well enough and you can manage it. Build tall tipi style fires with fairly long logs to raise the height of the fire and take advantage of that tall opening as well as get the heat up closer to the throat and the smoke pointed in the right direction.
Add adequate whole house make-up outside ventilation air. The fireplace alone will need about 500 cfm which is way more than can be expected through the combustion air system in the firebox. See "Balancing the Ventilation System".
Remove the damper that partially blocks the throat and replace with a chimney-top damper that won't be restrictive and that will trap warm air, rather than cold air, in the chimney making the fireplace easier to start.
Either rebuild the firebox to specifications or reduce the effective height of the opening by building up the inner hearth so that the fireplace is about 36" tall, one foot off the floor. The inner hearth can be raised with block and firebrick, recessed slightly and blacked out or covered with a grille so that the fireplace still visually "reads" 48" tall and the surround need not be replaced.