Our Rumfords are designed to have square openings - as tall as they are wide. Build the opening taller and the fireplace is apt to be temperamental, but the lower you build it the better it draws - at a slight expense in efficiency and emissions. In other words they take too much heated room air to carry away the smoke instead of just enough.
In some situations, such as for outdoor fireplaces or big fireplaces or when the customer is just careless about fire-building, we recommend building the fireplace opening a little lower. Six inches lower and it will be "bullet proof". A foot lower and it may suck small children off the floor - well, if the small children are smoking cigarettes it will at least suck the smoke up the chimney from several feet out.
from: Julia Lane
date: Tue, Feb 16, 2010
subject: Lower Fireplace Opening
We have a Rumford 42" 1 piece throat unit we are currently installing in a new home construction. The E dimension calls for the height of the throat to be set at 38 to 42" high above the hearth. We are concerned that the fireplace, from our perspective, seems to be out of proportion in the height of the face. Would it adversely affect how the fireplace functions if the E dimension (height of the throat ) was reduced to approximately 32"?
Please feel free to contact us at this email, or our office email at: firstname.lastname@example.org. We would appreciate a rapid response, in that we are going to stop construction awaiting your reply.
Office Phone: 325/223-8441
Rumford fireplaces, typical of 18th century fireplaces, are usually as tall as they are wide and ours are "tuned" to be square. Make the opening taller and it'll be temperamental and apt to smoke but make the opening lower and it will draw better.
[Back to Technical Discussion]
Rumford Fireplace Home Page
Copyright 1996 - 2010 Jim Buckley
All rights reserved.