In his thesis on the principles of fireplace design released in1799, Count Rumford highlighted the significance of the size of the flue as compared with the size of the fireplace opening. He recommended that the cross-sectional area of the flue ought to be about a tenth of the size of the opening. However, fireplaces tended to be smaller after the mid 19th century. Modern flue liner producers favor a ratio of one to seven, and there are sizing charts published that offer information on existing standards.
If your fire smokes or wont burn properly, see if opening a window improves matters. If it does, you require much better ventilation in the room. One option is to set up a window vent, although this may cause a problematic cross draft. A much more efficient kind of ventilation is either a single ducted vent set into the floor in front of the fireplace, or twin ducted vents set into the floor or external walls on each side of the chimney breast.
When wood and coal are burned, flammable gases, tarry substances, acids and dust are given off. However, since domestic stoves are fairly inefficient, not all of these substances are consumed. Rather, they rise up the chimney and some of them condense on the inside of the flue. Unburned carbon combines with these tars and acids, creating soot, which builds up over a period of time, therefore decreasing the size of the flue. It is important to have regularly used chimney sweeps at least twice a year, ideally before, during, and at the end of the heating season. The local trade directory sites contain information on fully qualified and appropriately insured sweeps. A soot loaded flue is a fire hazard, since the unburned elements of the soot can fire up, causing a chimney fire which can reach high temperature levels and damage the chimney Heating And Cooling Akron .
If a flue is too large, its size can be decreased to improve its effectiveness by the fitting of a liner. A range of methods and materials are made use of, including flue liners made of flexible stainless steel, ceramic, light-weight concrete sections, or concrete that has been cast. Other methods of decreasing the size of the fireplace opening in order to improve fire efficiency, is to raise the level of the hearth or to fit a baffle across the top of the opening. If raising the hearth level or including a baffle is not useful or is unsightly, then it may be worth asking a fireplace professional whether fitting a metal smoke hood or canopy in the opening is the best option.
