An Efficient Fireplace!
Old unused fireplaces are now being restored at an alarming rate today, and it is very important that the restored chimneys and fireplaces work efficiently after. To work efficiently, wood burning fires must have an adequate air supply and a good chimney to remove bad gases, smoke and dust.
The wood for the fireplace should be stacked in a grate elevated from the floor or hearth for air to circulate beneath the burning wood allowing the spent ash to fall through with enough space to accumulate without choking off the fire.
The Flue or Chimney should be sized properly for adequate air supply for the fire to burn and exhaust the gases effectively. Way back in 1799, a man by the name of Rumford discovered and published some facts on the importance of proper flue sizing for fireplaces. He stated that the flue cross-section should be at least one tenth the size of the fireplace opening.
Now, due to modern technology, fireplaces are being made smaller with today’s fireplace manufacturers all agreeing to a smaller ratio of 1:7 with published specifications on accepted standards. Should your fire burn improperly or gives off too much smoke, you should assume immediately that the ventilation might be in-adequate.
Try to alleviate the condition by opening a window if the situation improves then, you have the proof. To correct this problem, install a single duct vent on the floor in front of the fireplace or twin vents into the floor or walls to the outside, one on each side of the chimney.
Burned wood or coal produces flammable gases, black sticky substances and acids, many of these substances flow up the chimney and stick to the inside wall. Some of these un-burned gases tars and acids form soot and builds up over time reducing the cross-sectional size of the chimney.
So, that is why it is so crucial to have your chimney cleaned at least once a year before the heating season or after, but always use a certified chimney sweep for this important job. Remember this, a chimney laden with soot is a dangerous fire hazard, un-burnt soot will ignite and burn, reaching very high temperatures and could very well burn your house down too.
If you suspect an inefficient fireplace, get a qualified technician to check for proper sizing of the flue, if it is found to be too large, there are recommended fixes to improve efficiency by refitting with a liner made from flex stainless steel, lightweight cement sections or ceramic. There are still other ways to reduce the flue size to acceptable level, but consult your fireplace expert before trying anything yourself.
