How hot should a furnace exhaust pipe get?
This usually equates to a median pipe material temperature value of 86 to 100 degree F. When this temperature starts to exceed 130 degree F, it is usually an indication that there is a problem.
Can you vent a gas furnace into a chimney?
A review of the International Fuel Gas Code venting tables should be checked before venting into any chimney. Furnaces with an AFUE of 90% and greater use special venting material such as PVC or stainless steel. A 90% furnace should never dump flue gases into a chimney.
How hot does a furnace chimney get?
While this is a far cry from early furnaces that used to add 100 cubic feet of air, this introduction of air reduces efficiency of any mixture of dilution gases. More heat goes up the chimney at very high temperatures, in the range of 450° – 600°F.
What is the minimum size flue pipe that should be attached to a gas furnace?
Can a fireplace flue be too big?
When a flue is too big, the chimney can be too cold. Cold chimneys make keeping a fire lit more difficult. They also lead to condensation and possible mold inside the chimney brickwork. They key to making and keeping a great draft in your fireplace is making sure the proper sized flue is installed.
Can a flue be too big?
Flue pipe is too big for the furnace. Excessively large flues reduce the velocity of the combustion products, allowing them more time to dissipate heat through the pipe walls. Flues that were acceptable for natural-draft furnaces are often too large for the new, 80% induced-draft furnaces.
How do I know what size flue I need?
The ideal flue size is typically determined by the exhaust outlet of the stove or appliance. The rule of thumb for sizing a chimney liner is that you never want it to be smaller than the appliance exhaust hole and you don’t want the liner to be three times the area of the exhaust hole of the appliance.
Can you reduce flue size?
In no circumstance should you ever reduce the diameter of your flue system. The diameters quoted in the Building Regulations are minimum diameters only. If your stove outlet is greater than 6” then your flue system is going to be greater than 6”
How do I reduce the size of my fireplace opening?
Reduce the Opening Size – This can be achieved by laying an additional row of firebrick on the floor of the firebox. Before you start laying brick, you can test the solution by holding a piece of metal over part of the opening and watching to see if the draft improves.