In most cases a step up is also fine.
Gas fireplace flue size.
In general your should use the same size chimney diameter as the flue collar on your stove i e.
The way wood stoves and fireplaces work a correct match on fitting the flue size to the appliance is a must.
8 1 2 x 8 1 2.
Venting a wood stove.
In most cases you can also step up a size or two for instance a 6 stove could vent into an 8 insulated chimney.
As a general rule of thumb the area of a.
A 6 inch stove requires a 6 inch flue.
A flue that is too small won t allow the fireplace gases to exhaust properly and a flue that is too large will be cool down too quickly causing condensation and creosote buildup within the flue.
Improper flue sizes are a leading cause of poorly drafting fires.
To provide adequate draft and safe venting of combustion products the chimney flue for a fireplace has to be adequate in size or cross sectional area.
Stoves fireplaces central heaters.
The size and input btuh of each of the appliances being vented the size of the flue vent connector on each of those appliances this will be the bare minimum and is typically the size of the vertical flue vent connector between the appliance.
How to determine proper flue size.
This article series provides information about masonry fireplaces.
A 6 stove should use a 6 chimney or a 7 1 2 x 7 1 2 flue tile.
Outside diameter inches inside area square inches 7 1 2 x 7 1 2.
Fireplace flue size specifications relation of fireplace size to flue opening dimensions table of required chimney flue size and flue dimensions for masonry fireplaces.
Flue size common venting uses.