Chimney Air Flow Rate

The structure which provides ventilation for hot flue gases or smoke from a boiler stove furnace or fireplace to the outside atmosphere causes a flow rate.

Chimney air flow rate.

Typical air flow rates in cfm vary depending on the type of cooling system. Stack effect or chimney effect is the movement of air into and out of buildings chimneys flue gas stacks or other containers resulting from air buoyancy buoyancy occurs due to a difference in indoor to outdoor air density resulting from temperature and moisture differences. The higher pressure outside the chimney is the driving force that moves the required combustion air. Combustion boiler house topics fuels like oil gas coal wood chimneys safety valves tanks combustion efficiency.

The height that structure e g. Measured across the cooling coil typical a c air flow is about 400 to 450 cfm per ton of cooling capacity. Boiler heat load and chimney area boiler capacity and chimney area. Includes 53 different calculations.

Air flow and velocity due to natural draft air flow volume and velocity due to stack or flue effect caused by indoor hot and outdoor cold temperature difference. Q 3 7 m s 3 14 0 2 m 2 4 0 12 m 3 s. In a natural draft chimney the maximum flow rate you can obtain is only due to the contribution of buoyancy which is given as q c x a x sqrt 2 x g x h x ti to ti where constant c is. Natural draft chart si and imperial units.

Equations displayed for easy reference. Flow of air in pipes equation and calculator. Air flow conversion calculator. Finally sometimes air actually blows down the chimney but less frequently than you d guess it s usually something else.

That these equations can be used for dry air not for mass flow and energy loss calculations where air humidity may have vast effects. The air flow can be calculated as. Hydraulic pneumatics fluids design and engineering data. Flow of air in pipes equation and calculator.

By multiplying air velocity by the cross section area of a duct you can determine the air volume flowing past a. Chimney influences its ability to transfer flue gases to the external environment via stack effect. Air flowing down your chimney. The greater the thermal difference and the height of the.

V velocity of air in feet per second ft sec p loss of pressure due to flow through the pipes in ounces per square inch ounces in 2. But maybe your chimney is short and next to a larger part of the house or a bigger building. 350 cfm per ton of cooling capacity is required for high latent heat hvac applications. Natural draft chart imperial and metric units pdf.

Air velocity is measurement of the rate of displacement of air or gas at a specific location. The result is either a positive or negative buoyancy force.