The effect of negative pressure on ventilation volume.
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Our installation’s heating furnace is equipped with two fans: one is a blower that is responsible for forced ventilation, and the other is an exhaust fan that helps create a negative pressure inside the furnace. The negative pressure within the furnace is controlled by flue dampers. Could you help me analyze whether the level of negative pressure in the furnace affects the volume of forced ventilation entering it?
There is definitely an impact; the negative pressure exhaust fan is the underlying factor. The greater the negative pressure inside the furnace, the higher the ventilation volume per unit time, and thus the forced ventilation load decreases. Conversely, the lower the negative pressure inside the furnace, the higher the ventilation volume per unit time, and the more blocked the system at its end, resulting in an increased forced ventilation load.
Remember that when the negative pressure in the furnace is high, the air volume supplied by the blower increases； If the negative pressure in the furnace is low, simply reduce the air volume of the blower and make the corresponding adjustments.
Generally, the blower controls the oxygen content, while the exhaust fan controls the negative pressure
Does the magnitude of the negative pressure inside the furnace affect the volume of forced ventilation supplied to it? The magnitude of the negative pressure inside the furnace merely reflects the pressure conditions within it; it affects the volume of forced ventilation but does not play a decisive role. The factors that determine the volume of forced ventilation are the power of the blower fan and the opening degree of the dampers.
The induced draft fans and blowers control the negative pressure inside the furnace; this is likely achieved through instrument-based interconnection. As long as the parameters are adjusted properly, it will work
There must be an impact; otherwise why would they ask you to control the negative pressure? If the negative pressure is too high, it’s difficult to maintain the proper oxygen level, and the burner can easily go out. If the negative pressure is too low and it turns to positive pressure, it can easily cause injury.
Negative pressure certainly has no effect on forced ventilation; no matter how negative pressure changes, the amount of air that enters the furnace through forced ventilation remains unchanged. On the other hand, forced ventilation does affect negative pressure； Generally, forced ventilation is used in combination with natural ventilation, which also makes it easier to control the furnace. What do you all think? ；
First, it is necessary to maintain negative pressure to prevent backfire in the furnace from causing injury. Second, the oxygen level must be controlled to ensure complete combustion of the fuel. By ensuring these two conditions, adjustments can be made gradually; energy savings are the goal
The impact is significant; excessive negative pressure can lead to engine stalling, and it also allows a large amount of air to enter the furnace； If ventilation is too excessive, it will also affect the negative pressure.
In any case, the negative pressure in the heating furnace is proportional to the air volume flow; excessive negative pressure leads to an excessive amount of ventilation； If the ventilation volume is too high, the negative pressure will also be high ； It is mainly controlled by blowers and exhaust fans.