Define furnace draft control

Question

Describe briefly the term furnace draft control?

Answer 1

Balanced draft boilers are commonly employed negative furnace pressure. When both forced induced draft and draft are employed together, at some point in the system the pressure will be similar as that of atmosphere. Thus the furnace pressure should be negative to prevent hot gas outflow. Excessive vacuum in the furnace however generates heat losses through air infiltration. The most desirable situation is that the one have a very minor negative pressure of the top of furnace.