What is the usual effect of insufficient forced draft in a furnace?

Insufficient forced draft in a furnace primarily leads to incomplete combustion. This occurs because forced draft fans provide the necessary airflow to mix with the fuel for combustion to happen efficiently. Without adequate airflow, the fuel does not fully ignite, resulting in unburned fuel particles escaping. This not only reduces the overall efficiency of the combustion process but also contributes to the production of carbon monoxide and other harmful byproducts, which can increase emissions and diminish fuel efficiency.

Incomplete combustion can also lead to the formation of soot and deposits within the furnace system, creating additional operational challenges. Therefore, ensuring proper forced draft is crucial for maintaining optimal combustion and achieving desired operational performance in a furnace system.