🔍 Key Concepts

• complete combustion in oil-fired boilers • effect of air supply vs. fuel supply on smoke color and combustion quality • relationship between fuel temperature/viscosity and atomization at the burner

💭 Think About

• What does black smoke generally tell you about the fuel-to-air ratio in the furnace? Is there too much fuel or too much air? • If the boiler is panting (irregular firing and draft), which action would help stabilize combustion: changing fuel characteristics, reducing fuel quantity, or improving air/draft? • How does changing fuel oil temperature affect atomization and does that usually reduce or increase smoke if air remains the same?

✅ Before You Answer

• Black smoke usually indicates incomplete combustion due to insufficient air or poor atomization—keep that in mind when comparing the options. • Ask whether each option would increase or decrease the fuel-to-air ratio in the furnace. • Verify which action most directly improves combustion and reduces black smoke without making panting worse.