Understanding and Controlling Air Vents on Your Wood Burning Stove
The Air Vents
- Air Wash – The air wash feature involves drawing air over the glass window inside the stove, which helps keep the glass relatively clean. By constantly circulating air over the window, the buildup of ash and tar is reduced, though some accumulation may still occur over time. This air supply is typically from the secondary air vents, situated above the ceramic glass window.
- Primary Air – This air supply comes from the bottom of the firebox and is particularly useful when burning coal.
- Pre-Heated Secondary Air – When burning wood, it is essential to maintain a high firebox temperature to release the flammable gases from the wood effectively. The secondary air supply preheats the air before it enters the firebox, preventing a sudden drop in temperature caused by cold air. This preheated air is directed through channels near the firebox, ensuring the fire stays well-fed with oxygen.
- Tertiary Air – Many stoves also feature a tertiary air supply, primarily located at the back of the firebox. This supply aids in burning off the gases released by the fuel, resulting in increased efficiency and a cleaner burn. It can often be observed as a swirling vortex of fire.
Controlling Air Vents
When you begin lighting your stove, it’s crucial to have all air controls open. This provides the best chance for your fire to take hold, and some people even keep the door slightly ajar during the initial lighting process. Additionally, ensure that the ash pan isn’t too full, as excess ash can restrict the air supply.
Once the fire has established itself, you can adjust the air vents according to the type of fuel you are burning:
1. Wood Burning: When burning wood, you can close the bottom (primary) air supply entirely, as wood fires primarily require oxygen from above the fire.
2. Coal Burning: On the other hand, when burning coal, you should control the fire using the primary air vents, as coal fires predominantly draw oxygen from below the fire.