What is an Air Curtain Incinerator?
An Air Curtain Incinerator (ACI) is a device that burns woody biomass, like trees and brush. It has an insulated box to contain the biomass and a fan powered by a diesel engine that blows a curtain of air over the fire.
Oregon uses ACIs for fuels reduction projects, wildfire cleanup, to slow the spread of forest pests and disease, and to manage nursery, orchard, and winery cuttings. ACIs are a cost-effective alternative to traditional open burning and produce less smoke and particulate matter.
How does an ACI work?
Woody biomass is loaded into the firebox and the fire is lit. Once the fire is strong enough the blower motor is started and air is blown over the top of the fire. As the curtain of air passes over the top of the fire it catches smoke and particulate matter which are circulated back into the fire to burn again. As the plant material is burned down to ash and char more material can be added. The ash and char created are known as biochar, a valuable soil amendment.
There are many types of ACI units. Some are small enough to be towed behind a ¾ ton truck, others are large and are delivered on a flatbed. Units can be equipped to produce higher quantitates of biochar or captured heat energy and convert it into electricity.
Fall 2026 Demonstration Schedule
The goal of these demonstrations is to raise awareness of ACIs as a tool to reduce pollution, reduce fuel loads, utilize woody biomass, and create biochar, a valuable soil amendment that adds carbon to soil or compost and holds moisture, nutrients, microbes, and can even lock away harmful pollutants and other chemicals.
ACI demonstrations are for fire departments, municipalities, natural area land managers, Firewise communities, prescribed burn associations, nurseries, orchards, vineyards, arborists and tree care companies, citizens and land owners, and any anyone that has to manage woody biomass looking for alternative to chipping or pile burning.
During these demonstrations attendees will learn about and discuss:
What is and ACI and how do they work
What types of ACIs are available on the market
What types of materials can be burned in an ACI
Locations and types of projects ACIs are appropriate for
Safety considerations when operating an ACI
Permits, licenses, and notifications for proper ACI operation
When to hire a contractor vs purchase equipment
What is biochar, how is it created, and how can it be used
Smoke and air pollution reduction vs open burn or pile burn
Click on the links below for ACI demonstration event details and to register to attend.
Port Orford - Friday, November 13th
Talent - Tuesday, November 17th
Grants Pass - Thursday, November 19th