Air Curtain Incinerator FAQ — 93 Questions, Answered

An air curtain incinerator (ACI) is a high-capacity combustion system designed to process permitted wood and vegetative debris. A powerful blower directs a controlled sheet of air across a firebox or trench, improving combustion and helping keep smoke and embers within the burn area. ACIs are commonly used for land clearing, forestry, storm cleanup, and wood-waste management.

An engine- or motor-driven blower forces air through a manifold along the chamber, creating a high-velocity air curtain over the fire. Wood is loaded into the chamber and burns under the directed airflow. Correct startup, fuel loading, and maintenance are essential to achieve efficient combustion and control visible emissions.

The primary reason I recommend burning over grinding is the significant difference in volume reduction and disposal costs. Grinding an entire tree typically reduces its original volume by approximately 50%, leaving a substantial amount of material that may still need to be transported and disposed of. In contrast, burning can reduce wood debris volume by approximately 95% to 98%, leaving very little residual material. The financial difference is equally significant. Hauling and disposing of a 20-cubic-yard dump truck load of debris can cost approximately $500 to $1,000. Using an air curtain incinerator, that same volume of material can be burned for an estimated $20 to $25 in direct operating costs. The result is a potential savings of $475 to $980 per 20-cubic-yard load, while nearly eliminating the need to haul debris off-site. An ACI can dramatically reduce the volume of eligible wood debris at or near the project site, reducing the number of loads that must be transported and disposed of. Unlike grinding or chipping, the objective is destruction rather than creating a reusable product. The best choice depends on permits, debris quality, haul distance, tipping fees, reusable wood value, and site conditions.

Below you will find a description of how to save money and some formulas you can use to calculate the answer for your situation. Savings depend on avoided trucking, disposal or processing costs minus machine rental, delivery, fuel, labor, support equipment, permits, and ash management. For high-volume projects with long hauls or expensive tipping fees, the difference can be substantial. Burn Debris can create a project-specific comparison instead of relying on a generic savings percentage. Burning wood debris on-site with an Air Curtain Incinerator (ACI) can produce substantial savings compared to hauling and landfill disposal. For example, a project containing 20,000 cubic yards of wood debris would require 1,000 dump truck loads at 20 cubic yards per load (20,000 ÷ 20 = 1,000). Assuming each load weighs 6 tons and landfill tipping fees average $45 per ton, disposal would cost $270 per load (6 × $45), totaling $270,000 (1,000 × $270). At an estimated trucking rate of $140 per hour and a two-hour round trip, transportation would add $280 per load (2 × $140), or $280,000 for the project, bringing the total hauling and disposal cost to $550,000, or $27.50 per cubic yard. Alternatively, an ACI processing an average of 62.5 cubic yards per hour, within a typical operating range of 50–75 cubic yards per hour, could process the same material in approximately 320 operating hours (20,000 ÷ 62.5). Estimated burning expenses include $14,000 for two 28-day rental periods (2 × $7,000), $6,240 for diesel (320 hours × 3 gallons × $6.50), $11,200 for operator labor (320 × $35), $4,000 for delivery and pickup, $1,000 for permits, and $3,000 for ash management. These expenses total $39,440, or $1.97 per cubic yard ($39,440 ÷ 20,000), excluding support equipment. Comparing the two methods, on-site burning would save approximately $510,560 ($550,000 − $39,440), representing a 92.8% reduction in estimated disposal costs. Burning can also reduce the original wood debris volume by approximately 95%–98%, greatly minimizing the amount of material remaining for disposal. Actual savings depend on local hauling rates, disposal fees, material characteristics, equipment productivity, and operating conditions. Burn Debris can prepare a project-specific estimate to help customers determine their potential savings. Core Savings Formula: Total Savings = Traditional Hauling & Landfill Cost - On-Site Burning Cost Traditional Hauling & Disposal Cost: • Total Loads = Total Wood Volume (cu yds) ÷ Truck Capacity (cu yds) • Tipping Cost = Total Loads × (Tons per Load × Landfill Fee per Ton) • Trucking Cost = Total Loads × (Round-Trip Hours × Truck Hourly Rate) • Total Haul Cost = Tipping Cost + Trucking Cost On-Site Burning Cost: • Operating Hours = Total Wood Volume (cu yds) ÷ Burn Rate (cu yds per hour) • Fuel Cost = Operating Hours × Gallons per Hour × Fuel Price per Gallon • Labor Cost = Operating Hours × Operator Hourly Wage • Fixed Costs = Machine Rental + Delivery/Pickup + Permits + Ash Management + Support Equipment • Total Burn Cost = Fuel Cost + Labor Cost + Fixed Costs Per-Unit Savings: • Savings per Cubic Yard = (Total Haul Cost ÷ Total Wood Volume) - (Total Burn Cost ÷ Total Wood Volume)

Throughput varies widely with machine model, moisture, wood size, loading method, and operator practices. As a planning example—not a guarantee—an S327 firebox is a 63 cubic yard capacity. If you did a project burning mixed wood waste limbs, trunks and stumps that material typically burns at 75 cubic yards per operating hour would process roughly 750 cubic yards in 10 active hours, or 3,750 cubic yards over five such days. Larger machines can process considerably more under favorable conditions; ask Burn Debris for a model-specific estimate. Air Burners manufactures three primary sizes of stationary and skid-steered FireBox units: the **100 Series** (e.g., S116 / S119), the **200 Series** (e.g., S220 / S223), and the **300 Series** (e.g., S327 / S330). --- ### Baseline Assumptions & Conversion Rates * **Conversion factor:** $1\text{ ton} = 7.14\text{ cubic yards}$ * **Operating schedule:** * **Day:** 8 operating hours * **Week:** 5 operating days (40 hours) * **Month:** 4 weeks / 20 operating days (160 hours) --- ### 1. Air Burners S100 Series (S-119 / S-116) * **Manufacturer Throughput:** **3–5 tons/hour** (Midpoint average: **4 tons/hour**) | Period | Runtime | Tons Processed | Volume Processed ($7.14\text{ yd}^3/\text{ton}$) | | --- | --- | --- | --- | | **Hour** | 1 hr | 3 – 5 tons *(avg. 4)* | **21.4 – 35.7 yd³** *(avg. 28.6 yd³)* | | **Day** | 8 hrs | 24 – 40 tons *(avg. 32)* | **171.4 – 285.6 yd³** *(avg. 228.5 yd³)* | | **Week** | 40 hrs | 120 – 200 tons *(avg. 160)* | **856.8 – 1,428.0 yd³** *(avg. 1,142.4 yd³)* | | **Month** | 160 hrs | 480 – 800 tons *(avg. 640)* | **3,427.2 – 5,712.0 yd³** *(avg. 4,569.6 yd³)* | --- ### 2. Air Burners S200 Series (S-220 / S-223) * **Manufacturer Throughput:** **5–7 tons/hour** (Midpoint average: **6 tons/hour**) | Period | Runtime | Tons Processed | Volume Processed ($7.14\text{ yd}^3/\text{ton}$) | **Hour** | 1 hr | 5 – 7 tons *(avg. 6)* | **35.7 – 50.0 yd³** *(avg. 42.8 yd³)* | | **Day** | 8 hrs | 40 – 56 tons *(avg. 48)* | **285.6 – 399.8 yd³** *(avg. 342.7 yd³)* | | **Week** | 40 hrs | 200 – 280 tons *(avg. 240)* | **1,428.0 – 1,999.2 yd³** *(avg. 1,713.6 yd³)* | | **Month** | 160 hrs | 800 – 1,120 tons *(avg. 960)* | **5,712.0 – 7,996.8 yd³** *(avg. 6,854.4 yd³)* | --- ### 3. Air Burners S300 Series (S-327 / S-330) * **Manufacturer Throughput:** **9–13 tons/hour** (Midpoint average: **11 tons/hour**) | Period | Runtime | Tons Processed | Volume Processed ($7.14\text{ yd}^3/\text{ton}$) | | --- | --- | --- | --- | | **Hour** | 1 hr | 9 – 13 tons *(avg. 11)* | **64.3 – 92.8 yd³** *(avg. 78.5 yd³)* | | **Day** | 8 hrs | 72 – 104 tons *(avg. 88)* | **514.1 – 742.6 yd³** *(avg. 628.3 yd³)* | | **Week** | 40 hrs | 360 – 520 tons *(avg. 440)* | **2,570.4 – 3,712.8 yd³** *(avg. 3,141.6 yd³)* | | **Month** | 160 hrs | 1,440 – 2,080 tons *(avg. 1,760)* | **10,281.6 – 14,851.2 yd³** *(avg. 12,566.4 yd³)* | --- ### Side-by-Side Average Processing Comparison | Machine Size | Hourly Avg | Daily Avg (8 hrs) | Weekly Avg (40 hrs) | Monthly Avg (160 hrs) | | --- | --- | --- | --- | --- | | **S100 Series** | 28.6 yd³ (4 t) | 228.5 yd³ (32 t) | 1,142.4 yd³ (160 t) | 4,569.6 yd³ (640 t) | | **S200 Series** | 42.8 yd³ (6 t) | 342.7 yd³ (48 t) | 1,713.6 yd³ (240 t) | 6,854.4 yd³ (960 t) | | **S300 Series** | 78.5 yd³ (11 t) | 628.3 yd³ (88 t) | 3,141.6 yd³ (440 t) | 12,566.4 yd³ (1,760 t) |

From trees to animal carcasses to prevent the spread of disease. Typical candidates include untreated tree limbs, trunks, brush, forestry residues, and other eligible wood or yard waste, subject to the equipment manual and governing permit. Regulations differentiate wood waste, yard waste, and clean lumber. Painted or chemically treated wood, mixed garbage, plastics, and hazardous waste should not be assumed acceptable.

Yes, ACIs can process freshly cut green trees. The facts are 90% of the time the material burned are freshly cut trees from land clearing projects. While it is true that high moisture absorbs heat and can lower throughput and increase visible smoke, particularly during startup. But once you get the fire to operational temperature the smke clears in seconds. I would say the average time it takes to clear smoke is about 26 seconds. Combining wet loads with suitable drier material and maintaining a hot fire greatly improves results.

Well-operated ACIs can generate 95% less visible smoke than an uncontrolled open debris pile, especially once the fire reaches steady-state conditions. They are not literally smokeless: startup, wet loads, overloading, and poor airflow can produce visible emissions. Permit opacity limits apply to many units; no fixed percentage of smoke reduction should be promised for every site. The reality is that it has more to do with if you feed the fire to fast. Feed it slow and steady and there will be almost no smoke.

Generally, yes. The industry is all over the place with what they call these machines. They are even called destructors. They all use a curtain of air that blows on the fire. Air curtain incinerator, air curtain burner, firebox burner, and sometimes air burner are commonly used industry terms, although the underlying machines may differ. The most important distinction is whether the machine uses an above-ground refractory firebox or a trench/open pit configuration.

When getting permits you have to understand that government agencies vary the language they use. Some call it open burning and some do not. In the real world getting a permit or approval to use one of these machines comes down to asking your fire marshal how they want it referred to. An ACI operates over an open-topped combustion chamber, but it is a defined category of incineration equipment rather than an uncontrolled open debris pile. A regulator may classify or permit ACI activity differently from traditional open burning. Always check the applicable state and local rules before operating.

The main thing is the temperature and the curtain. The higher temperature burns the smoke and the curtain helps to hit the larger flyaway pieces back into the fire making them smaller and less likely to cause fires. Fires are still possible but rare if you follow the instructions. A debris pile burns with uncontrolled ambient airflow and is more susceptible to incomplete combustion and smoke. An ACI uses a mechanically generated air curtain and a defined combustion chamber to improve burning conditions and contain much of the combustion activity. Neither method is automatically exempt from environmental or fire restrictions.

The blower sends a high-speed stream across the top of the chamber, which recirculates hot gases and helps supply oxygen to the fire. It can retain heat and reduce the escape of smoke and embers when correctly adjusted. It is an airflow system, not a physical lid or complete emissions filter.

Smoke often contains particles and gases from incomplete combustion. The directed airflow helps mix those gases with oxygen and hot combustion products, promoting further burning before they escape. Overloading, inappropriate material, or improper airflow can still create smoke. The number one reason that creates a lot of smoke is filling the pit above the air curtain.

Fire temperatures are variable, not a fixed machine specification. A hot, established wood fire may reach temperatures well above 1,000°F in parts of the combustion zone, while temperatures near walls, ash, and incoming wet loads are different. Operators should use manufacturer instructions and approved instrumentation rather than assume one uniform temperature.

If you start your fire using hay bails with about 3/4 of a gallon of diesel per bail. one every 3 feet you can be at full operating temp in 20 to 40 minutes. The time depends on dry starter fuel, weather, moisture, loading technique, and model. Expect a startup period during which the fire and refractory heat up and smoke may be more visible. Follow the manufacturer’s startup sequence and any permit restrictions; Burn Debris can discuss expected startup practices for the actual machine.

Wood is heated to 1500 to 1800 degrees. This is very hot and very fast because wood ignites at 450 to 550 degrees. The burning wood releases combustible gases, forms char, and then burns down to ash and other residues. The blower continuously shapes airflow over the chamber to support combustion. Larger or wetter pieces typically require more time than small, dry material.

Airflow, oxygen mixing, retained heat, and consistent feeding can sustain more intense combustion than an uncontrolled pile. If you have ever fanned the flames of a fire then you know how the fire burns faster when it gets more air. So imagine taking a truck engine connecting it to a fan and then blowing it on a fire. That is why its fast. Actual results depend on wood size and moisture, operator proficiency, and whether the chamber stays within its recommended loading range. ACI performance should be compared using equivalent material and operating time.

Wood debris can shrink dramatically as combustible material is converted into gases, heat, and ash. For some projects, reductions approaching 95% or more by loose volume may be observed, but this is not a universal guarantee and should not be confused with weight reduction. The result depends on the starting material and how volumes are measured. Example 1: Land Clearing Slash & Orchard Prunings (The Ideal High-Reduction Scenario)Starting Material: Uncompacted, twisted tree branches, brush, and limbs piled with an excavator.Loose Volume vs. Weight: Because of branch angles, the pile is over 80% empty air. A massive 1,000 cubic yard loose pile might weigh only 70 to 80 tons. WOOD DEBRIS VOLUME VS. WEIGHT REDUCTION EXAMPLES ================================================== CORE CONCEPT: Wood debris shrinks dramatically as combustible material is converted into gases, heat, and ash. For some projects, reductions approaching 95% or more by loose volume may be observed, but this is not a universal guarantee and should not be confused with weight reduction. The result depends on the starting material and how volumes are measured. -------------------------------------------------- EXAMPLE 1: Land Clearing Slash & Orchard Prunings (The Ideal High-Reduction Scenario) -------------------------------------------------- * Starting Material: Uncompacted, twisted tree branches, brush, and limbs piled with an excavator. * Loose Volume vs. Weight: Because of branch angles and irregular shapes, the pile is over 80% empty void space (air). A massive 1,000 cubic yard loose pile might weigh only 70 to 80 tons. * Combustion Dynamics: Clean woody slash has a very low natural mineral/ash content (typically 1% to 2%). In an Air Curtain Incinerator (ACI), the cellulose and lignin convert almost entirely into water vapor and carbon dioxide gases. * Operational Result: - Loose Volume: Drops from 1,000 cu yd to 20-30 cu yd of fine ash (~97% to 98% volume reduction). - Weight: Drops from 75 tons to ~1.5 tons (~98% weight reduction). * Takeaway: When loose piles are dominated by open air gaps and clean vegetative wood, loose volume reduction frequently reaches or exceeds 95%. -------------------------------------------------- EXAMPLE 2: Hardwood Root Balls with Embedded Soil (The Heavy Mineral & Density Trap) -------------------------------------------------- * Starting Material: Large-diameter hardwood logs combined with excavated stump root wads encrusted with dirt, clay, and gravel. * Loose Volume vs. Weight: The starting pile has a much higher solid density and lower void ratio. A 500 cubic yard pile of dense logs and root wads often weighs 250+ tons. * Combustion Dynamics: The pure wood fiber combusts into gas, but the dirt, rocks, and non-combustible soil minerals inside the root balls cannot burn. They drop into the burn chamber and remain as solid residue. * Operational Result: - Loose Volume: Drops from 500 cu yd to 40-50 cu yd of heavy, dirt-laden ash and clinkers (~90% to 92% volume reduction). - Weight: Drops from 250 tons to 35-45 tons of residual soil and ash (~82% to 85% weight reduction). * Takeaway: Non-combustible inorganics (dirt, rocks, clay) cannot convert to gas. Even though the wood fiber burns, soil contamination prevents volume and weight reduction from reaching peak theoretical numbers. -------------------------------------------------- EXAMPLE 3: Dense Chipped Wood vs. Loose Brush (The Measurement Baseline Problem) -------------------------------------------------- * Starting Material: 100 tons of the exact same timber processed two different ways before measurement: - Scenario A (Raw Loose Slash): Occupies ~700 cubic yards due to large branch air voids. - Scenario B (Tub-Ground Wood Chips): Mechanically fractured and compacted, occupying ~250 cubic yards. * Combustion Dynamics: Both piles contain identical dry wood mass. When fully combusted, both produce the exact same physical leftover: roughly 10 cubic yards (about 1.5 to 2 tons) of ash. * Operational Result: - Scenario A (Loose Brush): 700 cu yd -> 10 cu yd (~98.5% volume reduction). - Scenario B (Chipped Wood): 250 cu yd -> 10 cu yd (~96.0% volume reduction). - Weight Reduction for Both: Identical at ~98%. * Takeaway: A high percentage of loose volume reduction often reflects how much empty air was in the pre-burn pile rather than additional mass destruction. Measuring loose, uncompacted volume magnifies apparent shrinkage compared to measuring chipped or tightly packed material.

There is typically 2% to 5% ash left over. Ash quantity depends on species, bark, dirt, mineral content, and incoming contamination. Clean wood leaves a comparatively small mineral residue, while dirty stumps and soil-covered material can leave considerably more. Plan for ash handling and approved disposal rather than assuming no residue.

it reduces hauling by 95%. For example if you are looking at a $30,000 hauling bill, the ability to reduce that to $5,000 / $10,000 is a good reason to burn the waste. So, the main advantages can include processing substantial wood-debris volumes near the source, reducing trucking and disposal demand, reducing visible smoke relative to open-pile burning, and shortening cleanup schedules. Disadvantages include permits, fuel, equipment, trained staff, site safety requirements, and the loss of potentially recoverable biomass.

Material must satisfy both the manufacturer’s specifications and the site's current permits. Federal rules identify categories including wood waste, clean lumber, and yard waste for certain ACI provisions, but local restrictions may be narrower. Verify whether material is untreated, uncontaminated, and appropriate before it enters the burner.

Yes, trees are made of wood. LOL. Any plant material can burn. Trees are a common ACI feedstock where permitted. For best production, organize the trees by size, remove prohibited contamination, and use a machine sized for the volume and largest pieces.

Basically you cut big tree into pieces that will fit in the 20' to 40' pit. Often, yes, if the tree physically fits the combustion chamber and can be handled safely. Large crowns, root balls, and long stems may need cutting or repositioning. The operator must not load material above the manufacturer's allowable height.

Yes, tree trunks are routinely burned. Diameter, length, density, and moisture strongly affect how quickly they burn. You can burn logs from 5' to 8' diameter, but its better to spit or shear the log. A machine sized for brush alone may not be the best choice for large hardwood stems.

Many ACIs can burn large logs, but the burn time increases substantially with diameter. You can burn on average 20 foot to 40 foot logs. Oversized pieces may need to be cut or positioned to maintain airflow and avoid protruding above the chamber. Ask for a recommendation based on the largest log diameter and length.

Yes, branches and brush are common and typically ignite faster than large logs. Feed them at a steady rate and avoid dumping large, tightly packed loads that restrict air movement or create sudden smoke. Branches can burn at about 50% to 100% faster than other debris. For example I have seen a S300 burn 100 to 125 cubic yards an hour. This is faster than normal material.

Stumps may be suitable when untreated and permitted, but attached dirt, rocks, and moisture slow combustion and increase cleanout. Reduce excess soil before loading and verify that the machine can accommodate their dimensions.

Some root balls can be processed, but they are challenging because they frequently contain soil, rock, and moisture. Remove as much dirt as practical and follow manufacturer and permit limitations. A material-heavy root ball may require preprocessing. Shearing the root ball will save you 75% of your burn time.

Yes, clean vegetative storm debris is a common ACI application. You will see these machines commonly on FEMA and Army Corp of Engineer projects. We have countless municipalities using them for storm debris. Sort out fencing, metal, household waste, treated building materials, and other contaminants before burning. Disaster-related authorizations do not automatically eliminate all permit requirements.

Clean trees, branches, and qualifying vegetation from hurricanes may be processed using properly permitted machines. Mixed hurricane debris must be sorted because flood-damaged building materials, plastics, chemicals, and trash may not qualify. Mobilization and site layout are especially important for high-volume operations.

Yes, we have lots of clients burning tornado debris. We can burn 400,000 cubic yards per month. Suitable vegetative tornado debris can be processed. Because tornado debris may contain roofing, insulation, wire, and household materials, screening and sorting are essential. Consult the local authority for emergency operating requirements.

Yes, untreated slash, limbs, and other eligible forestry residues are common uses. Production depends on the amount of dirt, moisture, and woody material size. Some forest locations also have heightened fire-prevention and seasonal restrictions. This is a common application for wild fire prevention.

This is the number one use for air curtain burners. Yes, eligible trees, limbs, brush, and stumps from land clearing can often be burned where permitted. Plan the project around clearing pace, hauling distance within the site, excavator availability, and air-quality restrictions.

Yes you can and the T24 or T26 is specifically designed for this. Orchard trees and agricultural woody residues may be acceptable, but verify contamination from stakes, plastic ties, wires, or chemical treatments and confirm the permitted feedstock. Some agricultural wastes are regulated differently from ordinary tree debris.

Pallets burn SUPER FAST. You need to confirm the pallets qualify as permitted clean, untreated lumber are typically allowed material. Painted, treated, contaminated, or mixed-material pallets should not be burned without explicit regulatory approval. Local permits may prohibit pallet burning even when federal definitions appear to allow clean lumber.

Clean, untreated lumber may qualify under some applicable federal ACI provisions, subject to state/local restrictions and the permit. Remove fasteners and any coatings or contamination as required by the operator's material-acceptance policy.

Do not assume demolition wood is acceptable. It can contain treated lumber, paint, glues, engineered products, insulation, or other contaminants and may be classified differently from clean wood waste. Burn only material expressly approved by regulators and the machine manufacturer.

Yes, many machines can burn wet untreated wood, but excessive moisture reduces effective heat and often lowers production. Start with suitable dry fuel as prescribed and feed wet material gradually into an established hot fire.

Yes, that is one of the practical advantages of properly operated ACIs. The extra heat helps burn of the moisture. Freshly cut wood typically contains more water than seasoned material, so expected throughput should reflect species, size, and moisture.

Moisture uses combustion heat to evaporate water before the wood can burn effectively. More moisture generally means slower burn rates, more fuel needed for startup, and greater smoke risk if the fire cools. It should be included in all throughput estimates. Moisture Level (Wet Basis)Material ExamplesThroughput Impact (% of Rated Capacity)Burn CharacteristicsLow (<20%)Seasoned slash, dry pallets, deadfall, kiln scrap100% – 110% (Peak rate)Rapid flame propagation; bright, high-temperature bed; minimal smoke; fast feeding intervals.Moderate (20% – 40%)Freshly cut softwoods (pine, fir), mixed clearing aged 2–4 weeks75% – 90%Standard rated throughput; requires steady loading to avoid smothering the bed.High (40% – 55%)Green hardwoods (oak, hickory), fresh storm debris, spring brush50% – 70%Noticeably slower; long dry-out phase inside the box; requires larger base coals.Extreme (>55%)Waterlogged timber, swamp clearing, fresh palms, root wads30% – 50%Severe throughput reduction; high risk of quenching the fire; auxiliary diesel or dry starter fuel needed.

An extremely wet load can cool the combustion zone and produce steam and visible smoke while burning slowly. Maintain a hot fire and use smaller, controlled additions within the equipment's instructions; avoid flooding the chamber with wet feedstock.

Yes. Soil and stones do not contribute useful heat, increase ash/residue, and can obstruct loading and clean out. Separate or knock off excess soil before burning whenever practical and permitted. This slows burning down a lot. Keep the material as clean as possible.

Unless expressly authorized for a specific unit and permit, exclude tires, plastics, garbage, hazardous waste, liquid fuels, pressure-treated wood, painted wood, chemicals, batteries, and mixed demolition trash. Maintain a material-inspection procedure before loading. Federal eligibility for particular clean wood categories is not permission for all waste.

Generally, treated lumber should not be burned in a standard wood-debris ACI. Preservatives and other treatments can introduce pollutants and place the material outside eligible clean-wood categories. Use an authorized disposal or recycling route. You need to speak to local officials. Fire will burn treated wood but the question is should you burn it?

Painted wood should not be assumed eligible and is generally excluded from clean lumber. Old coatings may contain toxic substances. Obtain specific regulatory approval before considering any coated or processed wood.

A wood-debris ACI is not a general-purpose garbage incinerator. Burning municipal solid waste can trigger very different legal requirements and may be prohibited by the machine's authorization. Keep household trash and mixed waste out.

No, not in an ordinary clean wood/vegetative-debris ACI operation. Such materials create substantial safety and emissions concerns and are outside the typical authorized feedstock. Follow appropriate hazardous and solid-waste management rules.

Yes. Federal rules provide an overarching framework, but state and local requirements and the individual permit can be stricter. The specific site's authorized feedstock list—not a general FAQ—controls what may actually be burned. Call BurnDebris.com if you need help.

Average 8 ton to 10 tons per hour. Throughput depends on machine model, wood species, moisture, dimensions, and how consistently the operator feeds the chamber. Provide the estimated wood type and condition for a credible tonnage range. Call William at the office if you need help.

Burn Debris discusses job-specific ranges, including approximately 20 loose cubic yards per hour for some S220 planning cases and around 75–100 loose cubic yards per hour for some favorable S327 applications. These are scenario estimates, not certified rates or minimum guarantees. Large logs, wet wood, and difficult handling can materially reduce output.

We find 0.9 to 2 acres per day as an average. If I was estimating a job I would use 1 acre per day. There is no universal acres-per-day figure: debris per acre depends on tree density, stem diameter, terrain, and whether wood is removed for sale. First estimate cubic yards of suitable debris per acre, then divide by the expected daily throughput. Burn Debris can help develop the estimate for a specific site.

Multiply expected operating throughput by actual productive burn hours, not simply the shift length. For illustration, 20 cubic yards per hour for eight productive hours equals approximately 160 cubic yards; at 75 cubic yards per hour it equals about 600. Startup, repositioning, refueling, and cleanout reduce net production time.

Multiply realistic hourly throughput by productive hours per day and operating days in the month. For example, 20 cubic yards/hour × 9 productive hours/day × 20 days = about 3,600 loose cubic yards. Actual output should include downtime and material variability.

Divide the loose debris volume processed by the usable cubic-yard capacity of the specific truck or container. At 20 cubic yards per truckload, 100 cubic yards/hour equates to five nominal loads/hour. Truck packing, weight limits, and actual loading volumes can change the result. Figure 7.14 cubic yards per hour per ton of burning capacity. • For an S220 the Chamber Turnover Ratio is: ~1.01 cubic yards burned per hour per cubic yard of capacity (0.82 to 1.18 yd³/hr per yd³ capacity) or and average do 1.5 to 2 dump truck loads. For the S327 • Chamber Turnover Ratio: ~1.13 to 1.25 cubic yards burned per hour per cubic yard of capacity (1.02 to 1.48 yd³/hr per yd³ capacity) or 4 to 5 average dump truck loads per hour.

A manufacturer's quoted maximum or a favorable demonstration rate should not be treated as an everyday guarantee. For quoting, use expected project conditions and separate a best-case peak rate from a conservative working rate. Burn Debris can help size equipment with practical production assumptions.

The major factors are machine size, wood diameter and species, moisture, contamination, blower condition, loading equipment, operator technique, weather, and time lost to cleanout or service. The bottleneck is sometimes material handling rather than combustion.

Maybe 20% to 30% if it was bone dry. But the facts are people don't wait. Cut the tree, strike a match, get the job over with and collect the check. Most people burn the trees same day or within a week of cutting them. You can freshly cut trees with water in them, the main thing is to get fire hot and feed it small amounts to keep it hot. Many people are cutting the trees and waiting a few days or weeks before they are ready to burn. There is no reliable universal percentage: most waste is burned green, freshly cut softwood branches and waterlogged hardwood logs behave very differently. Greater moisture generally reduces heat available for combustion and extends burn time. Use a field test or conservative estimate rather than promising a fixed deduction.

Small branches have more surface area relative to their volume and often burn faster. Large-diameter trunks and stumps remain in the chamber longer and can limit the rate of new material loading. A mixed-size feed can help sustain the fire, if loaded properly. For best results slip it to 15" diameter or less. Below 8" diameter burns really fast. Size can make a 50% to 100% difference in time.

Usually, yes. Large logs take longer for heat to penetrate, dry, and consume the interior wood. They are often the limiting factor when estimating throughput for land-clearing projects.

Stumps can burn slowly due to dense root structure, moisture, and trapped dirt. They also increase ash and cleanout demands. A project with many large stumps should be quoted differently from brush-only debris.

Consistent, measured feeding generally supports steady output, but overfeeding can cool the fire, impede airflow, and create smoke. The goal is to feed at the rate the existing fire can consume the material while respecting loading-height limits.

There is no fixed interval suitable for all models and feedstocks. The operator should observe chamber conditions, residual fuel, and smoke, then add manageable loads as instructed by the manufacturer. A dedicated feeder can improve consistency on high-volume sites. Ultimately, if its smoking wait for smoke to clear. That how to know when to load it. That can be seconds or minutes. We offer support to help you figure this out on your jobs. So if you are experiencing high smoke volumes exceeding the opacity limits (how thick the smoke appears in the air) call us we will help you. I would load in 24" layers of loose material. Call BurnDebris.com if you need more details.

You will find most areas allow the burning and hour after sunrise and before sundown. Obviously you have to ask the local officials. Many commercial ACIs are intended for extended daily operation when properly fueled, monitored, and maintained. Operations must respect the manufacturer's duty cycle, permit hours, weather restrictions, and safe ash/cleanout practices.

Only when the specific equipment, staffing, site, and permits authorize it. Continuous combustion needs around-the-clock trained supervision, fuel, fire protection, and ash-management planning. Do not assume 24-hour loading is permissible. Ask your fire marshal. Some times a state of emergency loosens restrictions. The machine can run 24 hour but you need to check the oil and water levels and monitor the engine temp and oil pressure. research the safe way to do the inspections engines are hot and you can be burned.

Burn-down time varies with how much material remains, the size of the wood, and the machine. Large trunks or stumps may continue burning much longer than brush. Stop feeding early enough to complete the manufacturer's shutdown procedures and permit obligations.

Fleet capacity is about 675,000 up to 1,300,000 cubic yards per month depending on the working hours. You could use 2000 cubic yards to 3000 cubic yards per hour. We have participated in disasters for about 30 years. If there is a need we will rise to meet it. Ultimately it depends on the number and models of machines actually available, transport distances, staffing, fuel, and site permits. Total theoretical daily volume is the sum of each deployed machine's realistic production, not simply fleet count multiplied by a peak figure. Contact Burn Debris for a time- and location-specific mobilization plan.

BurrnDebris.com has a custom built estimation system that we can use to help you analyze a job or your entire business volume and answer this question more thoroughly. It take about 10 to 20 minutes to do a free analysis. Ask for William at BurnDebris.com. Basically you divide the total eligible loose-debris volume by the realistic total productive cubic yards one machine can handle before the deadline, then round up. Machines will vary from 500 to 800 cubic yards per day per machine per 10 hour shift. For example, 50,000 cubic yards ÷ (500 cubic yards/day × 20 days) = five machines before contingency. Adjust for access, shifts, permit limits, uptime, and support-equipment constraints.

Yes. BurrnDebris.com has a custom built estimation system that we can use to help you analyze a job or your entire business volume and answer this question more thoroughly. It take about 10 to 20 minutes to do a free analysis. Ask for William at BurnDebris.com. Provide the estimated volume, project location, target completion date, types and sizes of wood, and work hours allowed. Burn Debris can estimate required machines and supporting equipment using conservative rather than peak production assumptions.

Start with target daily production, the material's size/moisture, and what equipment can feed the burner. Then match these requirements against the capacity and configuration of available machines. A high-volume site with large logs may justify a larger box burner or multiple units. figure 1.6 cubic yards per hour per cubic yard capacity of the box. Ask William Lombardo for help he knows. Call BurnDebris.com

Any time you need time compression. Lets say you have a job that would take 4 weeks but you need it in 1 week. Use 4 machines. An excavator can feed 4 machines at a time if you set them up properly. You must place them with space between them so the operator can move away from the heat. But 3 or 4 machines per excavator ratio is excellent. I can run an analysis for you so you can see the comparison. You can cut your cost by 50% to 75% easily. Multiple machines make sense when one machine cannot meet the deadline, where trucks or excavators can keep several units fed, or when separate debris piles make one central site inefficient. Check spacing, fire safety, permits, site layout, and whether each unit must receive a separate authorization.

DIRECT ACI OPERATIONAL COST PER TON (For Cubic yard rate see What does it cost per cubic yard to dispose of debris with an Air Curtain Incinerator?) (Excludes Mobilization, Permitting, and Support Loading Equipment) • ACI Rental / Depreciation: $2.00 – $4.00 / ton ($7,000–$10,000 per 28-day period) • Diesel Fuel (Blower Engine): $1.50 – $3.00 / ton (3–4 gal/hr @ $3.50–$5.50/gal) • Direct Operator Labor: $3.50 – $6.00 / ton ($30–$45/hr at 6–10 t/hr burn rate) • Ash Management: $0.50 – $1.50 / ton (on-site spreading/incorporation) TOTAL DIRECT OPERATING COST: $7.50 – $14.50 PER TON Divide total project cost by the actual tons processed, including mobilization, rental or ownership, labor, diesel, support equipment, permits, ash disposal, and demobilization. Cost per ton can look high on small projects and much lower when a machine is utilized steadily. We can prepare a project-specific estimate.

Use total all-in project costs divided by measured loose cubic yards processed. DIRECT ACI OPERATIONAL COST PER CUBIC YARD (Conversion Rate: 7.14 Cubic Yards per Ton | Excludes Mobilization, Permitting, and Support Loading Equipment) • ACI Rental / Depreciation: $0.28 – $0.56 / cu yd (derived from $2.00 – $4.00 / ton) • Diesel Fuel (Blower Engine): $0.21 – $0.42 / cu yd (derived from $1.50 – $3.00 / ton) • Direct Operator Labor: $0.49 – $0.84 / cu yd (derived from $3.50 – $6.00 / ton) • Ash Management: $0.07 – $0.21 / cu yd (derived from $0.50 – $1.50 / ton) TOTAL DIRECT OPERATING COST: $1.05 – $2.03 PER CUBIC YARD For example, a $13,000 all-in project that processes 5,000 cubic yards averages $2.60 per cubic yard. This is an illustration, not a Burn Debris price quotation.

COST COMPARISON: ON-SITE ACI BURNING VS. TRUCKING & LANDFILL DISPOSAL 1. DIRECT UNIT COST BENCHMARKS (at 7.14 cu yds / ton): • On-Site ACI Direct Operating Cost: $1.05 – $2.03 per cubic yard ($7.50 – $14.50/ton) • On-Site ACI Fully Burdened Cost: $2.20 – $4.50 per cubic yard ($15.70 – $32.00/ton) (Includes ACI rental, fuel, operator, mobilization, permits, and ash management) • Off-Site Trucking & Landfill Cost: $10.00 – $35.00+ per cubic yard ($70.00 – $250.00+/ton) (Includes truck loading, round-trip haul hours, scale queueing, and tipping fees) 2. 20,000 CUBIC YARD PROJECT SCENARIO (2,801 TONS / 667 TRUCK LOADS): • Short Haul (1 hr round-trip + $40/ton tipping fee): - Hauling & Landfill Total: $205,420 ($10.27 / cu yd) - On-Site ACI Burning Total: $48,500 ($2.43 / cu yd) - Net On-Site Savings: $156,920 (76% reduction) • Medium Haul (2.5 hr round-trip + $60/ton tipping fee): - Hauling & Landfill Total: $401,510 ($20.08 / cu yd) - On-Site ACI Burning Total: $48,500 ($2.43 / cu yd) - Net On-Site Savings: $353,010 (88% reduction) • Long Haul (4.0 hr round-trip + $85/ton tipping fee): - Hauling & Landfill Total: $611,605 ($30.58 / cu yd) - On-Site ACI Burning Total: $48,500 ($2.43 / cu yd) - Net On-Site Savings: $563,105 (92% reduction) 3. ECONOMIC & LOGISTICAL DRIVERS: • Factors Favoring On-Site Burning: - Round-trip haul times exceeding 1.5 hours - Landfill/transfer station tipping fees above $40/ton - High volume of loose, unground brush and root wads - Jobs exceeding 2,000 cubic yards • Constraints Favoring Off-Site Trucking: - Small volume projects (<1,500 cubic yards) where mobilization costs dominate - Strict air quality non-attainment zones, Red Flag warnings, or burn moratoriums - Inadequate setback distance (typically requiring 250–500 ft from structures/roads) - Soft, swampy, or restricted ground incapable of supporting delivery low-boys Compare the complete cost of onsite burning with container/truck loading, trucking cycles, fuel, labor, tipping fees, and unloading at the receiving site. Longer hauling distances and higher disposal prices tend to favor onsite processing. Site permits or access limitations can change that conclusion.

GRINDING VS. AIR CURTAIN INCINERATOR (ACI) COMPARISON Grinding creates a product that may have value or require removal, while ACI burning reduces eligible debris to a small amount of ash. Compare grinding equipment, wear parts, trucking of chips, disposal or sale revenue, and site constraints against ACI costs. Wood that has commercial biomass or mulch value may be better processed instead of burned. 1. DIRECT OPERATING & EQUIPMENT COSTS: • Equipment Capital: - Horizontal Grinder (700-1,050 HP): $750,000 – $1,250,000+ ($25k–$45k/mo rental) - ACI Burner (S200/S300 Series): $120,000 – $220,000 ($7k–$10k/mo rental) • Fuel Consumption: - Grinder: 22 to 32 gallons/hr of diesel ($80–$140/operating hr) - ACI: 2.5 to 4.5 gallons/hr of diesel ($10–$22/operating hr) • Consumable Wear Parts: - Grinder: $2.50 – $6.00+ per ton (carbide teeth, hammer tips, screens, belts) - ACI: <$0.25 per ton (no high-speed moving knives or screens) • Direct Processing Cost (excluding freight): - Grinding: $12.00 – $22.00 per ton ($1.70 – $3.10 / cu yd) - ACI Burning: $7.50 – $14.50 per ton ($1.05 – $2.03 / cu yd) 2. LOGISTICS & MATERIAL HANDLING: • Grinding Output: - 100% of material mass remains as wood chips. - A 2,800-ton job leaves ~7,500 cubic yards of chips requiring 75+ walking-floor semi-loads or ~280 dump truck loads to move off-site. • ACI Output: - 95%–98% volume reduction. - The same 2,800-ton job leaves only 70–100 cubic yards of residual ash, easily spread on-site or removed in 3 to 4 truckloads. 3. MARKET & REVENUE EVALUATION: • Grinding Wins If: - High-grade, clean wood feedstock. - Local buyers (mulch yards, pellet mills, bio-energy) pay $25+/ton delivered. - Delivery haul is under 25 miles. • ACI Burning Wins If: - Mixed brush, limbs, tops, or dirt-encrusted root wads. - No local biomass market (or disposal facilities charge tipping fees on chips). - Hauling chips off-site would add $15–$30+/ton in trucking costs. 4. SITE CONSTRAINTS: • Grinding Advantages: No burn bans, no smoke/opacity permits, operates in urban zones. • ACI Advantages: Handles dirt/rock without broken teeth; eliminates highway truck traffic.

Chipping may be a good option when small branches are clean and there is an economical market or use for chips. ACIs can be advantageous for mixed-diameter woody material with limited reuse opportunities, subject to permits. Pricing needs to include the ultimate destination of both the chips and the ash. CHIPPING VS. AIR CURTAIN INCINERATOR (ACI): LIFECYCLE DECISION GUIDE 1. FEEDSTOCK PROFILES: • Chipping / Grinding: - Acceptable option for: Clean limbs, pruned branches, uniform slash under 18 inches. - Critical Limit: Dirty root wads, gravel, and large-diameter trunk wood dull chipper knives and cause rapid wear parts failure. • Air Curtain Incinerators (ACI): - Best for: Any wood, especially mixed diameters, crooked tops, logs, stumps, and root balls. - Advantage: Rocks, dirt, and heavy soil do not damage cutting components; they drop to the bottom and are cleared with ash. 2. MASS BALANCE & END-DESTINATION LOGISTICS: • Chipping Output (100% Mass Retention): - Produces 3.0 to 3.5 cubic yards of chips per ton. - Must have a planned endpoint: * Sale to biomass/mulch plant ($15–$35/ton revenue delivered). * Broadcast on-site for slope stabilization / erosion control. * Landfill or compost facility tip fee ($20–$55/ton liability). - Hauling expense compounds at roughly $0.25–$0.40 per ton-mile. • ACI Output (95%–98% Volume Reduction): - Produces only 0.05 to 0.15 cubic yards of ash per ton. - Ash Destination: * Spread on-site as carbon-rich biochar and natural soil conditioner. * Minimal off-site haul (a multi-week job fits in 3 to 4 dump trucks). 3. REGULATORY AND PERMIT CONSIDERATIONS: • Chipping: Operates with zero burn permits, zero smoke restrictions, and unrestricted setbacks; ideal for urban interface and strict non-attainment zones. • ACI: Highly cost-effective on bulky and mixed waste, but requires local burn/air permits, weather monitoring, and typical buffer setbacks of 250–500 ft. 4. DECISION RULE: • Choose Chipping if you have a local buyer, wood is clean, small-diameter, and or on-site ground cover need that absorbs the volume without highway freight. • Choose ACI no matter the natural wood material or if material is dirty, mixed-diameter, has zero commercial market, and site permits allow on-site thermal reduction.

Calculate incoming debris volume or tonnage, landfill tipping charges, trucking, and any sorting costs. Air-curtain burning can avoid transporting most of the original wood volume to disposal, but the remaining ash still requires approved management. Disposal rules and landfill rates vary by location. DEBRIS DISPOSAL & ASH MANAGEMENT COST ACCOUNTING MODEL 1. CORE FORMULAS: • Inbound Tonnage = Total Volume (cu yds) ÷ Density Factor (typically 7.14 cy/ton) • Total Truck Loads = Inbound Tonnage ÷ Truck Payload Capacity (tons) • Trucking Expense = Total Loads × (Round-Trip Travel Hours × Truck Hourly Rate) • Landfill Gate Cost = Inbound Tonnage × Local Landfill Tipping Fee ($/ton) • Residual Ash Mass = Inbound Tonnage × Ash Content (typically 2% to 4%) • Ash Disposal (Off-site) = (Ash Tons × Landfill Tip Fee) + Ash Trucking Freight • Ash Disposal (On-site) = Inbound Tonnage × Spreading Rate ($0.50–$1.50/ton) 2. SAMPLE RUN: 15,000 CUBIC YARDS (2,100 TONS) OF WOOD DEBRIS • Assumptions: - 500 truck loads (30 cy / 4.2 tons per load) - 2-hour round trip travel time @ $135/hour - Landfill Tipping Fee: $55.00/ton - Pre-sorting mixed debris: $2.50/ton - Direct ACI burning cost: $10.50/ton • OPTION 1: TRUCKING & LANDFILL DISPOSAL - Pre-Sorting Cost: $5,250 ($2.50/ton) - Highway Trucking (500 loads): $135,000 ($64.29/ton) - Landfill Tipping Fees: $115,500 ($55.00/ton) ------------------------------------------------------------- TOTAL DIRECT LANDFILL COST: $255,750 ($121.79/ton | $17.05/cy) • OPTION 2: ON-SITE ACI BURNING (WITH APPROVED ASH DISPOSAL) - Pre-Sorting Cost: $5,250 ($2.50/ton) - ACI Burning Operation: $22,050 ($10.50/ton) - Ash Handling: * Path A (On-Site Soil Rake): $2,100 ($1.00/inbound ton) * Path B (Off-Site Ash Tip): $4,545 (63 tons ash hauled & tipped) ------------------------------------------------------------- TOTAL ACI COST (Path A): $29,400 ($14.00/ton | $1.96/cy) TOTAL ACI COST (Path B): $31,845 ($15.16/ton | $2.12/cy) 3. LOCAL REGULATORY CHECKLIST FOR ASH: • Agricultural / Soil Beneficial Use: Most jurisdictions permit spreading ash on-site as a soil liming agent if material was strictly unpainted, untreated wood. • Heavy Contamination / Soil Mix: If root balls contain unknown fill or industrial debris, ash may require Toxicity Characteristic Leaching Procedure (TCLP) testing prior to beneficial reuse. • Landfill Cover: Many municipal landfills accept certified clean wood ash at discounted tipping rates to use as daily landfill cover material.

Tub grinders can process substantial clean woody material into grindings but require wear parts, fuel, material handling, and a destination for the product. An ACI destroys eligible material rather than producing grindings. Large contaminated root balls can be difficult for either process and may require sorting. TUB GRINDER VS. AIR CURTAIN INCINERATOR (ACI): LOGISTICS & CONTAMINATION GUIDE 1. EQUIPMENT & OPERATING TRADEOFFS: • Tub Grinder: - Produces: Wood chips, mulch, compost amendment, or hog fuel. - Resource Demand: 600–1,050 HP engine, burning 25–40 gallons of diesel/hour. - Consumables: High cost ($3.00–$7.00/ton) in teeth, hammer tips, and screens. - Handling Liability: 100% of the mass remains on the ground. A planned destination (off-site haul or broad site spreading) is mandatory. • Air Curtain Incinerator (ACI): - Produces: 95%–98% volume reduction down to mineral ash and biochar. - Resource Demand: 50–75 HP blower engine, burning 2.5–4.5 gallons of diesel/hour. - Consumables: Negligible wear parts (no spinning cutter assemblies). - Handling Liability: Zero off-site trucking for the woody mass; small volume of ash can typically be blended into topsoil on-site. 2. THE ROOT BALL & CONTAMINATION FACTOR: • In a Tub Grinder: - Rocks and dirt cause severe abrasive wear and catastrophic hammer breakage. - High risk of thrown projectiles from the tub. - Clay clogs sizing screens, causing thermal friction and stoppage. • In an ACI: - Zero mechanical damage (dirt/rock simply drops to the bottom of the firebox). - BUT soil acts as an insulator, cooling the fire bed, causing smoke, and filling the box with non-combustible mass that requires frequent dig-outs. 3. REQUIRED FRONT-END SORTING PROTOCOL: • Use an excavator with a hydraulic thumb, grapple, or stump splitter. • Shake, drop, and split root balls to drop out 80%+ of packed dirt and rock. • Co-fire de-soiled stumps in the ACI with dry, seasoned tops to sustain internal temperatures above 1,600°F. • Divert excessively rocky or clay-bound root wads directly to earth fill.

Horizontal grinders provide controlled wood sizing for mulch, biomass, or hauling; ACIs prioritize reducing the quantity of waste to manage. Compare hourly production under similar materials, grinder maintenance, screen configuration, end-product value, and the burner’s permitting and operating costs.

YES. Typically 4 BurnDebris.com Air Curtain Incinerators (you can rent) costing $360,000 can out perform a $ million dollar grinder, and there is no generally no hauling when you burn. Either can be faster depending on machine sizes, wood type, feeding equipment, and what “finished” means. Grinding may process wood quickly yet leave a large product stockpile to move; burning takes time to consume material but leaves much less residue. Measure the whole disposal workflow, not just feed rate.

Longer haul distances increase trucking hours, fuel, driver time, and the number of trucks required to maintain pace. This can make an onsite ACI more competitive, provided permits and site logistics allow it. The breakeven distance depends on local trucking and disposal prices.

An Air Curtain Burner can eliminate 95% to 100% of the trucking. Estimate how many loads the original debris requires, then subtract the loads needed for ash and any rejected materials. Where eligible woody debris can be burned onsite, the reduction in outgoing loads can be substantial. Exact savings vary with truck capacity and debris compaction.

You can replace virtually all of wood debris hauling trucks. About 4 to 5 trucks per hour per air curtain burner can be replaced. There is no fixed equivalence because haul cycle duration is critical. For example, if burning eliminates 100 cubic yards/hour and each truck carries 20 cubic yards, that is five nominal outgoing loads/hour avoided—not necessarily five trucks. Convert avoided loads into trucks by accounting for each truck's turnaround time.

Multiply avoided truck trips by the full cost per trip, including loading, drivers, fuel, equipment, mileage, and wait time. Then subtract trucking still needed for ash or unacceptable material. A project-specific haul-rate comparison is the most accurate method.

Multiply the tonnage that would otherwise enter the landfill by its tipping fee and subtract ash/residue disposal charges. Verify whether fees apply by ton, cubic yard, or container. This is often one of the largest economic drivers for expensive disposal markets.

Multiply measured gallons burned per hour by your delivered diesel price. For example, three gallons/hour at $6.50/gallon is $19.50 per operating hour. Fuel consumption differs by engine, blower load, model, and maintenance condition.

Include diesel, operator and excavator labor, the excavator's ownership/rental and fuel cost, maintenance, ash handling, and an allocation of rental or ownership and transportation costs. Engine-hour cost is useful for comparing options, but cost per cubic yard better reflects project productivity.

A trained ACI operator must monitor combustion and safety; an excavator or loader operator generally feeds the unit. On large sites additional people may sort, stage, manage ash, coordinate trucks, and provide fire watch. Staffing must meet the manufacturer's instructions and any local fire or permit conditions.

Typical support includes an appropriately sized excavator or loader, suitable debris-staging space, diesel supply, fire-suppression equipment, and equipment for ash removal. Depending on site and permits, additional water, barriers, lighting, and fire-watch measures may be necessary.

A useful estimate includes machine rental or ownership allocation; outbound/inbound mobilization; unloading; diesel; operator and support-equipment costs; permits; insurance; ash management; and expected downtime or weather delays. Burn Debris can compare this total with trucking, grinding, or landfill alternatives.

Savings = the total cost of the best feasible alternative minus the all-in cost of the ACI option. Include any revenue or value from recovered chips/wood in the alternative scenario. Estimated savings should be presented with assumptions and a reasonable range, not as a guaranteed result.

There is no single minimum volume: mobilization makes small projects less attractive, while long hauling distances and high tipping fees can justify smaller volumes. The relevant question is when avoided disposal expenses exceed fixed and variable burner costs. We can calculate a breakeven cubic-yard quantity for your location.

Purchasing may become attractive when a company has predictable, repeated work and enough annual operating days to justify capital, maintenance, storage, insurance, transport, and resale risk. Renting typically offers greater flexibility for intermittent projects and transfers some ownership responsibilities. Compare multiyear total costs, not monthly rates alone.

ROI depends on the revenue or disposal savings actually produced, less fuel, labor, maintenance, insurance, transport, downtime, and equipment depreciation. A simple annual ROI estimate is annual net benefit divided by invested capital, but payback period and cash flow are also important. Burn Debris can help build a project-specific model using your expected utilization.