The Wood Gun™ wood gasification boiler by Alternate Heating Systems utilizes the most advanced technology in wood burning and is perhaps the most efficient wood burning device on the market today. This uncompromising multifuel system is ideal for any residential application where wood or wood by-products are used as fuel. The AHS Wood Gun™ is available in residential sizes ranging from 100,000 to 250,000 BTU’s and commercial sizes up to 1,000,000 BTU.

Features:

• Automatic cycling on and off in response to heating or hot water demand.
• Domestic hot water coil provides abundant quantities of hot water.
• Exceptionally safe and clean burning. The use of dense refractory material cast into specific shapes causes complete combustion to occur at temperatures of up to 2000° F.
• When operated properly in the gasification mode, visible smoke is eliminated and creosote formation inside the chimney is prevented.
• The large cyclone separator removes most of the fly ash resulting in very
  low emission.
• Spontaneous re-ignition of the wood will occur after an off period of 2-4 hours
  Re-ignition is dependent on the refractory temperatures.
• Automatic fuel delivery systems are available for wood waste products such as sawdust, shavings, woodchips and densified biomass. These are designed more for industrial/commercial applications rather than residential.
• Wood Gun™ readily adapts to new or existing hot air systems through the use of a heat convection coil.
• The design maintains all heated walls at the same temperature using a "water wall". This constant temperature eliminates stress fractures caused by differences in temperature between components of the boiler thus increasing it's life. In addition, this design produces greater efficiency because heat that is normally lost through a drywall is captured in the water wall.

Specifications:

Model:	E100	E140	E180	E200	E250
BTU/H (Max.) Wood	100,000	140,000	150,000	185,000	230,000
Oil (optional) **	80,000	130,000	160,000	160,000	230,000
Heating Surface	30 ft2	39 ft2	46 ft2	55 ft2	70 ft2
Water Capacity	60 Gal	80 Gal	80 Gal	95 Gal	140 Gal
Fire Box Capacity	6.5 ft3	10 ft3.	14 ft3	18 ft3	22 ft3
Max. Log Length	26"	30"	30"	38"	46"
Door Opening	14" x14"	14" x14"	14" x14"	14" x14"	14" x14"
Height	58"	64"	66"	66"	74"
Width	26"	26"	31"	31"	31"
Depth	44"	48"	48"	56"	66"
Flue Size	6"	6"	6"	8"	8"
Weight (lbs)	1,400	1,650	2,100	2,400	3,000
Domestic Coil Gal/min (Optional)	5	5	5	5	5
*Rec. Sizing: for 8-12 hour burn cycle (BTU/hr)	70,000	100,000	140,000	175,000	220,000

*Average hourly BTU output is based on a 8-12 hour burn cycle

Model:	E500	E1000
BTU/H (Max.) Wood	500,000	1,000,000
Net Steam Rating (BTU/H)	376,000	752,000
Heating Surface	116 ft2	192 ft2
Water Capacity	210 Gal	435 Gal
Gas/Oil Chamber (water capacity)	16 Gal	50 Gal
Height	90"	102"
Width	34"	48"
Depth	72"	78"
Flue Size	8"	12"
Weight (w/o gas/oil - lbs)	4,500	9000
ID Fan	.75 HP	2.0 HP
Minimum Boiler Room (w/o Gas/Oil)	12'x15'	16'x16'
Minimum Boiler Room (with Gas/Oil)	14'x15'	16'x18'
Load Door	18"x18"	18"x18"

How it Works
Wood gas is produced by applying heat to wood, a process called pyrolysis. The wood gas is drawn through the bottom of the firebox and into our uniquely designed refractory by an induction fan. The gases are combined with oxygen and combusted in the refractory. The super heated gases pass through the interconnected refractory tunnels and in to our uniquely designed swirl chamber. This is where the bulk of heat exchange takes place. The superheated refractory then continues to gasify the wood remaining in the firebox. After combustion the residual ash is combined with high velocity air flow to scrub the heat exchanger preventing any build up. This process allows us to maintain an unparalleled consistency in heat exchange. Most ash exits the unit and is collected in the cyclone ash separator for fast and easy removal.

The Wood Gun™ cycles on and off much like an oil or gas fired boiler. During the off cycle, fuel is not consumed because oxygen is not present in the combustion chamber. With the large superheated refractory mass, re-ignition of the fuel (usually occurs up to 5 to 6 hours later depending on boiler size) automatically when a drop in water tempurature signals the need for heat.

During the off cycle, wood gas inside the firebox condenses on the inner walls forming a solid that will eventually fall off. This combines with the remaining fuel thus adding energy that in many other boilers goes up the chimney.

Photos:



Carbon vs. Stainless Steel in our Wood Boilers
The internal surfaces of a Wood Gun™ Wood Boiler include any surface touched by the flame, smoke, wood or exhaust.  The internal surfaces may be manufactured with carbon steel or stainless steel - it's your choice.  We recommend stainless steel because carbon steel will show deterioration within 10 years though the unit may continue to function for as much as 20 years.  We have had stainless steel boilers in service for 20 years, and they show no sign of deterioration.  We use 1/4" thick 304 stainless steel (as opposed to 409) for unsurpassed quality.

Stack Temperature

Exhaust stack temperature is an indicator of transfer efficiency. During combustion, temperatures of around 2000° Fahrenheit can be obtained. Amazingly, our exhaust stack temperature ranges from about 260-300° Fahrenheit. This stack temperature is unheard of in the industry. The Alternate Heating Systems WoodGun™ is truly the pinnacle of wood fueled heating devices.