Wood Gun™ Multi-Fuel
Gasification Wood Boiler
The Wood Gun™ wood gasification boiler by
Alternate Heating Systems, Inc. utilizes the most advanced
technology available in wood burning today. We
believe, and *independent testing laboratory results indicate, that
this is the most efficient wood-burning device built today.
This uncompromising multi-fuel system is ideal for residential, commercial,
and industrial applications where wood and wood by-products are
available as a primary fuel source. The Wood Gun™ wood
boiler comes in sizes ranging from 100,000 to 1,000,000
Wood Gun™ wood boiler employs a down-draft wood gasification design
which burns wood of all types and moisture content. These wood boilers
work by drawing the wood gases off using an induction fan and then
burning them underneath the wood so that much more complete combustion
occurs. The wood is continually heated by the burning gases beneath it
so that the gases continue to rise from the wood - the wood itself
doesn't burn, only the gases. Since only the gases are combusted, the
AHS wood boiler can burn wood with a wider range of moisture content
than can a non-gasification wood boiler. An additional feature is
automatic switchover to oil heat, gas heat or electric heat backup. An
optional lockout feature maintains the secondary fuel mode in the event
the wood charge is expended.
Particle Fuel Delivery
When burning chunk wood in an AHS wood boiler,
if the system is properly sized, the fire box typically
only needs to be loaded two or three times a day (unless extreme
cold conditions prevail). Our automatic particle fuel
delivery option is ideal for customers with access to uniformly
sized wood pieces, chips, pellets, etc. If you want to
burn both chunk wood and wood particles in your AHS wood boiler,
it only takes about fifteen minutes (after shutting the system
down and allowing it to cool) to change the system from one
wood type to the other, but chunk wood can still be loaded even
when using the particle fuel delivery mechanism.
A close inspection will
quickly reveal why the Wood Gun™ wood gasification boiler is the standard by which all
other wood burning appliances are judged. Many of these unique
features are found only on the Wood Gun™.
How Superior is the Efficiency of the Wood Gun™ wood
The Wood Gun™ wood boiler is a combustion system capable of burning wood
and wood-based waste at a very high combustion efficiency,
resulting in very low stack emissions. Stack sampling on
operating units has yielded particulate levels 50% less than the
best results obtained by conventional up-draft boilers. This
level of performance is due to a number of unique design features
not found on other wood waste combustion equipment. In fact,
the Wood Gun™ is so different that conventional wood boilers cannot
be modified to incorporate these features without a complete
The stack temperature is an indicator of how
completely the fuel is being combusted. The Alternate
Heating Systems Inc. Wood Gun™ Boiler operates with one of the
coolest stack temperatures of any wood boiler on the market (if
not the coolest). The stack temperature of a Wood Gun™ runs
at less than 300 degrees fahrenheit (typically 260 - 280 degrees).
The low stack temperatures of our boilers are almost unheard of on
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
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 19 years, and they show no sign of deterioration. We
use 1/4" thick 304 stainless steel (as opposed to 409) for unsurpassed
Automatic cycling on and off in response to heating or hot water demand.
Domestic hot water coil provides abundant quantities of hot water.
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.
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.
re-ignition of the wood will occur after an off period of 2-8 hours.
Factors such as the quality and quantity of the fuel charge as well as
the size of the unit also determine how long a system can go without
burning and then have spontaneous re-ignition occur.
fuel delivery systems are available for wood waste products such as
sawdust, shavings, woodchips and densified biomass.
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 stove
thus increasing the life of the stove. In addition, this
design produces greater efficiency because heat that is
normally lost through a drywall is captured in the water wall.
Diagram of Wood Gasification Boiler
The Swirl Chamber
HOW DOES THE UNIQUE DESIGN OF THE WOOD GUN SWIRL CHAMBER DIFFER FROM OTHER WOOD GASIFICATION BOILERS?
The SWIRL CHAMBER is where 90% of the heat exchange takes place in the
Wood Gun. The Wood Gun refractory emits 2000 degree fahrenheit exhaust
air temperature which is directed into the SWIRL CHAMBER and has an
exiting exhaust air temp of only 275 degrees at high fire. This unheard
of heat transfer efficiency is due to our unique design. The exhaust
air spins through a large diameter drum assisted by a 3400 rpm draft
inducer making a swirling action. Both the exhaust air and the ash from
the wood, scrub the walls of the heat exchanger at a high rate of
speed, in turn keeping it clean and efficient. This self-cleaning
action prevents the troublesome routine cleaning of the heat exchanger
that has plagued the Wood Boiler industry for years.
*The temperature varies from Boiler size, wood quality, moisture content and flue height.
The CYCLONE ASH SEPERATOR is where the majority of the ash is
collected. Since the design of the Swirl chamber is to use the ash as a
cleaning agent, we can allow the ash to exit the boiler with the
exhaust air. The speed of the ash is increased using a high velocity
orifice, discharging it into a cyclonic action device (the CYLCONE),
spinning the heavy particles out of the exhaust stream and finally
funneling them into the stainless steel ash pan allowing the exhaust to
exit the cyclone top into the chimney pipe.
|Routine cleaning of combustion chamber
is necessary to
maintain optimum performance. Easy-open Inspection Doors Front
and rear make cleaning a snap.
||Improved Air Valve design permits easy replacement of gasket disc.
||The Air Valve closed.
||Removable Clean-out Plug provides
direct access to combustion chamber
inducing fan produces high velocity and intense flame in combustion
chamber. Unlike conventional heating equipment, the flame production in
the Wood Gun ™ follows a downward path with temperatures of up to 2000°
||Inside the wood chamber looking
through the wood loading door.
Alternate Heating Systems, Inc. standard sized Wood Gun™ Boilers are
smaller than the intermediate sized boilers but pack in the same
features and performance.
Wood Gun™ Wood Boiler Specifications*
|BTU/H (Max.) Wood
|Oil (optional) **
|Fire Box Capacity
|Max. Log Length
|Domestic Coil Gal/min (Optional)
|Rec. Sizing (BTU/hr)
|BTU/H (Max.) Wood
|Net Steam Rating (BTU/H)
|Gas/Oil Chamber (water capacity)
|Weight (w/o gas/oil - lbs)
|Minimum Boiler Room (w/o Gas/Oil)
|Minimum Boiler Room (with Gas/Oil)
* Specifications and design subject to change without
All specifications shown are approximate.
** Models E180 and above have a
built-in oil firing chamber that is present whether
or not the oil burner option is ordered (see Wood Gasification
above). On models E100 and E140 the oil burning chamber is
to the unit and is only included when the oil burner option is ordered.
Producing More BTU's
If more BTU's are needed than the maximum produced by one of our boilers,
then two or more boilers may be used together to produce the amount of BTU's
* Results of Fire Tests at
Arnold Greene Testing Labs
| Model: E180 -
Stainless Steel 1/4" Plate 304
4 Stack Size: 6" (positive pressure)
#2 FUEL OIL:
| Net stack temp: 126 degrees
|| Net stack temp: 227 degrees
| Smoke non-visible, hardwood
|| Smoke non-visible, #2 fuel oil
| Total Efficiency: 84.6%
|| Total Efficiency: 85.75%
Optional Wood Gun™ Wood Boiler Accessories Include:
Domestic hot water coil
Additional coil fittings
Four hour cycle timer with on/off switch and pilot light
Burner firing tube (Model E100, E140)
- Oil backup package with Riello F5 burner (E100, E140)
- Gas backup package complete including firing tube (E100,
- Oil backup package available separately - includes firing
chamber, oil burner nozzle, L6006A Honeywell Aquastat,
selector switch, indicator light and Wayne burner
- Gas backup package available separately - includes firing
chamber, oil burner nozzle, L6006A Honeywell Aquastat,
selector switch, indicator light, and Riello burner
Automatic switchover and lockout fan delay package - for
oil or gas burner backup - hydronic unit only
Automatic switchover and lockout fan delay package - steam
Oil backup package (Riello) purchased separately (Models
E180, E200, E250). Includes oil burner, nozzle,
selector switch, and indicator light.
Gas backup package purchased separately (Models E180,
E200, E250). Includes gas burner, nozzle, selector
switch, and indicator light.
Fuel feed tube and dual draft (Models E100, E140, E180,
E200, & E250)
Electric backup package (Models E100, E140, E180, and E200
Fittings only for electric backup
Steam control and fittings package (Model E180, E200,
Smoke exhaust hood with 265 CFM blower (standard) or 362
The Alternate Heating Systems Water Wall
Each Alternate Heating Systems boiler, heater and furnace is designed so that
every piece of steel is in contact with the water in the system that is used to
transfer heat to your radiant floor heat system, radiator, baseboard hot water,
or heat exchanger. This design ensures the most rapid and efficient heat
transfer from the firebox into the water. Efficiency is increased compared
to other boilers that do not have this feature by allowing less heat to escape
from the boiler surfaces before it is captured in the water.
The American Society of Mechanical
Engineers certification is available on any of our boiler lines for an
additional charge. This certification assures that
the pressure vessel has been designed and constructed in accordance with
the ASME Code. This certification is required for all commercial
installations. The certification is also required for some residential
installations depending upon local codes - it is up to the homeowner to
determine the need for an ASME certification on any boiler purchased.