Garn WHS-3200 Commercial Wood Hydronic Gasification Boiler
The GARN® Wood Heating System WHS-3200 is a highly efficient direct-gasification cordwood burner that heats an integrated, large water volume, thermal storage tank. The GARN® features several technical advantages over conventional wood burning equipment:
• Low Emissions: gasification is achieved with a high-temperature, non-modulated batch burn process.
• Simple: combustion air to the fire is not modulated, thus no motorized dampers or blowers that cycle on and off.
• High Efficiency: a large diameter, high surface area, 5-pass heat exchanger ensures efficient heat transfer.
• Safe: cool combustion air circulates around the combustion door keeping it cool to the touch.
- GARN® wood heating systems can burn cord wood, slab wood, dense wood briquettes, air-dried corn on the cob, pallets and other scrap wood. Emissions information is listed and certified for cordwood fuel only.
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GARN® hydronic wood boilers produce virtually no smoke because of its patented, two-stage wood gasification technology. A GARN® is not an outside wood furnace, outside wood boiler or an outside wood stove. However, it can be installed outside in a shed. The GARN® is designed to be installed indoors and provides hot water for heating your home, shop, business, or district heating system.
- Detailed below are the detailed design and compoents of the GARN® WHS and their funtioning purpose. The GARN® WHS series Hydronic wood boiler is big tank of water that you heat by burning wood. The fire is not modulated, the entire wood load is burned quickly while the heat is dumped into the large water tank. This results in a very clean, highly efficient burn. The outcome is less wood, less work, and less smoke, for you, the consumer. When the thermostat calls for heat, the pump turns on drawing the hot water out of the tank and into your heated space for distribution.
BURNING AND HEAT STORAGE:
1. Fresh air is ducted from the outside and enters the unit through an inlet in the back.
2. The fresh air travels through a tube immersed in the water and into the air collar.
3. The fresh air is circulated around the air collar before entering the combustion chamber. This keeps the collar relatively cool. The air collar distributes the air into the combustion chamber.
4. In the combustion chamber the wood burns in its first stage.
5. The smoke and exhaust from the fire enters the insulated reaction chamber. Additional fresh air is provided by the air collar. A high temperature secondary combustion occurs. The process is called direct gasification. Direct gasification burns the smoke and creates additional heat.
6. After exiting the reaction chamber the clean exhaust travels through 30 ft of tubing. Heat transfers from the very hot gases to the water in the tank.
7. The exhaust exits the GARN® WHS vertically or horizontally through a 6” insulated flue.
8. A digital controller automatically stops the induced draft blower when combustion is complete. The water is now hot and ready to be used for heat in a building.
Features of GARN® Batch Burner Wood Gasification Boilers
- Integrated Combustion
- Non-Pressurized Thermal Storage
- Double Weld Construction
- Secondary Gasification Combustion Chamber
- 5 Pass Heat Exchanger
- Large Insulated Loading Door
- Double Lock Safety Handle
- Hot Water Return (HWR) Dispersion Tube
- Manway Access
- Induced Draft Fan
- Air Cooled Door (Cool to the touch)
- Combustion Air Supplied from Outside
- 30 Years of Proven Technology
Benefits of owning an AMERICAN MADE GARN® Boiler
- Safe and Certified to be Installed Indoors
- No Overnight Loading or Fire Required
- Long Life, Low Maintenance Construction
- Reduced Wood Use, saving you Money
- Low EPA Qualified Emissions
- Easy to Load Fuel Chamber
- Cool to the Touch Loading Door
- Virtuall Smoke Free When Reloading Fuel
- Easy Maintenance (Step by step video instructions available)
- Simple and Readily Available Part Replacement
- Anodes with Water Treatment Minimize Corrosion
- Demonstrated Longevity
- Available Electric Backup
OVERVIEW AND OPERATION:
A GARN® WHS needs to be installed indoors. A designated area in a building, a separate building, or an attachment to an existing building is required.
This is the front of the GARN® WHS unit. The front is where you load wood, mount the blower, access the digital controller, drain the unit (when needed), and access the cleanout ports for periodic pipe cleaning. An overflow pipe is also provided so the first time you heat your unit the water that expands to the top of the tank comes out here. The GARN® WHS provides optional off-peak electric elements fittings up to 49.5 kW.
This is the back of the GARN® WHS. The back is where you connect to the 3” hot water supply and 2” hot water return, duct the fresh air intake, and vent with the horizontal exhaust (if applicable).
- Start a fire by loading the combustion chamber and adding some newspaper and small kindling. A simple match does the trick. The fire will heat up the tank of water.
- Reloading after a fire is easy, just open the combustion door. The induced draft blower ensure little to no smoke backdrafts into your space. You can then pile on more wood to get the water up to your desired temperature.
When your building calls for heat, a pump in your system turns on and draws the hot water from the tank and distributes it for heat. A fire need not be maintained constantly. That’s the idea behind storing the heat.
- The GARN® WHS is not pressurized and so cannot be directly connected to a pressurized system. The GARN WHS can interface with a pressurized system by simply installing a heat exchanger.
- When the GARN® WHS unit drops below the operating temperature of your system, start a fire and heat the water again.
|Specifications||Model GARN® WHS-3200|
|Maximum Heat Output †||700,000 btuh|
|BTU’s of storage (120 F to 195 F)||2,050,000 btus|
|Tested Efficiency (LHV)||85% *|
|Particulate Emissions output – PM2.5||Not Tested|
|Particulate Emissions rate – PM2.5||Not Tested|
|Nominal gallons of storage||3,200 gallons|
|Weight – Empty||7,500lbs.|
|Weight – Filled||34,500 lbs.|
|Recommended wood length||24″ to 42″|
|Recommended wood diameter||4″ to 12″|
|Combustion chamber length||50″|
|Combustion chamber diameter||40″|
|Combustion chamber volume||250 gallons|
|NPT supply flange||3″ (70 gpm MAX)|
|MPT return pipe||2-1/2″|
|Draft inducer motor||3/4 HP|
|Electrical requirements||115 VAC 15 amp|
|Flue diam. (2100°F Class A)||10″|
|Air intake diam. (single wall)– Includes screened intake hood||10"|
|Clearance to ceiling||36"|
†Maximum heat output is based on reloading once every 3 hours with 24 inch long split white oak, with 20% moisture content. Output rate is fuel dependent and will vary with wood type, moisture content, size and reloading frequency. GARN® WHS units are certified safe to burn cord or slab wood, densified wood briquettes and air dried corn on the cob.
*Tested to ASTM-E2618
This is the top of the GARN® WHS. The top is where you access the full-size manway (for water inspection and water chemical addition), anode rods (for corrosion protection), fill the tank with water, and vent with the vertical exhaust (if applicable).
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garn Maintenance: Replacing Manway Gasket
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Garn WHS-3200 Wood Hydronic Gasification Boiler Product Video