Outdoor wood boilers come in a variety of shapes and sizes. In most cases, the bigger the better for these things. Next, you need to consider whether the boiler is open or closed. It makes a difference in the way it is connected.
Closed systems can be connected directly to existing boiler systems in a primary secondary configuration. This means that the wood boiler will circulate across two tees in your home system and the home system will circulate water through the house.
If your outdoor boiler is an open system, you will need to install a stainless steel flat plate heat exchanger to separate the two lines. Connecting the heat exchanger is not very difficult if you follow the instructions correctly.
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These heat exchangers have a major impact on the heat transfer from the wood boiler to the internal heating system. It also keeps water from the internal system pressurized and insulated.
If you are installing your outdoor oven in a convection heating system, you will need to purchase a coil similar to your car's radiator to install in the space on the supply side of your existing convection oven. You will connect the water line from the external boiler to this coil.
Outdoor wood boilers can heat your home efficiently when properly connected to your existing heating system. If installed correctly, you won't see a difference in how your home heats. It will be warm and cozy. Make sure you do proper research before trying to install your wooden kettle outdoors.