Outdoor wood-fired boiler

It is made up of four main parts- the firebox, which can be either round or square, the water jacket, the heat exchanger, and the weather proof housing.

If not run hot enough, the exhaust gas will be thick and black, and the resulting ash will not be fully rendered.

Some newer outdoor wood boilers have a catalytic converter installed, to allow for a more efficient burn and treatment of the exhaust before it leaves the unit.

The most sophisticated systems use computer controls to direct air at different stages of the burn process at variable volume.

High efficiency outdoor wood boilers use down draft gasification must meet strict EPA Phase 2 Certification.