There are many things to consider when you choose how to heat your home. With so many different methods to choose from, you can take into account the cost, fuel availability, environmental impact and efficiency. Your choice will sometimes also be controlled by local legislation. In many rural areas, outdoor wood boilers are in use. You will recognize them as small sheds with a tall chimney. The reason why some want their heater in a separate building is that it lessens the risk of a house fire and carbon monoxide poisoning.
Since these boilers have much shorter chimneys than your house does, the smoke can infiltrate nearby homes. This is one of the reasons why these boilers are banned in many areas.
The smoke from these boilers is also more harmful, since the fuel burns slowly at a cool temperature.
Wood boilers work by heating up water that is then pumped to heat up your home. They can also be used to heat up other things, such as a pool.