Wood is better in environmental terms than Multi-fuel as the amount of carbon dioxide released into the atmosphere is approximately the same as that absorbed by the tree during growth. It is also a renewable resource, particularly when derived from plantations and cultivated woodland. For optimum results, we recommend logs should be seasoned for 2 years or more to achieve a moisture content below 20%. This will not only give twice the output of freshly felled timber but help avoid a build up of tar in your flue. Furthermore, if you can obtain hardwood logs this is better still as they will have around twice the calorific value of softwoods.