I am thinking about getting a outside wood burning water heater to heat my home. I came across a company that has a down draft burning system heater and they say it is the best this, best that, most efficiant ………. There must be some not so good points about this type,what are the pros’s and cons? Where can I find more information on this type and other out side water heating burners (corn,wood pellets) other than the manufacturer or sales person? What is the best one to get, can a person build there own, whre can one get plans to make a efficiant one…….?