I just finished the installation a couple of weeks ago and yes the Boiler is practically smoke free. The only downfall with an outdoor boiler is the amount of time and money the installation takes. In a typical year we burn around 1800 gal of oil right now the going rate is 3.60/gal which is 6480.00. I paid 8000.00 for the boiler and around 3000.00 for all of the extras. With that said we are talking about a 2 year payback. We looked into solar, but even with the state incentives it would still take 18 years before the system would pay it self back. Without a doubt a good gasification boiler is the best bang for your buck if you want to go green and save money at the same time.