I'm using a homemade boiler and this is year #5 with it. All steel, and I'm heating my 1000 sq ft garage with 10' ceilings, and a 1680 sq ft house. Both structures are well insulated. I built both around 2003-4. The boiler is 180 gallons, and uses 3+ cord to heat the garage from mid October to May 1. I'm very pleased with it, and it produces almost no smoke at all. In the last 2 years, I've added the house to the boiler. How much can adding 50-100 gallons of capacity help? I'm thinking adding a tank in my crawlspace, and insulating it very well. My last stove was 340 gallons, and it seemed to work so much better with less wood. I know there can be other issues, but capacity was the first thing that comes to mind. As of today, I have the temperature set point at 145 with a 15 degree differential. I increase the temperature as the ambient temperature drops over the winter.
Thoughts???