windthrown
361 Junkie
Run radiant heat under your tables!!!! Why heat the whole place when only the plants need it? If you are undersized for an OWB you must use a little Yankee ingenuity. Radiant? Coal? Thermal Mass? Electronic T-Stats? Insert or stove in house? It's all about trial and error. The folks here want to help.
Yah, that is the secret that several Russians that I know figured out when dealing with heating greenhouses. You do not heat the air, you heat the soil, and let that heat radiate up to the plants. Or you run heating coils and mats on benches if you have them, and that warms the pots and plants. I found that I had to move my plants in the greenhouse to the soil level, and not keep them on benches. They did a lot better being close to the ground, and the thermal mass that the ground provides.