I have a vigas 60 sitting in my shop hooked to nothing. Plan to have it fired next fall. Just trying to decide on either two 500 gal tanks or two 1000 gal tanks. Have room for either size although the two 500 gal tanks would fit a bit better. My house a good size 4 level split with new doors and windows and well insulated. I also plan to heat dhw and shop (44x48) new and insulated well. I don't want it hot in the shop just above freezing.