I was wondering how to calculate the size and determine the correct location of radiators/baseboard for the given room. I can understand that using Slant fin heat loss calculator I can calculate heat loss. The reason I ask this because my back family room extension has Slant Fin baseboard along two wall (3 walls of that room is completely exposed to outside) and 4th side of the room leads to open kitchen) and that room is not heating as great as I want. Mind that those 3 walls are full of windows and 1 door. Rest of the house had recessed radiators.

Coming from an oil guzzler Columbia, to a new gas-fired Columbia MCB boiler. New one is set up with no minimum - the Hydrolevel Hydrostat was set by the installers with no minimum temp (i.e. the boiler only fires when the stat calls for heat). So the water temp is getting down into the 70's before the house calls for heat, at which time it'll run for a while and maybe (today is the coldest day of the year so far) getting up to about 130 degrees or so. Then the stat is satisfied and she goes off for several hours. So is there any issue with allowing a cast iron boiler to operate like this? I know on older systems it was recommended to keep the boiler warm (my oil guzzler maintained proabably 120 degrees). Thanks!