A customer of ours in Bend, Oregon shared this picture of two 1500 Series heaters installed side-by-side on the south face of a new cabin construction. They chose to mount the solar panel for the fan on the side of each unit just in case seasonal snow comes up over the bottom face of the heater during the winter.
In this install our customer is getting 10k BTUh peak with two 1500 units, and chose to run independent fans on each unit - running at about 70-80 CFM each, both connected to a single thermostat with the living space. They are reporting a 20 deg increase in interior air temperature over the first hour of incident daylight at this time of year without yet having the space insulated.
A close up of the install is below - all and all a great looking installation which should provide years of fuel & electricity free supplemental heating!