 • As seen in the Trombe wall design and construction section, the performance of the Trombe walls is well characterized for a variety of design and climate parameters.Possible other modifications can be adding a rigid insulation board to foundation area and insulation curtains between the glass and thermal mass to avoid heat transfer into the building during undesired periods or heat loss from the Trombe wall to the foundation, or adding a ventilation system into the wall system (if the wall has upper and lower vents) to provide an additional heat transfer by air convection which is desirable to circulate the air evenly.• Energy delivery to a living space is more controllable than for a direct-gain system.