Although the use of solar energy is obvious for the energy intensive nature of low-grade heating processes, solar heating technology has not yet become commercially available even in favorable geographical locations with high solar potential. This is not surprising, taking into consideration the unreasonably high cost of solar plants relative to the level of technology of most of the commercially available components and systems. In the present work an improved low-cost large solar heating system design has been proposed, based on earlier design developments, suitable for applications in mild sunny climates where the prospects for the promotion of solar heating technology are very favorable. An analysis is developed which allows design and operational behaviour predictions of the physical system. Long-term efficiency and typical input-output performance is also investigated based on statistically processed long-term meteorological measurements for Athens, Greece. Derived results indicate that substantial performance would be expected for the proposed fractional cost system design. This may probably lead to market expansion of large solar heating plants through ＇＇commitment based＇＇ promotion schemes.