The use of concentrated single-sided and double-sided absorber evacuated tube heat pipe solar collectors is seen to be feasible for integrating solar thermal energy into buildings for heating demands. The concentrated double-sided absorber evacuated tube heat pipe proves better compared to the concentrated single-sided absorber evacuated tube heat pipe solar collector due to higher outlet temperature with greater temperature differential and improved thermal performance. The integration of this innovative system implies that the number of the evacuated tube heat pipe collectors needed to attain higher temperature is reduced. Furthermore, the size of reflectors and related reflector losses are reduced due to the truncated nature of the reflectors providing a low concentration ratio.