A most common and economical way of utilizing solar energy is to use a flatplate collector to capture incoming solar energy by heating either liquids or gases. Therefore, a solar collector should be the most critical part of the performance necessary for the system, since maximum available heat depends solely on the collector. In the present investigation, considering that most heat loss from solar collectors results from the natural convection between an absorber plate and a coverglass,it has been demonstrated that this natural convection can be suppressed and heat performances of a solar collector are enhanced by placing thin and poorly conducting honeycomb material between an absorber plate and a coverglass. By suppressing natural convection within collector spacing it has been shown experimentally that honeycomb structures effectively raise critical Rayleigh number, since they provide more shear surfaces.