An absorber plate is an essential component of some solar energy devices. As a primary energy conversion component, useful energy loss is not desired. The interactions and interrelationship between the parameters for use, insulation thermophysical properties, and ambient parameters are pertinent in the design of solar air heaters. A 2D finite element analysis was used to quantify the influence of edge convection heat loss on a simple absorber plate model. Results showed that the performance of the air heater can be significantly affected by edge heat loss from the absorber. The average temperature of the absorber, computed from the nodal temperature profile of the absorber, rose with superior edge insulation for low values of the heat transfer coefficient of the working fluid. However, when the ambient temperature was high, the average temperature of the absorber increased with poor edge insulation, although this condition is irregular due to fluctuations in the ambient condition. For low values of the heat transfer coefficient of the working fluid and low ambient temperature, the nondimensional edge loss flux was negligible for the absorber with superior edge insulation, and for high values of the heat transfer coefficient of the working fluid and low ambient temperature, the nondimensional edge loss flux was high for a poorly insulated absorber.