The importance of photoelectric heating by dust in planetary nebulae

We present theoretical self-consistent models of planetary nebulae including detailed dust heating. Galactic, LMC, and SMC abundance patterns are used in a comparison of dusty and dust-free models. We show that dust has a strong effect on the thermal structure and emission-line spectrum of highly ionized species in planetary nebulae. These models have implications for excitation and energy balance methods for determining central star temperatures. We present results for [O III] lambda 5007 and [N II] lambda 6583 lines for Galactic, LMC, and SMC abundances.