The importance of photoelectric heating by dust in planetary nebulae

We present theoretical self-consistent models of planetary nebulae includin g 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 str ong effect on the thermal structure and emission-line spectrum of highly io nized species in planetary nebulae. These models have implications for exci tation and energy balance methods for determining central star temperatures . We present results for [O III] lambda 5007 and [N II] lambda 6583 lines f or Galactic, LMC, and SMC abundances.