Thank you for your question on the Broan model 658 heater/fan unit. This model is rated at 70 cfm's with 4.0 sones when installed properly. We do not offer another heater/fan unit like this that would have a lower sone rating. The bulb heater/fan models are 70 cfm's with 3.5 sones and have a similar housing size. Other heater models that we offer that have a lower sone rating would also include a light. Please contact our Technical Support for more assistance at 800-637-1453.