None of the induction cooktops have exhaust fans. Is it necessary or not? If necessary, what are the options? I now use downdraft.

Hi - Thanks for considering our GE Profile Induction Cooktop! Most range or cooktop models do not require a ventilation system or have a CFM requirement; however, we recommend checking the local residential codes in your area to see if one is required. We also offer Universal 30" Telescopic Downdraft System UVB30SKSS. Raises over cooktop surface and retracts when not in use. This 370-CFM venting system with four-speed fan effectively removes smoke, grease, odor and moisture out of the kitchen air. We suggest to view the Quick Specs at the following link for dimensions: https://products.geappliances.com/MarketingObjectRetrieval/Dispatcher?RequestType=PDF&Name=UVB30SK_c3%202.pdf - You can also view the Installation Instructions for complete details: https://products.geappliances.com/MarketingObjectRetrieval/Dispatcher?RequestType=PDF&Name=49-80777-1.pdf - Check out our new Wall Ovens with PRECISION COOKING MODES- Select from preprogrammed cooking modes to get perfect results every time. Play Video: https://www.youtube.com/embed/EFa1TOdziwM?rel=0 - Also, the bright, 7" brilliant interactive touch screen makes it fun and easy to program the oven. Play Video: https://www.youtube.com/embed/F3CO4tNIfKc?rel=0 - * GE Profile™ Series 30" Built-In Double Convection Wall Oven PT9551SLSS / *GE Profile™ Series 30" Built-In Single Convection Wall Oven PT9051SLSS. We'd love to have you in the GE Appliances Family! Keep in touch - Sue