Dear dcoop2,

Thank you for your inquiry. It depends on the frequency and
type of cooking that is performed. Normally, every six months is recommended
for replacing the charcoal/carbon filters. The cost for carbon filter depends
on your model, usually $25 to $30 a set.

I hope this helps. If you have any further concerns, please
feel free to contact us. Our Business hours are M - F, 9AM to 5PM PST. If your
message is left after business hours, we will respond to you on
the next business day. Thank you for your patient.

Best Regards,

GV Customer Support