Most kitchen Chimney ships with a plastic pipe in India. You can use the plastic Chimney pipe during installation but it is not recommended to do so. The plastic pipes develop holes after a few months due to the hot air passing through them. So it’s better to go with the aluminum pipe which is more long-lasting than the plastic ones. They are not a costly accessory so it’s a no-brainer to go for them.
You need to make sure you buy the chimney pipe with the right dia. Check your chimney manual to see the pipe dia. It will be mostly 4 inches or 6 inches.