Cooker hood ducting - up an old chimney?

[robertoi]

Not sure if this is the right place to post this....

Im going to install a cooker hood in my kitchen, in a spot virtually directly under an old chimney breast in the room above.

Is it possible for me to pass the ducting up into the old chimney and vent it that way (about 5 to 6m vertical run), or would I run in to problems with fan power etc?

Thanks

 

[robertoi]

Just read somewhere else that doing this would not be a good idea.

However, comments on my alternative would be welcomed:

I have an RSJ running the width of my kitchen from the extrnal wall to a party wall. The cooker hood will be installed on the party wall, so a duct needs to get from that side of the kitchen to the other. I'd like to run the ducting alongside the RSJ if possible, and then box the two in together.

Obviously the RSJ is supported at one end by the external wall, so would making a hole for the ducting to exit by very close to that end of the RSJ, cause any problems?

Thanks in advance