Connecting chimney to suspended wooden sub floor to increase air flow?

[Safety First]

This is related to another larger post of mine today, but I am hoping the issue with separate title will gain some some input of it's own.

So, Question is, if you have an unused ground floor fireplace that is blocked off- plasterboard and no vents, would it be sensible to add ducting to connect the chimney to the sub floor in hope that the draw across the chimney will pull fresh air into the sub floor from air vents around the house? I think I need more underfloor venting and should avoid the chimney sweating...

The chimney, btw, is rain capped but with air flow...

Any input gratefully received.

 

[Nige F]

It worked for me

 

[Safety First]

Thanks Nige... Do you mean you vented sub floor as my post, up the chimney?