DIY CO2, worth a go?

I've done quite a bit of reading about CO2, but as with much internet research, I wound up with some conflicting info and different ideas about how best to proceed.

I should state that I really don't have any more money to throw at my grow unfortunately, so anything I do has to be rock bottom price, or ideally, free.

So my idea which I would like advice on is this:

Big bowl of warm water with yeast and sugar placed in the grow room when lights go on, removed just before lights off. Place it by the air intake duct and behind the circulation fan so it gets blown all over the grow room.

Any potential problems with this setup?

Will it deliver results, given there is an extractor fan running? Can't turn the fan off as heat will build up too quick.

Will it be sufficient CO2?

Will it be maybe too *much* CO2?

Is it actually worth running CO2, and if so, are there any better (cheap / free) ideas than yeast and sugar?

Not sure about the amount produced by yeast method but there are charts that tell you the quantity of CO2 required to raise the room amount based on size. Also you will not be able to exhaust from the room as it would be waste of effort.

have grown with DIY CO2, didnt notice the difference from without it given i used a small amount of fermenting material. we have plenty of CO2 in our air, some places more than others im sure but nonetheless theres plenty for them to feed off of, will be even more tomorrow.

with commercial CO2 emitters however, effects are quite noticeable in yield, bud is much more dense with a carbon rich environment. just make sure you dont get a leak, if you die you cant enjoy that harvest.

Ok, thanks, this clarifies matters and I don't think I will bother - I can't turn off my exhaust, the heat build up would be disastrous, even though they can cope with higher temps. I reckon it'd be 40 - 50 degrees C in there with no exhaust!

Thanks guys