What rooms should ventilation vents be placed in?

Hi,
We have open chimneys in two bedrooms in our house (built c. 1950) but no wall vents. Does anyone have any idea what the best solution is for ventilation? One option I thought was best was to close up the fireplace leaving a very small hole so that the chimney can be ventilated and then to add controllable wall vent or humidity sensitive wall vents. I am assuming here that since I have closed up the fireplace except for a small hole to ventilate the chimney that this would no longer be sufficient to ventilate the room. Anyone know what the airflow in a closed up chimney is like?
Thanks.

onq said:

Hi


A litre of gas produces a litre of water vapour which can build up all too easily

Click to expand...

Actually, I think that 1 litre of methane (at standard temperature and pressure) produces 2 litres of water vapour and 1 of carbon dioxide (at STP). For every cubic metre of methane burned, 1.6 litres of liquid water is produced at standard temperature.

CH4 + 2O2 -> CO2 + 2H2O