If the problem (smoke or fumes coming out the fireplace or stove) occurs only in windy conditions then this is a downdraught. The anti downdraught chimney cowls to use are: A) Static Anti Down Draught Chimney Cowl if your problem is not severe, the Static Anti Downdraught Chimney Cowl can be found here.B) A Spinner Anti Downdraught Chimney Cowl if the your problem is severe can be found here
Lack of Draught:
If the problem (smoke or fumes coming out the fireplace or stove) occurs when there is little or no wind, then this is not a downdraught. This is a lack of draught. Anti downdraught chimney cowls are not effective at resolving a lack of draught, therefore do not purchase one, there is only type of chimneycowl to solve a lack of draughtand that is anElectric Fan Chimney Cowl
Too Much Draught / Fuel Use / Noise / Up-Down Problem:
A Chimney Control can be used to resolve all three of these problems, however, it can only be fitted to an solid fuel open fireplace. The Chimney Control can also be used to prevent an up/down problem. An up/down problem is when smoke rises up and out of one chimney and is sucked back down an adjoining chimney pot.