Launched in 2005, the M.A.D (metal anti downdraught) brand of chimney cowls has become the most dominant brand in the UK.

Because the Aderyn cowl faces away from any wind, a low pressure zone is created on the lee side just above the chimney pot. The result is better chimney function, which reduces the chances of tar and creosote formation that can occur in sluggish flues. MAD Cowls manufactures 3 different models of static anti-downdraught chimney cowls – the Senior, the Junior, and the MAD. All models have an aerodynamic shape that will divert directional wind across the top of the chimney to draw the smoke out and preventing downdraughts. All Colt Cowls are manufactured in an ISO 9001:2015 accredited factory. To be sure you are getting Colt Cowls quality please look for a holographic version of the Colt Cowls Quality Mark above. This hologram only appears on official Colt Chimney Cowls so you can be sure you are getting the genuine article, and not an imitation.At J D Burford/Mad Cowls we regularly speak to customers who need us to specify the correct cowl for them, based on the specific set of facts they provide us with. When doing so, the most important question we ask is, what problem are they trying to solve when fitting the cowl? Often a customer will be under the misapprehension that there is a general purpose cowl for all applications. However, this is not always the case anymore, and although some manufactures still purport to be able to deliver such a cowl we believe that this is no longer the case, and such manufactures are out of touch with modern demands – using old out of date and redundant cowl designs. Observations have shown that birds do not like the Aderyn cowl. For obvious reasons! In addition, the moving body prevents birds perching and discourages approaches for the purpose of nest-building. Painted versions have a corrosive resistant powder coat finish, which makes it suitable for all fuels (see fuel chart)

Explained further– It is our opinion that no spinning/revolving chimney cowl is suitable for use with peat or smokeless fuel without increased levels of annual maintenance, that is why we do not offer a guarantee when these fuels are used. Mentioned within our product bulletin above gives customers an insight into the vast knowledge we possess in the field of metal engineering. Be assured we know the limits of the materials used within this product type; It is our expressed opinion that no spinning/rotating chimney cowl can cope with such acidity levels on a prolonged basis, without failing. If it is your desire to use the spinning cowl with smokeless fuel, all we ask is to be prepared to carry out maintenance at shorter intervals. That said, our spinning cowls are made to the highest standards, and should a customer want to use a MAD Spinner cowl outside our warranted recommendations, then we have spares on hand, to ensure that our spinning cowls can be serviced and/or repaired more frequently. The MAD Cowl is not to be used with smokeless fuel. It is recommended using the MAD Junior Stainless Steel or MAD Senior Stainless Steel when in use with more corrosive fuels such as smokeless fuel The cast aluminium base is exceptionally free-flowing and offers very low impedance to flue gases. The open body of the cowl has a clearance area greater than the chimney pot cross-sectional area and likewise offers very low impedance to smoke and flue gases. An effect of standard Chinese-hat type cowls which is not often appreciated is the tendency for smoke to ‘bounce’ off the underside of the cap and travel downwards thereafter. To understand the effect, try holding a spoon the right way up under a running tap! In certain conditions, this is enough to send the smoke right down to the ground where it can become a nuisance. By contrast, the Aderyn Cowl simply deflects the smoke, which can continue to rise at all times.Compact design which allows it to be fitted side by side where space between chimney pots is restricted iii) and lastly (which is common in the most popular of new smaller compact cowls that purport to achieve both of the latter), the senior does not restrict the flow of gases where smaller compact cowls often do. The wind blowing across the top of any chimney is rarely a smooth, steady, laminar flow. The proximity of another building, trees, adjacent roof pitches or other feature will cause turbulence which can frequently cause problems. Obstructions often produce ‘rotors’ that result in reverse flow in the chimney, or downdraught. Everyone has experienced reverse flow, which is commonly only temporary, but causes the fire or stove to puff clouds of smoke into the room. No cowl can be guaranteed to cure all types of downdraught as the causes are so varied, but tests and observations have shown that the Aderyn cowl is one of the best at doing exactly that because unfavourable downward air flows are split by the cowl and directed over each side of the pot, and the low pressure zone just above the pot is pre-served, maintaining chimney function.