A Guide to the Chimney Cowl
Posted on January 11, 2010 by Samuel Cheeseman ----- Advertisement
A chimney cowl is a device that is designed to increase the ease with which smoke can rise up through a chimney so it can be dispersed into the atmosphere and away from a building. The cowl will usually resemble a hood and is most often produced from galvanized iron, aluminium or stainless steel.
Benefits
Chimney cowls are fitted over a flue and prevent the backflow of smoke. Backflow occurs when strong winds overcome the updraft inside the chimney and force smoke down and back inside a building. This can cause serious health risks as well as smoke damage to the interior of a property. The issue of backflows pushing smoke down a chimney was particularly problematic in the past when coal was burnt frequently. Large amounts of smoke were produced and a chimney cowl installation was necessary to ensure that the smoke was discharged safely outside. The role of these devices is less important than it once was now that legislation and regulations are in place which in many environments promotes the usage of fuels which do not produce smoke. Chimney cowls in homes with wood burners and log fires are still prove to be very useful.
A cowl also performs the secondary functions of protecting a chimney from blockages caused by animals as well as stopping rain from entering. Many species of birds and small mammals will often try to build their homes inside a chimney. A cowl will prevent this from being a possibility and is often fitted with a metal grate around its radius to ensure unwanted visitors are kept out.
Different Chimney Cowls
There are various chimney cowl designs currently on the market. The majority are static but some will revolve. This turning motion helps to prevent any downdraughts. One of the most effective chimney cowl types is the H-style design. It is produced from pipes which form a shape similar to the letter H. This design is particularly effective at preventing downdraughts when winds are strong. These cowls can however look cumbersome which has meant that they have gradually been replaced by smaller and more aesthetically pleasing designs. In spite of this they are effective and energy saving designs which are now seeing their popularity beginning to increase again.
Pricing
Many chimney cowl suppliers now offer these products are very reasonable prices through DIY stores, builder’s merchants and online stores. These cowls are relatively easy to install as long as you have safe access to the chimney and are comfortable climbing onto the roof of your building. Chimney cowl fitting can often be completed by most able bodied homeowners. The most basic cowl designs can be purchased from around £10 or $15 and will be suitable for installation in private homes. Some of the more advanced rotating models are significantly more expensive and can cost well over £100 or $150. Most cowls will be priced towards the lower end of this price range somewhere between £20 and £50. If ordering Chimney cowl products from a catalogue or over the internet you will need to allow for any postage and packing costs in addition the price of your cowl.