Which Chimney Cowl should I choose?

Date Posted: 17 November 2016

How to choose the correct chimney cowl
If you know nothing about chimney cowls, it is difficult to know where to start!
Anti-downdraught cowls, wind cowls, spinning cowls, chimney birdguards, chimney caps and rain tops are just some of the products you will find listed under ‘chimney cowls’ on google and other search engines. You will also find chimney cowls come in a wide variety of price and quality.
At Colt Cowls we want to make sure you order the right chimney cowl for you. With this in mind, lets go back to the beginning…

Why do you think you need a chimney cowl?
You may have been told by your chimney sweep that you need a chimney cowl. You may have seen that the Joneses at number 48 have one, you may even have seen chimney cowls on display at your local builders merchant and thought…maybe I need one of those!?
Whatever the reason for your initial thoughts about chimney cowls, the likelihood is you have probably encountered an issue with your chimney, stove or fireplace. Perhaps you have had a lovely new fireplace installed and smoke is blowing back in the room when you light it on a windy day? Perhaps you have had a bird get trapped down your chimney?.. or even that rain water has been coming into your stove or hearth? Colt chimney cowls solve these chimney problems and that is why you might well need a Colt chimney cowl.

What do chimney cowls do?
Chimney cowls have 3 primary functions:
1.    Chimney Cowls help prevent rain entry into chimneys. The most basic function of a chimney cowl is to stop water ingress. Makeshift cowls were put on chimneys going back millennia!...and their main function was simply to stop water entering the dwelling.
2.    Chimney cowls stop birds and animals entering the chimney. Another reasonably basic function of a chimney cowl is to stop birds and other animals getting down a chimney and into your house. Birds are renowned for causing many problems when getting down chimneys and can go on to cause damage inside the house if they make it down alive. If they get trapped and subsequently die, there are issues of decay and the nasty odours and maggots this process might produce.
3.    Chimney cowls prevent downdraught. Downdraught is caused by negative air pressure at the top of a chimney. This can be due to many factors and is not a precise science. These factors can include nearby buildings, overhanging trees, swirling wind conditions, chimneys that stop short of the apex of the roof and many more. Whatever the cause, it can result in air being forced back down the chimney and out into the room through the fireplace. Obviously, on a day when you have the stove or fire on this can result in smoke puffing back into the room which is not only dangerous as it contains nasty gases including carbon monoxide which can be deadly, but is also extremely unpleasant for those in the room.
4.    Chimney cowls can increase draw . Although above we have said that chimney cowls have 3 primary functions, there is a 4th function which really comes under the 3rd fuction preventing downdraught. Some chimneys suffer from a lack of draw. In other words, when the fire is lit it struggles to ignite and the gases do not flow up the chimney rather the smoke stays down in the fireplace or stove. This can sometimes be solved by warming up the chimney (by burning some newspaper inside the chimney) as cold air can often act as a plug in the chimney preventing the hot air from rising. However, there are other solutions including Rotorvent® chimney cowls which actively increase draw.

Which cowls suit which functions?
Colt Cowls have lead the market in the manufacture of chimney cowls since 1931. We have more experience than anyone in solving chimney problems. The Colt Cowl, invented in 1931, was the first commercially successful anti downdraught chimney cowl. In the last 80+ years over 3 million have been successfully installed. Therefore we believe we are well qualified to provide an easy to use guide for chimney cowls. Below we list the best chimney cowls available on the market for the functions already listed. To learn more about these cowls simply click on the links to be taken to the relevant page.There may be multiple entries for some cowls as they have multiple functions.

Rain prevention in chimneys:

Rain Top Earthenware
High Top BIrdguards
Top Lid 3

Bird and animal entry protection in chimneys:

High Top Birdguards
Cone Top Birdguard
Bucket Top Birdguard

Chimney cowls that reduce or eliminate downdraught:
Colt Tops
Colt Top 2’s

Chimney cowls that prevent downdraught, prevent bird entry and reduce rain entry (Universal or All Purpose cowls):
Colt Tops
Colt Top 2’s

Chimneys  cowls that increase draw:
Rotorvent Ultralite
Rotorvent Turbolite
Mini Rotorvent


How to fit a chimney cowl: Fitting a chimney cowl, fitting a birdguard, fitting a spinning cowl, fitting a pot hanger cowl

Check out these great videos on how to fit a chimney cowl. Fixings for chimney cowls include strap fixing with jubilee band, and hook bolt fixing depending on the type of chimney cowl being fitted.

We hope that the above guide helps you make your final decision on which chimney cowl is suitable for your needs. Please note that each cowl will have a suitability for each fuel. This can be seen on each product page.

Lastly, please note that if you search for these chimney cowls through search engines be sure to use the correct descriptions to be certain you are buying an official Colt Cowl product. Sadly with the boom in the solid fuel industry since about the mid 2000's a number of inferior chimney cowl companies have come into the market and attempted to make similar looking products out of inferior materials. One last check to be certain you are buying a Colt Cowl is to look for the Colt Cowls quality seal, a small circular hologram which distinguishes you product as Colt Cowls quality. The Colt Cowls quality hologram can also be seen in the chimney cowl fitting videos above