H Cowl Anti Down Draught Chimney Terminal
If you are having down draught or up draught issues with your chimney this H Cowl might be the solution.
Fit easily within minutes, no tools are required to assist the fitting process you simply use adjustable toggle clamps to secure the H Cowl to the Chimney Pot.
The H Cowl is made from a durable corrosion proof stainless steel and is designed to fit the majority of conventional chimney pots
The H Cowl will prevent rain ingress and promote positive updraught.
It has no moving parts once fitted and will be silent in whatever weather conditions.
The H Cowl is designed to fit over all standard chimney pots with an 8 inch internal diameter.
If your pot is not 8 inches or if the chimney pot has an unusual design like an external lip we can get a custom made H Cowl for you that will fit. Call us on 066 71 36 486 to discuss this option.
How the H Cowl Chimney Terminal Works
In normal or still air weather conditions the hot gases and smoke pass up the chimney and exit out of the top of both o of the vertical tubes.
If wind drives downwards in turbulent weather conditions the air moving down the tubes induces suction as it passes the horizontal tube and the hot gases and smoke exit out of the bottom of the vertical tubes.
H Cowl Dimensions
Height (standing pre install) 500mm
Width 750mm
Depth it goes into Chimney Pot 230mm
Height (post install) 270mm
What is the Difference Between the H Cowl and the OH Cowl?
H-Cowl
In normal or still air conditions the hot gases and smoke pass up the chimney and exit out of the top of both of the vertical tubes. (See diagram below on left)
If wind drives downwards in turbulent conditions the air moving down the tubes induces suction as it passes the horizontal tube and the hot gases and the smoke exits out of the bottom of the vertical tubes. (See diagram above on right)
OH Cowl (Available to order here!)
In normal or still air conditions the hot gases and smoke pass up the chimney and exit out of the top of both of the vertical tubes. (see diagram below on left)
If wind drives downwards in turbulent conditions, the air moving down the tubes increase in velocity because it is restricted as it is forced through a narrow gap as it passes over and around each end of the horizontal tubular section projecting half way into the vertical tubes.
The increase in velocity (basically a venturi effect) induces suction as it passes the horizontal tube and the hot gases and smoke exit out of the vertical tubes. Any upward gusts of air will also act in a similar manner so this design of OH cowl becomes very effective in windy conditions where the chimney is subject to downdraught. (see diagram above on right)
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is there a H-Cowl solution for 2 opening from 2 fireplaces on one chimney?
Afraid not Tommy sorry.
Can u put a h cowl on a chimney that has a liner in it
You can of course Desmond! As long is pot has an 8 inch internal diameter it will be fine.
Our chimney has a 10.5″ outer diameter. We get serious down draught! Would you have a h cowl that May solve our problem and what price please?
What is the inner diameter Clement. If it is greater than 8 inches we can get one custom made for you. It will cost about 40 euro extra though.
Hi… I don’t know whether I need a H Cowl, OH Cowl or the spinning cowl… have terrible downdraught in windy conditions… cannot light the stove in this case… Chimney is stainless steel one off the stove- built to spec- right height etc, house is a bungalow… need to get this sorted as it is a waste.
The H Cowl is especially designed to address down draught issues so it should help solve the problem.
I have an oil converted Aga, hugh problem when there is an east wind, it almost goes out. Any thoughts?
If doesn`t have huge downdraught problems, Storm Cowl will be perfect in this situation. Is round and will assist on wind redirection.
If there are downdraught problems as well, H Cowl would be the best, but is a massive cowl and don`t know how will face to a strong wind. Still think that Storm Cowl could be the best solution.
we have a stove & have had a spinning. Cowl which helped with lighting the fire with the updraught however its passed its best & we want to replace it with something similar but not a spinner as it keeps us awake at night. Any options?
The best cowls for updraught are Spinning and H Cowls. Given the noise issues you have had with the spinning cowl I would suggest trying the H Cowl.
I’ve a stove which has very little draw on calm days , we replaced our chimney flues recently with ceramic flues due to fire damage and my builder said that he installed a spinning cowl to address the draw issue. However , on calm days or until the fire is well lit opening the door will emit a lot of fumes from the stove . Is there any other cowl to help with this issue?
I would hope that a H Cowl might address the problems you are having but I can’t 100% guarantee it would. We are selling them for over 3 years now and the only time we ever had a return was when the customer didn’t have a standard 8 Inch Chimney Pot. Even in that case we were able to get the manufacturer to make a custom size for the customer. It is also possible that there may be a structural issue with the installation of the new flues
I HAVE A STANDARD FLUE AND BURN COAL OR WOOD AND HAVE DOWN DRAUGHT WILL H COWL SOLVE THE PROBLEM.
There can be no guarantees with anything but in 4 years selling H Cowls we have yet to find a customer dissatisfied with the product.
Also check out the
I have an octagon chimney pot, is it possible for the manufacturer to make a suitable fitting H-Cowl?
Hi Catherine, If you email over the internal and eternal dimensions of the chimney pot plus a photograph of it we can make enquiries when the manufacturer and see what they can do. Email sales@purchase.ie
What pot diameter (internal) is suitable for the ‘H’ pot?
8 Inch Internal pot Robert!
I have newly installed wood pellet stove it’s burn normally on calm weather but alarm goes off on windy days saying there blockage . I think the problem is downdraught problem. Which cowl would solve this
Hi John,
If the issue is downdraught an OH Cowl is your best option. If it is an updraught issue then the H Cowl is best suited.
Hi i have skme updraught problem. Will oh cowl fix this or have to get any other cowl.
Every chimney is different but in general yes it will work. However if the chimney pot is lower than the nearby buildings or trees, won`t matter what type of cowl is used as you still won`t create enough up draught. In this situation only a chimney extender might solve the problem.