The o h cowl is the recommend cowl for blow backs in a fire place.
H shaped chimney cowl.
This causes the wind to flow around the cowl which actually causes an increase in chimney draft.
With the dragon the wind turns the cowl in the opposite.
Although the h cap has a distinctive advantage over most other downdraft caps it fell out of favor because of its bulky looks.
A h style cap cowl is a chimney top constructed from chimney pipes shaped like the letter h.
An h cowl can be fitted to a round flue or pot with internal diameters between 100mm to 304mm.
Chimney cowls are hoods that fit over the top of a chimney stack.
How the h cowl chimney.
Normally caused by low chimney stacks and obstructions that can be around the chimney pot and is mostly noticeable when winds are blowing in a certain direction.
This cowl is strap fitted and hand made from 316 stainless steel and is suitable for all fuels.
It has no moving parts once fitted and will be silent in whatever weather conditions.
These are constructed from h shaped pipes and work by separating the combustion gases from the turbulence and winds that bring down the drafts.
This rotating action prevents the wind from blowing down the chimney stack.
The h cowl is made from a durable corrosion proof stainless steel with a terracotta finish and is designed to fit the majority of conventional chimney pots.
They are designed to increase the upwards movement of air in the flue ensuring that any smoke or other harmful gasses produced by a fire are quickly removed from your home.
The h cowl has a shaft which is just slightly under the diameter of the cowl so for example a 125mm h cowl will have a shaft with a diameter of around 120mm.
There are two types.
The h cowl is made from stainless steel recommended for solid fuels including coal wood and oil.
Revolving chimney cowls revolving chimney cowls are designed to eradicate downdraught in chimneys flues and ducts.
Stainless steel rotating chimney cowl.
Fitting to a prefabricated chimney system slide the cowl inside the chimney system.
The h cowl will prevent rain ingress and promote positive updraught.
The most popular type of chimney cowl is the h style or h pot and it has a definite advantage over other caps because it stabilizes the draft so your fireplace works more efficiently.
With the globe type the wind catches the fins and the globe rotates.
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.
In order to comply with regulations h cowls for gas come factory fitted with mesh birdguard inserts.
It then slides inside the chimney or flue system.