If there’s one thing that a stove or fireplace can’t do without, it’s oxygen. But, with today’s relatively air-tight homes, supplying your fire with sufficient air can be easier said than done. But, that’s where air vents come in. Keep reading and we’ll tell you exactly what sort of air vents you require to get your stove or fireplace burning properly.
Why are air vents important for fireplaces and stoves?
This may seem like a question with an obvious answer, but if you’re attempting to run an open fire in your home (be it in a fireplace or a stove), a sufficient oxygen supply is a fundamental ingredient in a well-burning fire.
Fire is a chemical process. When fuel burns, it reacts with oxygen from the surrounding air, releasing heat and generating combustibles such as smoke and soot. This process is known as oxidation.
Air contains around 21 percent oxygen, with most fires needing at least 16 percent oxygen content to burn.
So, without a sufficient oxygen supply, your fire simply won’t burn properly.
If you find that you don’t have a sufficient oxygen supply for your fire, then the solution is to install additional air vents.
But, how can you tell when you need additional air vents? You’ll find out below.
How can you tell if you need air vents for your stove or fireplace?
When it comes to the subject of air vents, one of the most common questions we receive from customers is, “do I actually need air vents?”
This is a question which doesn’t have a hard yes or no answer, but there are a few things to look for that’ll tell you whether your stove or fireplace would benefit from the installation of some air vents.
Your fire or stove is difficult to light/isn’t burning properly
This is the most obvious sign that your stove or fireplace could benefit from the installation of air vents.
If you find that the fire in your stove or fireplace is very difficult to get started (despite sufficient kindling and firewood), then there may not be sufficient oxygen reaching the fire to enable it to catch light.
Equally, if the fire in your stove or fireplace burns poorly, leaves fuel unburnt, gutters or even goes out, then that’s a surefire sign that it doesn’t have a sufficient supply of oxygen.
You live in a new build home
If you live in a home built from 2008 onwards, then it’s likely that you’ll need to supplement your stove or fireplace with additional air vents.
It’s because of something called ‘air permeability’.
Air permeability refers to the rate of airflow passing perpendicularly (i.e. at an angle of 90º) through a known area (e.g. a living room).
It is also referred to as ‘air leakage’ and essentially means the amount of air your home will ‘leak’ out. Due to modern building methods, new build homes tend to be a lot less ‘leaky’ than older homes.
Current building regulations require that newly constructed dwellings achieve an air leakage rate of around 5m³/hm² or less (this is the air leakage rate per hour, per square metre of envelope area). In general, homes built after 2008 achieve this level of air permeability (or less).
Therefore, because homes do not leak air as much as they used to, it means that many fireplaces and stoves are unable to ‘pull in’ sufficient oxygen to maintain a proper burn.
You are using a stove with a heat output over 5kW
Even if your home is not a new build, you may need to install additional air vents if you’re using a stove with a heat output of 5kW or more.
This is simply because your stove will be attempting to pull in a larger volume of oxygen than you will have available in your home. Installing additional air vents will provide the required air supply for your stove to reach its specified heat output.
A general rule suggests that you’ll require 550mm² of additional ventilation for each additional kW of heat output over 5kW.
You have poor chimney draw
Chimney draw refers to the flow of air from inside your living room, through your stove or fireplace and up and out of your chimney.
Chimney draw should occur automatically and is driven by the difference in pressure between the inside and the outside of your home.
However, the draw of your chimney can be interrupted in a number of ways. The first most common interruption of chimney draw is due to your house being too ‘air tight’. This can affect the balance in pressure so that your chimney ceases to draw air into it. This is solved relatively easily via the installation of extra air vents.
The second most common cause of chimney draw issues is obstructions and blockages within the chimney cavity. Buildups of creosote or bird nests can affect the draw of your chimney; however, they are easily removed by an experienced chimney sweep.
So, with the most common causes of poorly burning stoves and fireplaces out of the way, let’s take a look at the different types of air vents that are available to improve the performance of your stove or fireplace.
What types of stove and fireplace air vents are there?
If you’ve determined that you need to install some additional air vents, then what are your options? Below, we’ve set out the main types of air vent that are commonly used in UK homes.
Integral stove air vents
If you have a stove installed in your home, then you may choose to boost its oxygen supply using an integral air vent.
An integral air vent simply involves a pipe leading from a hole in an external wall, to the firebox of a stove. Because an integral air vent uses a tube to connect the hole in the wall directly to the stove, it has the benefit of eliminating any drafts from your living space.
However, only certain stoves will work with integral air vents. What’s more, because you need to connect the air vent to the stove using a pipe, this limits where you can place both the air vent and the stove in your home.
Wall aircone vents
Shop Now - Rytons Aircone Vent 5”
The other most popular types of air vent for use with stoves and fireplaces are aircone vents which sit within a hole in an external wall.
These types of vents typically have features such as:
> A draught reducing panel to help air disperse evenly into the living space (reducing the likelihood that you will experience a direct breeze from the vent).
> An external baffle to prevent water from running through the air vent into your living space.
> UV stabilisation of the external grill on the air vent. This slows down the effects of sunlight on the vent.
> The ability to paint or wallpaper over the interior-facing section of the air vent to help ‘hide’ the air vent on the inside of your living space.
> HETAS-approved, meaning that the air vent is safe for use with solid-fuel appliances such as wood burning stoves.
Note - if you’re buying a wall aircone vent for use within a high-rise building, plastic vents are not suitable.
Anti-draught air vents
Shop Now - DR21 Anti-Draught Air Vent
Whilst air vents, such as the wall aircone vents above, do include measures to reduce direct draughts, some people may wish to go a step further and reduce draughts altogether.
As illustrated above, dedicated anti-draught air vents use a labyrinth baffling system which regulates air flow, ensuring there is sufficient air flow to help your stove or fireplace burn properly, but prevent gusts or breezes from entering your living space.
The DR21 anti-draught vent which is pictured above is a particularly innovative air vent (and has been featured on BBC’s Dragons Den) and has a number of useful features, including:
> Air throughput of 3400mm².
> HETAS approved.
> Tested by BRE according to BSEN13141.
> Easy installation.
What’s more, the DR21 anti-draught vent can accommodate very powerful stoves (15kW or more). Simply use two air vents.
Fitting tips for fireplace and stove air vents
Once you’ve selected the appropriate air vents for your home, it’s time to install them.
Below you’ll find a number of tips which you can follow that’ll ensure you get the best performance out of your air vents:
> Remember, if you’re installing a stove in a new build property (built after 2008), you must ensure that you install at least one, permanently open, air vent within the room in which the stove is situated.
> Install your air vents in locations where they aren’t going to be accidentally covered up.
> If you live in a property with a suspended floor (i.e. floorboards with a cavity underneath), then you can always install the air vents in the floor rather than the wall.
> Place the vent as close as possible to your stove or fireplace. After all, it’s the reason you’re installing an air vent in the first place! This will reduce draughts across your living space and keep your home warmer.
> Your stove or fireplace will draw air from the vent. So make sure you aren’t situating them in such a way that a breeze will be drawn through living areas e.g. you don’t want an air vent on one side of a sitting room and the stove on the other. Every one sitting between the vent and the stove will feel a breeze!
Trade Price Flues: the home of stove and fireplace air vents
So there you have it; our complete guide to air vents for fireplaces and stoves. If you’re having issues with getting your fireplace or stove to burn properly, then it’s highly likely that a lack of air supply will be the source of the problem.
But, this can be solved with an appropriate air vent - available now from Trade Price Flues.
Shop air vents at Trade Price Flues now
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