About Us

As you can see, I do know what it’s like to install an air vent!  I installed over 1100 between 2008 and 2016, after which I retired.
I always hated putting in the air vent, and if a draught free vent was specified with a 5” diameter hole instead of 4” it was even worse; (I reckoned it took 3 times as long to drill a 5” hole straight through a wall than a 4” one from both sides).  Customers also hated the vents and often ended up blocking them up as soon as I left.
The DR21 air vent is designed for all stoves.

It has a number of advantages over competing designs:
  • The hole is 100mm, and yet the free air equivalent is 3400 sq mm. This is because the air vent sits on the outside of the wall, and does not reduce the size of the hole through the wall.
  • The hole does not need to be drilled straight through the wall from one side, you can use a pilot drill and drill from each side, or even use a breaker to go through the centre if the drill is snagging badly in wet brick, or it’s engineering brick you have to go through. You can use a plastic tube, or even a flexible tube if necessary, to go through a cavity wall.
  • The black DR21 air vent blends in with rainwater pipes on most houses. It can be hidden (e.g. behind foliage or a wheelie bin), and/or painted to match the wall colour. It is easy to change the colour in minutes with Plastikote spray paint, available widely online at £3.50 in 27 different colours, or CALFIRE heat paint.

If there is already a vent which does not reduce draughts (e.g. a louvred vent), the DR21 air vent can easily, and quickly, replace it.

If it’s a 100mm louvred vent then the DR21 air just slots over where the old vent cover is, and if it’s the standard plastic vent cover, even the holes are in the same place.

If there’s a 125mm vent, or a clay/brick vent then the DR21 air vent fastens over the top. This is the only vent which can replace any existing vent (you cannot increase a 100mm hole to a 125mm hole.)

It can also be used for:

  • Replacing underfloor air vents which will stop a draught blowing under your floor, while allowing enough air for the vital ventilation.
  • Replacing a bathroom vent, such as the one with the flaps which rattle all night. Should be a straight swap.
  • It is not best used to expel air from the kitchen (the fat in the air will eventually clog it)

If you already have a stove which is over 5kw installed it should, by law, have an air vent. It will not work efficiently without one as it will be struggling for air.

However, if your stove is under 5kw it is unlikely that you will have a vent; there is a concession which says that stoves under 5kw do not need an air supply. BUT, when this concession came into being, houses had windows and doors which did not fit very well, and a small stove could get enough air through these leaks. Windows and doors now fit, depriving the stove of the air it needs for combustion, and it will struggle. This means it will not be as efficient as it could be; it will use more fuel, it may also smoke, the glass may go black* and it may be difficult to light.

So, apart from improving the efficiency of your under-5kw-stove, and reducing the fuel it uses, fitting a vent has another advantage. At the moment your stove will suck air from wherever it can find it, and often the only place it can get it is through, or under, the door into the room, which might well be diagonally across the room from the stove, causing a draft round your ankles. But a stove will suck air from the easiest source when it is burning. When you fit a vent you can choose where you position the vent to avoid this unpleasant problem (full instructions are included with every vent).

To sum up:

End User. The DR21 air vent is very end-user friendly and easy to fit, and is priced at £19.99 incl VAT and P&P.

“Hi, You said it would take 15 minutes to fit, and I did it in 7. And the effects were immediate!” B.T. Cardiff.

Trade. The DR21 air vent:

  • Will save you time and effort to fit
  • you can fit one with every stove regardless of size, meaning that it is unlikely that you will have to go back because the stove was not working as your customer had expected.

"Love the product easy to fit easy to seal to the wall!” A.S. Angus
“Hi, It really is as quick and easy to fit as you say. Customer's happy too.” L.D. Exeter

DR21 Ltd is a family business, run out of my home-town of Knutsford, Cheshire. We’re a small company, but our product is made entirely in England and is manufactured ISO 9001:2015 standards. It was independently tested on the 24th October 2016 by BRE, one of the major facilities in the UK, and subsequently approved by HETAS.

The DR21 air vent is affordable enough to form part of any standard quote and its draft reducing qualities and modern look can be used to upsell customers to a higher-powered stove than they might otherwise have bought.

The DR21 air vent can be retro-fitted in minutes and can give you an added income stream when you carry out your annual service.

I think it is one of the most exciting developments in solid fuel installation in years, but don’t take my word for it, watch our video. We point a garden blower at a standard air vent and the DR21 air vent. The results speak for themselves.

Your sincerely,


David Gattie
Inventor of the DR21 air vent

*There are many reasons your glass can go black and lack of air is only one; the commonest is poor or wet fuel.

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