Many people seem to forget that a chimney is actually designed to “suck” warm air away from a room and the fire burning in the grate. This is the way that it is designed to work to ‘draw’ the smoke away with the hot air that rises above the fire, ensuring that it does not enter the room.
Cooler air replaces the air lost up the chimney and provides the oxygen required to keep the fire burning. The problems arises when the fire is not in use, as the hot air from the room will be drawn, unwanted, up the chimney. This is often referred to as the “Stack Effect”.
The solution is to block the chimney temporally to stop this draw. Also by blocking the chimney you reduce other household draughts as cold air is pulled in to your homes to replace the warm air lost up the chimney.
What is required is a temporary draught excluder that will fit up your chimney. There is a range of options that you can choose to do the job, but the key thing is that it must stop the air flow and should ideally be easy to insert and remove without getting too sooty.
How Does the Chimney Sheep Work?
The Chimney Sheep is a section of wool which is held on the end of a sturdy plastic handle, which screws into the woollen head or “sheep” so that you can insert it. It is low-tech simplicity at its best. All you need to do is stuff it up your chimney and then give it a little tug back down to ensure it is securely inserted.
You do need to ensure that you get the right size Chimney Sheep for your flue; there are 9 different sizes. This is the only messy bit as you need to stick your in the (unlit!) fire and measure the size, which is very easy.
- For a circular flue – measure the diameter
- For a square or rectangular flue measure the width and length
Then take these measurements to the sizing chart on the Chimney Sheep website and you can very quickly work out the size you need.
The fit should be snug one so that no draughts can get up the chimney and that the Sheep will be held in place by the sides of the flue. It should fit into the narrow part of the flue – you will feel it as you push it firmly into place. A gentle tug back will ensure a secure fit.
The handle and a useful tag will hang down into the fire place to remind you to remove it before your light the fire again.
Looking After Your Chimney Sheep
This is a fantastically easy bit of low tech kit to look after. When it is removed it will be a bit sooty and dirty. Put it in a sturdy plastic bag or leave it in the coal scuttle until needed next.
If you do feel it could do with a wash, you just remove the plastic parts and washing on a wool cycle, but don’t tumble dry it.
Some chimneys are rough, particularly stone and brick ones. This can fray the edges of the wool, but this can be tidied up with a pair of scissors. If the Sheep becomes misshapen it shouldn’t matter, just remove it from its clamp and turn it round so it is inserted the other way, so it fills the flue easily again.
DIY Doctor Opinion on the Chimney Sheep
There really is nothing not to like about this really simple solution to an age old problem. It’s not revolutionary, but then it doesn’t need to be. We love low-tech when it does the job and there is nothing to go wrong.
In short we think that this is a great, cost-effective solution for anyone with an open chimney or flue.