Having an open chimney is like leaving a window open all the time. Chimneys are designed to draw air out of a property. Any time the fire isn’t lit, precious centrally heated warm air from your house is being sucked out. You don’t necessarily notice the warm air escaping, but this causes cold air to be pulled in, creating the cold draughts that you can feel. It’s estimated that around 5% of household heat is lost up the chimney, but it’s an issue that is generally ignored by the insulation industry.
There’s a new product on the market, a Chimney Sheep™, that is designed to plug the gap in the chimney throat just above the fireplace, keeping the warm air in the room and significantly reducing cold draughts. It’s made of a thick layer of felted sheep wool on handle. Although a low-tech product, the wool had to be the right combination of stiffness to hold itself in the flue, and compressibility to fit a range of different chimney shapes and sizes.
After trying out a range of wool types, Cumbria-based inventor Sally Phillips found the wool from the hardy Herdwick, a local mountain breed, had the ideal properties. The product relies on being a little bigger than the chimney opening, so measure your chimney then choose a Chimney Sheep™ that is a few centimetres bigger on each dimension. If you want to light the fire, take out the Chimney Sheep™, put it in a wrap or bag and keep it until the fire is completely cold. The product is very robust and is designed to be inserted and removed hundreds of times.
The complete range of Chimney Sheep including chimney draught excluder accessories are available to buy online here from BHL.