Many wood fired cook stoves require quite a bit of space behind them to operate safely, but many folks that buy wood cookstoves have small cabins or log homes. Obadiah’s Woody Chain came up with a solution by employing some simple engineering formulas (shhhh, don’t tell anyone). In these videos, Woody explains how his heat shield for wood stoves works and shows you how they install.
Woody’s double layered heat shield for wood stoves is actually a convection generator, It works without electricity and operates on the principles of thermodynamics. The heat shield is hollow, open on the top and bottom. As the radiant heat from the rear of the stove hits the heat shield, it is absorbed by the first layer of steel, which also heats up, heating the air in-between the next layer of steel. It begins to rise like a hot air balloon and exits the top of the heat shield carrying with it some of the BTUs that would have been transferred to the second layer of steel in the heat shield. This is called “convection”, and it’s all perfectly natural, takes no outside energy to create, and the ability of the heat shield to cool itself works much like the radiator in a vehicle cools the engine.
Woody says that his heat shield will increase the convection heating ability of the wood cookstove by at least 30%, transferring the radiant energy that would have been absorbed and trapped in the wall behind the cookstove. This is where the fire danger begins if the wall is framed with wood; simply adding a layer of brick in front of it doesn’t do much more than absorb and hold heat, which is not really a good idea as over time the wood in the wall will dry out.
It takes three things to make combustion: Fuel, heat, and oxygen. No spark is needed for a very real and common fire danger called “spontaneous combustion”. Country folk will remember the neighbor’s barn that burned down when their hay caught fire by itself… Because they put it away damp. This occurs due to the material drying out to a zero moisture content and, as excess heat is applied over time, enough air can get in through electrical holes and POOF- many years down the road, on a really, really cold night when the fire is burning hot, combustion happens. This is a major cause of fires in North America.
Some very simple measures can prevent this from occurring: Caulk your plumbing and electrical holes with fireproof caulk (as required by commercial code in many states these days). Follow the tag on the stove if it has a UL listing for clearances to combustibles. If you don’t have the room, you can reduce your needed clearance by 68% by prepping your walls as Woody shows you in the video “Installing a Cookstove Safely in Tight Quarters”. Or, you can buy a ready made heat shield that bolts to the back of your Wood Cook Stove.
To see more about our heat shield for wood stoves, check out the videos below and please visit Obadiah’s website here.