If you have a cast iron stove, you no doubt know how to manage the flue and dampers and how long it will provide heat to your home. But there are a few “hacks” that you can improvise that will allow you to capture, store and radiate more heat longer. This can be especially useful at night when you might not want to wake up at 3 in the morning to put another log on the fire.
It could also come in handy if you’re facing a particularly cold period of weather. We had wind-chills of -30 degrees Fahrenheit in Michigan last winter, and I used some of these tricks to get the most out of our cast iron stove.
There are several factors that affect the radiance of a wood-fired stove.
- The stove material. Cast iron is the most common stove material, but there are also masonry stoves that are built with fire brick and other materials to hold heat longer.
- The size of the stove and the amount of mass that is exposed to the air.
- Venting and the amount of stove pipe that is exposed to the air, including second story rooms.
- The type of wood that is used. Soft woods burn hot, but fast. Hardwoods burn low and slow.
What we’re going to explore are ways to retain the most heat from your wood-burning stove. For the sake of argument, let’s assume you have a medium-size cast iron stove. There are some fundamental things you can do to increase its ability to hold and retain heat.
1. Increase the mass of cast iron. This sounds a bit complicated but it’s as easy as placing some dry cast iron utensils, like a Dutch oven or a frying pan, on the stove top. The utensils will get quite hot — but that’s the idea. You want to capture as much heat and hold it as long as possible.
2. Place some fire brick in the stove and the stove top. Fire brick is relatively inexpensive and you’ll only need enough to put on the bottom surface of the firebox. They’re about two inches high, so you might be reducing the size of your firebox somewhat. That’s when you can go a different route and place the bricks directly on top of the stove. Don’t stack them too high. The benefit of fire brick is that it holds heat longer than cast iron.
3. Reconsider your chimney venting configuration. Be careful here. Stovepipes should have a vertical configuration and a double-walled insulated pipe anywhere it bisects the structure, such as a second story floor or roof. However, there may be an opportunity to install a single-walled length of stove pipe to draw more heat from the pipe to the surrounding air.
4. Install a catalytic combustor. These are honeycombed shaped inserts that are covered with platinum to create a more efficient burn in your stove. They don’t work in all stoves, but are worth considering if you want to improve efficiency. The primary benefit is that they help to burn much of the smoke that is normally wasted heat in a traditional stove.
Proper installation and venting are critical safety factors for any wood-burning stove. These ideas are improvised solutions, and the two safest options are the insertion of fire bricks into the base of the firebox, or the installation of a catalytic combustor if your stove can accommodate one.
Placing anything on the stovetop, whether it’s cast iron utensils or fire bricks, requires some added care and attention in the event something falls to the floor.
Of course, these alternatives are proposed as short-term solutions in the event of extreme cold. If you need to combine too many improvised solutions like this, you might want to consider a new stove.
What tips would you add to this story? Share your advice for wood-burning stoves in the section below: