A wood stove heat reclaimer, also known as a heat exchanger or a heat reclaimer fan, is a device that recovers and redistributes heat that would otherwise be lost up your chimney. It’s an excellent way to increase the efficiency of your wood-burning stove and make the most of the heat it produces. In this technical guide, we’ll walk you through the process of building your own wood stove heat reclaimer.
Understanding the Concept
A heat reclaimer works by capturing the heat from the hot flue gases as they exit your wood stove. These hot gases are usually lost into the chimney, but a heat reclaimer extracts that heat and uses it to warm the air in your living space. This not only makes your stove more efficient but also reduces the workload on your primary heating system.
Materials You’ll Need
Double-Wall Stovepipe: You’ll need a section of double-wall stovepipe, which is designed to safely handle the high temperatures produced by your wood stove.
Tubes or Heat Exchanger Fins: You can use a set of heat exchanger tubes or fins. These can be made of copper, aluminum, or steel, and they will transfer the heat from the stovepipe to the air.
Metal Sheets: To create a housing for your heat exchanger, you’ll need some sheets of metal. Sheet metal or aluminum is suitable for this purpose.
Sheet Metal Screws: Use these to secure the metal sheets together to create the housing for the heat exchanger.
Fan: A small, high-temperature fan will help push the warm air into your living space.
Thermal Switch: To control the fan, you can use a thermal switch that turns the fan on when the heat exchanger is hot enough.
Mounting Brackets: These will be used to attach the heat reclaimer to your stovepipe.
Screws and Bolts: You’ll need these to attach the mounting brackets and the fan.
Thermal Insulation: To minimize heat loss and ensure the warm air flows into your room, you may need thermal insulation.
Building the Heat Reclaimer
Measure Your Stovepipe: Measure the circumference of your stovepipe where you plan to install the heat reclaimer. This will determine the length of your heat exchanger tubes or fins.
Construct the Heat Exchanger Housing: Create a metal housing for the heat exchanger using the metal sheets. It should be a cylinder that fits around your stovepipe with enough space for the tubes or fins.
Attach Heat Exchanger Tubes or Fins: Insert and secure the heat exchanger tubes or fins inside the housing.
Attach the Mounting Brackets: Attach mounting brackets to the housing to hold the heat reclaimer in place on the stovepipe.
Mount the Fan: Attach the fan to the housing, ensuring it is positioned to push air into your living space.
Wire the Thermal Switch: Connect the thermal switch to the fan, ensuring it will turn on when the heat exchanger reaches a sufficient temperature.
Install the Heat Reclaimer: Place the heat reclaimer on the stovepipe, ensuring it is securely held in place by the mounting brackets.
Connect the Fan: Wire the fan to a power source, and it should start when the thermal switch activates.
Add Thermal Insulation: To minimize heat loss, consider adding thermal insulation around the heat exchanger housing.
Benefits of a Homemade Heat Reclaimer
Cost-Effective: Building your heat reclaimer is more economical than purchasing a commercial model.
Increased Efficiency: A heat reclaimer helps your wood stove operate more efficiently by capturing and redistributing heat.
Lower Energy Costs: The extra warmth generated by the heat reclaimer can reduce your reliance on other heating sources, saving you money.
Eco-Friendly: By using more of the heat your wood stove generates, you reduce your carbon footprint.
Conclusion
Building a wood stove heat reclaimer is a practical and cost-effective way to make your wood-burning stove even more efficient. By capturing and redistributing heat that would otherwise be lost, you can enjoy a warmer and more energy-efficient home. Follow these steps carefully, and you’ll be on your way to maximizing the benefits of your wood stove.