Is there anything better than soaking in a warm hot tub under the stars? The only thing that might be is doing it for free. As the photo shows, you don’t need expensive electricity or propane to heat your water. All you need is a little ingenuity, some spare parts, and a good old-fashioned fire.
This clever hack turns a simple campfire into a powerful hot tub heater. It’s a brilliant, low-tech solution that uses a simple principle of heat exchange. Water is pumped from the tub through a metal coil placed directly in the flames, and heated water is then returned to the tub. This process circulates the water and steadily increases its temperature. It’s an ideal setup for a cabin, a remote campsite, or just for anyone who loves a good DIY project.
How to Build Your Own Wood-Fired Hot Tub Heater
Ready to try this yourself? Here’s a conceptual guide to how you might build a similar system.
WARNING: THIS PROJECT IS FOR INFORMATIONAL PURPOSES ONLY. INVOLVES EXTREME HEAT, FIRE, AND WATER, WHICH CREATES A RISK OF BURNS AND SCALDING. IMPROPERLY HEATED GALVANIZED METALS CAN RELEASE TOXIC FUMES. PROCEED WITH EXTREME CAUTION AND ONLY IF YOU HAVE THE NECESSARY KNOWLEDGE AND EXPERTISE. WE RECOMMEND CONSULTING WITH A PROFESSIONAL.
What You’ll Need:
- A metal coil: Use a durable pipe, like non-galvanized steel, copper, or stainless steel. Galvanized pipe can release toxic zinc fumes when heated.
- A fire pit: A sturdy, fire-resistant container for a wood fire.
- A water pump: A small submersible pump or an existing hot tub pump.
- Hoses: High-temperature hoses to connect the coil to the hot tub’s pump system.
- Firewood: To heat the water.
Step-by-Step Instructions:
- Create the Coil: Carefully bend your metal pipe into a coil shape. This maximizes the surface area exposed to the flames, allowing for faster heat transfer.
- Set Up the Fire Pit: Place your fire pit on a non-flammable surface, away from any structures or flammable materials. Create a base for the coil to rest on inside the pit, allowing flames to reach it.
- Connect the Pump and Hoses: Place a pump inside the hot tub. Connect one hose from the pump to the inlet of your metal coil. Connect a second hose from the outlet of the coil and feed it back into the hot tub.
- Heat the Water: Once all connections are secure, start a fire in the fire pit. Turn on the pump to begin circulating the water. The water will flow from the tub, through the heated coil, and back into the tub, slowly raising the temperature. Monitor the water temperature with a thermometer to avoid overheating.
This clever project is a great way to save money and enjoy a unique, off-grid experience. What other outdoor projects have you seen that use fire to make life a little more comfortable?
