Having your own swimming pool in the garden is a real luxury. Pool heating is necessary so that this oasis can also be used when the outside temperature is cooler. Wood appears to be an attractive way to effectively heat the water. The raw material is renewable and burning it creates a romantic campfire at the same time. The construction of such a variant is not difficult and does not involve high costs.
Inspiration from Scandinavia
Wooden hot tubs are common in Sweden. Heating with pine, spruce or birch is normal not only in the house but also in the sauna and pool. For a more efficient use of the heat from the fire, the Swedes build stainless steel ovens directly into the basin. These models are fired through an opening in the upper area. Exhaust gases are released into the air through a chimney. The advantages of this variant are manifold:
- Stainless steel conducts heat directly to the water
- no energy loss via hose lines
- Lighting from the pool possible
Building your own stainless steel furnace requires not only welding skills, but also expensive materials. But this Scandinavian variant offers inspiration for alternative solutions. With recycled
Materials and a little craftsmanship, you can build a wood-burning pool heater that is outside the pool.Build an external fire barrel
In this variant, the pool water is passed through copper pipes that run through a fire barrel. The fire heats the water, which then flows back into the pool. This variant is suitable for pools with a volume of around 30,000 liters. For larger pools, the efficiency is not sufficient to bring the water temperature to a comfortable level. To build the water heater you will need:
- an old oil barrel: 60 liters capacity
- thin-walled copper pipe: 10 m length, 15 mm diameter
- Hacksaw and metal drill
- Disused grill grate, perforated sheet metal or sturdy wire plate
- Hammer and nails
- Crimp connectors and hose connections
costs
The copper pipe is the biggest cost factor in this construction project. Depending on the provider, you have to reckon with four to six euros per meter for a 15 millimeter thick pipe. If you don't have an oil drum
available, check used goods stores for discarded models. A new metal barrel of this size costs around 30 to 40 euros. Nails and fasteners cost around ten to 15 euros.Tip: For a smaller model, you can convert an old beer barrel into a combustion chamber. This gives the barrel a new use.
building instructions
Saw off the lid completely and drill holes in the lower area in two staggered rows. These openings are used to supply air so that the fire can burn properly inside later. Additional openings in the upper area ensure that smoke and gases can be extracted. The openings should have a diameter of two to three centimeters. The smaller the holes, the more openings the fire barrel needs. Since the wood should ideally burn above the ventilation openings, a precisely fitting and coarse-meshed storage area for the wood is integrated in the middle area. Drive long nails all around the barrel from the outside so that the ends point into the interior. They serve as a fixation for the wooden shelf. Slide the cut piece into the barrel from above before placing the spirally bent copper pipe.
Tip: Fill the copper pipe with sand and pour water into it. You can then bend the tube into shape over a resistor like a wheel rim.
Shape pass
The copper pipe runs along the walls of the fire barrel, with the water flowing through the pipe from the bottom up. To increase the efficiency of the self-made water heater, you should also bend the upper part of the copper spiral along the barrel opening into a spiral. The flames burn below this spiral and the rising heat
is used optimally. The inflow and outflow are routed through additional openings in the combustion chamber so that the system can be connected to the filter system outside the barrel:- Provide inlet and outlet with crimp connectors
- Place the hose adapter on the crimp connector
- Connect the inlet to the return of the filter pump
- Direct the drain into the basin
Application and mode of action
Light a fire on the shelf in the combustion chamber and place the lid on the barrel. The chimney effect ensures an optimal air supply, because the fire draws air into the interior through the openings. The metal wall of the combustion chamber concentrates the radiant heat from the fire. Smallest amounts of wood can thus be used efficiently. They burn completely, creating high temperatures. A fan ensures better burning effects. In this case, you should pay attention to an optimal water flow so that the heated water quickly gets into the pool. A circulation pump supports the flow. With an air temperature of around 18 degrees Celsius, it can take up to eight hours for the pool to heat up to 28 to 30 degrees Celsius.
Alternative: solar heating
A wood-fired pool heater must be operated for a long time in order to achieve the desired effect. A more convenient option is to use alternative energy sources such as solar energy. A simple variant is to lay a 50 meter long garden hose on the roof of the gazebo in a spiral arrangement. The system is connected to the return from the pool filter. It takes a powerful pump to make the water flow through the hose.
