Do you have a roaring fireplace producing considerably more heat than you require in your living room? Why not use the additional heat for your wetback hot water system? A wetback is just a set of tubes integrated into your fireplace that you can use to pump water through to heat it.
Wetback hot water cylinders are typically utilized in smaller homes for systems with little heating needs. They frequently function without a pump since they are installed as siphonic systems, which rely on the hot water rising naturally to create a fluid flow through the HWC and back to the wetback.
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How a wetback hot water cylinder works
A piped water connection connects the wood burner with wetback to a stored water heating cylinder. Some of the heat generated by the wood burner is utilized to warm the water in the hot water cylinder during the winter. When the wood burner is out of use during the summer, the hot water cylinder functions like a regular cylinder, heating the water using an electric element.
Choosing the right wood burner and cylinder is crucial when using a wetback system. Here is a list of the several hot water cylinder types that work with wetback systems.
Copper wetback cylinder with low pressure
Wetback hot water cylinders made of low-pressure copper are common. Water rises into the cylinder as it warms up in the fire’s wetback. In the circuit and woodburner, cold water then substitutes the hot water that was previously rising. This cycle keeps going until the cylinder heats up. This kind of system is a “open system,” which means that the circuit and wetback systems circulate the water used in the residence.
Mains pressure standard coil cylinders made of stainless steel
This option is utilized in setups where the cylinder cannot be placed near the wood burner in a close, elevated position. This method uses a closed water circuit, but a specialized high-temperature circulator pump pushes heated water through the cylinder coil. The usable water in the cylinder receives the heat via the coil.
Mains pressure stainless steel thermosyphon coil cylinders
This is quickly gaining popularity as the ideal cylinder option. A thermosyphon coil connects a mains pressure cylinder to a wetback fire. The thermosiphon effect—in which warmer water rises and cooler water falls—moves water through a coil inside the cylinder. As a result, you don’t need a pump to circulate water, and even during a power outage, you can still heat your water. Through this coil, heat is delivered to the usable water in the cylinder.
Consider the cylinder size.
It is best to be able to store more water to absorb this extra heat to profit from the wetback system to its fullest potential. It’s preferable to install a wetback cylinder with a bigger volume capacity than a typical household cylinder when it’s practical. As a result, less hot water is released, and the cylinder can hold more heat. The most typical cylinder installed in a home is 180L. However, when there is room, wetback installations often range from 250L to 300L.
Conclusion
Wetback has its uses, and it’s something to consider if you want to lower your hot water bill.