Wood-fired hot tub manufacturers such as Kirami, Royal Tubs, Skargards and others never miss a chance to boast their state of the art, faster than ever water heating time, which is typically three to six times quicker than that of electric heaters.
Hot tubs with electric heaters, on the other hand, are virtually instantaneous. Once installed, they need nothing more than to be plugged in and turned on to heat up the water. To compete with electric heaters, wood-fired hot tub producers have innovated solutions that provide hot tub lovers with a combination of the two. Read on to discover how a hybrid wood-fired and electric heating system works, what its capacity is and whether all top wood-fired hot tub brands in the UK offer it.
Why use a hybrid heating system in a wood-fired hot tub?
For wood-fired hot tubs, low-powered electric heaters are primarily used to maintain the water temperature once it has been heated by the main wood-fired stove and to prevent water from dropping to freezing temperatures in winter.
Wood-fired and electric heating systems can be effectively combined into a hybrid approach, so there’s nothing to stop you from using both heaters at the same time to speed up the water heating process. Since wood-fired hot tubs already achieve fast heating, the hybrid system cuts that process down even more for excellent results.
Below are the three key practical benefits of a hybrid wood-fired and electric heating system in a hot tub:
1) You can use the electric heater when you are unable or have no time to use the wood-fired stove.
2) You can rapidly heat the water in the hot tub with the wood-burning stove, then comfortably maintain the temperature with the electric heater for hours or days on end without needing to stoke the stove with an extra log or re-fire it.
3) You can switch the electric heater on when subzero winter temperatures are approaching. You can maintain the water temperature above 8°C, so you can rest assured there will be no damage caused by frost, and you won’t have to drain the water.
How do electric heaters combine with wood-fired stoves?
In a hybrid heating system, the electric part of the duo will typically be installed by the water filter that serves as a water pump to circulate water through the heater. Some systems may be designed to use the water circulation of the hydro massage system, or the electric heater may have its own dedicated pump. The point is that the electric heater will only do its job when water is circulated through it.
Another benefit of an electric heater is that it is compact and easy to control. Most feature a thermostat which allows you to select the desired temperature level. Some have an automated switch that enables them to respond to thermostat readings, while more basic models may require you to manually plug them in to set them to work.
Can an electric heater do the job alone?
Over a period of approximately 20 hours, an electric heater of around 3kW can bring the water up to a toasty temperature for the ideal dip, consuming some 60kWh of electric power. In winter, this heating time can be longer, so it just depends on your level of patience and how far your power budget extends.
We note that we are unable to produce exact numbers for how long you would need to wait for an electric heater alone to heat a wooden hot tub since these figures are highly dependent on factors such as the size of the hot tub, time of year, mains water temperature, level of hot tub insulation and the capacity of the heater itself.
Taking a practical example from our own experience, we found that a six-seater hot tub containing approximately 1200 litres of water took us 22 hours to heat with a 3kW electric heater in winter with an outside temperature of 0°C.
What is the capacity of an electric heater in a wooden hot tub?
Wood-fired hot tub makers are unlikely to risk the need to add in a special electric power installation for you to house in your garden, so the electric heaters used typically consume low levels of power, varying at around 3kW. Such heaters can be connected to a regular power outlet to get them going.
The top wood-fired hot tub brands in the UK offer the following options for hybrid heating:
Skargards – 2kW
Gardenvity – 3kW
Royaltubs – 3kW
Kirami (The Log Company) – 2.3 to 3.3kW
Timberin offers a uniquely wide variation of electric heaters. The standard model starts at 6kW which can be upgraded to 9, 12, 15 or even 18kW! In addition, Timberin offers a more cost-effective solution of a floating 300W electric heater to prevent the water from freezing.
How can you improve the efficiency of your heating system?
Lined wood-fired hot tubs can be insulated to help you save on firewood and keep the water warmer for longer. This can be a wise decision to make as a hot tub owner, as adding polyurethane insulation only costs approximately £150 extra. Reviews left by hot tub owners indicate that this extra insulation is a worthwhile investment, as it keeps the water warm for notably longer periods.
Another essential part or accessory of a wood-fired hot tub to maximise heating efficiency is an insulated cover. Whether or not this is included in your hot tub package depends on the manufacturer, as in some cases you may have to purchase it as an additional accessory yourself. As we’ve learned ourselves, an insulated cover is a game-changer for hot tub heating. It speeds up the heating process and keeps the water warmer for longer since a hot tub has a considerable surface area, causing it to quickly lose heat if left uncovered. When deciding on a cover to purchase, you can choose between plastic, wooden or insulated faux-leather lids. The latter produces the best result.
Summary
The key benefit of a hybrid heating system that combines both a wood-fired stove and an electric heater in a wood-fired hot tub is the comfort and convenience it brings to quickly heat the water and maintain it at an optimum bathing temperature for as long as needed, with no additional work required.
This hybrid system also gives you the confidence to keep using your hot tub throughout winter. When you keep the electric heater on, you can rest assured that your hot tub will not be susceptible to frost, which can get into the water circulation system and damage your hot tub.
A further benefit is that the secondary electric heater can shorten the water heating time. What’s more, it does this without requiring any additional power outlet installation from your side. Plus, if you’re patient enough, you can even heat the water with the 3kW heater with just the flick of a switch.
While a hybrid heating system may not be a must-have for every hot tub owner, it is certainly a worthwhile investment for extra convenience and hands-free operation.
