What You Need to Know About Spa Heating
With so many different spa heating options available, it’s hard to know which to choose that will work efficiently and not cost the earth to run. Let us walk you through the pros and cons of each so you can find the best choice for your needs.
Standard Electric Element / Variable Output Heater
Did you know that most spa pools on the market today already have a built-in conventional heater? These are the standard when it comes to spa heating and they do a good job of warming the water and maintaining your set temperature.
A typical plug-in (10 or 15amp) spa heater may experience load shed shutdown however, once you turn on the jet pumps. Make sure the built in heater is a variable output heater; this will optimise performance to maximise heating output whilst the spa is in use. When you turn on the jet pump, a variable heater will assess how much power it can use to continue to heat your spa and avoid load shedding shutdown, so your spa stays warm while the jets are in use.
On average electric heating will warm water at a degree an hour and are designed to be kept warm once your water reaches the desired temperature to be most economical. Although your initial heat up will take some time, keeping the spa at ‘jump in temperature’ is the best and most economical way to utilise these heaters, instead of heating from cold each use. The benefit of this heating is that they are fuss free being contained underneath the spa cabinet, no additional connections or installation is required, and they do their job well. For most people, this is all that they need to use and enjoy their spa, but if you’re looking to reduce your running costs further, this is when external heaters will come into play.
External Heat & Cool Pump
These air sourced heat pumps are the most energy efficient and cost-effective way to heat your spa. The heat pump will override your spas built in conventional electric element and draw up to 75% less energy. Heat pumps also use 55% less energy than natural gas. The time these heaters take to warm the water is very similar to the standard built in electric element, but just think of them as a much more efficient way of doing it. Another added bonus is that they have the ability to actively cool the water down, whereas all other units can only heat. This is a great option in the summer months if you want to use your spa or swim spa as a splash pool to cool off in Summer. As these units are external, keep in mind that it will need to be installed by a spa technician and that you will need to find somewhere nearby to place it and the closer to the spa, the better. We wouldn’t recommend going any further than 5 metres away to ensure it is working optimally.
Spanet heat and cool pumps are fully integrated into our operating systems which means there's no need to have an electrician install wiring. The power is sourced directly from the spa. A worthwhile investment, your heat pump will save you thousands of dollars over it’s life time.
SpaNET recognised that air sourced heat pumps are the most energy efficient method of heating and became the first spa controller manufacturer to develop a interface to offer true integration to a spa pool. SV Series POWERsmart heat pumps do not have a separate keypad for adjusting settings, rather they feature a dedicated interface to connect to any model SV Series spa controller allowing all temperature, settings, and diagnostic adjustments to be conveniently controlled via the spa pool’s topside keypad. Be aware that some non-integrated external heat pumps will only allow for heating but not cooling and they will need to be turned on & off at the actual heater which means you need to get out of your spa to adjust temperature settings.
The plug-&-play heat pump interface allows instant connection of a SV Series heat pump to your spa, slashing heating costs by up to 75%. No additional power circuit or cabling is required as the SV Series heat pumps plug straight into a SV Series spa control. The spa control automatically detects the heat pump on startup and disables the electric element of the spa control. The installation of a heat pump will result in massive savings to your electricity bill allowing you to cost effectively keep your spa at temperature and ready to use all year round.
How long does it take for a spa to heat up?
On average, both these forms of electric heating will warm or cool water at a degree an hour and are designed to be kept warm once your water reaches the desired temperature to be most economical. Although your initial heat up will take some time, keeping the spa at ‘jump in temperature’ is the best and most economical way to utilise these heaters, instead of heating from cold each use. The biggest draw card for gas heating systems is the speed that they can heat water. Let’s take a 1,000 litre spa pool for example; when paired with a gas heating system the water can be heated from cold in around an hour.
Which heating system is the best?
Our Sapphire spa pools and swim spas come standard with an adequate heating system for the volume of water you need to heat.
Typically, as the size of the spa and volume of water increase, so does the need for an increase in heater size. These heating systems are supplied by Sapphire Spas within the price of your spa purchase:
- Spa pool / 2 hydrojet pumps / <50 jets / approx 1000 litres of water - 3kw variable output heater
- Spa pool / 3 hydrojet pumps / >50jets / approx 1000 litres of water - 6kw variable output heater
- Swim spa plunge / 2 hydrojet pumps / approx 30 jets / approx 6000 litres of water - 3kw variable output heater
- Swim spa classic / 3 hydrojet pumps / approx 50 jets / approx 6000 litres of water - 6kw variable output heater
- Swim spa smartsaver / 4 hydrojet pumps / approx 60 jets / approx 6000 litres of water - 5.5kw heat and cool pump
- Swim spa extreme / 5 hydrojet pumps / approx 80 jets / approx 6000 litres of water - 8.8kw heat and cool pump
- 12kw heat and cool pumps are also available for more rapid heat and cool times
You have the option to upgrade your heating system with most spa models; you’ll just need to ensure the controller that is running the system is compatible.
How can I heat my hot tub faster?
In your efforts to heat your spa faster and in the most efficient manner, take into consideration the quality of the hardcover and the structural insulation that is installed around your spa pool or swim spa.
Any heating system will maintain your set water temperature best if you put your spa cover on whilst heating. There are good and bad quality spa covers however, so check the density and thickness of the foam, integrity of the vinyl (should be marine grade), ensure it has an aluminium channel to reinforce your cover under pressure, and safety locks are also important to prevent your covers lifting off in high winds.
A highly insulated spa shell is the best way to reduce heat loss and keep running costs to a minimum. Our heatlockthermo+ 4 stage insulation system allows Sapphire to create the most energy efficient spa in the world today.
The biggest draw card for gas heating systems is the speed that they can heat water. Let’s take a 1,000 litre spa pool for example; when paired with a gas heating system the water can be heated from cold in around an hour. When compared to an electric heater at a degree an hour, you can see why this is a big selling point.
Now before you do decide on gas, keep in mind that they come in second best in terms of energy efficiency to the external heat & cool pumps, so if running costs are your concern then this may not be the best option for you. Gas heating is ideal for people that will not be using their spa on a regular basis, such as people with holiday homes, who need the spa heated fast for occasional use. These units require a little more in terms of installation as you will need the gas line connected, as well as a spa technician to finish the connections to the spa.
I have added this option in for discussion, but the truth is that solar is not a viable heating option for spas. The average temperature that spas are used at is 37.5 degrees and a solar system is not reliable enough to heat and maintain these high temperatures. We want a nice warm spa mostly during the cooler months when there tends to be less sun around and the opposite in the warmer months. This can be used as a back up for your spas built in conventional heater, but due to the high set up costs involved, most people turn to an external heat and cool pump as these are a cheaper option and much more efficient.
If you are on the market for a swim spa or spa pool anywhere in Australia then choose an option below to learn more.