How much electricity does a spa pool use? (Spa pool running cost estimate)

If you're thinking about purchasing a hot tub, spa or swim spa, there's a good chance one of the first questions you may have is, "How much does a spa cost to run?" This is not the easiest question to answer as there are so many variables to consider. For example; what’s the temperature outside? How much is the spa being used? How has the spa been installed? What is the quality of the spa?

A poor quality spa pool in a cold climate, used often and installed on a deck is going to cost considerably more to run than a good quality spa pool in a warm climate, not being used often and installed on a concrete pad.

To put this in perspective, a spa can cost as little as 30-40 cents per day to operate, or as much as $4-5 dollar per day! Quite a difference.

To get a little more specific, we can look at the experiences of our Spa World customers over the past years. A premium spa pool such as a Vortex Spa™, in an average climate such as Auckland or Melbourne, being used 3-4 times per week, will cost between $30 and $50 per month over summer and between $60 and $80 per month over winter. The same spa in Brisbane would cost less to run in Queenstown or Tasmania.

A luxury spa such as a Jacuzzi^® or Hot Spring^® will cost 20-30% less than this. A value spa such as a Lifestyle Spa™ will cost 20-30% more to run.

As such, there is one ‘truth’ when it comes to spa pool running costs, and that is; the more you invest upfront, the less you will spend over time. You may consider this to be an inconvenient truth, but it is true nonetheless. Why? Read on.

How spa insulation impacts monthly electricity costs

Most of the cost of running a spa is related to the heating of the spa’s water. Heat loss from water needs to be replaced by using the spa’s heater. The less heat lost from the water, the less the heater has to run and the less power you use. Insulation slows the heat loss and therefore the more effective the insulation, the lower the heating cost.

There are many types of insulation that are used in spa pools and manufacturers and retailers naturally claim that theirs is the best! But to cut through the marketing hype, more is better. And when I say more, I don’t mean layers, I mean thickness. One thick layer of foam is better than 5 thin layers of marketing hype.

As such, you will find that the pricier spas on the market use what is called ‘full foam’ insulation, in that the entire cavity between the spa’s shell and the inside of its surrounding cabinet is filled with foam.

So why don’t all spa manufacturers use full-foam insulation? Two reasons; firstly, it costs more. Secondly, if the spa springs a leak, it is much harder to find and fix. As such, only those manufacturers who are confident their spas won’t leak, use full foam. Otherwise, they will have a warranty nightmare.

How spa covers affect monthly spa pool energy costs

Heat escapes from spas by convection or evaporation and so the cover of the spa needs to use insulation to stop convection and a tight seal to stop evaporation. Once again, more insulation is better and a good cover seal is critical.

You will discover covers on cheaper spas are thin and light with poor sealing properties, whereas covers on more expensive spas are thick, heavy and provide a strong seal against evaporation.

The best quality covers will include padded seals through the middle fold and around the edges, further preventing heat loss.

Does this mean that the cover of a more expensive spa is difficult to take on and off? Yes. However, help is at hand in the form of a cover lifter, a mechanism that assists you to remove the cover. Higher quality cover lifters use a gas shock to assist the removal meaning even the littlest of old ladies can remove the thickest and heaviest of covers.

Control systems and energy efficiency

‘Smart’ control systems found on quality spas measure heat loss over time and use artificial intelligence to maximise the efficiency of the heating cycle. This can shave as much as 20% off the heating cost.

Furthermore, smarter control systems can be programmed to only run when your power is the cheapest. This might be during the day if you have solar panels, or in the earlier hours of the morning when power costs are at their lowest.

The energy cost of two-speed vs circulation pumps

There are various types of pumps used in a spa. Whilst they do not draw as much power as the heater, they are still a factor in running costs.

Cheaper ‘plug and play’ spas often use a two-speed pump. As the name implies, the single pump can operate at a low speed for filtering and heating and higher speed when you want the massage jets to run. Even at low speed, a two-speed pump will use more power than the second type of pump - a circulation pump.

A circulation pump (circ pump for short) is dedicated to heating and filtration, leaving the bigger (and hungrier) ‘jet pump’ to only come on when you are using the spa. Not only does the circ pump system use less juice, it generally lasts longer, does a better job of filtering the spa’s water, and is much quieter. Your neighbours would prefer you to purchase a spa with a circulation pump.

How your spa’s location and the installation can affect running costs

Believe it or not, this affects running costs. A spa that is installed on a deck in a windy part of the back yard, will cost more to run than a spa installed on a concrete pad in a sheltered area. Basically, the wind blowing over (or under) the spa cools it down, just like blowing on your wet finger cools it down.

If you are installing a spa onto a deck, it is a very good idea to lay some form of insulating blanket down on the deck under the spa.

Summary

So in summary, buying a cheap spa, whilst attractive at the time of purchase, will end up costing you far more over the life of the spa. Running costs of $4-5 per day are not unknown in cooler climates. However, investing more upfront can dramatically reduce the lifetime cost of spa ownership, reducing running costs to as little as 30-40 cents per day in warmer climates.

If low running cost is of primary importance, choose a spa with the following attributes:

• Full foam insulation or close to it
• A thick heavy cover with good seal (with a cover lifter)
• A smart control system
• A circulation pump
• And finally, have a think about where the spa is going to be located.

I hope this helps you find the perfect spa.