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Does a Hot Tub Use A Lot of Electricity?
When purchasing a hot tub, it’s natural to investigate how much electricity it’ll use and how this will affect your energy bills each month. There are so many hot tubs available today—some more energy-efficient than others—and they each use a different amount of power depending on several factors like their voltage, location, and insulation.
Let's give you a straight answer, right at the top of the article.
Most modern hot tubs will use less than $1.00 in electricity per day.
In this article, we're going to show you three things:
- What affects a hot tub’s consumption
- How you can calculate the impact it’ll have on your electricity cost
- What you can do to bring those costs down
Let's get started.
What Affects a Hot Tub's Electric Consumption
Here are the 6 most common factors that affect how much power your hot tub uses and your hot tub energy cost:
The Heater Voltage, Kilowatt Hours (kW/hr), and Your Circulation Pump
Calculating voltage and power usage can be a bit complicated, but hot tub manufacturers make it simpler. They supply you with the kW rating of the heater. Once you know the kW rating of your heater, then you multiply this by the cost per kW hour supplied by your utility company. This will tell you how much it costs to run your heater for one hour.
We’ll take a closer look at how you can use these figures to calculate your hot tub’s electricity usage later in this article.
When you first open your hot tub, you may need your heater to run for a number of hours to warm the large volume of water. For many people, this means warming the water by about 30°F, which requires somewhere between 35-40 kW of energy. So, multiply your utility company's electricity price by 40 and you should have a rough figure for your initial heating.
After that, your hot tub heater will not run all the time. So, your costs will vary depending on the next five factors.
Circulation pumps also affect your energy usage every month. Many hot tubs use a 1500 watt pump, so it costs a few pennies every hour to run.
There are several features on a hot tub that determine how energy efficient it is, so it’s always worth researching any hot tub you’re interested in before you make the purchase. Here are some things to look out for:
- High-quality insulation on all sides of the unit
- Adjustable venting for your heater, circulation motor, and space
- Low filtration rates and clear filters
- Thick, hard-tapered hot tub covers to hold in the heat
We’ll delve a little deeper into some of these features in a later section.
The location of your hot tub is an important factor in its energy usage as it determines how hard it has to work to keep it heated. If you have room for a hot tub indoors – or under some sort of outdoor canopy – then you can create a more ambient environment for your hot tub to operate. The warmer the climate around the hot tub, the less it has to work. The less it has to work, the lower its energy consumption.
Create a special room for your hot tub that includes plenty of ventilation to avoid mold but also retains heat and reduces air circulation.
Size of the Hot Tub
If you choose a large hot tub, it’ll have the capacity to contain much more water than a smaller version. This might sound grand, and you might be able to entertain more people in it, but it means the hot tub has much more water to heat. And when it has to heat a lot of water, it naturally needs a lot of power to make sure it's always at an enjoyable temperature.
Of course, a large hot tub also retains a lot of heat, so these can be a great choice if you buy one with good insulation, use a cover, and keep it in a warmer room.
It’s not always about the energy a hot tub needs to heat the water inside that determines how energy efficient it is, it’s how much heat it keeps in, too. Most energy-efficient hot tubs should have at least six inches of dense foam insulation on the inside, so make sure you consider this when researching the best hot tub for you.
You can upgrade the insulation yourself. Look around the hot tub cabinet and see if any pipes are exposed. These can be wrapped in foam insulation. You can also use products like floating thermal covers and a solid top cover to insulate your hot tub when it's not in use.
As with most electrical items in the world, advances in technology means the newer they are, the better they perform. This goes for hot tubs, too. Newer hot tubs are much more energy-efficient than older models – they’ll have been specially designed with your energy bills in mind and manufactured to use less power than their predecessors.
How to Calculate Your Hot Tub's Electricity Usage
There are a couple of things you’ll need to know before you can calculate the amount of electricity your hot tub uses like the temperature you want the hot tub to be and the size of your hot tub. Here’s a formula you can use:
One gallon of water takes 8.33 British Thermal Units (BTUs) to heat by 1℉. So, you need to multiply the number of degrees the water needs to be heated by 8.33, then multiply that figure by the number of gallons of water in the hot tub.
For example, to find out how much energy a 400-gallon hot tub needs to be heated from 60℉ to 95℉ (an increase of 35℉), you’d use the following calculation: 8.33 x 35 x 400 = 116,620 BTUs. You can then divide this figure by around 3,000 to calculate the kWh.
Your energy supplier will charge you by the amount of kWh you use, so find out your supplier’s rates for cost per kilowatt and multiply this by the number of kWh you worked out the hot tub uses to find out how much it costs to run.
How to Make Your Hot Tub More Energy Efficient?
Full insulation – a hot tub will either come fully or partially insulated. Full insulation will reduce the amount of energy your tub uses, so it’s a good idea to keep the insulation in mind when you’re shopping.
A hot tub cover – the hot tub cover isn't just for keeping your water clean, it’s preventing heat loss too. A thick, good-quality hot tub cover will help keep the heat in and reduce its energy consumption. Plus, if you keep the cover on while you heat it up, it’ll decrease the heating-up process time, too.
Thermal blankets – thermal blankets are cleverly designed to float on the surface of your hot tub’s water and keep heat from being released from the water’s surface. Thermal blankets can even be used when you’re in the tub.
Does Turning Down a Hot Tub Save Money?
Yes, you can save a little money on your energy bills by turning your hot tub down, but the savings you make will be very minimal. If you’re using one of the fairly old hot tub models, you might see some more notable savings, but all new hot tubs are designed to be energy-efficient, so it's unlikely you’ll see any significant difference in your energy bills by lowering the temperature.
Is it Cheaper to Keep a Hot Tub On All the Time?
Because modern hot tub heaters are cleverly manufactured to take less energy to maintain a temperature, it will use much less energy when maintaining a hot tub’s water temperature than it would if it had to heat an entire tub of water from scratch each time it was used.
Reheating your water will inevitably increase your energy bill, and that’s because it takes a lot of time and power to heat a hot tub to the temperature it should be.
Does it Cost More to Run a Hot Tub During the Winter?
As the temperatures tend to drop in the winter, your hot tub will naturally be cooler in these months than it is in the rest of the year. This does mean it will need a little more energy to keep the water warmer, but the impact on your energy bills will be minimal.
However, if you choose a hot tub with great insulation and a high-quality cover, you can help keep the water warmer for longer and reduce both the amount of work your water heater has to do and your hot tub costs.
How Much More Expensive is a Large Hot Tub Than a Small Hot Tub?
Larger hot tubs have more water to heat, so they will be a little more expensive to run than smaller options – but the difference in the cost of energy won't be drastic. If you’re buying a large hot tub, the key is to choose an energy-efficient model.
As a rough guide, the difference in monthly cost between running a large 460-gallon hot tub in comparison to a 210-gallon tub is around $4 for some of the most energy-efficient models.
Should I Upgrade to a New Hot Tub to Reduce My Electric Bill?
Older hot tubs, like those made over a decade ago, needed a high-powered jet pump to heat the water which had a noticeable impact on a household’s monthly energy usage and bills. If your hot tub is this old, then it’ll definitely be more cost-effective in the long run to upgrade to a modern, energy-efficient model.
Find the Right Hot Tub That Works For Your Family
Our cost estimate is useful to help you understand the power costs of your hot tub. Maintenance costs, the number of times per week you use the hot tub, and whether you use a floating blanket will all affect your final total.
However, here's the bottom line:
Almost everyone can run a hot tub for less than $2.00 per day, all costs included.
So, for less than a Starbucks, you could enjoy all the social and health benefits of your own hot tub.