Do more pumps and jets mean a more powerful hot tub?
Updated 8th May 2019
For most people, one of the motivations for buying a hot tub is therapeutic. They want to relive the aches and pains of daily life. Or perhaps, help treat a chronic condition such as arthritis or Fibromyalgia. So It’s not surprise that one of the most common questions we get is around how many pumps and jets a hot tub has.
The basic understanding is usually that the more pumps and the more jets a hot tub has, the more powerful it is. And that this will lead to a more powerful massage. This usually leads people to believe that hot tubs with more pumps and/or jets are better than hot tubs with less.
It’s a totally understandable misconception to have. It does make sense.
But it’s not true.
The hydrotherapy power of a hot tub is reliant on a number of things including:
- Pumps
- Jet number, style and size
- Plumbing
- Flow rate
- Size of hot tub/volume of water
How many pumps does your hot tub need?
Understanding electrical power and hot tub pumps
A standard power socket in a home is 13 AMPS. Most hot tub operate off of 13 AMPS (plug and play) or 32 AMPS.
The hot tub pumps require an electrical input in order to operate. If the hot tub pumps try to pull more electricity that they are supplied, the electricity will trip. This is a built in protective measure to prevent cables melting and fire.
Hypothetically speaking, if your hot tub had no limit on power. Then more pumps would equal a more powerful hot tub.
But, there are a couple of very important things to remember when buying your hot tub.
1. Hot tubs don't have an unlimited supply of electricity
Houses don’t have an unlimited supply of power.
Hot tubs are supplied a limited amount of the overall household electricity (usually between 13AMP – 32 AMP).
Whether you have 2 pumps. Or 4 pumps. They will be limited by this power supply.
Usually (not always), if a hot tub has two pumps they will twice as powerful as a hot tub with 4 pumps, as the power will need to be split between them.
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Myth: More pumps = more power
Hot tubs are limited by the power supply. It is very likely that if a hot tub is advertised as having lots of pumps (eg. 4) that each pump is less powerful than a hot tub with 2 pumps due to the limit on electrical supply.
2. Hot tub pump brake horsepower vs continuous horsepower
Most manufacturers will use Horsepower to determine how much power the pumps will have.
But again, this can be a bit of a misnomer.
Most manufacturers use brake horsepower (BHP), rather than continuous horsepower. The BHP is the power and speed of the pump as it starts up. This only lasts for a couple of seconds. Then the power drops to the continuous horsepower. So, in other words, brake horsepower is higher and sounds better.
Plus, BHP is a measure of how much energy a pump consumes. It doesn’t necessarily indicate flow rate as this has more to do with the size of plumping and pipework.
Well designed, efficient pumps and hot tubs will move a lot of water, with as little energy and horsepower as possible.
Myth: Higher horsepower = more powerful hot tub
Hot tub manufacturers often advertise high BHP, which isn't the best to determine continuous power and water pressure. The best designed pumps and hot tubs move lots of water efficiently through a combination of powerful pump and well designed plumbing.
Why is understanding this important?
Manufacturers and retailers regularly advertise the pumps on hot tubs as a way to make them seem better than competitors. But once you understand that hot tubs are limited by their electrical input. And that BHP doesn’t necessarily translate into strong jets, the number of pumps is a less impressive stat.
Yes, of course, some pumps are more powerful than others. But there is a whole host of other factors that affect the power of the hot tub.
What does determine the power of your hot tub pump?
It’s not that horsepower doesn’t matter. Higher continuous horsepower will potentially allow for a more powerful pump.
But you should be more concerned with the flow rate. You won’t usually find out this information easily as it’s dependent on a few things. As well as the pump power it relies on the plumbing and pipework size and the jet design.
That’s why looking at the number + power of pumps isn’t really a reliable way to determine the hydrotherapy power of a hot tub.
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How many jets does your hot tub need?
Again, jets, much like pumps are a numbers game with hot tub manufacturers. A lot of manufacturers just add as many jets as possible to make it look more impressive.
But again, this usually isn’t the case. The number of jets you have should be proportional to the size of the hot tub and the number of pumps.
Things that matter:
1. Number/power of pumps
2. Size of the hot tub
3. Placement of the hot tub jets
Think of it this way, if you have 100 jets and 1 pump, each jet will be very weak once the pump power is split between them. Alternatively, if you have 1 pump for 30 jets, each jet will get a little extra power.
Similarly, if you have a 2 seater hot tub, 1 pump and 30 jets will be enough. But if you have a 6 seater hot tub with 1700litres of water, you may need an extra pump, and extra jets to focus on the target areas of the body.
This is the reason that most premium hot tub manufacturers work on a ratio of approx. 1 pump per 20-30 jets.
It’s also not enough just to supply power to a hot tub and stick in as many jets as is possible. It’s about placement. A well designed hot tub will specifically place the hot tub jets to target pressure points. This will help loosen muscles and relieve pressure.
In summary
So, how many pumps and jets do you need in your hot tub?
It’s no surprise that most of the best hot tub manufacturers in the world use a similar ratio of pumps vs jets. Jacuzzi, Hot Spring, Coast Spas, Artesian, none of these premium brands have loads of pumps and hundreds of jets. They all loosely follow the ratio of 20-30 jets per pump.
The answer is, that the number doesn’t really matter. The ratio of pumps to jets. And the number of pumps relative to the size of the hot tub is much more important.
The best way to understand how powerful a hot tub is, and whether it is suitable for you is to try it out. Either stick your hand in front of a working jet. Or get in and wet test it to understand the true power of the hot tub.
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