Are Heat Pumps Worth It for Hot Tubs?

Thursday, 31st Aug 2023 in Buying guides, Tips, Uncategorised
Are Heat Pumps Worth It for Hot Tubs? | A6 Hot Tubs

We get asked a lot, Are heat pumps worth it for hot tubs? The simple answer is, yes. But Let’s go deeper in this short read.

While air source heat pumps of all kinds have been around for a while now they have recently started making their way into the hot tub industry due to rising electrical costs. However, it goes further than that, they also reduce the environmental impact of running a hot tub.

They can reduce energy costs by up to 70% depending on atmospheric conditions and the existing heating cost of your hot tub.

With choices ranging from kW for small hot tubs all the way to large swim spas, and inverter or ON/OFF models, things can get confusing. With the information below from our experts ranging from the simple to the more intricate details, you’ll be in the know.


How do air source heat pumps for hot tubs work?

The principle behind a heat pump is essentially the opposite of an air-conditioner. While an air-conditioner produces cool air, a heat pump emits warmth. Let’s break it down.

  • First, a fan draws in the surrounding air, which passes over the evaporator/refrigerant coil.
  • The heat from the air is then transferred to a circuit containing eco-friendly gas.
  • Next, the gas is heated to a high temperature via a built-in compressor. In the heat exchanger, the gas transfers its heat to the pool water.
  • Finally, the gas returns to its liquid state and flows back to the evaporator to repeat the process.

This process is not only eco-friendly, but it’s also incredibly efficient, meaning you get to enjoy a relaxing soak while saving money on your energy bills.

Our air source heat pumps are specifically designed for hot tubs, so you can rest assured that they are of the highest quality and perfectly suited for the task at hand. We take pride in knowing that our customers have the best heat pumps available. This is through us only providing the most durable, long-lasting and reliable systems for any hot tub or swim spa.

What is the difference between ON/OFF and Inverter heat pumps?

The initial difference you’ll see is in the cost of each heat pump system. The ON/OFF heat pumps tend to be cheaper as the technology is much simpler. They’re either on full power or off.

The inverter models tend to cost a bit more to buy but offer more savings. This is due to them being variable speed and able can change the amount of power they use. They’ll do this by measuring the heating demand, water temperature and air temperature. Meaning if they don’t need to come on full power then they won’t.

The below graph shows the power usage of the INHEAT Inverter Heat Pump compared to the same ON/OFF system.

A lot of top-end inverter heat pumps have smart tech within them that checks the ambient air temperature and adjusts the fan speed to get the best efficiency out of the heat pump. These models, therefore, tend to cost more upfront but cost less to run. This cost difference can be made back anywhere from 1 year to 5 years, depending on the model and usage.

The below information shows the difference in the Aquark AquaIntel heat pump energy consumption, compared to an ON/OFF heat pump of the same power being used for a swim spa.

Aquark AquaIntel Heat Pump | A6 Hot Tubs

Advantages & Disadvantages of Heat Pumps

What are the benefits of running an air source heat pump over the electric heating element in my hot tub?

  • Reduced heating costs: A heat pump installed and fitted to your hot tub or swim spa will use up to 70% less electricity heating the water. With the rise of running costs of a hot tub, this can bring down your costs a substantial amount each month. Having a good idea of how much it’ll cost to run your hot tub or swim spa is important.
  • Faster water heating: The extra power that comes from an air source heat pump will heat the water at a much faster rate. This means on water changes you can drain, clean and usually be back up to temperature the same day. This is especially useful for holiday let hot tubs with changeovers.
  • Environmentally Friendly: If you’re conscious of the environment then adding a heat pump to your hot tub system may help. They will reduce the environmental impact of a hot tub. This is due to them being able to source the surrounding air and using less electricity than the internal heater unit within your hot tub.
  • A cheeky summer cool-down fan: When the heat can get a bit too much in summer you can get lovely cold air blown out the front of your heat pump. This isn’t an advertised benefit of any heat pump but we know customers who love to cool down using the breeze.

Are there downsides to installing a heat pump?

There are far more positives to installing a heat pump than negatives but we like to be completely transparent with our customers.

  • The initial cost is quite high: You need to work out how much you’re using now compared to what you could save and how quick the payback would be. Some people estimate 1 year based on use and their tariff while others can be up to 5 years, so just work out what’s right for you.
  • Space: Heat Pumps are fairly sizeable units and to minimise heat loss from the external pipework they need to be as close to your hot tub or swim spa as possible. They also need a lot of space around them for air to be pulled in and through the heat pump. Blocking an allotted space here will make them less efficient.
  • Reduced efficiency in cold weather: Effectively extracting thermal energy from outdoor air becomes increasingly difficult as the temperature drops. Fortunately, cold-climate heat pumps are continually improving, making them increasingly efficient in frigid regions. Always check the operating temperatures before buying.

Hot tub heat pumps that ARE worth it.

Here at A6, we’ve spent years installing heat pumps for hot tubs, swim spas and pools. This has given us a rounded experience of the best options for your specific needs. We’ve chosen the best options on the market for reducing your heating costs.

If you’re finding it hard to choose come and talk to our team of friendly professionals waiting to help.

Can a heat pump be fitted to any hot tub or swim spa?

Most hot tubs and swim spas can be fitted with a heat pump. Sometimes this option may not be available with older models. This is due to the build and components that make up your hot tub or swim spa.

To install a heat pump a modification is needed to the pipework inside the hot tub or swim spa. The water is diverted through the external heat pump and pumped back into the system. The power is taken directly from the hot tub control box so no additional external wiring is needed.

What’s right for your spa space

An older hot tub or swim spa model may not be the only reason people might not enjoy the idea of a heat pump being connected to their hot tubs and swim spas. Some owners may want to consider and favour the aesthetics of their swimming and soaking space.

While you can get some smart-looking heat pumps, like the Aquark Mr Silence inverter heat pump, there’s no getting around the fact you’re going to have what essentially looks like an air-con unit sitting next to your home spa. There are ways around this for above-ground hot tubs and swim spas, like using dividing walls, gazebos and pergolas to break up the area.

Swim Spa Sunken Within Decking | A6 Hot Tubs

If you’ve meticulously landscaped your space or sunk your home spa, this might spoil the look and vibe you’re going for. Choosing to forgo the heat pump savings in favour of the aesthetics is up to you and how you use the given space.

We’re always here to help customers find the best way to enjoy their hot tubs and swim spas. We can also provide help with planning and landscaping ideas for a new hot tub or swim spa, and how you’d make the most out of the space for your needs.

Closing Thoughts

So, in closing, are heat pumps worth it for hot tubs? Yes. For any newer hot tub or swim spa a heat pump can be a great asset for keeping down your running costs. Although a larger initial spend is needed you’ll usually see a return of this cost in the first few years of use. An air source heat pump can accrue hundreds of pounds in savings off your annual energy bills, paying for itself several times over in the time you’ll own it.

Investing in one can be an incredibly effective way for hot tub owners with the upfront cash, and the space, to slash both their energy usage and carbon footprint. And who doesn’t want to increase their savings in the face of the rising energy costs?

Air source heat pumps are a key component in the future of the hot tub world. With technology improving and manufacturers innovating steps forward like the rise of the heat pump have made owning a hot tub more affordable. This means that more and more people can enjoy both the mental and physical benefits offered.


Frequently Asked Questions

How much electricity do heat pumps consume?

Heat pumps are a great alternative to electricity, with the average heat pump running at full load consuming around 2.3Kw of electricity per hour.

A quality air source heat pump will only use around 0.7kW of power per hot tub heating cycle. By way of comparison, a standard electric heater will use around 3kW during a heating cycle – over three times more.

Do air source heat pumps bypass or replace the built-in hot tub heater?

A heat pump can either replace or supplement a standard hot tub heater.

Having both a heat pump and an electric heater can be incredibly useful for holiday lets, which need to empty, refill, and reheat their spa water between guests.

But for domestic use, the hot tub’s electric heater will almost always be disconnected and replaced by a heat pump.

What happens to my electric heater inside the hot tub?

It remains in place as it’s still needed for the sensors to tell the circulation pump when to start and kick in the heat pump.