Reduce your heating bills and carbon footprint

With an Air Source Heat Pump from The Tub Company you can heat your water from the air. More efficiently and with Less carbon.

Optimize your energy usage now and use your hot tub all year round.

  • They can work with almost all new or existing hot tubs, making them ideal for new owners or current owners looking to lower their running costs.
  • Less Energy – Heat pumps use far less energy than conventional heaters
  • Less Carbon – Lower energy usage means a reduced carbon footprint. Electricity is becoming greener over time also.
  • Proven Technology – Heat pumps use similar technology to air conditioning which is extremely reliable and requires minimal maintenance.

Our Air Source Heat Pumps start from just £1,299

  • Prices from just £1,299 (plus installation)
  • Uses the latest inverter technology for even more efficient running
  • WiFi connectivity
  • Heating and Cooling
  • Super quiet operation
  • Outstanding quality and durability
  • Low maintenance
  • Simple operation, fully automated once set up

How does an air source heat pump actually work?

Some history to heat pumps

You may not have heard of air-source heat pumps until recently but they are not new. How they work certainly isn’t. Based on refrigerator technology which was first invented back in 1755!

An air source heat pump works by extracting heat from the outside ambient air, it then transfers this heat into the water in the hot tub.

The saving is made because the only electricity used is to power the process. No power is used to heat the water. Meaning compared to your conventional heater more heat can be created for the same amount of power…up to 16 times more for the same price!

They operate under the 2nd law of thermodynamics, which is heat always flows from a hot to a cold body. They function the same as your refrigerator, but in reverse. 

The workings of an air source heat pump

The air source heat pump contains 4 major components

  1. A compressor
  2. A condenser
  3. An expansion valve
  4. An evaporator

The refrigerant gas is passed through these components

  1. Outside air is drawn over the evaporator which contains cold refrigerant gas, because this gas is colder than the ambient air, heat from the air is transferred into the colder body of gas.
  2. This slightly warmed gas is then pumped through a compressor. When a gas is compressed it naturally increases in temperature   
  3. This hot gas is then drawn through a condenser/heat exchanger which transfers the heat into the hot tub water.
  4. Now the gas needs to be cooled again, this is done by passing it through an expansion valve which releases the pressure on the gas allowing it to call. Just like an aerosol, inside the aerosol, the gas is under pressure, and when you press the button the gas comes out cold, this is the gas expanding.

The cycle then starts again with the cooled refrigerant going back into the evaporator.


The main performance figure of an air source heat pump is the COP (Coefficient of performance). This is the ratio of electricity used to heat output produced. For instance, a heat pump with a COP of 5 means that for every 1kw of heat used, 5kw of heat is produced.

So in money terms, if a unit of electricity costs 34p per kw/h, using the internal heater to produce 5kw of heat it would cost £1.70. An air source heat pump would cost 0.34p to produce the same amount of heat.

Our air source heat pumps can operate in temperatures down to -12c and under average UK temperatures of 10c offering an average COP of 5.6. In peak conditions, this can rise to 16.

Not quite as straightforward of that

The output of an air source heat pump is dependent on a number of variables, these include ambient temperature, water temperature and humidity. So the COP of a heat pump does vary. For instance, at 25c outside the heat pump might have a COP of 7:1, but at 5c the COP will drop to a COP of 4:1.

Another factor is the technology used within the heat pump so the hardware and the refrigerant gas.

Different refrigerant gases perform differently. Modern heat pumps use R32 gas which is usually effective down to around -15c

The second main component is the compressor used, of which there are main two types – on/off and inverter.

Types of air source heat pumps


On/Off compressors are either on or off, so all or nothing. They cannot vary their output or power usage. Newer inverter-style air source heat pumps can run at variable speeds, so on a warmer day when less heat is cooled, they can run slower meaning less power is used. The inverter heat pumps use less power than the on/off heat pumps.


The second main component is the compressor used, of which there are main two types – on/off and inverter.

The most efficient heat pumps (like what we supply) use inverter technology. So instead of the equipment in the heat pump being either on or off (fan, compressor, expansion valve) they can vary in speed which means they run only as much as required, therefore much more efficiency and cost saving.

So how does an air source heat pump save you money?

The saving over a conventional heater comes because no electricity is used to generate heat. Heat pumps have the ability to produce more heat than the equivalent electricity used. 

What are the advantage of air source heat pump?

1. Low running costs: Air source heat pumps are much more efficient than traditional heating systems and use significantly less energy, which can result in lower running costs.

2. Eco-Friendly: Air-source heat pumps can use renewable energy sources and do not produce carbon emissions, making them an eco-friendly heating choice.

3. Versatility: Air source heat pumps can be used to heat and cool a space, making them a versatile choice for year-round comfort.

4. Low maintenance: Air source heat pumps require little to no maintenance, making them a reliable and convenient choice for hot tub and swim spa owners.

5. Simple to install: Air source heat pumps can be fitted to virtually all hot tubs and swim spas so anyone can take advantage of their energy-saving advantages.

Commonly asked heat pump questions

Our air source heat pumps start from £1,299 for a 7.5kw inverter model. This includes WiFi controls with heating/cooling functionality. Installation varies from around £350.

It’s difficult to give a definite payback figure. Like all renewable sources of energy heat pump output is variable according to ambient temperature.

If we take the average UK temperature of 10 celsius and assume a hot tub at 38 celsius, then the COP at this temperature is around 4. So you could on average be looking at reducing your heating costs by up to 4 times. 

For a hot tub, we would suggest either a 7.5kw or 9.5kw model. This would give you plenty of use all year round and even down to -12 celsius.

For a swim spa then either a 9.5kw or 12.5kw version would work well.

We would recommend an annual service for your heat pump, but our full-service option will include the heat pump service.

Yes, we can fit a remote switch to enable you to switch between or use both heating sources when you need an extra boost – this is ideal for holiday rentals who have limited time to heat up the hot tub for new guests.

Our air source heat pumps are whisper quiet and operate between 40 and 52db, for context 40db is the same as a quiet library. 50db is the same as a refrigerator. Our heat pumps use variable speed fans so they can run at lower speeds making them quieter

Our heat pump will work down to temperatures are low as -12 Celsius. It may not feel like it sometimes. but on average the UK is a mild climate. With average UK temperatures around 10c in the UK so our heat pump will offer great performance all year round.

One of the advantages of an air source heat pump is with the higher output of an air source heater they can heat much faster than your electric heater. But it will depend on several factors, including hot tub insulation and most importantly ambient temperature. In good conditions, it can be as fast as 3 or 4 hours. In winter this will be slower as there is less heat to extract from the air but still offer a similar performance to your internal heater.

Yes, you can, although currently it may not possible to use it to heat both the hot tub and swim spa at the same time due to the different temperature requirements. But it can be used to heat one or the other. so if you don’t use the swimming pool during the winter months it can be used in the hot tub during these times with some plumbing changes.

If you have a need to heat water then yes it can be used, although as it would be plumbed directly into the hot tub or swim spa, it would just depend on your needs and if it could be adapted.
Of course. With the larger volume of water, you would most likely need a larger unit. Give us a call for a chat about this.

Many many years! Our heat pumps are supplied with a 3-year warranty and a 7-year warranty on the compressor. As long as correctly maintained heat will always be 100% efficient.

Yes, a heat pump can be used to heat a hot tub. Heat pumps are an efficient and cost-effective way to heat a hot tub, as they use the ambient air temperature to transfer heat into the water. Heat pumps are available in a variety of sizes and configurations for hot tubs, and are typically installed outside the hot tub. Heat pumps are a great choice for hot tubs, as they can heat the water more quickly and efficiently than alternative heating sources.

Most hot tubs and swim spas are compatible with an air-source heat pump. Things to consider are:

  • Plumbing – Is there sufficient access to the plumbing to divert the water through the air source heat pump?
  • Circulation pump – Some hot tubs are fitted with small low-output circulation pumps which might need additional work to adapt to work with a heat pump.

If you have any questions please get in touch with us

Our air source heat pump has its own control system built-in which you can set the temperature and adjust other settings. Configuration is simple you just set the heat pump to the maximum temperate you require, and then day-to-day adjustments are made from your hot tub or swim spa as normal. It’s that simple.

When installed an air source heat pump will bypass the in-built heater in the hot tub. However, we are able to. In some cases, you might still want to take advantage of the internal heater. For instance, holiday let premises might require a fast heat-up time so using the electric heat at the same time will boost heating times. Speak to us if you require additional flexibility with your heating options.

  1.  The hot tub is switched off and drained down. Don’t worry if your water is hot, we can put it back into the hot tub afterwards. It won’t be wasted.
  2. Plumbing is installed to allow the water to flow through the heat pump.
  3. The internal heater is disconnected and the heat pump wiring is connected.
  4. The heat pump can then be connected to the plumbing and wired in.
  5. We can then refill your hot tub and power it up the hot tub.
  6. The heat pump is then programmed and set up for your desired temperature

And we’re all done. The installation process typically takes around 3 – 4 hours

Air Source Heat Pump Ready The Tub Company Suffolk

Contact us for using the form below for further information on Air Source Heat Pumps For Hot Tubs