Vian Power S7 Plus – 7KW -Air Source Heat Pump

Vian Power S7 Plus (price includes delivery to mainland UK)

Product Manual

What is the Warranty?

Heat Exchanger – 5 Years

Compressor – 5 Years

All other parts – 2 Years

Please note, if you decommission the unit over winter, make sure there is no water left in the unit at all. It should be blown out. Frozen water damage is not covered under warranty.

What is the Vian Power Air Source Heat Pump Range?

The Vian power Air Source Heat Pump Range is a new range of Air Source Heat Pumps. Specifically targeted at the UK and European market for retrofit Hot Tubs and Swim Spas, the range of air source heat pumps comes in 4 different models.

They are available in 5KW, 7KW and 9KW models and there are two different options – “Standard” or “Plus”.

Unlike the “mini” range of Air Source Heat Pumps, these are mode comparable with the Comfortline range that you know I am very enamoured too on this blog and my YouTube Channel.

They do require hard cabling into your mains supply so you will perhaps need to consult an electrician for the work (or just power it off your Spa Pack main block and disconnect your electric heater 😉 )

In terms of the units themselves, they come with a titanium heat exchanger which is a nice touch as too is the temperature rating right down to -10C for the Plus models and -5C for the standard range.

What is incredibly nice of the manufacturer is to actually state the COPs all the way down to the -10C range. This is certainly something that is not common and very much welcome. You can see exactly what kind of levels of performance you are going to be taking about.

What is the difference between the “Plus” and “Standard Models” models?

There are two main differences between the plus and the standard models. Firstly, the plus models are rated to a lower temperature -10C whereas the Standard models are only rated to -5C.

Secondly, the standard models are “on/off” models whereas the “plus” models are fully inverted. The difference here means that the standard models will be running at 100% all the time regardless of the temperature setting and ambient temperatures.

A fully inverted model can calculate that it might only need to run at 67% for example to achieve the temperature that it has been set to given the ambient temperature.

In short, fully inverted models are more efficient than on/off models.

What are the standout features of the Vian Power Air Source Heat Pumps?

I think that the COPs (Coefficient of Performance) that are on offer for these models is pretty good indeed. If we take the middle of the road 7KW at 25C we are looking at a COP of almost 11 and at 0C 4.5 which is pretty good indeed. Even at -10C you are still going to get 3.5x the amount of electric in out in terms of heat. Pretty good indeed.

All units as you would expect can heat up to 40C which is a given if you are running a hot tub.

The titanium heat exchanger is also good for longevity although these days, this seems to be somewhat standard even in cheaper Air Source Heat Pumps.

This is a true all season Air Source Heat Pump given the temperature rating of this Air Source Heat Pump.

How have the Vian Power Air Source Heat Pumps Been tested in the field?

When I first saw this product, I did call the manufacturer for more info and to get the inside scoop. I was told that they had over 100 of these units deployed for over a year in the field for testing before they were planning to launch this model.

According to them, the feedback from the “testers” was really positive indeed which gave them no concerns to launch this to the mass market. They also had a number of pre-order for the model too which again is encouraging.

What is the temperature rating of the Vian Power Air Source Heat Pumps?

This range of air source heat pumps will operate from -10C for the plus range, and -5C for the standard up to +43C. That is quite a large operating temperature range indeed for an Air Source Heat Pump.

How do I connect a Vian Power Air Source Heat Pump  to my existing hot tub?

The first thing that you are going to need to do with your Vian Power Air Source Heat Pump  is find a suitable location to cut into the pipework on your hot tub. Ideally, you are looking to add the Air Source just before, or just after the circulation pump.

Below shows the ideal location to cut the pipes on this particular hot tub.

Next, you are going to want to use one of the connection kits that I have prepared. They come with everything you need in order to connect them to your existing tub.

Just be mindful of the direction of flow. The front of the pump is always suction.

When is the Vian Power Heat Pump Range Available?

According to the manufacturer, this model will be in stock for the UK and Europe from mid-February 2023.

Which countries are the Vian power range of Air Source Heat Pumps Available?

This range of Air Source Heat Pumps is available in the UK and Europe.

HOW IT WORKS

INSTALLATION

Electrical Requirements:

The heat pump does not need any additional electrical installation on site as the unit can take its power from the hot tub or swim spa.

Location:

The heat pump requires a minimum of 500mm of inlet space and is recommended to have 1m of unobstructed space for the fan outlet.

Planning:

Each installation will vary, and a site survey to review and discuss the best fitment and location for the heat pump can be arranged. This is a great opportunity to discuss the best option for the installation of the heat pump and answer any questions.

Fitment:

When installing the heat pump some basic modifications to your hot tub or swim spa will be made. This is too plumb the heat pump into the heating and circulation system. There will be an inlet and an outlet pipe plumbed into the hot tub base or cabinet to provide circulation through the heat pump.

HOW DOES AN AIR SOURCE HEAT PUMP WORK?

The fan in the air source heat pump draws air over a network of tubes that look a little like a car radiator.

These tubes are filled with an eco-friendly R32 refrigerant. The air then passes over the tubes warming up the refrigerant and turning it from a liquid into a gas.

This gas is passed through a compressor which increases the pressure and significantly raises the temperature of the gas, which is then passed through a titanium heat exchanger.

The swim spa or hut tub’s water circulation system is plumbed through the air source heat pump and the heat from the gas travels through the heat exchanger, which in turn heats the water from the hot tub or swim spa as it passes over it.

The refrigerant then cools and turns back into a liquid and starts the process all over again.

Due to how the system works, our air source heat pumps will still produce heat even if the ambient air temperature is below zero as the compression process of the refrigerant gas creates a lot of heat.

Not only is this a far more cost-effective solution to heat your hot tub or swim spa, but it is also much more eco-friendly option.

REAL WORLD TESTING

The chart above shows the KWh used by the heat pump to maintain the set point of 40°C. The rest period is for 31 days between the 8^th Dec 2022 and the 7^th Jan 2023.

This was an ideal test period as the beginning of the test on the 8^th Dec 20022 the UK experienced a very cold spell with temperature dropping several degrees below zero.

Figure 1 shows the recorded temperature on the 10^th of Dec 2022 of -3.1°C and the chart shows the KWh usage 5.62KWh. Compared to figure 2 showing the temperature for the 4^th of Jan 2023 being 11.5°C KWh usage reduced to only 1.66 KWh.

The total KWh used by the heat pump over this period was 116.21 and this equals to an average of 3.75 KWh per day. As the ambient temperature rises, we can easily see that the efficiency of the heat pump increases significantly.

To equate these KWh figures to cost, we simply multiply the figure by the current KWh rate. At the time of publishing the KWh rate is capped at £0.34.

10.12.2002 – Ambient temp = 3.1°C / 5.62 KWh used / £1.91 Heating Cost

04.01.2023 – ambient temp = 11.5°C / 1.66Kwh used / £0.56 Heating Cost

• Test Location is Chichester, West Sussex, UK, – All figures are just relation to the heating. – The hot tub is outdoors and not under a gazebo or shelter.
• The electric heater is disconnected so all heating is supplied by the heat pump only.-We are testing a Vian 7KW S7 Plus Air Source Heat Pump.
• The heat pump is set to boost made. The hot tub is a mid-specification model of approx. 1550 liters of water. – The hot tub is set to be heat to 40°C
• We have used an older cover for these tests that is slightly waterlogged (to mimic real world). – The pipes the heat pump are not insulated.
• The heat pump is within 1 meter of the hot tub. The hot tub has economy cycles set as follows:

Tub goes into economy from 10.00pm to 10.00am, so does not heat for 12 hours overnight, 7 days per week.

Then a second economy mode from 1.00pm to 4.00pm it also won’t heat)

These recordings and data are only for representative purpose as there are so many variables with different locations, temperatures and usage that could result in different figures. Whilst not independently vetted, we have performed a test to measure the KWh power consumption of our Vian 7kw S7 plus heat pump to show some of the real-world results. We used a simple inline KWh meter that connects to a smart home system to measure and record usage.

We choose to undertake this testing during the colder months and incorporate a very cold period of weather to record the results in these conditions. As the ambient temperature increases through the season then the efficiency of the heat pumps will increase, and the KWh usage will reduce.

Even at the time of testing being the colder months, we believe it is clear to see that a Vian Power Heat Pump is an extremely efficient heating solution for your hot tub or swim spa.

LOW COST HOT TUB HEATING

A Vian Power Air Source Heat Pump can be up to 75% more energy efficient than standard heating options. Simply put, they produce more heat (energy) than they use in electricity (energy).

The relationship between the power used by the heat pump at the heat it generates is referred to as Coefficient of Performance (CoP). For example, if pump has a Cop of 8, then it will produce x units of heat for every one unit of electricity consumed.

The electric heater in a hot tub or swim spa is known as a resistance heater and is very much like the element in a kettle. This resistance heater can only ever have a CoP of 1. This means for every 1 x kilowatt of power used by the electric heater then only 1 x kilowatt of heat is produced. If compared with a standard electric heater in a hot tub, then we can easily see that an air source heat pump is a far more efficient and cost-effective way of heating your hot tub or swim spa. This is because using the example CoP of 8 then for every 1 kilowatt of power consumed by the heat pump, the 8 x kilowatts of heat are produced.

The CoP of an air source heat pump will vary depending on the ambient temperature and the mode function set on the air source heat pump.

DIFFERENT TYPES OF TCHNOLOGY:

ON/OFF heat pumps. When ‘on’, these models will draw a constant amount of power to operate, they can be considered to always be at maximum power when working.

INVERTER models have the benefit of being able to have their power consumption varied and, in some cases, this is done smartly by the machine itself based on the ambient temperature and heating demand. Sometimes referred to as stepped inverter, these models may have stages or steps of power use. Step 1 for example would be a very low power mode, step 3 a medium power use and step 5 would be full power. They also have the added benefit of being quitter than ON/OFF heat pump.

FULL DC INVERTER models can regulate the power consumption over a much more fluid range so rather than steps or stages of power draw like a stepped inverter machine, they can vary the power they consume across their whole range. This technology makes full DC inverter heat pumps the most efficient types of machine over the long term. Full DC inverter models are also very quiet.

By using far less energy than traditional heating methods, an air source heat pump is not only good for the enjoyment but still save hot tub and swim spa owners a considerable amount of money. It is no wonder why hundreds of owners are opting to have an air source heat pump fitted to their hot tub or swim spa.