Integrated Heatpump (iHP) FAQ

Find information about how the iHP works, environmental benefits and more.

What makes the iHP better than conventional heat pump water cylinders?

Conventional integrated heat pump water cylinders are slow to heat, large and inefficient. To optimise efficiency, most heat pumps are designed to operate at a lower temperature and can struggle to heat the entire contents of a cylinder to a useable temperature. Some heat pump cylinders can take up to 10 hours to reach a useable temperature. They can also be difficult to transport, install and maintain.

The Mixergy iHP is a revolutionary solution to heat water, combining Mixergy’s patented adaptive water heating technology with our new Stratos heat pump technology. It is smarter and more efficient by only heating the water you need.

How does it heat the cylinder?

It can heat the cylinder in 3 ways:

1. Fast-boost – this mode uses Mixergy’s patented top-down heating. It exploits thermal stratification to heat the water from the top-down. This means it can deliver useable hot water in under 30 minutes.
2. Eco-mode – this makes the most of the Stratos heat pump head unit. The whole cylinder heats at the optimal temperature and for the optimal times, making it 3x more energy efficient than a direct electric cylinder.
3. Solar-boost – you can connect via the current clamp. Our interface will switch the head unit on at a set threshold.

How’s it going to help achieve net zero?

All Mixergy cylinders support our national effort to reach net zero.

Heat pumps are set to play a key role in the provision of heating and hot water in new homes through the Future Homes Standard (FHS). We see that iHP can be an important part of the scenarios being developed for new homes under the FHS.

For retrofit, iHP offers a good solution to improve the EPC rating of existing housing stock.

All integrated heat pump hot water cylinders will provide a low-carbon, efficient way to produce hot water, cutting running costs by half compared to a standard electric water cylinder. What makes iHP better in this product category is the fast reheat performance.

Why is the iHP a good solution for installers?

The Mixergy iHP is a game changer for installers who want to offer their customers cutting-edge heat pump and hot water technology. With no additional training required, they can market themselves as a renewable installer. They simply need their G3 certification.

The modular design with the separated tank and heat pump head unit makes it easier to transport, install and maintain.

1. Easier to carry and handle.
2. Simple connection of the heat pump to the cylinder, meaning less labour time.
3. Plug-and-play connectivity of the Mixergy controller.
4. Easier servicing.

How is the technology advanced?

The Mixergy iHP uses innovative, patented technologies which are revolutionising how heating is done and monitored:

1. Heating stratification with a heat pump – our top-down heating approach exploits thermal stratification to enable users to heat only what they need.
2. Sensor technology embedded within the cylinder allows for the state of charge to be monitored, giving the user full control to heat just what they need.
3. Optimal use of grid demand side response – a unique ability to flex to the grid by responding to grid frequency fluctuations.

Is it noisy?

It’s very low noise. When in operation, it emits a noise like that of a conventional fridge, which is around 45-50db.

Why can it be smaller?

The iHP heats the cylinder from the top down in fast-boost mode, using Mixergy’s patented thermal stratification technology.

This means our cylinders can be up to a third of the size of a conventional alternative.

Does it need any installation considerations?

Like other integrated heat pump cylinders, the iHP requires ducting to the outside. This is because it takes in air and dispenses cold air out.

It can likely fit in most home designs, and your Installer or builder will advise on the right ducting set-up for you.

Finally, your Installer will require G3 certification to install the cylinder.

We recommend the following ducting suppliers:

• Aerfoam insulated mass flow ductwork
• Verplas Self-Seal Thermal

What is the COP performance?

Like other integrated heat pump cylinders, the COP performance will depend on the efficiency of your installation. The shorter and straighter your ducting, the better the performance. The table below can help you determine how efficient your iHP can be:

Maximum recommended total duct length = 20

How much carbon does it save?

Compared to a conventional cylinder, the Mixergy iHP saves upwards of 5 tonnes of carbon per unit.

	Conventional cylinders	Mixergy iHP
Carbon CAPEX
Cylinder alone	270	270
Heat pump head unit	0	350
Total	270	620
Carbon OPEX
Daily consumption of energy	4.5	1.5
Carbon intensity of grid electricity	0.2	0.2
Years of service	25	25
Total carbon emissions	8.2125	2.7375
Carbon savings through reduced energy consumption	5.475
Carbon OPEX	8.2125	2.7375
Carbon CAPEX	0.27	0.62
WLC	8.4825	3.3575
WLC Savings	5.125