Heat Pump Cylinder Solutions

There are a few types of heat pumps, the most popular being air source heat pumps and ground source heat pumps. An air source heat pump collects thermal energy from the outside air whereas a ground source heat pump collects the energy from the ground. Both utilise this energy to heat the home and provide domestic hot water.

An air source heat pump unit, sometimes referred to as an air-to-water source heat pump, transfers heat from the outside air to water. This in turn heats your rooms via radiators or underfloor heating. It can also heat water stored in a hot water cylinder for your hot taps, showers and baths.

Heat from the air is absorbed into a fluid. This fluid then passes through a heat exchanger into the heat pump, which raises the temperature and then transfers that heat to water.

Click here to see The Energy Saving Trust website provides essential reading related to heat pumps and also the unfounded myths.

There are a number of reasons why people look to switch to heat pump technology as their chosen heat source including;

• Reduction in your CO2 emissions
• Eligible for a Government grant under the boiler upgrade scheme and ECO4 scheme
• Provides domestic hot water and home heating in an environmentally friendly way
• No gas supply needed – suitable for off-grid properties with electricity used to run the heat pump and boost the hot water cylinder
• Reduces your dependence on fossil fuels
• Suitable for both new build properties and refurbishment projects
• Works even in low winter temperatures

The air around us contains thermal energy – or heat. Heat naturally flows from a warmer place to a colder place.

To provide the heat energy in a home when outdoor temperatures are colder, we need heat to flow in the other direction – from a colder place to a warmer place. But how does it do it?

When the pressure of a gas increases, the temperature also increases. When the pressure decreases, the temperature decreases. This relationship between pressure and temperature is the key to how a heat pump works. The gas is called a ‘refrigerant’ and a heat pump uses electricity to compress this refrigerant, increasing the pressure and therefore the temperature.

As the refrigerant’s heat is transferred to your home through the heat exchanger, it cools down a little. The refrigerant is then allowed to expand so that it cools even further. It’s now cold enough to absorb more heat from outside and begin the process again.

The heat delivered to the heat exchanger can then be used to heat your home. This would normally be done using a central heating system – but it could also be done using warm air in either an air-to-air heat pump or an exhaust air heat pump.

A heat pump cylinder is a well-insulated tank, which stores water after it has been heated via a heat pump system, either air source or ground source.

The cylinder is designed with a highly efficient coil to extract the low temperatures and transfer to heat the volume of water in the cylinder. They are supplied with an immersion heater pre-fitted to the cylinder to allow for the pasteurisation cycle, ensuring the water does not develop any bacteria such as legionella.

There are many advantages of a Mcdonald cylinder including:

• Ability to cope with the high demand of hot water in larger homes

• Reduces the need to continuously heat water

• Can be used alongside other renewable heating solutions

• If used with a renewable heating solution, reduces the consumption of energy generated by fossil fuels, providing savings to the homeowner on energy bills

An air source heat pump system will always require an efficient hot water cylinder for storing the home’s domestic hot water. The heat pump cylinder can provide hot water at temperatures ranging from 35 to 55 degrees Celsius.

There are a number of considerations to aid efficiency, not least to make sure the chosen cylinder is heat-pump compatible.

In addition, buffer tanks can also be specified for use with the heat pump, expanding the heating capacity and reduces unnecessary cycling of the heat pump. These can be separate cylinders to the main cylinder, or combined into the same foot print with tank on tank configurations.

Heat pump cylinders offer many advantages over traditional hot water heating systems including:

• Increased Efficiency: A key benefit is improved efficiency. Heat pump cylinders extract heat from the air or ground, resulting in less energy use compared to conventional electric or gas heaters. This in turn delivers lower energy bills.
• Renewable Energy Compatibility: Heat pump cylinders can be effectively combined with renewable energy sources like solar panels. This allows you to heat your water with minimal reliance on fossil fuels, reducing your carbon footprint.
• Suitable for Larger Homes: Heat pump cylinders can meet the hot water demands of bigger households. They store heated water, ensuring a consistent supply even during peak usage times.
• Heating Contribution: Some models of heat pump cylinder have a ‘tank on tank’ configuration, allowing for the heat pump to heat a small buffer store which in turn contributes to the properties heating requirements. This reduces the ‘cycling’ of the heat pump and maximises the input.
• Government Incentives: In many regions in the UK, installing a heat pump cylinder might qualify you for government grants or subsidies, making them a more attractive investment.

A traditional gas boiler operates at 70-80°C, therefore providing a higher kW output through a standard indirect coil than a heat pump, which generally operates at 55°C. As the heat pump is a lower temperature heat source, it is essential to maximise the heat transfer to the water held within the cylinder.

Measuring a heat exchanger performance purely by its surface area is inaccurate, especially when comparing coil types such as a plain, copper integron (finned) or stainless steel corrugated heat exchanger.

The internal coil design in an ECOflow heat pump cylinder differs from a POWERflow indirect or solar cylinder, with the heat pump cylinders incorporating either a double or triple pass coil. What is critical is that the purpose designed heat exchanger provides optimised heat exchange, low pressure drop and allows higher flow rates to allow to heat pump to perform to its most efficient.

Our STEELflow heat pump models, whilst utilising corrugated stainless steel coils, are designed to also maximise the lower temperatures from a heat pump. These are manufactured using wider bore coils to increase the flow rate and improve heat transfer.

The ECOflow unvented range offers slimline models with as little as 400mm overall diameter, with the STEELflow starting at 475mm diameter.

While domestic unvented cylinders can be manufactured from either copper or stainless steel, the bespoke design flexibility of copper provides the perfect solution to speed up and simplify the installation, where standard stainless steel products cannot fit.

With a wide range of diameters available to choose from, providing the flexibility of a range of slimline options, and the ability to adjust the tapping positions to suit the installation, the ECOflow has become the perfect choice for installers.

Our range of heatpump cylinders are available as pre plumbed alternatives.

The benefit of having all the components factory fitted provides uniformity of the installation, especially across a new build development, to ensure ongoing support and issue diagnosis.

Having a pre plumbed configuration also allows for the first fix plumbing to be completed without the need for the units to be onsite until required.

In most instances, the coil of an indirect cylinder will be for use with either a high temperature boiler or solar thermal technology. This will mean that the existing coil will almost certainly be too small for use with a heat pump, therefore not provide sufficient heat transfer resulting in longer cylinder reheat times at the lower water flow temperatures supplied from a heat pump unit.

The internal coil used with a heat pump cylinder is designed to maximise the lower temperatures from a heat pump. With the ECOflow range, we use a high heat transfer integron copper coil in a multi pass configuration.

Our operations manager, David Stewart, talks through the fantastic benefits of our ECOflow cylinder range.

Alternative energy is energy that does not come from fossil fuels, and therefore produces little to no greenhouse gases like carbon dioxide (CO2). This means that energy produced from alternative sources does not contribute to the greenhouse effect that causes climate change.

These energy sources are referred to as “alternative” because they represent the alternative to coal, oil, and natural gas, which have been the most common sources of energy. These fossil fuels emit high levels of CO2 when burned to produce energy and electricity.

Alternative energy, however, should not be confused with renewable energy, although many renewable energy sources can also be considered alternative. Solar power through roof mounted solar panels, for example, is both renewable and alternative because it will always be abundant and it emits no greenhouse gases.

Renewable energy is generated from natural sources, such as the sun, wind, biomass and water, with renewable energy sources being naturally replenished.

It’s also often referred to as “green energy” and “clean energy” as the process of generating energy from these renewable sources emits no or little greenhouse gases – unlike fossil fuels like coal and oil. Moving away from these traditional sources of energy is a key step in our efforts to take action for climate and combat climate change.

The main insulation method on our alternative energy range is high density injection foam, that is then cased to not only maintain the temperature of the store for the maximum period, but also provide an aesthetic finish that is easy to clean. 

The ECOflow is available with 50mm of insulation as standard, however, for where lower heat loss is demanded, the units can be bespoke designed with insulation thickness up to 100mm.