Hybrid Heating Systems FAQs

A hybrid heating system combines more than one heat source to fulfil the space heating and hot water requirements for a property. Such hybrids usually bring together a renewable heating product, such as an air source heat pump, with a traditional fossil fuel appliance, such as an oil or gas boiler. Hybrid technologies provide households with a solution to incorporate renewable energy into their central heating system when a heat pump, or other renewable product, is unable to fulfil the entire heating and hot water demand.

The Grant EvoLink Smart Hybrid System Hub is a compact wall-mounted unit that allows an Aerona air source heat pump to be installed alongside most existing domestic heating systems, such as a gas boiler. The EvoLink Smart allows renewable energy to be incorporated into a heating system while keeping the existing boiler as a supplementary heat source.

Each type of hybrid system works differently depending on its design and configuration. The EvoLink Smart Hybrid System Hub is controlled by the Grant Aerona Smart Controller which operates the original heat source (gas or oil boiler) when required, allowing the Aerona³ or Aerona 290 heat pump to operate as much as possible. The EvoLink Smart will ensure that the desired comfort level is maintained with the boiler being called in when the heat pump is unable to satisfy the space heating or hot water load. 

A hybrid unit enables the optimum use of both an inverter driven air source heat pump and a traditional heat source, whether that be a highly efficient condensing oil boiler or an existing fossil fuel appliance with the EvoLink Smart. Throughout the year, as the ambient air temperature (and consequently the heat demand of the building) changes, a hybrid will provide the most efficient use of both the renewable and non-renewable energy sources. The EvoLink Smart Hybrid System Hub allow end-users to benefit from low carbon heating for the majority of the year with the boiler used as a back-up during colder periods.

Heating system radiators in existing properties are usually sized using the higher water flow temperatures produced from a boiler and so, to meet the same heat demand using the lower flow temperatures produced by a heat pump, the radiators would normally need to be increased in size. Using a hybrid unit combines the higher flow temperatures produced by a boiler, with the efficient operation of a heat pump, to meet the buildings heat demand throughout the year.

When the weather is warmer, i.e. in the spring and autumn, the heat pump works independently and the existing radiators can meet the heat demand with the lower flow temperature. This allows the very efficient use of electrical energy to drive the heat pump for large periods of the heating season. When the weather gets colder, the boiler operates to provide the additional energy required negating the need to increase radiator sizes.

This is a complicated question to answer. Any cost benefit is dependent on a variety of different factors, including the heat demand of the property, the type of heating system currently installed, the pattern of heating usage, the cost of both electricity and heating oil at the time of installation. Consequently, cost benefits will vary from one installation to another.

The EvoLink Smart is designed to be wall-mounted and installed indoors with sufficient access clearances which are outlined in the Installation Manual. The EvoLink Smart has a white case so it is ideally suited for installation in a kitchen or utility room. The EvoLink Smart should not be installed outdoors.

The EvoLink Smart can combine an Aerona³ or Aerona 290 heat pump with a traditional fossil fuel heating system including oil boilers, gas boilers, LPG boilers and modulating biomass boilers. The Grant Evolink Smart is suitable to use on systems with a space heating demand of up to and including 28kW.

Yes, by working the Aerona Smart Controller, both the Aerona air source heat pump and the existing boiler are controlled by the EvoLink Smart in response to either space heating or hot water demand from the heating system controls (ie. room thermostats and taps).

Yes, the EvoLink Smart Hybrid System is suitable for installation with combi boilers as well as standard and system boilers.

A hot water cylinder is usually made from stainless steel with insulation surrounding it and an outer casing. Inside the cylinder, there will be one or more coils which transfer the heat generated by the heat source into the water contents of the cylinder. Cylinders are designed to store the hot water which then feeds to the taps in your home. Unless you have a combination boiler, it is likely that you will have a separate cylinder for your domestic hot water. All air source heat pumps, solar thermal systems and hybrid installations require a separate cylinder.

Cylinders typically come in sizes from 150litres up to 300litres. The size of hot water cylinder that you require will depend on the number of occupants in your home and your demand for hot water. For example, a family of four will have a larger hot water demand compared to a single occupancy home because they will use the taps, showers or bath more often. If you are researching a new heating system for your home, please speak to your installer who will be able to advise you about the most suitable size of cylinder you will need.