What is a Hybrid or Bivalent Heating system?
A hybrid or bivalent heat pump system uses a combination of renewable energy and fossil fuels to heat your property.
One component is the Air Source heat pump, and the other is your traditional gas, oil, or LPG heating. This hybrid system is unique, because there are two key components working together to maintain efficiency all year round.
A hybrid heat pump system is designed to suit your heating needs, whilst simultaneously cutting your energy use and utility bills. The key benefit for a hybrid system is efficiency. The system switches between renewable and fossil fuel, choosing the technology that is most efficient at any given time. This ensures consistent comfort, but it also means that neither technology must work so hard to achieve the desired performance.
How does it work?
An air source heat pump is fitted outside and connected to your existing gas, oil or LPG heating system.
The heat pump will take care of most of the heating needed during a large part of the year.
Modern Air Source Heat Pumps come with a weather compensator that modulates the heat produced to what is required when working. This allows the system to vary the temperature in the radiators themselves. The colder it gets outside the warmer the radiators will be and vice versa.
In the colder months the heat pump may not be able to cope alone (due to different factors related to your house) and the existing boiler is then switched in to get over these colder periods.
Hybrid or bivalent systems have one controller which usually operates the system in 2 or 3 different modes depending on the system - switching to each mode as required.
Mode 1 - Heatpump Only
Mode 2 - Combined Heatpump & Boiler
Mode 3 - Boiler Only
The switch over points between the different modes will be tuned specifically to your house requirements.
Where are Hybrid systems best suited?
Older or larger properties with a high heat loss where a heat pump alone would not be capable of providing enough heat during cold weather.
Where a multiple heat pump installation is not possible due to the lack of electric power supply to the site.
A Hybrid system is also worth considering if you don’t wish to disturb your whole house due to the fact radiators and pipe work may need upgrading to accommodate a heat pump alone.
In all cases, improving the energy efficiency of your home first will help you reduce your heating needs and in turn enable you to run a smaller capacity and cheaper heating system.
The benefits of Hybrid Systems
Lower fuel bills.
potential income through the UK government’s Renewable Heat Incentive (RHI) - More information
lower home carbon emissions
Integration with other energy sources
As with most renewable technologies, Hybrid Systems are able to integrate with other technologies:
Solar Thermal - Solar Thermal may provide all your domestic hot water needs during summer removing the need to run the heat pump at all, and so saving yourself the cost of the electricity.
Solar PV - Solar PV is the perfect combination for a Heat Pump as the electric generated from the PV Panels will help to power the Heat Pump.