The detached home, based in Alton, Hampshire, was previously heated by a combination of technologies including solar PV, a biomass boiler and a hot water heater. When the homeowners purchased the property in early 2017, they scheduled significant refurbishment works and replacing the existing heating system was one of the projects. The layout of the ageing system did not meet the homeowners’ lifestyle requirements so a new approach to heating their home sustainably was required.

Selecting an efficient, effective and environmentally friendly system was important for this install. “From the outset, we wanted to maintain the idea of keeping our energy footprint to a minimum,” comments the householder. “With no natural gas in the area and our previous experience with other more traditional systems, our choices were limited. However, after discussions with Paul Humphrey of Humphrey and Crockett Ltd, the innovative Grant hybrid heating system was introduced to us. Utilising an air to water heat pump and oil boiler, Paul suggested that the VortexAir Hybrid would meet our requirements and overcome the problems of the previous heating system.”

In this instance, the larger VortexAir Hybrid model was chosen comprising of a 16kW Aerona³ air source heat pump and a 21/26kW VortexBlue oil fired boiler. The VortexAir Hybrid cleverly couples these two technologies with just a single flow and return connection to the house, thus enabling a simple installation.

For this installation, the hybrid was fitted as a complete unit behind the property’s games room with the services installed in a trench running across the paddock into the house. The VortexAir offers excellent flexibility when it comes to siting as the hybrid can either be installed as a single unit (with both the heat pump and boiler sited outdoors) or separately with the heat pump located externally and the oil boiler installed inside. Furthermore, for distress purchase situations when a property requires heat to be restored quickly, the oil boiler can be installed first as a stand-alone unit with the heat pump being fitted at a later date.

Alongside the installation of the hybrid, new radiators were also fitted within the property. “It was explained to us that, to get the best out of our heat pump and to reduce the use of the oil boiler, the new radiators should be oversized if possible,” continues the homeowner. After carrying out the heat loss calculations, it was decided to install radiators which were oversized by approximately 30%. In addition, all of the pipework which was previously mounted on the surface has been removed and replaced.

The VortexAir Hybrid uses an advanced control system which automatically monitors the system temperatures. The unit is able to seamlessly switch between a number of different modes of working, whether that be the heat pump, the oil boiler, or a combination of both technologies. Within the first month of the system operating (November through to early December),” writes the householder, “the oil boiler did not need to operate at all and during that time, we had days when the daytime temperature did not rise above 4°C and the night temperatures were freezing or just below.”

The homeowners are thrilled with their new heating system which delivers the best of both worlds with the renewable heat pump working with the back-up of an oil boiler when required. “We are so pleased with the finished installation,” concludes the homeowner. “Aesthetically, the installation has exceeded all our expectations and, from an operational perspective, it has been amazing.

The temperature throughout the entire house and separate games room are kept at a constant level.