Within the curtilage of the Georgian Grade 2 Listed Grove House near Thirsk, stands The Coach House. Its vast upper floor has now been restored and transformed into a modern living and entertainment facility complete with separate bedroom accommodation. The renovation project has maximised the energy saving potential of renewable technologies and PIR insulation to ensure heating and air conditioning running costs are minimised. The versatile Unico HVAC System  has been chosen to provide the perfect indoor temperature and ensure personal comfort throughout the year.

The owners have also been renovating the three floor formal Georgian main residence, but only on a limited basis as they did not wish to spoil the internal symmetry of the building. The Coach House provided the scope for more extensive work and the creation of a space that could be used for overnight guests and as an entertainment area, complete with a cinema size TV, state of the art hi-fi and a home for a comprehensive vinyl music collection. Having previously experienced overnight Yorkshire summer temperatures of around 40º C, it was also essential that the adjoining bedroom should be effectively cooled for a good night’s sleep in the years to come.

“For heating and cooling, it made perfect sense to consider an all-in-one solution that could heat and cool both rooms effectively, rather than specify separate underfloor heating and air conditioning systems. I was attracted by the versatility of multi-purpose HVAC (Heating, Ventilation and Air Conditioning solution) systems that are popular in the United States. This would be better than risking damage to the property with a hydronic solution,” says owner Dave Smith.

His research led to Unico System UK and their principal UK Partner, Bell Plumbing Supplies. They designed a system which would meet all of the owners’ requirements in terms of personal comfort, interior design in harmony with an historic property, quiet operation and integration with the other energy saving technologies used in the renovation.

Satisfying stringent Building Control requirements has meant that the basic fabric of the Coach House has been retained. However, many structural elements, including the main truss and roof timbers, were rotten and had to be replaced. Using prefabricated cassette walls, great emphasis had been placed on ensuring high thermal efficiency throughout. The vaulted ceiling of the 18 x 5 metre building has 150mm of PIR insulation, the walls have 100mm, with a 100mm air gap to the original brick walls, with a vapour and air barriers fitted. The floors have a minimum 200mm of glass wool between floor joists.

High performance solar PV Slates have been specified for the traditional roof and a false wall was created to run from top to bottom of the building, hiding all the associated pipework and electrics. A battery storage system stores free energy that is generated and a thermal battery for hot water complete the wholly sustainable solution.

As would be expected when retrofitting a Unico System within a heritage building, the installation was by no means straightforward. Local Unico Specialist Partner, Safegas of Wetherby, carried out the intricate work, using all their experience and creativity to ensure that all challenges were overcome. The ground floor of The Coach House, which had acted as a coal shed, provided the ideal space to locate the Unico System 1218 Air Handling Unit and is easily accessible for maintenance. It is linked to a Daikin split air conditioning system with the external unit on the adjacent outside wall.

A new king truss was required to replace the original and was fitted in the middle of the entertainment room to support the steel ridge beam. Visually, it reflects the historic interior of the building. This meant that the main service ductwork had to be split into two parts, with Unico’s flexible supply ducting woven through the spars of the king truss above the eventual ceiling height. The result is a balanced system that performs exactly as originally intended.

As so many additional flexible ducts were installed to get round the king truss, there was no room in the ceiling for the system’s return duct. This was therefore located at floor level behind the TV projector, unobtrusively positioned by Safegas with easy access when the filter needs replacing. The fact it fitted into the 400mm studwork seamlessly was a bonus. The Unico System is visually discreet, with the round room outlets aligning with downlights and blending with the interior decor.

“Safegas were a really good fit for the project and came up with solutions that worked extremely well. They coordinated the job carefully with Unico, Bell Plumbing, Daikin and other suppliers to ensure a smooth installation and commissioning. The system runs at a murmur, which I think is down to the efforts spent tuning the system in the first place. You hardly know it’s working. It’s the highest compliment I can give it,” says Dave.

The owners now have a highly energy efficient self contained bolt hole within the original building that maximises use of the latest renewable technology. It has extremely low day to day costs and Dave estimates that when running, the Unico System is using around just 500 watts, a very low consumption for the approximate 300 cubic meter space that has to be heated or cooled.

For Safegas the Coach House project has demonstrated the versatility of the Unico system and was completed on time with all on-site issues successfully addressed. ” The customer required a heating and air conditioning system that was minimalistic, quiet and offered very fast warm up times.  Unico has met all these stipulations and demonstrated the retrofit potential for a property of this type. We are well placed to take on similar heritage building retrofit installations,” says Daniel Theaker, Safegas Technical Services Manager.