Unico makes short work of energy-efficient self build
When Jonathan Powell decided to build himself a house in Frome he had a vision, not only of an architecturally-unique property with stylish glass atrium, but also of a house with the ultimate in energy efficient design. To this end, he chose SIPs (Structurally Insulated Panels) as the main building component. SIPs consist of a foam core sandwiched between two layers of wood which, due to excellent insulation and airtight properties, can reduce energy costs by up to 70% when compared to traditional fibreglass-insulated buildings. This means that heating and cooling equipment can be downsized accordingly. After achieving an impressive R-value by using SIPs, Jonathan then selected a Unico system to provide quality energy-efficient heating and ventilation.
“I wanted a system that heated and ventilated the house because it is tightly sealed. I didn't want underfloor heating because it is expensive and tedious to install, and doesn't ventilate. And radiators take up too much wall space and again don’t ventilate,” explains Jonathan. Furthermore, the central glass atrium, which supports an indoor ‘jungle’, was designed to provide passive solar heating. The Unico system circulates the warm air which gathers at the top of the house to the lower levels as part of its normal operation.
A single Unico air handler was installed in the loft room to provide heating and ventilation. In heating mode, an efficient heat exchanger and fan transfers heat from warm water supplied by a thermal store to the high-velocity warm air system. The thermal store is essentially a large hot water tank which is heated either by solar panels or when that fails by economical night-time electricity. In ventilation mode the air handler dumps stale, warm air and pulls in fresh from the shaded north-facing wall for a cooling effect. In order to ensure air stays fresh in the heating mode - but without venting valuable heated air unnecessarily - a Telaire carbon dioxide monitor was installed. When carbon dioxide levels exceed 1000ppm an electric damper operates within the Unico system, providing ventilation until concentrations decrease below the activation threshold.
The building was designed to circulate air through the very structure of the house, and be seen to be doing so. The plenums, suspended from the ceiling and left visible, feed the high-velocity air into fibreboard interior walls. Outlet slots have been cut out of the fibreboards, and an opening to the loft room allows air to complete its circuit and return to the handler. Only in some of the harder-to-reach places did Jonathan utilise Unico’s conventional ducting and air outlets.
Jonathan, a hands-on self builder, is delighted with his Unico system, especially as it took him just five days to install on his own. “After attending a short Unico training course I found the installation went very smoothly. The system requires only limited plumbing and wiring. Unico could not have been more helpful with advice and training. Ten out of ten!”