Hotham Construction Services Limited was set up just over a year ago by Martin Hotham, though his association with Exeter based OMNIE goes back far further, through his experience as a plumbing and heating contractor.
For the new-build five-bedroom house hear Ripon, Hotham Construction is making use of insulated concrete formwork (ICF) for the walls of the half buried structure, as well as a highly insulated pitched roof supported by JJI engineered timber joists, to keep heating loads to a minimum. OMNIE therefore determined that a 7kW LG Therma V air source heat pump would be sufficient to feed the Ultimate and OgeeBoard UFH circuits, along with all of the domestic hot water requirements. OMNIE also designed and supplied a full MVHR system for the house, utilising a Zehnder unit offering industry leading efficiency standards.
Martin Hotham commented: “I have been installing OMNIE air source heat pumps and underfloor heating, as well as the Zehnder MVHR systems, in properties for over five years and had no hesitation in going to them for this house we are building on behalf of a private client. OMNIE’s technical team has not only provided all of the specifications and detailed layout drawings for the build, but trained our people in the installation of the LG heat pumps, as well as a visit last year to the ALPHA INNOTEC KASSENDORF factory in Germany.”
“Then towards the end of the job, when we have completed installing the heat pump, OMNIE’s engineer will come to carry out the commissioning work. In terms of the underfloor heating here, our upper floor (at ground level) construction makes use of metal web joists which we cover with 18mm chipboard to create a safe platform, before we lay a waterproof membrane and the OMNIE Ultimate boards followed by the pipes and the levelling compound. It offers a very good base for a tiled floor.”
Developed in conjunction with Tilemaster Adhesives, the 18mm thick, precision routed XPS insulation panels feature a special ‘diffuser channel’ concentric to the pipe runs. These significantly increase contact and heat transfer from the pipes when the Levelflex self- levelling compound is laid across the installed 12mm PE pipework.
Ultimate’s design further enhances bond efficiency and resists subsequent tile movement; while the boards’ ease of installation and overall low construction depth mean the product fits within all three of OMNIE’s LAYFAST, ULTRALOW and TILEOVER technology categories. Then for the lower ground or basement, OMNIE’s OgeeBoard XPS panels were laid throughout the bedrooms, bathrooms and a generous sized gymnasium which adjoins the home’s plant room. They are available in thicknesses of 35, 50 and 75 mm to take 16.5mm thick PE-RT pipe laid directly into the routed channels which protect the circuits from damage until a screed is laid. This gives good heat transmission though output depends on the final floor covering chosen as well as water flow temperature.