We increased floor heating efficiency by enhancing convective and radiative heat delivery from an innovative underfloor heating pipe while controlling pumping power. Computational fluid dynamics and energy and thermal modelling were used to explore pipe cross sections, materials and spacing patterns within typical screed build ups. The study examined flow regime, internal pressure loss, external heat flux distribution and room level comfort metrics under low temperature operation compatible with heat pumps. Metrics included delivered heat per unit pump power, warm up time, surface temperature uniformity and local peak limits for comfort and surface integrity. Mesh and parameter sensitivities on fluid properties and set points underpinned robust comparisons between concepts. A specific cross section and spacing variant improved near surface heat flux uniformity and reduced hydraulic losses at target flow rates, broadening the low temperature operating window. We provided Flexigas with evidence based design rules and a clear path to prototype build and test, plus a reproducible model to accelerate iteration across pipe sizes and room layouts.