At sub-zero temperatures the heat loss from two Oase Biotech Screenmatic filters equated to 3.2 kW. These filters are part of a filtration system for 2 No. Internal Koi Carp ponds maintained @ +22°C. The application of tailor made insulation jackets by Total Thermal Services reduces the heat loss by 2.9 kW, clearly this represents a significant fuel saving during cold weather and provides a relatively quick payback period against capital cost.