How to avoid melt-down of your Solar Heating System Solar (over) Heating How to avoid melt-down of your Solar Heating System SH - A Miller August 2011
Overview Bad Experience Why did it do this Re-design Advice SH - A Miller August 2011
Bad Experience Pressure excursion Melted Expansion Vessel SH - A Miller August 2011
Bad Experience Pressure excursion Melted Expansion Vessel Leaks SH - A Miller August 2011
Bad Experience Pressure excursion Melted Expansion Vessel Leaks Melted pump station SH - A Miller August 2011
Why did it do this Simple Layout Normal Operation PUMP STATION EXPANSION VESSEL TANK HEATING UP SH - A Miller August 2011
Why did it do this Tubes Designed for stagnation but not the other components Layout Vapour Convection STAGNATION – VAPOUR BUBBLE - 270° PUMP STATION EXPANSION VESSEL NO FLOW Fully hot TANK SH - A Miller August 2011
Layout STAGNATION – VAPOUR BUBBLE - 270° PUMP STATION EXPANSION VESSEL NO FLOW Fully hot TANK SH - A Miller August 2011
Re-design Anti-siphon loop Secondary circuit SH - A Miller August 2011
Layout – Re-design AUX. TANK (UNLAGGED) PUMP STATION EXPANSION VESSEL SH - A Miller August 2011
Layout – Re-design AUX. TANK (UNLAGGED) PUMP STATION EXPANSION VESSEL NO FLOW Fully hot TANK SH - A Miller August 2011
Conclusions Do not assume installers know it all Ask some awkward questions Plumbing skill greater than average plumber’s Layout needs careful design SH - A Miller August 2011