Double Coil Cylinder

It works by taking advantage of the fact that hotter water floats on cooler water. The cylinder has two heat exchanger coils arranged one above the other. The boiler (or other auxiliary heater) is connected to the upper coil, with the solar circuit connected to the lower one. When the boiler is providing heat to the cylinder, a heating fluid is pumped from the boiler to the cylinder, where it flows inside the coil. The coil has thin metal walls which conduct the heat into the surrounding water. The heated water near the coil expands and becomes less dense than the surrounding cooler water, and so rises. Cooler water at the top of the cylinder falls to replace the rising hot water. This so-called "convection current" means that the boiler heats the top part of the cylinder above the boiler coil.


Model 300 Lt 500 Lt 1000 Lt 1500 Lt 2000 Lt
Weight kg 130 190 360 450 570
Outer Diameter 642mm 740mm 1010mm 1116mm 1272mm
Height 1415mm 1710mm 2065mm 2247mm 2500mm
Internal Tank 3mm 3mm 4mm 4mm 5mm
Upper Exchanger Square m2 1.03 0.93 1.56 2.2 2.2
Lower Exchanger Square m2 1.35 2.26 3.1 4.9 5.2
Cold Water Inlet 1” 1” 1-1/4” 1-1/4” 1-1/4”
Hot Water Outlet 1” 1” 1-1/4” 1-1/4” 1-1/4”
Circulation 1” 1” 1-1/4” 1-1/4” 1-1/4”
Exchanger Outlet 1-1/4” 1-1/4” 1-1/4” 1-1/4” 1-1/4”
Exchanger Inlet 1-1/4” 1-1/4” 1-1/4” 1-1/4” 1-1/4”
Sensor ½” ½” ½” ½” ½”
Resistance 1-1/4” 2” 2” 2” 2”
Magnesium Anode 1 2” 2” 2” 2”
Cleaning Flange 108 108 108 108 108
Insulation Polyurethane Polyurethane Sponge PVC Cover Sponge PVC Cover Sponge PVC Cover