• Caleffi SolarCon Storage Tank - 119 Gallon Tank - NAS20124

    - Double Lower and Upper Coil - No Electric Element Backup

    Product ID • NAS201240000

  • $2,839.75
  • Quantity:
  • Estimated Overland Truck Shipping Truck Shipping


The Caleffi solar water heater NAS20124 119 Gallon Tank has two internal coils. A heating medium is passed through the solar panels into the lower internal coil as long as there is an adequate temperature difference between the heating medium and stored water in the tank. The internal coil is located as close to the bottom to facilitate the transfer of heat even at lower solar panel temperatures. If the tank falls below termpeature, the upper coil is connected to the backup heat to ensure hot water 100% of the time. The Caleffi NAS20124 also comes with an electric boost that will act as a backup if either of the two heating coils fails to raise the tank temperature high enough.  This would be common if you are using a wood boiler as a backup heat source for the upper coil but do not want to run your wood boiler during warmer months.

During periods of water flow through the water heater. hot water is drawn from the top of the heater and cold water comes into the bottom of the tank (by a dip tube or bottom inlet). On the NAS20124 double coil tank, if the hot water demand should exceed the solar heat input or there is an insufficient temperature difference between the heating medium and stored water, the heating element thermostat will activate the backup heat source that will send heat to the upper coil.

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Technical Specs

Caleffi SolarCon Storage Tank - 119 Gallons NAS20124 Tech and Specs

  • Lower Hot Water Coil
  • Upper Hot Water Coil (Backup)
  • Actual Tank Volume Amount
    108 gallons
  • Tank materials
    Porcelain coated steel
  • Tank insulation
    2 Inches non-CFC foam
  • Tank external cover
    Powder-coated steel (20-24 ga.)
  • Power requirements (electric element)
    240 VAC
  • Power consumption (electric element)
    4.5 KW
  • Insulation thermal conductivity
  • Anode rods
    2 each magnesium
  • Internal heat exchaner coil (lower)
    1-1/2 inches by 36 feet
  • Connections
    1 Inch NPT
  • Maximum working pressure
    150 psi
  • Testing pressure
    300 psi
  • Temperature and pressure relief valve
    210°F / 150 psi max
  • Maximum tank temperature
    180 Degree F
  • Recommended maximum delivery hot water temperature
    120 °F
  • Upper Coil Volume Solar
    2.76 gallons
  • Lower Coil Volume Boiler
    1.84 gallons
  • Upper Coil Surface Area Solar
    14.14 (sq feet)
  • Lower Coil Surface Area Boiler
    9.42 (sq feet)
  • Uppper Coil Friction Loss Solar
    .60 (feet of head)
  • Lower Coil Friction Loss Boiler
    .40 (feet of head)
  • First Hour Rating
    282 gallons
  • Recovery Rate Solar & Backup
    182 gallon per hour
  • Standby by loss
    1.2 F Degree per hour
  • Agency approval
    UL listed

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