SUNSYSTEM SWP NL 500

SUNSYSTEM SWP NL 500 indirect domestic hot water tank for heat pumps

The SUNSYSTEM SWP NL 500 indirect domestic hot water tank is a DHW tank designed for systems with higher domestic hot water demand, featuring 1 coil heat exchanger with an extra-large heat transfer surface. It is a particularly advantageous choice for heat pump systems where fast and efficient hot water production is required even at lower flow temperatures.

The tank comes with a 432-litre capacity, titanium-enamelled internal surface protection, 50 mm thick rigid PU insulation and an external PVC jacket. It can be operated on mains systems with a pressure of up to 10 bar, making it a suitable solution for detached houses, larger properties or buildings with increased hot water consumption.

The built-in, extra-large coil heat exchanger can be connected to a heat pump, a condensing boiler or solar thermal collectors. The heat exchanger coil with a surface area of 4.6 m² and a capacity of 28.3 litres offers significantly greater heat transfer capacity than average-sized heat exchangers, ensuring efficient heating even with a lower-temperature heat source.

The heat exchanger is located in the lower part of the tank, so the natural circulation of the warming water helps heat the entire water volume evenly. The hot water circulating in the coil transfers its heat to the mains water in the tank, enabling fast heating — even within an hour, depending on the system layout and the output of the heat source.

The SUNSYSTEM SWP NL 500 also features a recirculation connection, which increases user comfort with a suitable system layout. With a recirculation line, hot water can be available more quickly at the taps, so there is no need to run off the cooled water in the pipework. The recirculation circulation pump is not included with the tank.

On request, the tank can be ordered for an additional charge with an electric heating element / thermostat set, as well as an accessory set consisting of an 8 bar safety valve, a thermometer and 3 height-adjustable feet. The electric heating element can be used as an alternative heat source, for example when the heat pump, boiler or solar thermal collector is not in operation.

Key features

• Indirect domestic hot water tank for heat pump systems
• 432-litre steel tank body
• 1 coil heat exchanger with extra-large heat transfer surface
• Heat exchanger surface area: 4.6 m²
• Heat exchanger capacity: 28.3 litres
• Titanium enamel internal tank protection
• Cathode / anode type internal surface protection
• 50 mm thick rigid PU thermal insulation
• External PVC jacket
• Fitted with a recirculation connection
• Bottom / side inspection opening
• Drain connection
• 2 side measuring points for a thermometer or temperature sensor
• Internally threaded connections
• Maximum tank operating pressure: 10 bar
• Maximum tank operating temperature: 95 °C
• Maximum heat exchanger operating pressure: 16 bar
• Maximum heat exchanger operating temperature: 110 °C
• Factory quality control: 15 bar test pressure on the tank body, 25 bar test pressure on the heat exchanger
• Energy efficiency class: C
• Can be connected to a heat pump, condensing boiler and solar thermal collector

Design optimised for heat pump systems

One of the most important advantages of the SUNSYSTEM SWP NL 500 is its extra-large heat exchanger coil. Heat pump systems often provide lower flow temperatures, so efficient DHW production requires a larger heat transfer surface. The 4.6 m² coil helps the tank deliver adequate domestic hot water performance even with a lower-temperature heat source.

The relatively low operating temperature of the heat exchanger can help reduce limescale build-up on the heat exchanger surface, even with continuous use.

Optional accessories

• Electric heating element / thermostat set
• Electric heating element with 3 / 4.5 / 6 kW output
• 8 bar overpressure safety valve
• Thermometer
• 3 height-adjustable feet

Standard equipment

• 432-litre steel tank body
• Heat exchanger coil with enlarged surface area
• Mains water connections
• Recirculation connection
• Bottom / side inspection opening
• Drain connection
• 2 side measuring points for a temperature sensor or thermometer
• 50 mm PU thermal insulation
• PVC external cladding
• 3-year manufacturer's warranty against tank corrosion perforation and water leakage

Useful information about capacity

For domestic hot water tanks with a heat exchanger, it is worth distinguishing between nominal, gross and net capacity. The nominal capacity is a rounded figure intended for guidance, which often also appears in the product name. The gross capacity refers to the actual internal tank volume, including the heat exchanger and its internal capacity. The net capacity indicates the usable domestic hot water volume, which is typically also shown on the energy label.

Recommended use

The SUNSYSTEM SWP NL 500 indirect DHW tank is recommended for heat pump systems and systems combined with a condensing boiler or solar thermal collectors. Thanks to its large capacity and extra-large heat exchanger surface, it is particularly suitable for larger detached houses, apartment buildings or systems with increased hot water demand, where fast, reliable and efficient domestic hot water production is important.