Natural Refrigerant Air-to-Water Heat Pump

The S-ASX-NT range comprises 4 models offering LTHW heating, as well as Hot Water production, in 60,70,80 and 90kW outputs in the A7W35 condition. The NT product designation refers to the R290 natural refrigerant utilised in this range of machines which delivers high heating efficiency with an ultra-low GWP of 3. These machines use tandem scroll compressors and are capable of delivering up to 72°C at the outlet. Depending on the model the units achieve a COP of 4.34 to 4.39 at nominal output in the A7W35 condition. The control system allows the unit to be operated in a cascade of up to 16 units.

All the machines are suitable for outside installation and are supplied as standard with low noise set-up, soft start compressors, an integrated circulating pump and a loose supplied degassing valve to safeguard against hydraulic contamination.

Heat energy from the ambient air is obtained from the R290 refrigerant circulating inside a bank of copper and aluminium fins and then this energy is passed, after the compression cycle, to the heating circuit through a stainless steel brazed heat exchanger. The circuit is controlled by the standard supplied temperature probes and pressure transducers and is protected by high and low pressure switches. Additionally, as the R290 refrigerant is classified as highly flammable, the unit is designed with leakage sensors, alarms, separated electrical control and inverter casings, as well as an ATEX classified evacuation fan built in as safety features. The plate heat exchanger and all hydraulic pipework is thermally insulated to avoid condensation and avoid heat loss.

The S-ASX-NT units are fully reversible and can operate in cooling mode in the summer months achieving minimum EER of 3.34 at 35°C ambient air and 18°C flow.