Water heaters are appointed to heat air in air conditioning and ventilation systems of rectangular cross-section.
It is used for heating supply air, recirculation air or their mixture in compact stationary ventilation and air conditioning systems of industrial public or residential buildings.
Construction
The heater housing is made of galvanized sheet metal. The tube collectors are welded from steel tubes with a synthetic paint surface treatment. The heat exchange surface is made of 0.1 mm thick aluminum plates stretched over copper tubes. The standard execution is two-row with alternating geometry.
Operating conditions
The maximum permissible water temperature is 100°C. The maximum allowable pressure is 1.6 MPa.

| Type measurement | Dimensions, mm | D-NVP weight, kg | |
| B | H | ||
| D-NVP-40/20/2 | 400 | 200 | 3,3 |
| D-NVP-40/20/3 | 400 | 200 | 4,9 |
| D-NVP-50/25/2 | 500 | 250 | 5,2 |
| D-NVP-50/25/3 | 500 | 250 | 6,2 |
| D-NVP-50/30/2 | 500 | 300 | 6,2 |
| D-NVP-50/30/3 | 500 | 300 | 7,4 |
| D-NVP-60/30/2 | 600 | 300 | 7,4 |
| D-NVP-60/30/3 | 600 | 300 | 8,9 |
| D-NVP-60/35/2 | 600 | 350 | 8,7 |
| D-NVP-60/35/3 | 600 | 350 | 10,4 |
| D-NVP-70/40/2 | 700 | 400 | 11,5 |
| D-NVP-70/40/3 | 700 | 400 | 13,8 |
| D-NVP-80/50/2 | 800 | 500 | 14,3 |
| D-NVP-80/50/3 | 800 | 500 | 17,5 |
| D-NVP-90/50/2 | 900 | 500 | 15,5 |
| D-NVP-90/50/3 | 900 | 500 | 19,1 |
| D-NVP-100/50/2 | 1000 | 500 | 16,8 |
| D-NVP-100/50/3 | 1000 | 500 | 20,6 |

