NKV 100-4

How to use water heater diagrams:

Air Speed.  Starting from 250 m³/h on the air flow scale draw a vertical line ¹ till the air speed axis which makes about  3.75 m/s.

• Supply air temperature. Prolong the line ¹ up to the point where it crosses the outside air temperature (blue curve), e.g. -15°C; then draw a horizontal line ² from this point to the left till  crossing  water in/out temperature curve (80/60 °C). From this point draw a vertical line ³ to the supply air temperature axis on top of the graphic (+27°С).
• Heating coil capacity. Prolong the line ¹ up to the point where it crosses the outside air temperature indicated as red curve (e.g., -15°С) and draw a horizontal line ⁴ from this point to the right to the intersection of water in/out temperature curve (e.g., 80/60 °С). From this point draw a vertical line ⁵ up to the scale of heating coil capacity (5.2 kW).
• Water flow. Prolong the line ⁶ down to water flow axis at the bottom of the graphic  (0.067 l/s).
• Water pressure drop. Draw the line ⁷ from the point where line ⁶ crosses the black curve to the pressure drop axis. (5.2 kPa).