Use this engineering calculation for a transparent preliminary estimate or independent arithmetic check when geometry, materials, loads, operating conditions, and units are defined consistently.

Hot Kelvin (K)

Required number input.

Cold Kelvin (K)

Required number input.

Theoretical maximum heating COP of a reversible heat pump, Th/(Th−Tc), using absolute hot and cold reservoir temperatures. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Heating Cop

The resulting heating cop returned as a number.

• Fan, pump, turbine, and propeller performance varies with speed, flow, head, density, efficiency map, cavitation margin, installation, control, and off-design operation. Similarity or ideal-power equations do not replace manufacturer curves.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check assumptions against drawings, measurements, current material data, and the applicable design code. Apply required load combinations and safety factors, then obtain qualified review and testing for consequential designs.

• Radiative Heat Transfer

  Net ideal gray-surface radiation exchange against a large isothermal environment using absolute kelvin temperatures.

• Pump NPSH Available

  Available pump NPSH from absolute suction pressure head plus velocity head minus vapor pressure head; supply losses are already reflected in suction pressure.

• Aircraft Stall Speed

  Level-flight stall speed from aircraft weight, air density, wing area and maximum lift coefficient: Vs=√[2W/(ρSClmax)].