mMPXV7002DP Airspeed measurement

[nadi_abumahfouz]

Hello,

I'm using mMPXV7002DP and I'm trying to convert the output to measure airspeed. I'm not sure I'm converting the voltage to pressure in a right way or not. based on the data sheet the minimum output voltage is 0.5 equal -2kPa and the maximum is 4.5 equal 2kPa. so based on this I have this equation

pressure = ((voltage - Vmin) * (Pmax- Pmin) / (Vmax- Vmin)) + Pmin

Vmin = 0.5

Vmax = 4.5

Pmin = -2

Pmax = 2

I have 3.3V refrence and 14bit ADC and I'm converting the ADC to Voltage

voltage = (((ADC * 3.3) / 2^14)) - 2.5; 

the "- 2.5" based on the datasheet is the offset value of the sensor.

my last step, I'm calculating the Airspeed, 

pressure = 0.5 x density x velocity x velocity
density  = 1.225kg/m3 for sea level air density.

my problem is I'm not sure am I calculating everything in a right way or am I missing something? because I'm trying to measure inside a closed room also the room has AC and I'm getting negative pressure all time.

Thanks,

Nadi