Question

An electrical heater is a form of sensible heating process, and heats 0.1m/s of air from 15°C and 80% RH to 50°C? The barometric pressure is 101.325 kPa. Using the psychrometric chart given, determine the heater wattage.

Answer 1

Answer:

The heater load =35 KJ/kg

Explanation:

Given that

At initial condition

Temperature= 15°C

RH=80%

At final condition

Temperature= 50°C

We know that in sensible heating process humidity ratio remain constant.

Now from chart

At temperature= 15°C and RH=80%

$h_1=38 \frac{KJ}{kg},v=0.8 \frac{m^3}{kg}$

At  temperature= 50°C

$h_2=73 \frac{KJ}{kg}$

$So\ the\ heater\ load =h_2-h_1$

The heater load = 73 - 38 KJ/kg

The heater load =35 KJ/kg