Recently I came across this requirement of calculating heat required to heat air (for AHU), I came across two simplified formulas, as follows.

Please also note the learning from this workout at the bottom!

Learning!

for delta T, Centigrade vs Fahrenheit are different!

I was thinking, as long as its Delta (Difference between two temperature), °F and °C doesn’t matter! I was WRONG… See following example

Raise temperature of air from 10 °C to 110°C, Temperature difference is 100°C

Where as in Fahrenheit, its 50°F (10°C) to 230°F (110°C) i,e difference is 180°F!