Composition of Air

2007-03-22
COMPOSITION % by volume
N2 Nitrogen 78.03
O2 Oxygen 20.99
A Argon 0.94
CO2 Carbon dioxide 0.03
H2 Hydrogen 0.01
others parts per million
Ne Neon 0.001230
He Helium 0.000400
Kr Krypton 0.000050
Xe Xenon 0.000006

Fourier’s Law

2005-11-29

Fourier looked at heat flowing through building  materials, and his experimental results produced ideas such as thermal conductivity, resistance and the thermal transmission co-efficient or u-value. Read the rest of this entry »


Compound Interest

2005-10-10

In design work, there is a business side of things that depends on loans and investments.  There is also a business side of things where people invest different amounts for different periods of time in helping you — and you might have to figure out their share of things in the future.

There is also the idea of inflation and cost of living — as you have to design to a cost, a budget, you have to sometimes predict the future costs involved.

This is a small introduction to the basics of compound interest, included here in the hope that it may help. Read the rest of this entry »


Flow Rate Calculations

2005-10-10

This is  a technical article on calculations pertaining to volume and mass flow rates of fluids. Read the rest of this entry »


Ventilation Grille Sizing

2005-03-30

The aspect ratio is

Length
______   of the grille.
Breadth

(Total volume flow rate [m3 . s-1]).(100)
______________________________________________= Area (m2)
(No. inlets).( inlet velocity [m . s-1]).( per cent free area)


Fluids Constants

2005-03-24

This is a technical reference post that simply lists all the physical constants used in fluid calculations. Read the rest of this entry »