# Ventilation Systems

1. Sep 4, 2006

### melpec

Hi...Prbably a stupid question but here it goes:

I have some equations here, some of them have a G for rate of generation and others have E for rate of evaporation (both of them have units of volume per time).

My question is: if I know that I have 3 galons of a chemical at the beggining of the day in one tank and at the end of the day I only have 2 galon...then I lost 1 galon per day...but is this number E or G? I mean...I don't understand what is the difference, I know there is an equation relating them but I don't understand the concept.

2. Sep 4, 2006

### 3trQN

Is the problem that you dont understand the difference between Generation and Evaporation?

What is meant by generation in this context?

Evaporation is pretty self explanatory with regards to the description, however generation remains ambiguous with what you have described.

Generation sounds like it could possibly describe, among other things, the water condensation in a system.?

You have a variable volume, if you know the rate of evaporation and your final volume you can therefor calculate how much of the substance has entered the system ( possibly what generation is referring to here ).

Consider a sink of water. Water evaporates throughout the day, and you start with a known volume(V). At the end of the day you measure again the volume of water in the sink(V).

From a formula for the rate evaporation (based on the conditions) you know that you loose x ammount of water through evaporation during the day.

You know that the change in the volume of water is related to the ammount of water lost and the ammount of water gained through the day, where G is the amount gained.

(V-V) = G - x

That is one possible interpretation of the meaning of Generation and G in this context. Im guessing though.