The Class of Flood

After extraction, we have 2 kinds of water, to be evaporated. 
Free water, laying on the floor or on a vertical surface. Water molecules are spread out and evaporation is greatly speeded up, by the energy of air flow.

Bound water, is the water IN the wet material and is much less affected by air flow. Heat energy gets to the bound water better than anything and gives the molecules of vapor, energy to escape the hold the drop of water has on them.

After evaporation of the "free" water, we proceed to get the water “in” the wet materials out by changing the liquid to a vapor. (Evaporation)  All this vapor, we’re putting into the air, must be removed. If not removed, properly, moisture can absorb into porous materials or condensation could form. This is called secondary damage.
Here’s where, class of water, is considered.
It tells us how much wet material we might have and how much evaporation there will be.

1: Small area, maybe a corner of the room
2: The whole floor, possibly wet carpet and pad, less than 24 inches up the wall - more evaporation than a one
3: The whole room is wet, ceiling, walls and floor – the most evaporation

4. Tough to dry materials.                                           

One of the major uses of knowing the class of flood is to know how much vapor will be going into the room every 24 hours. We must remove as much vapor as we create.Another, lesser reason can be communication. The size and extent of the water intrudion is easily described..... 1, 2, 3 or 4.

There is a chart based on classes and the type of dehumidifier you are using, that gives a number to use in calculations. This number has been figured over years of observation.
It’s based on how many cubic ft are required to have 1 pint of vapor in the affected (wet) area.

Initial Dehumidifier Requirements 

                                                    1          2         3           4

Conventional Dehu                 100      40       30        N/A

A one needs a box 100 cubic feet square to have a pint of moisture. A two, because it is wetter, only needs a box 40 cubic feet square, to have a pint of moisture and so-on.

These numbers are used with the following formulas.

For refrigerant dehumidifiers:
1        Cubic feet of room
2        Divide by number from chart
3        Divide by the rating of the dehumidifier - paperwork when you bought it

For desiccant dehumidifiers:
1.       Cubic feet of room
2.       MULTIPLY by number from the chart
3.       Divide by the rating of the dehumidifier

So, the bottom line is, classes help figure how much vapor you will have and how many dehumidifiers, of a certain size, you will need to run.

The most important process, in water restoration is evaporation, while vapor removal is close behind.

If you are not sure how all this works, attend an IICRC Water Restoration Class.

          MAKE MONEY!

          Dennis Klager
          IICRC Instructor















Copyright 2012 by Dennis Klager