evaporation research :)

Heyy everyone!!! :)

Ok well today i thought itd be good to do some more research into evaporation- as that is mainly what my research experiment is all about!! Once of the things ms zhang said we could talk was, the impact our investigation or research would have on society. And because water is such s scarce commodity, and my research is about minimising water evaporation from swimming pools, i thought it would be good to actually get some statistics about how much water exactly is lost through evaporation from swimming pools. Now to the research!!

What is evaporation?
Evaporation is the process whereby liquid water becomes a gas and dissipates as the water temperature is increased. Eventually, a saucepan of water will ‘boil dry’ as all the liquid becomes a gas and disappears into the atmosphere.

Calculating evaporation...

Calculating evaporation rates is a very complicated process, with many variables such as water surface area, water temperature, air temperature, air pressure, air density, wind speed, and humidity among others - all affecting evaporation.

Main factors affecting evaporation, and some interesting facts (i thought were interesting)...

Factors:
1. pool surface area
2. the temperature of the water and air
3. humidity
4. wind

Facts:
1. The bigger the pool, the more surface area, therefore, a greater
evaporation volume.
2. The highest evaporation rates occur when the differences
between water and air temperatures are the greatest. This may
not be in the middle of a hot day when the pool is in use. At this
point the water and air temperatures may be quite close. Later at
night the pool water may remain warm, but the air temperature
has fallen substantially - that means a greater temperature
difference between the air and water - and greater evaporation.
3. The drier the air is, the greater the evaporation rate. In very
humid conditions less evaporation occurs.
4. The final and very significant factor for home pools is wind.
A breeze of just a gentle 11 kilometres per hour can more than
double the evaporation rate by removing the insulating layer of
warm, moist air directly above the pool surface.

How much water does your pool actually hold?

To put things into perspective, here are some of the sizes and capacities of pools that you would typically find in backyards right across Australia. Ok so i actually did do a proper table, but whenever i do tables and post them on to blogger they come out soo small and unclear!! So yeah maybe this is a better option, just simply writng it out without the boxes...

Pool Length Pool Width Average Depth Water Capacity
Pool length pool width average depth water capacity
8.0 metres x 4.0 metres x 1.3 metres = 41,600 litres
9.2 metres x 4.5 metresx 1.3 metres =53,820 litres
10.0 metres x 5.0 metres x 1.3 metres = 65,000 litres

Thats alot of water!! Think of now how big the evaporation levels would be!! :o :O :O shock face- lol.
Ok, now ill do a table for the mean daily evaporation rate. Ive only included the 5 major cities- Sydney, Melbourne, Brisbane, Adelaide and perth.and also ive only included the 6 hottest months, which is from October to march, as this is generally when swimming pools are most in use. So yeah here is the table!

Mean Daily Evaporation Rate (mm)

6 month
average
o n d j f m
Sydney 5.8 6.5 7.4 7.2 6.4 5.3 6.4 mm
Melbourne 4.6 5.7 7.4 7.5 7.3 5.8 6.4 mm
Brisbane 6.4 6.7 7.6 7.9 6.7 5.8 6.9 mm
Adelaide 5.3 7.2 8.1 8.9 8.4 6.4 7.4 mm
Perth 5.3 7.4 9.1 10.2 9.8 7.9 8.3 mm

Ok so this is the table. I know its come out a little weird but it took me ages just to align it this far!!! Btw the letters at the top stand for the month, so o is October, n is November etc.

The following table shows the average DAILY evaporation in litres for the same three pool sizes i used for the beginning table, across the five capital cities.
It should really astound you, as to just how much water is lost from swimming pool per day as a result of evaporation. Well i know it really astounded me!! And remember, these figures are in litres!!!!!!! Wow, beware, its alot!!! Ok heres the table:

Mean Daily Evaporation Volume (litres)

Pool Size Surface water
Area capacity Sydney Melbourne Brisbane Adelaide Perth


8.0x4.0m 32.0m2 41,600l 205 205 221 237 266
9.2x4.5m 41.4m2 53, 820l 265 265 286 306 344
10.0x5.0m 50.0m2 65,000l 320 320 345 370 415

xoxo Mira