EVAPORATIVE COOLERS TO
KEEP FOOD FRESH
First type..... Evaporative cooler charcoal
Second type. Evaporative cooler bricks
Third type... Porous pots with sand ...ZEER pots
Forth type... Low Medium and High pressure spray
Fifth type.... Small home fridge
Basic idea of evaporative cooling
However it is usual the higher the
temperature the lower the
humidity except places like the coast of Kenya which is tropical and is hot and also high humidity but the whole world is getting hotter and farmers struggle to make a living because of deterioration of farm fruit and vegetables so they need some ideas to help. Evaporative cooling is being used more and more to keep farm produce in good condition and in poultry houses and cows and pigs and rabbits.
There are farm advisary officers in every country who are happy to give help and advice and show how best for you to use evaporative cooling
FIRST SECTION. CHARCOAL
SECTION TWO. BRICK AND SAND COOLERS
Many thanks to Roseline Marealle
Shade for the evaporator
Keep the fruit cool in the shade
Find a strong box that has no rot or damage. Get some dry sand put the sand in the box. Keep the box inside in the shade. Keep it dry. Store your root vegetables deep in the dry sand. They will stay fresh for weeks.
SECTION THREE ZEER POTS
Put the ZEER pot outside in the hot air but in shade and in a breeze if possible.
SECTION FOUR .. SPRAYS
Presure water misting systems are very simple. You just need a pump to presurise the water and some water tubing and some nozzles. Turning on the pump gives water droplets coming from the nozzles. For low pressure misting the droplets are large. The large water droplets wet everything and there is an air temperature drop. You can use this to water your garden. Shops use this to water fruit and vegetables to retain freshness. All the materials pump, water tubing and nozzles for low pressure misting are not expensive. Often you do not need a pump you can just plug in to your ordinary hose water outlet.
Medium pressure misting the water droplets are smaller and you can use this to provide a cool place in your garden for yourself or friends to sit in the garden the temperature will be a lot lower than ambient but you will get very slight water on your clothes. The medium pressure pump is more expensive
High pressure misting can lower the temperature in an area in your garden such as your patio to make a cool area to entertain friends. the water droplets are extremely small similar to a light fog the water causes no water on people and gives a good drop in temperature. Works even if the humidity is a bit high. This makes for good cooling outside on your patio The high pressure pump is quite expensive
Medium pressure misting
and High pressure misting can be used by farmers to keep an area
cool with increased humidity for farm fruit and vegetables to
keep them in good condition until transported to market.
You only need a few things
water tubing and water nozzles. .
You dont need a lot of tubing or a lot of nozzles. Maybe 2-4 would do
About 12volts dc at 2-3 amps for the water pump
Maybe solar panel to run the pump
Good water Good water filter. Some pumps have a water filter built in.
A high pressure misting pump is very expensive some are over $1500 US however expensive high pressure misting pumps are designed to run 10-20 nozzles and run for days and weeks. I have seen considerably very much cheaper 1000 psi water pumps on ebay and other places so it is possible to buy alternate equipment and make your own high pressure misting system to keep your fruit and vegetables cool and well hydrated.
If these medium and high pressure misting systems can keep people comfortable even in very hot conditions they can certainly do the same for farmers' fruit and vegetables on the farm, on the way to market and at the market as well. A small outlay for a proven evaporative technology will give the farmer far better fruit and vegetables to sell at the market.
Low Pressure Misting System
Low pressure misting runs at 40 to 60 psi which is about the same pressure as your city water is very useful for hand held misting to water plants and does have a small temperature drop but the water drops are not small and will wet a person Useful low cost misting system
Mid Pressure Misting System
In comparison to low pressure misting system, mid pressure sytems require 160 or 250 psi misting pump to operate and uses finer nozzles and the water droplets are small which almost eliminates wetting
High Pressure Misting Systems
High pressure misting starts at 1000 psi and can go up to 1500 psi. They produce microscopic sized water droplets like a very faint fog. People or chairs and tables do not get wet but the temperature drops very much and gives a cool environment in your garden for entertaining friends and can be used indoors if required
Section 5 Small fridge for home use
A lot of people in Kenya do not have the money to buy a proper fridge. Other things maybe clothes for children school fees and other costs come first but it is possible to build a small fridge for home use. I have built a small home water cooled fridge using peltier cells. Here are some pictures.
It works quite well and is very easy to make
even at home with next to no tools but there is a problem.
The cost just for parts is between 8000 and 10,000 Kenyan shillings
I am trying to make this better