palin_81

hai expert,
Can anybody design me a simple system for water sprinkler using solar panel as a energy to run a pump to boost the water out?at the same time using heat sensor to control the pump only when temperature arise and stop once temperature at the setting value....thanks..please help

blueroomelectronics

How large is the solar panel?

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palin_81

i really not start yet but need an advice to proceed.i just planning to build for my final project.Any suggestion on design circuit,pump size,etc.The roof size leight about 2 meters and width about 3 meters.

rjvh

hi palin

what do you want to spinkel? the lawn? or the roof? LPG tank? fires?

what kind of pressures do you run do you have a water resoirvoir or pressurised water that feed the system

what are the desired flow rates and what kind and size of pipe work your thinking at?

robert-Jan

palin_81

i dont have any spec yet but i was wondering the pressure that might enough to go until 2 meter,the pipe sizing was about 1/2 inch and i use it to cool down the roof temperature.I am thinking to put the heat sensor or termistor underneath the roof to determine the actual temp.i need a electrical/electronic diagram to put it together.Can anyone draw me a system that fulfil the requirement.

Boncuk

Hi palin,

just to cool the roof of your house you don't need "rivers" to flow down the roof. Keeping the roof wet is all you need.

Cooling is achieved by evaporation of water using the so called "chill effect".

The amount of water to be distributed over the roof is not great and you might get along with a fairly strong water pump of the kind used in camping mobiles.

From the roof size I suggest to mount five spray nozzles approximately 1m above the roof top and have the water being sprayed evenly.

Spray nozzles (usually used to spray insecticides) can be found in garden accessory shops. Most of them are adjustable for throughput and spray angle.

For the pipes I suggest copper hoses of 8mm diameter inside. (10-12mm outside). Fittings are easily to be soft soldered (using soldering tin) which is strong enough to withstand high pressure up to 10bar (~200psi)

For automatic operation you just need a thermistor and and a comparator circuit to be followed by a relay switching the pump on. If your solar panels deliver enough current you won't have to stabilize the output voltage. Just hook up the pump directly to the panels.

Boncuk

palin_81

ok thanks guys,i get the point.....i will try to ilustrate it in a drawing and pass it down here for ur guys view,but how its look like when u talk about the comparator.Can u please draw the circuit please?i really need to understand the circuit.

3v0

Have you seen this page?
Roof Sprinkler Cooling Systems

The one down side to this is mineral buildup on the roof from the water. I would love to do this but the mineral content in our water is high and my blue netal roof would look awful in short order.

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3v0

Do not like posting twice in a row but the edit...

Regarding mineral buildup. If one used enough water to ensure that some of it made it to the end of the roof it should carry away some of the minerals that would haved been depsoited on the roof. Maybe do a rinse every few minutes to flush it.

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HarveyH42

Would a good rain rinse off a good portion of the minerals? Wouldn't think they would have a good opportunity to get baked on with the constant misting. The smooth coated metal should also resist to some extent.

Would be a decent project using stored rain water. We are frequently considered to be in a drought condition. Don't think it would go over well, but could definitely use some additional cooling during the hot days.

3v0

Both good points. I think it may depend in part on what the minerals are. The roof has seen a bit of sun in the 3 years it has been on. Maybe a coat of automotive wax to seal it ?? Power buffer, yes.
I have been thinking about this sort of thing for a number of years. Recall some people used soaker hoses to deliver the water. My house has central air but it is expensive to run. Most of the time I use a swamp (evaporative) cooler. I like the humidity. When the temperature goes over 100 the air does not cool enough to be comfortable, and it is has high humidity.

Although we are in a drought city water is plentiful. We live over an aquifer and the city has more water capacity then it can use. Running water over the roof to cool the house has got to sound wasteful to anyone on water rationing. (Been there done that elsewhere). The bottom line is that the cooling with water is much cheaper then central air.

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palin_81

good idea guys,i was wondering to make a drainage at the end of the roof to collect back all the water to tank and suck back to use for the sprinkle.This will make less water use.At the same time,any electronic guys would help me to design a circuit that wil make this spinkle running auto depanding on temp.

palin_81

for ur guys info,im from malaysia and the climate here was hot and able to reach 40degree instanly.If i choose to use the aircond it will be more costly in term of billing.So i choose alternative way to make a simple project and able to works.Water pay here was not so high comparing with electricity.

3v0

If you recycle the water you will want to dump it and start with all new water on a regular schedule. Maybe dump it each night. If not you end up with mineral soup and an ugly roof.

Maybe collect the runoff water and use it on a lawn or garden. If you do that you can do without a pump. A 24V valve from an automated lawn irrigation system can easily control the water supply. A temperature sensor in the attic would be a good choice. A microcontroller to monitor the sensor, cycle the water, and display info on a LCD display.

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rjvh

hi Palin

I live in cambodia and have the same climate as that you have

it works better if you make from you're pipe work a grid system

use metal pipes (preferably copper or aluminium but steel would also do) and pump water throug it

metal are far superior of conducting heat/cold than any plastic

this grid system you will install under your roof plates and one side of the roof plates (underside inside your house) you put insulation with a reflective cover facing inside thehouse and so also your pipework grid

the storage tank (size should be calculated on the heat load of your room)
is preferably buried in the ground

that is the basic

you can go further by making a second system in the open air that you use in the night to pump water through to cool it further down in the night air

you will have to use solenoid valves if you want to have it all automatic and use temp sensors when you want to pump or not

how much is your budget to make this

i make these systems for heating up water (as a hobby) (also in my work i have to deal with it) but these systems are the same as that you want to cool down things

you can go prety far as it comes to the automation side of it

it's actualy a very nice project to do this kind of project micro controler based

Robert-Jan