Solar Water Heating Trials 1- 2008

[solarhope]

Hi Kempster, I only used 15mm tube, but I guess finned would be better due to the bigger surface area.

My garage roof is now full of solar PV, and the 6 hot water panels are now a fan assisted radiator used on an oil fired boiler - see other You tube vids on my channel and my web site solarhope.co.uk - Regards Martin.

[tavdrinker]

do you have a coil in the tank or are you just heating the entire contents?

[solarhope]

Hi - Tavdrinker,

The entire 120Ltr water tank is pumped through the panels at about 2 Ltrs/min when called for, out at the bottom return to the top.

The tank temp sensor is fitted towards the bottom of the tank.

Martin.

[kailuafrog]

Have you tried fitting more tubing in your panel?

By the look of it the water seems to travel a bit fast through your collector.

[viking1au]

Wouldn't it be more efficient with reflector substance beneeth the copper coils to assist in heating them faster?

[solarhope]

Hi Viking,

The copper tubing is bonded to the aluminium panel and both are painted matt black to absorb as much heat possible from the sun.

This year I have removed the Perspex and casements to see what difference this makes to the heat transfer to the water, looking quite promising so far.

This would be a cheaper alternative for countries that are blessed with more reliable sunshine than the UK!

Regards Martin.

[eddiefreddie39]

Bravo  5stars

[solarhope]

Hi digiman - I guess any copper or aluminuim will work as the solar collector and you will get a higher flow rate with the 22mm pipe - Martin.

[solarhope]

Hi digiman - The insulation is about 5mm thick and they say it is equivilent to 55mm of polystrene - Martin.

[rlennard2]

Hi Martin, great to see someone going beyond the 'This might just work' stage and monitoring actual output. My small garage project transfers around 120W on a sunny day - enough hot in a couple of hours to wash my car! The next step is DIY heat exchanger for the house hot water system. Where did you find your 12V pump?

[solarhope]

Hi riennard2,

Thanks for your comments.

I'm afraid this has not been the best of summers sun wise - typical.

The pump I bought on ebay for about £60. cannot find the link - drat!

It is a brushless type and runs at about 1.2A

It will pump about 15L per min with no pipe resistance and about 2L through the 70 odd Metres of 15mm pipe I have.

Hope this helps - good luck with your project.

Regards Martin.

[solarhope]

Hi Joulian,

Thanks for your comments.

The software I wrote using visual basic, and the electronics is based around a Velleman P8055 I/O board connected to the laptop usb.

The 4 temp Sensors are based around the LM35DZ chip and the pumps are switched via 12v relays.

I did not run the 2 panels I had last winter so I have no data -- I will try it this coming winter with 6 and see how it goes.

Regards Martin.

[joulian0720]

where did u get the program for your laptop and the computer board. I like ur set up. very professional :)

And how did it do at nite , I am trying to figure it if you can have hot water at nite and for how long

What temp was it getting up to in the wintertime ( for example coldest sunny day )

[mostvideosolar]

luvely stuff martin, I have an old tank sitting in my garage ready for the water project next year, but i'm making the cansolar heater at present, I'm making two units, one small 48" x 32" (12v based) & a full size 96" x 48" unit. All my cans are glued & at the case building stage.

P.s is it normal silicon or heat resistant on the panels & normal black paint or heat resistant? Once again Luvely stuff.. the electonics look interesting..thanks.. MostVideo

[solarhope]

Thanks - The paint and the silicon are just the regular stuff from screwfix - Good luck with your project let us know how you get on - Martin.

[solarhope]

Thanks - I've replaced the mains pump with a 12volt type, which works fine atabout 15 Watts and pumping just over 2 Litres per hour.

Now working on a PV panel - waiting for cells from the USA.

Will keep you posted - Martin.

[solarhope]

That should read - 2 Litres per Min.

[matrixm777]

Nice work Martin...

[solarhope]

The next challenge is to replace the mains pump with a low voltage jobby and power it from a photo voltaic panel.