DIY geyser conversion to solar

J

jls_n

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Oct 24, 2007
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Location
Kempton Park
Hi

The installation for my solar tubes for the geyser where finished yesterday.
We did a DIY installation. I've attached a link to show some pictures of the installation.

http://mybroadband.co.za/photos/showgallery.php?cat=596&ppuser=42335

Please feel free to comment or suggest better ways to improve the system.

On sunday afternoon after the system was drained twice to make some improvements. We refilled the geyser and switched everything back on. Starting from around 22 degrees ,the temp in the geyser reached around 55 degrees at 17:00 the afternoon. Took a shower, temp dropped to around 49 degrees. went back up to 55 degrees. No heating element is used, its pure sun power.

ISSUES:
Hot water Missing
Its monday morning. The system is set to use the heating element to warm the water. 4:30 is the usual time for me to take a shower. Water started of a bit cold but got warmer. about a minute into my shower the water got cold again, and after a while it warmed up again.
I think this could be related to the pump turning on and pumping cold water thru the system.

Probes:
The system makes use of 2 probes to determine the temp diff between the collector and the geyser. The collector has a nice place to install the first probe. the second probe is a problem as this needs to be installed close to the geyser as possible to measure the temp. I installed it in the copper line that feeds the collector. Problem is that the pipe gets cold quickly.
Any ideas on where to install this would be helpfull.

Equipment used to convert my existing geyser.
18 Evacuated tubes + Collector
Aluminium Roof frame ( Nice frame compared to some of them )
Wilo RS15 pump
SR868 pump controller

Copper pipe
Conex fittings ( Cant solder or too lazy to to it )


Things todo:

The next few days will be used to find the best settings to achieve the best results for heating the geyser.

We also looking at ways to get the probe inside the geyser without causing leakes.

Thanks
:D


PS:

The company i used to get the equipment from is Sunpower.
There website is http://www.sunpower.co.za.

Price for the equipment. R 9085
 
What did al this cost you?
 
Is that with any subsidy?

It will be interesting to see how much it saves you each month.
 
No subsidy.

next 2 or 3 months will i know what the saving will be.

For now i will just enjoy the hot water provided by nature
 
Hi

How much water does the collector hold? Does it hold enough to replace the water used by the shower?

I've just launched a website dealing with some of these issues www.powersaving.co.za, it may be useful.
 
The geyser is 150l.

The collector on the other hand only holds about 3-4l ( i'm thumb sucking the values, dont know the exact size. )
 
Does the water from your solar collector circulate through the geyser continuously?

The reason I'm curious is that with the collector only holding a small amount of water, any large demand on the geyser will empty the collector quite quickly.
 
The pump controller controls the flow of water thru the geyser.

It takes a temp reading from the collector and from the geyser. If the reading is more than the set limit the pump switches on and moves the hotter water from the collector back into the geyser.

The pump i'm using is using around 48watts of power.
 
Another Kempton boykie like me!! woot woot! :D

Back on topic - the R9085 you spent, was that only for the panel, or did it include the pump and controller?

How old is your geyser (roughly) - and is it insulated properly? That will help keep the water warm for the early morning showers.

Monitor it over the next few days and please let us know how it works for you? Today was very hot and sunny so I'm sure you're sorted. It would be interesting to see the performance with cloudy days and cold nights.

Lastly, what suburb in Kempton? (PM it to me if you don't want it public) Purely for my own curiosity and to start making long term plans myself.
 
Hey

The price included the following.

18 evacuated tubes
Collector
Aliminium frame for the roof
Wilo rs15 pump ( 48 watts on its lowest speed setting )
SR868 v3.0 Pump controller.
and also the black plastic insulation.

Yesterday was warm. The temp in the geyser reached around 65 degrees. The only time the element was used is from 03:30 - 05:00.

Will send some updates once i made the modifications for the thermostat.

Later
 
Ta for the info.

Please keep us posted how it's going - I'm sure a lot of people here want to know what to expect if they do switch to a system like that.

It's much better to hear it from a "normal" person than a sales rep!
 
Update

I did the final modifications to my solar geyser.

The timer for the geuser is set to start at 03:30 and to shut off at 05:00. However should the geyser hit the 55 degrees mark it switches of the element.

The rest of the time its pure sunshine.

We did had a issue yesterday when my wife needed hot water around 09:00 in the morning to clean the washing machine. I simply went to the controller hit the heating button and a hour later the wife had hot water. After that it was back to normal sun power.

Ive checked my system as i type this email. the temp for the probe outside on the roof registers 54 degrees. the geyser is on 54 degrees as well.
The weather outside is overcast. no sun.

I'm still waiting for the day when it starts overcast to see what temp will be reached on the system.

Till later
 
I have done a similar thing though I just had 3no 1m2 normal glass plate collectors which I picked up and refurbished so I got them free. I got a Grundfos 15W pump and I used my existing 150l geyser like you. Currently though I am switching the pump on and off manually but I have recently borrowed some temperature logging equipment so i can see what it is doing. If I switch the pump on at about 9am I can raise the temp in the geyser from about 45 degrees (what I am left with after the night) to about 60-70 degrees within a couple of hours but I have to switch the pump on and off myself. I am thinking of installing a control system on it. Yours looks quite complex. Any advice?
 
Hi

The controller is expensive but my setup is quite simple.

The controller has 2 probes. 1 is for outside the roof to measure the collector.
2nd one is for the geyser. The timer is set to start circulating the water if the outside is 8 degrees warmer than the geyser. and switches off when the diff between 1 and 2 is 1 degrees.

then its just my geyser element thats connected to the controller via a relay.

U could always use a normal timer switch for the geyser, But the days when it rains or not hot enough, then it will start pumping cold water.

Enjoy
 
hi im in cape town im really interested in exactly how the tubes get conected to your old geyser (i dont mean the type of plumbing fittings but where do the inlet and outlet connect to) im assuming its a standard electric heated model with the element and thermostat retained for backup? most of the diy stuff on the net is from northern hemisphere and i havent found anything that uses the type of geysers we all know

thanks
bob
 
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