August 2009 is looking better

[Ivan]

Greenbeast - from tonight's experiments, I'd say I need 7-10litres to do the hot fill for the wash at the beginning of the cycle.

Add this to my dishwasher's requirements (I'm guessing around 15litres/day) - so using say 25litres per day of solar-heated water for washing machine/dishwasher in exchange for a saving of around 1.1kWh/day seems like a good idea.

[Greenbeast]

Good stuff, now get that timer sorted!

[Pip]

Two years of figures.  Installation was end Aug 2007, hence the Sept start date.

Nice info, thanks for the posting. For me August was disappointing this year, looks like last year was worse.

Pip

Rob's graph below

[rob26440]

Pip - How did you do that?  I tried to insert the graph but it wouldn't cooperate!

Yes - a couple of odd months (Nov & Feb) when you look at the comparison but the 2 totals are not that far apart.  Down about 5% on last year.  Apart from Jan & April, the daily average temperatures are pretty close over the period.

I reckon the real kWh is probably about 1/2 that registered on the TDC3  (I haven't done much fiddling with the settings to improve the accuracy).  I compared the TDC3 kWhs to some calcs based on days when I had control of the hot water usage (i.e. sunny days, only me in and no hot water used) and could take multiple/regular readings on the 5 sensors on the DHW cylinder.  (Must get a 1 wire system installed!)

[Pip]

Pip - How did you do that?  I tried to insert the graph but it wouldn't cooperate!

OK here goes.

Using the generic packages you  get with Windows:

• In your Word doc, select the area you want to be in the image.  In this case I selected the text above the graph and the graph itself using the mouse.
  
• Copy to the clip board.  Right mouse Click->Copy, or Control C
• Open M$ Paint and paste the clipboard contents.  Edit->Paste, or press Control V.
• Reduce the size of the Paint document canvas to fit the image by grabbing the little square in the bottom  RHS and drag it up to the size of your image. Otherwise you will get a big white boarder.
• Save As  giving it the name you want, and suggest file type of  Gif or PNG as these are compressed, and good for this type of picture.

Bingo!

As for the TDC3 readings, I have spent a bit of time measuring flow rates and calibrating the offset for in the heat metering, but I think my system may be under reading.  I am gathering more data on usage before tweaking anymore.

If you are interested, I documented my calibration method here. http://www.navitron.org.uk/forum/index.php/topic,7538.msg83609.html#msg83609

When I get more real data I will post the results for discussion.

Cheers
Pip

[rob26440]

Pip,

I did that and it didn't work.  However, I'll try again - this time with the (rather crude) 24hr average temps for Jan 08 to Aug 09.  The temps are taken at 0800, 1600 & 2400 each day so not a meteorologically accepted methodology.  But it does provide a comparison.

Thanks Rob.