March 2009 Temperatures

[dhaslam]

Six hours full sun from 9am to 3pm.   Collector at 52C and cylinder top and bottom showing 49C.  Log shows 13Kwh which is about correct but difficult to estimate opening temperatures against water used. 60 tubes, south facing, 250 litre cylinder, about 2 X  11 metres 10mm  pipe.    

[WeeVic]

excellent!!! I boiled a few kettles of water today using the navitorn solar panels....  As long as i got a hot coffee i`m happy the noo!! hee hee   

Keep us posted with your results!! They help others online... 

[Gixer]

Moved this over to March, a recap on yesterdays temp readings

Time     lower tank temp     upper tank temp in deg C

10:00   8.2                       9.4
11:00   9.4                      12.1
12:00   11.2                     13.0
1:00     14.3                     15.9
2.00     17.5                     18.8
3:00     21.5                     22.9
4:00     25.3                     25.5
5:00     26.5                     26.2

It all finished around 5pm as the sun was getting very low by then.

That's 40 tubes East, 60 Tubes West and a 300 liter tank.

I make that 6.44 Kw input from 5 panels giving  1.288KW each.

So last night a full tank of 26deg water top to bottom.


Today the weather let us down a bit,

 9:00        9.7         24.7   Sunny
10:00        11.6       25.0   Sunny
11:00        12.1       25.7   Sunny               one shower was taken otherwise the lower temp would have been 14.2 ish
12:00        16.6       24.6   Very cloudy
1:00          15.4      23.9    Snowing / cloudy
2:00          18.6      24.6    Snowing / cloudy
3:00          20:5      22.8    Snowing / sunny
4:00          22.3      23.1    Cloudy
5:00          23.0      23.1    Cloudy

As you can see we had all sorts of weather today. Even so the temps finished almost the same as yesterday.

We could say the temp rise at the bottom of the tank was 13.3 deg C. That would give us 14.63Kw. But this would be wrong.

Very wrong, as the top of the tank started out at 24.7C and ended up lower than it started. So we have not heated 300ltr by 13.3deg C.

This is where it all becomes confusing, very hard to work out how much heat was gained today.

I suspect most people take their readings from the bottom temps. Unless your tank is fully cold to start with the temp rise + kw means very little.

[Paulh_Boats]

30 tubes/120L

Less sun than yesterday but top of tank peaked around 68C, roughly a 15C rise.

http://www.millibee.com/logtemp/tank.htm

-Paul

[langstroth2]

Gixer

I see what you mean. I average tank temp (top/middle/bottom) at start (9am) and for the end (5pm) and take the difference as reflecting the energy input. It's still crude but it does account for any top tank temp drop even though the bottom temp has risen significantly.

Of course if Mrs langstroth hits the Boiler HW boost button in the middle of the day then its all rather academic 

[Paulh_Boats]

Yikes! Another record high for this year - 30 tubes/120L, started at 55C peaked at 75C 79C 80C (top)

http://www.millibee.com/logtemp/tank.htm

Boiler last used one week ago.   Time for a frotter style tub!

[langstroth2]

Yep, plenty of sun today. 34C rise.

Ave tank temp at start a low 20C (11 - 17 - 32)
Ave tank at 15:45: 54C (52 - 54 -55)


40 tubes / 140L

[dhaslam]

Soon will need to set up the heat dump.    At the moment collector 57.  bottom of tank 51 and top of tank 56.  I will probably set the transfer temperature at about 60C so that there will be  some heat stored in the buffer tank for dull days.   Putting  the pump on variable speed again seems to have increased collector temperature a bit which increases the top of tank temperature.
 
60 tubes 47mm, 250 litre cylinder,  850 litre buffer tank.   

[rt29781]

Very Sunny today.  13.6 kWh from the PV which is about 40kWh on the solar thermal.  149 tubes sw facing on 38% slope roof.  House at 23C (by 12 noon then heating switched to the pool) and pool gained 1.5C today.  Last 3 days we have seen 13.7kWh then 7kWh (due to cloud) then !3.6kWh on the PV so that is 40kWh, 20kWh and 40 kWh on the 149 57mm tubes.  House in Aude in France.  The solar storage got to 50C but that will disappear into the house in the evening.  The collector temperature fluctuates between 63C and 66C from 10.00 until 16.00 then drops gently as the sun fades.

[rt29781]

Almost the same as yesterday 13.4 kWh on the PV,  house at 25C, pool at 19C and Jacuzzi at 21C.  Air temperature max of 22C outside.

[StBarnabas]

Hi RT
any way you can pipe your excess heat to Northumberland?

[rt29781]

Hi StB,  We used to live in Aberdeen for 10 years so understand cold.......Temperature 23C outside today and the next 2 weeks forecast to be sunny.  So hopefully the pool will be at swimming temperature (25C) next week some time, although my wife needs 28C to get in the water....

[rt29781]

Pool at 20.2 C, Jacuzzi at 22.6C, house at 23C  13.4kWh on the PV, circa 40kWh thermal.  150 x 57mm ET SW facing 38% slope  SW France

[sjaglin]

Hi BobT,

I think you are in Lezignan-Corbiere, you can see PV installation nearby on :

http://www.bdpv.fr/carte_installation.php

It would be nice as well if you could register!

I am the "contrary" of you, I am French living in the UK, our installation is a bit more modest (20 tubes and 2.1kW-PV).

Good day here as well, bottom of the tank at 52 degrees at the end of the day and 4kWh for the PV.

Enjoy the spring in France!

Stef

[rt29781]

Hi Stef,

We are near Lezignan, good detective work.  I try to remain fairly anonymous on the internet, never sure who is collecting the information......