Straight forward install in South Wales

[martin W]

Hi all,


pics will b up once I can sort out how to do it!


Finished the solar installed on Tuesday with Ivan ..... faffing about with tidying other things up continuing.....

47mm Tubes x 30 installed on due South facing roof at about 35° Angle
172 Litre Thermal Store (50mm insulation) located in attic which feeds into Halstead combi boiler at max temp of 50°C
TDC 3 controller
2 People using hot water

Captains Log
Installed finished at 6pm Tuesday17th March - store filled with cold water 12°C Panel at about 35 degrees for 30 minutes or so....

18th March 5 am Day One
S1 (solar manifold)       = 7°C Damn cold outside tooo!
S2 (bottom of cylinder) = 14°C
S3 (top of cylinder)      = 15°C

Day turns out sunny, so Max temp of store S3 = 37°C at 18:22 pm (wifey used washing machine during day without permission! thus affecting temperature)

This temp of 37°C enables me to turn combi boiler down from max water temp to min (from about 26Kw to 8Kw ) saving about 2/3rds the gas used for heating hot water Solar is now reducing my carbon emissions and giving me a return on my investment already (shame about me methane! ) Two reduced cost showers later and two very happy people.


19th March 4:50am Day Two
S1 (solar manifold)       = 4°C Damn cold outside tooo!
S2 (bottom of cylinder) = 24°C
S3 (top of cylinder)      = 29°C

Day eventually turns out sunny, so Max temp of store S3 = 49°C at 18:22 pm

Martin W turns combi boiler off and has a free HOT shower.... water starts to get cooler, so combi turned back on to let wife have hot shower (reduced cost one at that too). Store temp drops to around 44°C after first free hot shower.


Friday 20th March 2009 5:30am Day three
S1 (solar manifold)       = 7°C Damn cold outside tooo!
S2 (bottom of cylinder) = 27°C
S3 (top of cylinder)      = 35°C

Looks like I am loosing around 5 degrees out of store overnight - Is this normal?
Nice sunny day today....

Max store temp 58°C at 17:33pm. Wife used washing machine twice today.....

Looks like we will both have free hot showers tonight... we achieved two free showers store temp went form 57°C to 51°C


From my calculations we are seeing around a 22°C net gain in water temp each day, but also a big loss overnight of around 4/5 degrees. Is this heat loss normal?

Over each day we have put around 4.5 KWh of energy into the water (worked out from 4184 joules to raise 1litre 1°C - 3.6million joule per KWh) how has everyone else fared the last 3 days with a 30 tube panel? Is this a normal gain for a 30 tube panel at this time of year on a good day.


So Far I Am Well Chuffed With Results, disappointed with heat losses from cylinder - watch this space for a photo of a BIG insulated closet around the cylinder (well it is in a draughty attic).

[MR GUS]

the question should be, is not lagging your hot water tank normal!

..cmon! ..super lag it

[martin W]

Ok the question is....

on a 50mm thickness insulated cylinder located in an attic with ouside temp about 4°C overnight is it normal for the cylinder to lose about 5°C from a starting temp of around 40-45°C?

Last night 2x free hot water showers!


Supper lagging has started

[sjaglin]

Hi MartinW

During the winter I measured our heat loss overnight and it was about half a degree an hour and the tank is solarcyl  sc2005 168L, it has the original insulation, not sure about the depth.
You have  a sensor at the bottom and one at the top, the variation of temperature could also just be the effect of sanctification, the hot water produced at the bottom needs to diffuse in the rest of the tank. Not sure, anyway the tank is in the attic, mine is in our airing cupboard so I don't think your heatloss is too bad!

Oh! Time for my (free) shower!



Stef

[Billy]

Yes it is apparently normal to a certain degree.  I have a super insulated tank with good pipework insulation and I would kill for only a few degrees.  My tanks is to all intents and purposes outside and not in an airing cupboard.

If you search "the importance of cylinder insulation" you will find the thread and see how far we have got in finding where this heat is going.  I think Paul was so deranged by his heat loss that he filled the box round his tank with fluffy stuff to a depth of several meters and the temperature still dropped.

Fascinating subject.

[Hugo]

Ok the question is....

on a 50mm thickness insulated cylinder located in an attic with ouside temp about 4°C overnight is it normal for the cylinder to lose about 5°C from a starting temp of around 40-45°C?

Last night 2x free hot water showers!


Supper lagging has started

Martin w, My cylinder is in the loft, super insulated to 70mm (more to come  ) my overnight loss is 6°C on a cold night.
I try to fill the bath up early so as to get more solar gain in the late afternoon, seems to work.

[martin W]

guys thanks for the replies... its reassuring that 5 degrees loss was normal

temporary supper lagg is finished (proper lagg will be completed after heat dump and WBS are installed over next weeks)

Cylinder is now in a box 750mm deep x 900mm wide. So it now has around 175mm thickness of B&Q recycled plastic bottle loft insulation front and back and 200mm on each side. I also put 400mm on top of box so around 500mm of top of the tank.

I wasn't able to record the temp before we went to bed last night, but from memory we only dropped around 1°C overnight form top of cylinder temp of 44°C

[martin W]

another photo of panel on roof..cant seem to work out how to get other photos in same post.. keeps saying they are too big

[Billy]

Yeah, you have to size the pictures according to how many you want to post.  The max size is 128kb total so if you want to post four pics then they need to be about 30kb each.  A little quality is lost but not much, having said that I tend to post on pic per post cause I like a big piccy.

I resize my pics in the vista picture thingy only because that's what I can do.

Have an applaud, nice job,   

[martin W]

Cheers for that Billy, I thought it was 128K per pic and max 4 per post  no wonder I could only uipload one

[Billy]

I know because I did it and couldn't understand what was wrong, takes one to know one   

 

[martin W]

Just an update:


HAD FIRST STAGNATION TODAY.


All seems fine  - no leaks (waiting for collector to cool down from 190°C to see if anything broke).

We went to sunny Brean sands for Saturday and Sunday and the damn sun came out . On Friday night (as I still haven't fitted my heat dump) I used up the hot water in our store until temp was below 40°C so as to give us a change of not stagnating over the weekend.

Came home at 4pm on sunday and system had stagnated with store at 90°C and collector at around 190°C. It looks like the Max store temp was hit around 12 midday so 50°C rise on 172 litres of water from a 30 tube system in about 1 1/4 days is good (well the sun did shine).

Solar system pressure around 2.1 bar with temp at 174°C and pressure relief valve has not operated so all being well everything should be working as normal tommorrow.