Newbie

[SolarRoofSols]

@puddy, are you on commission for each time you mention homesun in a post?

 

[Steve_rutland]

Hi Bigbaddave

 

[Steve_rutland]

Anyone know how to alter the tariff on PvOutput.org?
Mine will be 13.99p but it seems to be defaulted to 45p.

 

[Vegelen]

Go to your Pvoutput solar pv systems 'Daily Output' page.
Click on Statistics > Edit Tarifs.

 

[Steve_rutland]

Hmmmm, still can't find anything to change.

 

[Steve_rutland]

Interesting to see that the East & West systems are outputting almost the same kwh. Will have to check sometime my exact orientation.

 

[puddy]

@puddy, are you on commission for each time you mention homesun in a post?

No. Do I have to ask you what I post first?

 

[SolarRoofSols]

Indeed not, just interested.

 

[Steve_rutland]

Wow! 34.5kwh!
Well pleased with that

 

[Steve_rutland]

Quick update, just over 3 months on and have produced 3385kwh. The West orientation seem to be marginally better than the East at the moment, but there's not much in it.

 

[Steve_rutland]

Another quick update....have now got an Immersun heating a separate cylinder to supply our hot water as our boiler can't accept preheated water. Water is heated to 80°c, is pumped through a heat exchanger to heat the incoming mains and the resulting hot water passes through a blending valve to give us hot water at the taps. 2 solenoid valves controlled by a top of tank stat controls which source the hot water comes from. In 5 days, the Immersun has put 50kw into the water

 

[Worcester]

Another quick update....have now got an Immersun heating a separate cylinder to supply our hot water as our boiler can't accept preheated water. Water is heated to 80°c, is pumped through a heat exchanger to heat the incoming mains and the resulting hot water passes through a blending valve to give us hot water at the taps. 2 solenoid valves controlled by a top of tank stat controls which source the hot water comes from. In 5 days, the Immersun has put 50kw into the water

Hi Steve ,

Good to hear that the systems performing well.

What's the difference between preheating the water and the HEX? Is the HEX in advance of the boiler or is it after? Do you 'assume' that the primary source is the preheat tank if so why bother with the hex and not just blend the output from that tank? - Care to post a schematic of the plumbing and controls, (confused) thanks.

Thanks

 

[Steve_rutland]

Am using the cylinder as a heat store only and using the HEX to give me mains pressure hot water. It's a vented cylinder. The boiler will alarm if you try and feed it with preheated water. Will try and draw up a schematic when I get in from work. Am looking at a speed controller for the pump now rather than the blending valve to see how efficient I can get it. That said, the return back to the tank is cold so it's probably not worth it....but I do like to twiddle

 

[Steve_rutland]

Righty, hope this comes out ok.
The tank top stat controls S1 & S2. If the tank is above the stat value ( 48c ) then S1 opens and heats the HEX, if below...S2 open and the boilers fires. Should point out there is a flow switch where DHW is on the drawing which is a live feed to the stat...then DHW. Both valves are normally closed. Using this system due to having a combi condensing boiler which wont accept preheated water but still wanting mains pressure hot water without the need to get a specialist in to fit a pressurised tank. Works a treat!! ;-)

 

[Worcester]

OK, I see what you've done, now let me put my thinking cap on.

I reckon we might be able to use a solar controller with it's variable Δt values and multiple pt1000 temperature sensors to give you what you need.

What you call a blending valve I presume is a Thermostatic Mixing Valve as normally installed on the the outlet of DHW cylinders or on the inlet to bath taps etc.

Couple of points concerning the water regs:
I am not sure also that the 2 port valves you have used are suitable / legal for potable water - I presume you used 'normal' 2 port central heating valves?
Also from the regs point of view it looks like you missing a check valve as well.

More normal practice would have been to convert your combi to a system boiler and use an unvented cylinder - then as you realised you need to be G3 certified to install / play with / configure those as otherwise they are literally bombs if not installed correctly.