Small house WBS / Solar system

[cjw]

Hi Stuart,

Attached is the plan for mine.  I haven't added in everything on the drawing for the solar as it's supplied as a package.  The solar has three temperature probes: one on the panels and two in the store, but I haven't read about the logic yet.  The thermal store does have two thermal pockets for the PRT probes.

I'm ending up with a three pump solution as that's what the thermal store manufacturer (McDonald Engineering) recommends.

If I expand the system I'll probably do something similar to yourself, but I'd like to see how this one works first and how often we're actually going to use the WBS.

Cheers,
Chris

[Stuart]

Due to not allowing space for my loading valve setup, when I've built the fireplace. 
I had a cuppa tea and a rethink. version 12 was born.

Also moved the gas boilers return higher up as its pointless for it to be heating the rest of that water in the slave tank.

please let me know if there's anything obvious!

Stuart.

[cjw]

Looks good.  Would the coil on the second tank be better being at the top of the tank?  Maybe it's something that can't be changed, but I can't see how the hot water at the top of the second tank will be useful apart from the situation where you've heated the water with WBS and you need the gas boiler on at the same time.

Also is there a way you could circulate the heat from the thermal store to buffer tank should the solar get too hot instead of dumping heat?

Out of interest, what TMV valve are you using on your central heating?  I thought about using one but I'm a little worried about using it as I have an anti-boil stat on the top of my tank that is going to turn on the central heating to a couple of bathroom radiators with no TMVs to dissipate heat.  If I install the TMV then I might end up recircing the CH without removing any of the v. hot water.

Cheers,
Chris

[Stuart]

Hi Chris,

Good point about the coil in the second tank, however is something i cant move. I intend to see how were doing with the solar input and out hot water use. It may be i end up swapping the 2 coils if were making too much solar hot water. There boiler coils anyway so not ideal might need to run them in series eventually.
I also think I need to add an open vent to the tank. The valve is a bodge as i cant fit the components to make a loading valve behind the fire. there is only room for a all in one unit. maybe one day I'll find a second hand one to install.

I'll have to look at the TMV's the CH one is rated to flow hotter than the other model.

Stuart

[Stuart]

The TMV is Caleffi and does not mention boiling water protection, so should be OK then. Long as the valves are set right!

Ver 13 Showing the pipe layout as it is going in and the Rad on its side to aid flow

[Stuart]

here's the link to the construction phase

http://www.navitron.org.uk/forum/index.php/topic,11189.0.html