Solar Thermal Design Help

[pottsiwebber]

OK so I've got to the point where I need to finalise my solar thermal system design.

As I've said elsewhere I've got a 216ltr Navitron store for DHW currently being heated by the pellet boiler and WBS. I have a South facing roof with a steep pitch and I'm going to have to place the collector as high as possible on the roof and pretty much as far away from the thermal store as possible. I need to do this to avoid any risk of shading from my neighbours enormous Ash tree in their back garden, if I place the collector correctly I will avoid any shade all year round.

In this position on plan I'm looking at around 12m from the store to the far edge of the panel plus a couple of meters for the height difference and a couple of meters for routing here and there gives me about a 16m one way run between store and panel. Will this cause me any significant problems or require anything other than 10mm copper pipe?

My second issue is the roof I'm mounting on is a warm roof with no void below. I could and probably will use the ridge void which will no doubt require much swearing to get the pipes through. Has anyone done anything similar?

Third is the location of the controller. Can the temperature sensor cables be extended so I can mount the controller downstairs or will this screw up the readings? i.e. are they sensitive to cable resistance mains interference etc. I'm hoping they are two wire resistive thermal devices and are not.

And last but by no means least if I go with my original sizing of 30x47mm tubes and find its not enough can I simply add another panel at a later date? I'm assuming they are just daisy chained together so this wont be a problem.

Thanks in advance of replies.

[dhaslam]

There should be no problem with the longish run and  panel  sensor normally  has a long run anyway so it doesn't make much difference.  You can correct the reading by a few degrees if you want to have the readings accurate.   Are there  any  cupboards upstairs that you can use to route the pipes?  The 10mm pipe is easy to route , except that it comes rolled up,  but  the insulation would make it awkward to  thread through a narrow space.    If you feel that the collector may  not  be big enough you should go for larger in the beginning.    The 58mm tubes would give you 50% more output, more appropriate to your cylinder size,  and  still only have one, slightly larger, panel to mount and connect.     

[Brandon]

ditto, on that store I would go with 30 58mm.

[pottsiwebber]

Thanks for the input.

[pottsiwebber]

A little help with the shopping list would be appreciated, so far I have:

58mm 30 tube collector
TDC3 controller
Circulation pump
Antisyphon valve 15mm
Pressure system kit
Solar antifreeze
Antifreeze filling kit
Pitched roof mounting kit
10mm copper pipe
Armaflex insulation
Armaflex joint tape

Apart from the bits and pieces I can pick up at B&Q for the installation are there any "arrghhh why didnt I remember to by that" items have I forgotten?

And does anyone know the spec for the copper pipe supplied by Navitron. Is it 10mm to BS 2871 : Part 1 : Table W, annealed (EN 1057 soft). Suitable for water and gas installations or some exotic solar variety?

Ta.

[desperate]

How about a bit of lead for the flashing and some Denso tape to keep the birds off the external insulation, dunno about the spec of navitron supplied 10mm, but ordinary soft copper in a coil is fine, how about some 10mm straight connectors, come to think of it.

Dont bother with   B@Q     go to a real plumbing shop, you'll get better stuff and a source of info, and maybe even a discount.

Desp

[pottsiwebber]

How about a bit of lead for the flashing and some Denso tape to keep the birds off the external insulation, dunno about the spec of navitron supplied 10mm, but ordinary soft copper in a coil is fine, how about some 10mm straight connectors, come to think of it.

Dont bother with   B@Q     go to a real plumbing shop, you'll get better stuff and a source of info, and maybe even a discount.

Desp

I only buy odds and sods from the aforementioned never to be mentioned again DIY outlet and as you say they can be expensive and are most definitely clueless. I get large orders of plumbing gubbins from a well known supplier that rhymes with cress, bought shed loads off them when I plumbed the bathrooms, WBS, boiler & thermal store.

Birds like the insulation then I'll remember that, come to think of it I remember back in my surfing days the seagulls in Newquay used to pull lumps out of the foam on my roof rack.

[Brandon]

I would advocate brass compression inserts for the 10mm, as if you are not best familiar with using soft copper then the olives can crush the pipe, and it can create leaks, I use them as a matter of course, as it means I don't get called back, and you know that the first time will do it.  (you will have to de burr the pipe end to get the insert in.)

You could also do away with the anti freeze if you use the frost protection on the controller (MCS non compliant mind, and will not work if the power fails)