Help to DIY Solar Water Heating

[matt_w]

Hello!

I've searched and now read all posts containing "DIY" and "Solar", and still no nearer an educated idea if I can do it, so I hope it is ok to post up asking....

Our house is now wood heated - 7KW stove which keeps the rest of the house warm by leaving the internal doors open. I collect (rescue?) wood from the skip at work (broken pallets), and also collect tree wood through our voluntary conservation work and trees I fell for people. In the summer I made the bold move to switch off the water heating completely. We have an electric shower, Mrs W just switches the water on when she fancies a bath, which at the moment is perhaps once a fortnight. I also heat water on the stove which is then often poured into the washing machine drawer at the right second. Should have got a fire with a back boiler!

We discussed switching the hot water back on for winter, but the present arrangement seems fine. Especially as when I worked it out we were using around £0.75 per day to heat the water tank (and cooking)

We've an almost perfect south facing pitched roof and we live on the north Hampshire to Berkshire border, so it seems ideal to fit solar hot water evac tube whotnots to. I'm a competant DIYer and have no issue with plumbing (but prefer speedfit these days!). Our boiler is an old vented system, one hot water tank, one cold water header tank and one central heating header.

A friend sent the following ebay link http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0385636306
as a basic kit.

The part I'm rally not at all sure about is about using my existing hot water tank. Can I use an array of valves so that I can (manually) switch the heating source from solar to gas? I thought initially a simple t-valve at the feed to the heating coil, but if the gas boiler came on that might cause a wee issue, so I thought I would need to issolate the heating coil, but to have a path for water from the boiler (or solar) to circulate back to the heat source. Also I have no idea how or what the traditional tank coil is fed with (I assume it is water, perhaps with something added, oes it come from the same small central heating header tank?) Can I use the same fluid for an evac tube based solar in combination with the gas?

Whilst I've no real issue to semi permanently turning off the gas, we've our first child on the way and I expect that if we sell the house later without the gas, it might prove more tricky.

So, I would prefer not to replace the tank if at all possible, especially as the tank appears to have been installed first in the house and then the walls built around it so I cannot get to half of the pipes!

If the price is right then I would pay labour for a good job, but realistically have no idea how much a reputable job should cost.

Any help and tips would be very gratefully received.
Thanks,

[contadino]

If you don't want to replace the tank, then maybe a Willis Solasyphon could be an option.

http://www.willis-renewables.com/features-benefits.htm

It sits alongside your existing tank and feeds hot water directly into it.

I emailed them about 6 months back and they quoted a price of £245 delivered to London. I'm sure you could fabricate something similar yourself if you're handy enough. Alternatively, I believe that several companies offer retrofit coils for existing tanks, although I've no idea how much they cost.

[Big Al]

http://www.thegreenlivingforum.net/forum/

This link used to be the New house farm / its not easy being green forum. Do your searching there as there is a whole raft of info on there on solar thermal.

HTH

BA

[matt_w]

If you don't want to replace the tank, then maybe a Willis Solasyphon could be an option.

http://www.willis-renewables.com/features-benefits.htm

It sits alongside your existing tank and feeds hot water directly into it.

I emailed them about 6 months back and they quoted a price of £245 delivered to London. I'm sure you could fabricate something similar yourself if you're handy enough. Alternatively, I believe that several companies offer retrofit coils for existing tanks, although I've no idea how much they cost.

interesting.. seems like a a small additional tank plumped in parrallel. I'm surprised that it manages to heat the tank in all honesty without some form of pump arrangement. Retrofit coil - that should be easy enough, although with hard water I've no idea what the inside of our tank is going to look like!

maybe if I'm going to do it I should just do it properlly and be done with it.... Now I'll start searching for kits I suppose!

Thanks everyone.

[homegrown]

hi
try these links and hope they help

homegrown


ps feel free to ask for other info i used to sell sokar systems

http://www.bigginhill.co.uk/solar.htm
http://www.diyhotwater.com/
http://www.motherearthnews.com/Green-Ho ... eater.aspx
http://www.solarfriend.co.uk/
http://www.reuk.co.uk/Simple-Solar-Water-Heating.htm

[KathyLauren]

The normal configuration (at least around here) is that you install a second tank in the cold water line that feeds into the existing water heater. The second tank is the heat exchanger for the solar. The tubes on the roof contain food-grade antifreeze (in case any of it gets into the water supply), which circulates to the coil in the heat exchanger. The cold water in the heat exchanger gets heated by the hot coil from the solar collectors. When you want to use hot water, you draw it from the regular water heater, which draws its supply from the solar heat exchanger.

The net effect is that, when the sun is shining, the water heater only uses energy to keep the water hot, since it is already hot when it gets there. On the other hand, if the sun doesn't shine for a while, the water heater is still online and will heat the water from scratch if there is no warmth from the solar.

[matt_w]

Just showed this post to my husband (we're just in the process of fitting solar panels and reworking our heating system), and he advises a visit to the navitron forum (just google navitron and you'll find it), which he has found really helpful and informative. He also says many plumbers are very wary/ignorant and so called heating engineers can be either expensive or precious about the systems they fit. Be aware that push fit fittings may not be suitable as solar panel liquid can get very hot. You may also not be aware that fitting a pressurised system is a notifiable building process through Building Control, although if you're retaining your header tank this may not apply. Hope this is of help to you.

thanks for the navitron link - I just got around to check it and very pleased that I did

One thing was bugging me about roof mounting - there's only a video on the website... perfect..

Now just need to persuade Mrs V that we should do this / afford this before baby #1 pops out :)


Thanks!

[iks]

This site has useful information

http://www.instructables.com/id/Solar-T ... Five-Doll/


A couple of month ago I was at a website that were selling some plans and they looked really well but I don't remember where it was.

[matt_w]

update - solar now fitted and running.
Yesterday saw 174 litres of water at 55 degrees.... I enjoyed a long hot bath :-)

Kit installed - Navitron 30 tube kit. Very pleased, was very easy to fit, although the instructions were, er, well 'guidance notes' that needed a lot of adapating to the individual setup. Overall a good result.

[harymartinn]

Well solar heated water can be collected and stored to be used when needed as, solar heated air is real time.Being that your heating needs are mostly at night, and domestic hot water is always used, I would thing solar water would be the better way to go.