Help to DIY Solar Water Heating

Solar energy, wind turbines whatever it is then here is your place to talk about it.
Post Reply
matt_w
Jerry - Bit higher than newbie
Jerry - Bit higher than newbie
Posts: 38
Joined: Wed Nov 11, 2009 9:51 pm
Location: Hampshire UK

Help to DIY Solar Water Heating

Post: # 178296Post 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
Living the good life
Living the good life
Posts: 474
Joined: Mon Mar 26, 2007 4:39 pm
Location: Apulia, Italia

Re: Help to DIY Solar Water Heating

Post: # 178333Post 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
A selfsufficientish Regular
A selfsufficientish Regular
Posts: 1640
Joined: Mon Apr 28, 2008 10:28 am
Contact:

Re: Help to DIY Solar Water Heating

Post: # 178354Post 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
Member of the Ishloss weight group 2013. starting weight 296.00 pounds on 01.01.2013. Now minus 0.20 pounds total THIS WEEK - 0.20 pounds Now over 320 pounds and couldn't give a fig...
Secret Asparagus binger

matt_w
Jerry - Bit higher than newbie
Jerry - Bit higher than newbie
Posts: 38
Joined: Wed Nov 11, 2009 9:51 pm
Location: Hampshire UK

Re: Help to DIY Solar Water Heating

Post: # 178414Post matt_w »

contadino wrote: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.

User avatar
homegrown
Living the good life
Living the good life
Posts: 440
Joined: Sun Oct 04, 2009 11:03 am
Location: North Canterbury, NZ, somewhere between reality and heaven

Re: Help to DIY Solar Water Heating

Post: # 178435Post homegrown »

Our remote ancestors said to their mother Earth, "We are yours."
Modern humanity has said to Nature, "You are mine."
The Green Man has returned as the living face of the whole earth so that through his mouth we may say to the universe, "We are one."

Author Unknown

User avatar
KathyLauren
Living the good life
Living the good life
Posts: 447
Joined: Wed Aug 05, 2009 11:57 pm
latitude: 44.5
longitude: -66
Location: Nova Scotia

Re: Help to DIY Solar Water Heating

Post: # 178750Post 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
Jerry - Bit higher than newbie
Jerry - Bit higher than newbie
Posts: 38
Joined: Wed Nov 11, 2009 9:51 pm
Location: Hampshire UK

Re: Help to DIY Solar Water Heating

Post: # 179921Post matt_w »

SusieGee wrote: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 :iconbiggrin:

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
margo - newbie
margo - newbie
Posts: 11
Joined: Mon Mar 01, 2010 10:20 pm
Contact:

Re: Help to DIY Solar Water Heating

Post: # 188756Post 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.
Visit my humble web site Diy Solar Panels
"Treat the Earth well. It was not given to you by your parents. It was loaned to you by your children"
~ Kenyan Proverb

matt_w
Jerry - Bit higher than newbie
Jerry - Bit higher than newbie
Posts: 38
Joined: Wed Nov 11, 2009 9:51 pm
Location: Hampshire UK

Re: Help to DIY Solar Water Heating - now fitted and running!

Post: # 188820Post 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

Re: Help to DIY Solar Water Heating

Post: # 194044Post 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.

Post Reply