Solar water heater.

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Rwy in Sight
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Solar water heater.

#1 Post by Rwy in Sight » Thu Jan 10, 2019 9:21 pm

I am in the market for a solar water heater. I understand there are some characteristics, but I would welcome any advice from people having install such a unit previously.

I aim to acquire one with a 120 capacity, but beyond that I am open to suggestions.

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Re: Solar water heater.

#2 Post by Pontius Navigator » Thu Jan 10, 2019 9:48 pm

Where are you? If in UK I just don't see how the economics stack up. Quite some years ago we were given a quote of £4,000. My fuel bill at the time was high but included electric and gas. Gas covered central heating as well as water. The pay back would be well over 10 years.

Today my gas bill alone is £600 which includes heating and cooking. Hot water is perhaps £200-£250.

The problem in UK is the system is a heat exchanger system rather than direct. If you use expensive fuel to heat water it might be worthwhile.

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Re: Solar water heater.

#3 Post by Alisoncc » Fri Jan 11, 2019 12:18 am

Many many years ago once read that fluoride in drinking water corrodes aluminium. As most roof supported systems used to use very thin aluminium piping for it's lightness, meant they had a limited lifetime in areas with fluoridated water. Remember looking at the economics, and payback time exceeded lifetime of system. Don't know if that is still the case.

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Re: Solar water heater.

#4 Post by Slasher » Fri Jan 11, 2019 12:30 am

RiS our resident solar powerist Ex-Ascot would be the best bloke to talk to.
http://www.youtube.com/watch?v=24m-V2f9-sY

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Re: Solar water heater.

#5 Post by Sisemen » Fri Jan 11, 2019 1:13 am

Had solar hot water for a number of years in both houses. Nothing but praise - mind you, we do actually have sunshine in this neck of the woods!

Only practical advice I would give is go for a quality product that has a solid name. Cheapies will let you down eventually.

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Re: Solar water heater.

#6 Post by Rwy in Sight » Fri Jan 11, 2019 7:28 am

Thanks for the wise words. I am currently renting an apartment and as a part of the deal, I shall install such a heater in exchange of a lower rent. The area where I live has plenty of sunshine and from where I sit I can see at least a couple of units. I am not in the balcony.

Alisonc, I don't know about the water. Most systems offer a 5 year warranty and I intend to follow the maintenance requirements.

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Re: Solar water heater.

#7 Post by Alisoncc » Fri Jan 11, 2019 9:35 am

Rwy in Sight wrote:
Fri Jan 11, 2019 7:28 am
Alisonc, I don't know about the water. Most systems offer a 5 year warranty and I intend to follow the maintenance requirements.
RiS, from my perspective the issue was the "Return on investment". If the system saved "x" number of pounds per year in utility bills, had a total cost of "y" pounds, but had a lifetime of number of years times the annual savings significantly less than "y". Then it would be economically unviable.

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Re: Solar water heater.

#8 Post by Rwy in Sight » Fri Jan 11, 2019 5:37 pm

Alison,

I save a small amount of money each month - the landlady has accepted to receive a lower rent and I would save money in utility bills. I don't really care to leave behind a solar water heater that would have a longer life than let's say five years which is a good initial term for renting a house. So my calculations are a bit different although yours are essentially correct assuming Y overpasses X before the end of its lifetime.

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Re: Solar water heater.

#9 Post by Pontius Navigator » Fri Jan 11, 2019 7:47 pm

Alison, the pipe weight would be insignificant when compared with the water tank, assuming a roof mounted system as in a direct heat system. The 'wonderful ' systems in quarters in Cyprus in 1970s were out of commission in 2000s.

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Re: Solar water heater.

#10 Post by Alisoncc » Sat Jan 12, 2019 1:22 am

Alisoncc wrote:
Fri Jan 11, 2019 12:18 am
Many many years ago once read that fluoride in drinking water corrodes aluminium. As most roof supported systems used to use very thin aluminium piping for it's lightness, meant they had a limited lifetime in areas with fluoridated water.
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Sent from my PDP11/05 running RSX-11D via an ASR33 (TTY)

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Re: Solar water heater.

#11 Post by Rwy in Sight » Sun Jan 13, 2019 8:28 am

I have not considered aluminium piping. I think we use copper here.

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Re: Solar water heater.

#12 Post by Ex-Ascot » Wed Jan 16, 2019 1:15 pm

Sorry RiS only just seen this thread. We have a fantastic system see below. It comprises of black glass tubes. Never seen it in Greece though. Even in weak sunshine it produces very hot water. The tank is well insulated and will maintain the water hot for days. It would be fine for your monthly shower. :YMPARTY: You know that you are very welcome to visit and inspect it. Doesn't even require you to get on a ship. Can't remember the cost but it wasn't expensive. Can look it up for you if you wish.
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Re: Solar water heater.

#13 Post by Rwy in Sight » Tue Jan 29, 2019 8:44 pm

I acquired a normal one (one with a metal frame) I have not used the initial supply of water yet - only used about 4 or five times and it gives a decent temperature even if it is still winter here. The cost was 550 € for the unit with a 3 m2 collector and another 250 (without a VAT receipt) for the installation.

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