Solar hot water heater

[IanL]

Hi all does anyone have solar hot water heater system installed in their house. I am looking into getting this and was wondering if any of the members have this and can shed any light on the pros or cons on solar hot water systems.

Many thanks
Ian

[mithrandir (Andrew)]

Originally Posted by IanL

Hi all does anyone have solar hot water heater system installed in their house. I am looking into getting this and was wondering if any of the members have this and can shed any light on the pros or cons on solar hot water systems.

We've had one (Solahart Black Chrome with two panels) for over 10 years. With only two of us in the house, in summer with a few consecutive sunny days it gets excessively hot, even after the bleed valve opens. It has off-peak backup and for much of the year the switch is off at the mains.

Pick one with a closed cycle and heat exchanger. In Brisbane the antifreeze they put in ours would not really be necessary but probably helps as an anti-corrosive. By not having fresh mineral laden water running through the panels it will last longer.

[Brundah1 (David)]

Hello Ian,

I installed a split system Solar HWS 3 years ago in our 5 bedroom 10EP house. Govt incentive paid about 30% of the cost and the system is designed for a 30-35 year life. So we will use approx 50% of that life before we move into a retirement villaige. In four years I have switched on the booster for two days.

Most efficeint solar systems are the roof mounted type as the thermal gradient does the cycling to stroage for you.

Major structural issue is that modern roofs (and some old ones) are often just strong enough to only support themselvesSo if you have a 4 -5 bedroom house you may not safely apply 750Kgs to 3 or 4 roof frames! Hence the option of a splt system.

Split systems require a small pump to circulate the water to the storage tank. The most efficient pumps were developed by the Europeans for under floor central heating systems integrated with HWS they use 24watts.

The next major issue is the collectors ("what heat the water"). Solarhart originals often lasted 30 years (depending on water quality), some modern system (I'm not mentioning which brands ) have cut costs and build quality including no longer using black chrome copper collector tubes, but rather Colorbond pipes of dubious quality. Only some brands still use black chrome copper and toughened glass panels that will resist all but the heaviest hailstorms.

Be aware that the salesperson will ask you "how many people normally live with you?" not "What is the sleeping capacity of you house?"

Another option is Airpump HWS, but they tend to be noisy and best suit areas with less sunshine or the lack of suitable north facing roof space.

I have no affilaition, nor do I accept bribes etc. Just 40 years of engineeering experience and good research skills.

Do not grab the first, or the cheapest system! Hope this focuses your mind.

Cheers,

David

[IanL]

Thanks,

I am just doing some research on it at the moment as I am looking at going this way for hot water and to save a bit of money once the system pays itself off.

Thought I would ask the question to the to folk like yourselfs who have all ready been through the process.

Many thanks
Ian

[JimmyH155]

When we lived in the bush 65 klm north of Gympie in a slice of paradise, 20 years ago, one of our first things was to get a solar panel on the roof. We went for a Solarhart and it was fitted easily, along with pressure pump and all bathroom and kitchen connections. in just one day.
It was BRILLIANT
There were 5 of us in the house - 3 kids with lots of washing and showers. One time we had cloudy weather for 3 days, and even after that time, the water was still tepid! we did not have electric backup.
It would frequently boil in the roof.
Ours was the first one in the bush and all the neighbours thought we were crackers - they said we should have purchased some more heiffers Our next door neighbours (1 klm away) once showed us their new acquisition - a copper water boiler. They had to fetch the water, fetch the firewood, light it up and then wait for the water to be hot enough to start the washing. We said we were happy to get our hot water direct from the sun - at the turn of a tap........