Bernd Felsche wrote:
> Daryl Walford <dwalford@[EMAIL PROTECTED]
> wrote:
>> Athol wrote:
>>> Daryl Walford <dwalford@[EMAIL PROTECTED]
> wrote:
>
>>>> We are installing an approx 4kw system on Friday and I've been
>>>> told the total cost is approx $55,000, thats 21X200 watt panels
>>>> arranged in 3 rows of 7 on 30deg tilt frames onto a flat roof.
>
>>> Ouch.
>
>>>> Most systems we install are under 2kw for two reasons, firstly
because
>>>> most houses don't have enough north facing roof space to fit anymore
>>>> panels and secondly because of the cost.
>>>> You might change your mind about installing a system if you don't
>>>> qualify for the rebate now that its been means tested.
>
>>> Our place is effectively at 45 degrees to the compass. The extension
>>> that we're planning will have a decent sized NE facing surface and a
>>> hip facing NW. Dunno if it's even really viable to install a solar
>>> hot water setup on it.
>
>> I only know one person who has a solar hot water system, its just over
>> 10 yrs old and its already paid for itself more than once.
>> Earlier this year a pipe inside one of the two panels started leaking
so
>> it had to be removed to be repaired, whilst it was being repaired the
>> system operated fine on just one panel so with a two panel solar hot
>> water system there is more than enough solar power to heat your water
so
>> being a few degrees from north shouldn't be too much of a problem.
>
> I've had SHW for about 35 years. The 'newer' system is 20 years old.
> Sacrificial anode got replaced about 3 years ago when I had the
> house re-roofed with steel (and insulated).
>
> Installers tend to drop the heater on whichever surface looks
> convenient. The clever dicks will orient it for maximum insolation
> during winter. You'll probably get too much in summer anyway.
>
> Slightly away from North is probably better than true North. A few
> degrees East may work better to get the water hot sooner in the day.
> It's somewhat dependent upon where the clouds tend to be in your
> part of the world.
>
> If in doubt, put panels on the NE and NW roof sides. :-)
> Keep the storage tank out of the wind, if you can.
>
> Make sure that you get an inline gas booster, controlled by
> thermostat. You should never need to touch it except to add gas.
Very few houses have roofs orientated exactly the right direction, we
install panels as close to north facing as possible but thats usually
dependent on roof space which is less of a problem with hot water but
panels that generate electricity take up a lot more space than hw so
there is less choice.
As you say its not so critical in summer, the mates system has a 1000lt
tank inside his roof space and on a very hot day the water is close to
boiling.
The SHW was designed into the house from new and part of the design was
to use a water jacket on the wood burning heater as a booster but the
system worked so well without it it was never fitted.
Daryl
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