Posted by spshaffer on December 28, 2006, 4:13 am
I've been posting some questions lately, and slowly but surely (with
everyone's help!) I am putting together a good plan for a system down
I'm in the process of a renovation and have the walls opened up, so I
am trying to put as many pieces in place now, but I'm not planning to
get the panel until the summer.
I live in Northern Virginia where we still get some good freezes, so I
am thinking that Closed Loop is the option there.
My previous post was about getting an electric hot water tank that
could support solar down the road.
Regading that tank...there seems to be two choice; one that has the
heat exchanger in it and one where I'd bolt on an external heat
I'm curious about the operational differences between the two...
In the situation where the tank has the heat exchanger built in, it
seems that I only have to circulate one loop of fluid...the
non-freezing closed loop fluid from the panel.
But in the situation of the external heat exchanger, won't I be
circulation to loops of fluid? One loop from the panel and one loop of
fresh water from the tank?
Bonus question: What should I be concerened about regading the "in
wall" copper runs coming from the panel down to the basement (e.g.
Posted by Solar Flare on December 28, 2006, 4:33 am
Drain down. No insulation is good enough to stop cold from entering
forever and why cool the fluid in the panels and delivery pipes every
night? Lower the thermal mass to reheat next sun day.
Posted by SJC on December 28, 2006, 5:08 am
Here is a system diagram for a drain back system.
I would consider the Rheem Solar tank, the heat exchanger is probably more
The quad rod external is a sort of thermosiphon exchanger, the hot water rises
circulates in the tank without a pump. Not as efficient, but some people want low
cost and use what they have.
Posted by Jeff on December 28, 2006, 5:48 am
Holy Cats, that's better than a $,000, at least it is here:
<URL: http://kingsolar.com/catalog/mfg/rheem/rhm80hx.html />
Whats the downside of just running a load of copper tubing through a
solar reservoir and then feeding a small conventional hot water heater?
I imagine you'd want to keep the conventional heaters losses low (lots
of insulation) as they will not be made up by solar.
Posted by SJC on December 28, 2006, 2:21 pm
Yes, some people actually pay real money for their systems.