Hot Water

[smiley]

If you do just a single loop of pipe, that loop of pipe will cool down just about the time you're finished flushing cold water from the pipes and get some hot water into your shower.
Perhaps a small tank would warm up somewhat on a warm day, assuming you're planning to use the water at night.

Cliff has the right idea. Search tempering tank in attic and you'll get a whole bunch of ideas. The tank is a buffer allowing cold water in one end and warmed water out the other.

 

[muddstopper]

I would think for the cost of 300ft of pex, you could build a simple solar collector and see some real benefit from all your labor and money. Make a trip to the local dump and pickup a good used hotwater heater and use it to store your solar heated water. A collector of about the size of a sheet of plywood can probably heatup all of your hotwater needs. I think a homemade collector would be easier and cheaper to build that buying all that pex and then trying to mount it in your actic.

 

[pat32rf]

And when you do decide on the final heat solution, add as much hot water storage as you can. If the heat is free, use as much as possible to heat all the water you can....