Used solar water system

I acquired a used solar hot water system, supposedly in good working order. (So why would they remove it?) We have stored it a few years, thinking we would put it on a little net zero cabin. That project has never happened so we are planning on adding it to our own house to preheat/heat water for our radiant floor.
There is no manual for this particular system that I can find, though I did find a manual for a similar looking water heater on the Bradford White site, which indicates this is an open loop water heater. I am planning to separate our current system from the potable water anyway. Currently we have an open loop system heated with a propane high efficiency water heater.
Should I use plain old water as was apparently used before or something with antifreeze added? If we use plain water, how do we insure it doesn't freeze and break anything?



I can find no manual for this part and am not sure what to do with it other than hook up water to the appropriate seeming pipes and plug it in.

Anyone offering experience with this or a similar system would be appreciated.

Reynolds Aluminum
Crown Top Heat exchanger
Solar Commander
Volts 115 Amps 1.51 Hz 60
Model 100 SN 2872-B-1

It didn't quite post as I intended. Here is a picture of one of the panels. They have some white clouding on the side. I hope I can dismantle it and clean it off.

Says bwc in the picture these may be them. http://www.bowmanwalker.com/services/solar/

Actually that is the brand name on the water heater, which is a Bradford White, but thanks. This system would have been installed many years ago, I would guess over 20. Doubtful I would find the installer still. I am hoping there might be an "old permie" about who had or has one. I don't think Reynolds aluminum is even in the solar game anymore, so quite some time ago.
I found this ad for the system from 1983....
http://news.google.com/newspapers?nid=932&dat=19830719&id=s6dPAAAAIBAJ&sjid=slIDAAAAIBAJ&pg=4088,1485281

the only one i have had anything to do with used a closed system , it had a frost protector valve that dumped the water in the pannel ,akind of frost stat on the top of the pannel on the roof htat was suposed to dump the water when it was freezing it failed and the pannel split , i welded it up ( Aluminum ), it took a while to dismantle and reasemble AND put back on the roof , i think that system should have used antifreeze , but someone decided to go for water instead , it had its own pump / thermostat system / header tank , and a heat exchanger coil in the hot water cylinder , the whole system was to complex and relied on utility power for it to work , an ice storm took out the electricity and the pannels full of water froze and busted , I am certain with a little thought you can do better than that system !

More googling with the correct system name and I found a few references from people who have owned these systems, and it seems they are closed loop systems after all. I even found a guy in PA who acquired one used and wrote a blog post about refurbishing it. I will try and contact him to see if he has any manuals or other useful information to get ours working. He updated sometime this year and said it has paid for itself three times over since he got it going 5 years ago. http://robertsprojects.blogspot.com/2009/09/solar-hot-water.html

Nice score! This looks to be a sweet little system.
Do you have only 1 collector?
It looks like you have an 80 gal tank, this would typically have 3 collectors, at least 1 sq ft/gal is the rule I was taught. I don't know what your heat exchanger is rated for, so check that before hooking up any more panels.
I would not use the solar as a pre-heater to your standard 40? gal water heater, but would tie them in parallel to prevent low temps in the solar tank from growing Legionella bacteria. It looks like you have a bronze circulator for hydronic heating and a smaller one for the panel so you can pull the big pump if you are going to use this for DHW.
Run propylene glycol in a mixture appropriate to your climate. Since glycol degrades thermal performance, you want to use as little as possible.
To clean hard water deposits; fill a 5 gal bucket with white vinegar and water, hook up a hose to the inlet and place the bucket under the outlet, run the pump for 1-2 hours and all calcite will be dislodged. Collectors can be cleaned in the same manner. I would probably just flush the tank really well.
You may want to invest in a modern controller like the DS.
Good luck.