SunEarth Sun Siphon Yea or Nay

[Greg Hilfman]

Hi, I'm new to the solar water heating world, as well as this forum. I live in sunny S. Cal, am looking at installing a SunEarth SunSiphon system for a fairly small guest house I'm building. I don't have a space for a ground level storage tank, so this "on the roof" siphon system seems like a good bet. Yes, I have adequate structural support. I would be feeding the output into an LP tankless heater (Takagi Jr., which has the required input thermostat).
My question .. has anyone had experience with these, good or bad? I've received a fairly inflated quote for installation & am thinking of doing it myself, as I've had a fair amount of plumbing experience. Any "heads-up" would be appreciated.
TIA

[Ralph Day]

Helo Greg

Welcome. you'll find all kinds of interesting stuff here.

My experience with Takagi Jr and a solar hot water system is largely good. My only advice would be to have a switch for the Jr accessible (not from the shower of course) so you can shut it off if the input water temp is warm enough for use but not too warm. My Jr unit will cycle on and off when the input temp is comfortable for use at almost straight hot setting. The result is hot and cold running water on the shower user.

Takagi has a remote controller (not me) which would be helpful too. Paul will see this post and be able to input about temp monitoring. With a display of solar water temp you could easily tell wether you needed the Jr unit to flash.

In sunny southern Cal you may not fire the Jr much at all. Mine spends the spring and summer months "off" unless we have a sustained stretch of cloudy weather. We increased the angle of the solar collector this spring so no ideas yet how that will affect the winter solar input...previously ther was none. I wouldn't even clean the snow off it. Snow, unless you're a skier, is that white stuff the movie studios make out of plastic.:D

Ralph

[Greg Hilfman]

HI Ralph ... really appreciate you taking the time to give me your feedback. I'm a little confused about your info on the Takagi Jr. cycling on & off. I thought the thermostat would be accurate enough to either fire the unit or not, depending on the water temp coming off the roof. Are you saying that the thermostat can't make up it's mind, hence the cycling?
regards,
Greg

[Ralph Day]

hi Greg

I found the unwelcome cycling on and off happening when the input water temp was at about body temp. this happens in spring and fall usually, and i think the setting for the takagi output temp is a factor too.

The remote temp control module would be a worthwhile investment. if you found that you had cycling, upping the takagi output might stop it happening. Overall, it's a good mix. if your rooftop tank is insulated you'll not lose a lot of your day's gain in the night.

ralph