As I mentioned in the solar water column I have had solar hot water system since about 1982. I have worked as a plumber and an electrician -both of these skills I learned in the 80s. I have moved this system twice on my roof over time. One was a major remodel the others as a 50 year of install I did about 10 years ago. This system was paid for thru rebates thru the local utility back then. Jimmy Carter got that fire lit in 79.
The system is a freeze drain down direct system . I have done 3 of these systems . The other two got destroyed due to wildfires on homes long ago in our state . They roof panels are two 4x8 solar water panels with 1 inch headers with the piping sloping downhill to a sunspool valve. The system is controlled by a independent every brand differential controller . The controller reads two temps -one on the cold side of Tank at bottom the other on roof on top of panel pipe. When the difference is enough it turns on the pump to bring down that hot water.This model also has 2sensors (two in the panel -you install them there for freeze protection) to detect freeze temps. Then the system drains down. I have had this fail a few times in the past 40 years and put the whole system on a electronic timer so it drains down every nite (exercise is good for the valve). They are a pain to silver solder when the pipe freeze inside the panel as I have done this as well on the roof.That way its not dependent on a sensor to activate other than the two sensors that tell the pump (small stainless Taco) to bring down the hot water .I also put in a small pressure take up tank to take care of an fluxations to the pressure system. We are on a well I might add so water is a big deal for up.. Been on this place 49 years so I know the systems well. The well is 110 foot deep 3/4 Hp submersible pump (220V). The solar loop is pumped thru a Rheem solarAide tank. It has two side taps in middle of tank as well as two top feeders for cold in and hot out. The loop goes thru the middle connections . I have been thru about 3 pumps so far as they take a beating. They are low draw pumps that handle really hot water.
The hot water is directly feed into the Rheem 40 gallon water heater The house hot water then runs into a tempering valve so no excessive hot scalding water gets thru. Except for take off to our dishwasher as this water can be as hot as it gets.This valve can be manually adjusted to suit our needs. The photos on my water shed show some complexity that most heater sheds do not have this much plumbing. For one on the far right is acetal vac unit and off the lower tap on water heater is a grundfus smart recurculator pump that provide hot water instantly at all taps on that loop. This pump operates any many speeds and is on auto as it learns your usage and goes off as soon as you are away .I put this in abut 5 years ago-its great water saver on hot water.I labeled all flow direction and whats what for others. This direct drive drain down system is a great low cost way to preheat water. When I added the electric solar system tow years ago I decide to use the Sol-Arcs smart load extra power we produce to add a 3500 watt heater element to the Rheem solar aide tank and now that extra electric heats that tank as well as the SHW panels. We have had this going nearly a year now (June). In the future we may get a small hot tub and redirect this Sol-Arc load to that. I also have a stash of SHW panels to heat that tub with. Many got rid of them when their systems failed and had no repair options here. My plumber friends also called me to take them down and away. I have had SWH for 4 decades now and its been very worthwhile for us as a preheat system thats got paid off in the 80s.
The system is a freeze drain down direct system . I have done 3 of these systems . The other two got destroyed due to wildfires on homes long ago in our state . They roof panels are two 4x8 solar water panels with 1 inch headers with the piping sloping downhill to a sunspool valve. The system is controlled by a independent every brand differential controller . The controller reads two temps -one on the cold side of Tank at bottom the other on roof on top of panel pipe. When the difference is enough it turns on the pump to bring down that hot water.This model also has 2sensors (two in the panel -you install them there for freeze protection) to detect freeze temps. Then the system drains down. I have had this fail a few times in the past 40 years and put the whole system on a electronic timer so it drains down every nite (exercise is good for the valve). They are a pain to silver solder when the pipe freeze inside the panel as I have done this as well on the roof.That way its not dependent on a sensor to activate other than the two sensors that tell the pump (small stainless Taco) to bring down the hot water .I also put in a small pressure take up tank to take care of an fluxations to the pressure system. We are on a well I might add so water is a big deal for up.. Been on this place 49 years so I know the systems well. The well is 110 foot deep 3/4 Hp submersible pump (220V). The solar loop is pumped thru a Rheem solarAide tank. It has two side taps in middle of tank as well as two top feeders for cold in and hot out. The loop goes thru the middle connections . I have been thru about 3 pumps so far as they take a beating. They are low draw pumps that handle really hot water.
The hot water is directly feed into the Rheem 40 gallon water heater The house hot water then runs into a tempering valve so no excessive hot scalding water gets thru. Except for take off to our dishwasher as this water can be as hot as it gets.This valve can be manually adjusted to suit our needs. The photos on my water shed show some complexity that most heater sheds do not have this much plumbing. For one on the far right is acetal vac unit and off the lower tap on water heater is a grundfus smart recurculator pump that provide hot water instantly at all taps on that loop. This pump operates any many speeds and is on auto as it learns your usage and goes off as soon as you are away .I put this in abut 5 years ago-its great water saver on hot water.I labeled all flow direction and whats what for others. This direct drive drain down system is a great low cost way to preheat water. When I added the electric solar system tow years ago I decide to use the Sol-Arcs smart load extra power we produce to add a 3500 watt heater element to the Rheem solar aide tank and now that extra electric heats that tank as well as the SHW panels. We have had this going nearly a year now (June). In the future we may get a small hot tub and redirect this Sol-Arc load to that. I also have a stash of SHW panels to heat that tub with. Many got rid of them when their systems failed and had no repair options here. My plumber friends also called me to take them down and away. I have had SWH for 4 decades now and its been very worthwhile for us as a preheat system thats got paid off in the 80s.
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