i build a DIY evacuated tube solar hot water heater system back in 2010
piped fully lagged, non return check valves, basiclly all the stuff myself...works great!
15 X evacuated tubes
200L ground reticulating tank
connected to a instantaneous gas heater
all still working great!
(recently the gronfos circulationg pump failed, and also took out the differential control board.)
made steam for a day or so!! tripping the PTR valve like a kettle due to no water flow in the collector (incredible how well those evacuated tubes work) (hit 126deg on the collector) but the emergncy re-cool function could not cool it down as the pump failed
That has all been replaced and is working again, but it raised a question in my mind...
There is no speed control on the differential controller as it compares the water temp coming out of the collector and the temp at the bottom of the reticulating tank and just turns on a output relay that applies power to the pump. simple on/off based on temperate
Q: what is the optimum pump speed? Low, med, high ? (has been set on high for the entire install)
what’s the general consensus?
Cheers,
Richard
(next project a solar powered pond fish feeder!)
piped fully lagged, non return check valves, basiclly all the stuff myself...works great!
15 X evacuated tubes
200L ground reticulating tank
connected to a instantaneous gas heater
all still working great!
(recently the gronfos circulationg pump failed, and also took out the differential control board.)
made steam for a day or so!! tripping the PTR valve like a kettle due to no water flow in the collector (incredible how well those evacuated tubes work) (hit 126deg on the collector) but the emergncy re-cool function could not cool it down as the pump failed
That has all been replaced and is working again, but it raised a question in my mind...
There is no speed control on the differential controller as it compares the water temp coming out of the collector and the temp at the bottom of the reticulating tank and just turns on a output relay that applies power to the pump. simple on/off based on temperate
Q: what is the optimum pump speed? Low, med, high ? (has been set on high for the entire install)
what’s the general consensus?
Cheers,
Richard
(next project a solar powered pond fish feeder!)