On Nov 16, 2020, at 5:23 PM, Scott SV Tengah <Scott.nguyen@...> wrote:

Second update: I measured the pump flow rate on the original flojet with a hose and bucket and it was 6.5 liters per minute. 

I measured the flow rate on the brushless set at 25% duty cycle and it was a bit over 5 liters per minute. That lower flow rate probably explains some, but not all of the 60% energy savings I am seeing vs. the brushed motor.

Frigoboat literature states that you need to supply 3.8 liters per minute, so even at my lower flow rate, I'm well over the requirement.

What is really odd is that the fridges seem to run better in that they're running less and use less energy. I surmise there may be some truth in Craig Briggs explanation about how warmer water results in more efficient compressor operation. My freezer, which gets cooling water that has been warmed by the first and second fridges, seems to be drawing less energy. Overall, I have a daily power surplus that is greater than the water pump energy savings (with solar output accounted for) can explain.

So far so good. Now let's see if it lasts!



--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com