Selecting a solar water pump - new circulating pump technologies for solar hot water? - Page 5

Mikesolar · 10-18-12, 06:50 PM

Quote:

Originally Posted by Daox

How would you recommend figuring out the most optimal flow rate of any ol panel (be it new or old)? Could you make a setup where you put a thermal sensor before the panel and then after it, then adjust flow rate so that the temp delta was X degrees?

That's what the variable speed controls do. It overcomes having to know the best flow rate for a particular panel. The best flow rate in December is not the best on in March or July. Plus, any European pump station will have temp gauges on supply and return and a flow setter. The flow setter allows for you to changes the max flow and the control reduces as need be based on the dT you pick. lots of experimentation is possible but I am 99% sure the max speed will be less than expected with your panels, and mine, to maintain a good dT.

Daox · 10-18-12, 07:05 PM

Alright, great. That is doable since I am making my own differential controller. Out of curiosity though, what commercial controllers are capable of doing this?

For my own setup a DC pump might be easier for me to control... I'm not sure how I'd control the speed of an AC ECM motored pump, but I can look into it.

Mikesolar · 10-18-12, 07:40 PM

Quote:

Originally Posted by Daox

Alright, great. That is doable since I am making my own differential controller. Out of curiosity though, what commercial controllers are capable of doing this?

For my own setup a DC pump might be easier for me to control... I'm not sure how I'd control the speed of an AC ECM motored pump, but I can look into it.

Most of the RESOL, Steca, or other common European controllers will do but there is no reason you cannot make it work from scratch. A RESOL model that can do it is about $220 - $300 depending on where you get it.

look for the DeltSol BS Plus

Mikesolar · 10-18-12, 07:44 PM

AC ECM pumps are often PWM controlled or variable frequency drives so you can make a controller with an Arduino. The good thing about the T-D pump is that it is PV controlled for speed but the bad thing is there is no feedback about it so you don't really know how it is doing other than manually looking at gauges.

10-18-12, 07:05 PM	#42
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Alright, great. That is doable since I am making my own differential controller. Out of curiosity though, what commercial controllers are capable of doing this? For my own setup a DC pump might be easier for me to control... I'm not sure how I'd control the speed of an AC ECM motored pump, but I can look into it. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

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10-18-12, 07:44 PM	#44
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	AC ECM pumps are often PWM controlled or variable frequency drives so you can make a controller with an Arduino. The good thing about the T-D pump is that it is PV controlled for speed but the bad thing is there is no feedback about it so you don't really know how it is doing other than manually looking at gauges.