PanWorld 200 vs. 250?

[ca1ore]

Probably a long shot, but anyone have any hands on experience with these two pumps. I'm having some issues with the 200 not being enough flow to properly feed my chiller. The 250 eats 100 more watts, has a higher head shutoff, but isn't rated at much more total flow. I suspect that with the head pressure on my system I'd see much better performance. Anyone use it?

 

[DLHDesign]

but isn't rated at much more total flow

200 is rated at 1750 GPH while the 250 is 1900 GPH. Which does seem like a smaller jump than some of their other pump models... The +6ft head pressure seems about inline with the flow rate jump...

I'm curious what kind of chiller setup you're running that isn't served by the 200? I'm running the 50PXX as my mixing-station pump and that thing moves water like a beast. For comparison; I run my chiller off my DT's return manifold and it only gets a fraction of my total flow (which is ~2000GPH from a COR-20 at 100%) yet is able to reduce my ~150gal tank a full degree in a matter of minutes...

 

[ca1ore]

I'm running a trade winds 3/4 HP chiller that requires between 1,080 and 2,700 GPH. In my setup, the PW200 nets me about 1,250. So, it's above the minimum for the chiller but only just. The chiller has no issues keeping the tank at the proper temperature, but it switches on and off a lot. Not technically short cycling I suppose, but more frequently than I'd like. Essentially the unit cools the internal volume of the exchanger faster than the incoming water. I've worked around this by programming a larger setback, but moving to a larger pump is a consideration also. Thus the musing on the PW250 or even a larger Iwaki. Just not sure either would improve the situation enough to be worth the cost. For other reasons, I'm limited to pumps that have a 1" suction thread, so reeflo and others aren't practical options (plus, I've become spoiled by the bulletproof panworld models).

 

[DLHDesign]

Gotcha. I've got a similar problem with mine (quick on/off cycles). I've been working on getting my tank temp lower via other means (less T5 lighting; more LED, more efficient return pump, better about cleaning pumps and such, etc.).
My goal is not so much chiller longevity as chiller efficiency. When my chiller kicks on, it doubles the overall energy draw of my tank, so I don't want it to run any longer than it needs to. As such, I have it set for a pretty low temp (72F, I think?) as a backup, and use the Apex to turn it on/off to get my tank temp to drop. I've not actually done any trials to see if there's a better way to use a chiller, to be honest... More flow makes sense, for sure. Mine is run off a manifold, so I'm only getting a fraction of the flow you've got...

Here's today's temp vs. power draw, for example. Each chiller spike is about an hour, I guess? :-\

 

[ca1ore]

The other issue with my chiller is that it pulls 13 amps - higher than any of the apex outlets can handle. I'd looked at a smaller chiller (1/2 HP) but couldn't find any that were native 1 1/2" PVC. 1" kills the flow. Maybe I will pick up a panworld 250 and experiment.