pump suggestion

[lastlight]

So here's the dealio:

Picked up a new chiller thanks to a super-generous Abchaos and now I need to bring it online. The chiller will be in the basement as close to the ceiling as possible to reduce head pressure and the pump will run externally next to it. I will need to get a siphon going to prime the pump but only once. The chiller requires about 500 gph (Pacific Coast CL-650) and I've been told the unit will add roughly 4 feet of head. Water will siphon from the sump to the pump next to the chiler then be pushed back to the sump. The vertical distance between sump and pump will be another 4 feet roughly.

I'm unsure if the 4 foot drop counts in head loss because in a way it's like putting a chiller inline in a closed loop. From what I understand a closed loop has no head loss and the pump could in theory be 4 feet below a tank or 50 feet.

I'm choosing an external install for two reasons: don't want to pay for a pump that's powerful enough AND quiet enough for the livingroom sump and space is tight in there as it is. I'd love to use another eheim internally but at 900 gph at zero head I doubt a 1262 would be up to this.

So before I spend a few dollars any suggestions?

I was thinking a mag 12 or quiet one 6000. I then have the luxury of valving each back a little if need be.

[sphelps]

The only head pressure will be from pipe friction so something rate at about 900gph will be perfect, just use a little bigger pipe if possible

[lastlight]

You think an eheim 1262 will do it?

If realistically I only have to worry about the head loss from the chiller I'd agree...if it turns out to be more than just the chiller head loss that pump won't be enough.

1262 is 80w and while they aren't very efficient these days they are reliable. The mag 12 is more flow in case there really is more head loss than just the chiller... but is 110W.

[PoonTang]

If possible why not just plumb it into the sump return pump?

[lastlight]

My sump return is actually an eheim 1262. I really have my doubts it could pump down into the chiller and out and maintain the 500 gph the chiller needs. Also I don't want to lower the turnover in the display. That'd be the head loss with the chiller plus more than 2m climb. Be lucky to get a trickle out of it I think.

[abcha0s]

I think the closed loop principal would apply.

I think a 1262 would be enough. I don't think it's critical that the flow through the chiller is exact. I think they specify the optimal flow for maximum efficiency, but it would be difficult to match it exactly.

The other thought that I had is that the recommended flow through the chiller probably has something to do with the internal temperature sensor. If you configure the set point a little lower on the chiller and use your Ranco, it might be fine to run with a lower flow rate.

- Brad

[abcha0s]

Originally Posted by lastlight

My sump return is actually an eheim 1262. I really have my doubts it could pump down into the chiller and out and maintain the 500 gph the chiller needs. Also I don't want to lower the turnover in the display. That'd be the head loss with the chiller plus more than 2m climb. Be lucky to get a trickle out of it I think.

I agree with that. If your planning to use a 1262, it would have to be an additional one.

[lastlight]

I think I will try and acquire another 1262 to at least give it a shot.

What does the set point do exactly? I haven't had a chance to read through the booklet yet lol. I want the thing to come on at 80 and cool until the tank is 79. Is 80 the set point?

I think I also read about people blowing fuses like crazy when the flow through the unit was not sufficient?

[abcha0s]

That is the set point I am referring to. I forget the details, but you also set the variance. The chiller is more efficient with a larger variance. I don't think it likes the constant on/off duty. They do explain it in the manual.

If your using an external temp controller, I would make sure that you don't set it to turn on and off too frequently. With the apex you can control temp to within +/- 0.2F - However I think that would be a bad idea. I think the minimum the chiller permits is +/- 0.5F

[lastlight]

Oh yeah I see. The ranco works with 1 degree F increments for the sensitivity.