Feeding Chiller from Siphon Drain

[ca1ore]

No, as I noted previously, the temp probe for this chiller is inside the chilling chamber.

 

[ca1ore]

Based on the recommended flow rates for the unit, I bet you're not going to see much/if any loss of flow with it.

I have come to a similar conclusion. Thus I will try it on the main return and if it does materially detract from flow I will go from there. In retrospect, I rather wish I had bought the 1/2hp version. Would have been sufficient and less difficult to feed. Oh well.

 

[mcarroll]

I have come to a similar conclusion. Thus I will try it on the main return and if it does materially detract from flow I will go from there. In retrospect, I rather wish I had bought the 1/2hp version. Would have been sufficient and less difficult to feed. Oh well.

Put it on the market and wait for a seller. Downgrade with you find one.

 

[ca1ore]

An interesting observation, to wit ....

When I upsized from a 265 to my current 450 I assumed (always dangerous) that both my heating and cooling requirements would go up, thus the bigger chiller and more heaters. What I found was twofold. One, the ratio of surface area to volume goes down as you go bigger so heat gain or loss to the environment is less per net gallon. Two, since I went from a glass tank 12 mm thick to an acrylic 1" thick, the insulating properties went up. Clearly I'm a complete dumb butt for not anticipating both ahead of time LOL.

 

[mcarroll]

An interesting observation, to wit ....

When I upsized from a 265 to my current 450 I assumed (always dangerous) that both my heating and cooling requirements would go up, thus the bigger chiller and more heaters. What I found was twofold. One, the ratio of surface area to volume goes down as you go bigger so heat gain or loss to the environment is less per net gallon. Two, since I went from a glass tank 12 mm thick to an acrylic 1" thick, the insulating properties went up. Clearly I'm a complete dumb *** for not anticipating both ahead of time LOL.

Good observations nonetheless! Thanks for sharing!!

 

[kirbuno]

They call that experience. [emoji3]

 

[mcarroll]

They call that experience. [emoji3]

time ( mistake + learning ) = experience

 

[ca1ore]

So I ended up choosing to run my main return through the chiller instead of using the drain. I was able to further remove some plumbing constraints from the pressure side of my PW200 so as to only lose about 50 gph from the net. Still 1,300 on 400 net display gallons; quite sufficient. Hopefully will improve the function of the chiller with more flow. I have no way to easily enlarge the suction side of this pump. It's 1" and 1 1/2" out; not something one would typically recommend, though the 15' of net head on the output negates any possible cavitation problems.

 

[mcarroll]

It's 1" and 1 1/2" out

How do you calculate the effect of friction losses on the inlet @Brew12? ....after accounting for the pipe diameter, is it still mostly a function of pluming length?

If so, then it seems like if it's only a foot or two of inlet then the effect might be insignificant. (< +1 feet of head pressure vs 1.25" inlet plumbing)
http://www.freecalc.com/fric.htm

Pressure Loss (psi): 0.29 Head Loss (ft): 0.6
Line Number:
Date: 5/18/2018
Nominal Pipe Size: 1
Pipe Schedule: SCH 40
Flow Rate (gpm): 23
Viscosity (cP): 1
Specific Gravity (water=1): 1.025
Temperature (F): 79
Pipe Roughness (ft): 0.00015
Actual Pipe ID (in.): 1.049
Fluid Velocity (ft/sec): 8.54
Reynolds Number: 71075
Flow Region: Turbulent
Friction Factor: 0.025
Overall K: 0.57
Piping Length (ft): 2

Pressure Loss (psi): 0.07 Head Loss (ft): 0.2
Line Number:
Date: 5/18/2018
Nominal Pipe Size: 1.25
Pipe Schedule: SCH 40
Flow Rate (gpm): 23
Viscosity (cP): 1
Specific Gravity (water=1): 1.025
Temperature (F): 79
Pipe Roughness (ft): 0.00015
Actual Pipe ID (in.): 1.38
Fluid Velocity (ft/sec): 4.94
Reynolds Number: 54027
Flow Region: Turbulent
Friction Factor: 0.025
Overall K: 0.43
Piping Length (ft): 2

In fact, if this is correct, then the calc suggests that even if the inlet were 3/4" there'd only be +2 feet of head loss. Seems like that should be incorrect....feels like it should be a lot more at 23 GPM...

Pressure Loss (psi): 0.99 Head Loss (ft): 2.2
Line Number:
Date: 5/18/2018
Nominal Pipe Size: 0.75
Pipe Schedule: SCH 40
Flow Rate (gpm): 23
Viscosity (cP): 1
Specific Gravity (water=1): 1.025
Temperature (F): 79
Pipe Roughness (ft): 0.00015
Actual Pipe ID (in.): 0.824
Fluid Velocity (ft/sec): 13.84
Reynolds Number: 90483
Flow Region: Turbulent
Friction Factor: 0.026
Overall K: 0.75
Piping Length (ft): 2

 

[Brew12]

How do you calculate the effect of friction losses on the inlet @Brew12? ....after accounting for the pipe diameter, is it still mostly a function of pluming length?

If so, then it seems like if it's only a foot or two of inlet then the effect might be insignificant. (< +1 feet of head pressure vs 1.25" inlet plumbing)
http://www.freecalc.com/fric.htm




In fact, if this is correct, then the calc suggests that even if the inlet were 3/4" there'd only be +2 feet of head loss. Seems like that should be incorrect....feels like it should be a lot more at 23 GPM...

Those numbers look pretty good to me. I suspect that if you kicked flow up to 25gpm you would see the friction impact skyrocket. The impact of pipe friction shouldn't start becoming a significant factor until you get close to the maximum flow rate of the pipe.

 

[ca1ore]

The effort necessary to properly enlarge the suction side piping is significant - more than I am willing to entertain. It would require draining down the sump, over-grinding a bigger hole (while hoping the bottom wasn't tempered - it's an old tank so nobody to ask). As it turns out, the net flow has stabilized at around 1,320 ..... versus 1,350 prior to going through the chiller. Much less of a loss than, frankly, I was anticipating. Upsizing to 1 1/2" flex on all the return lines was one of the best things I ever did to recover some flow.

 

[ca1ore]

Those numbers look pretty good to me. I suspect that if you kicked flow up to 25gpm you would see the friction impact skyrocket. The impact of pipe friction shouldn't start becoming a significant factor until you get close to the maximum flow rate of the pipe.

That makes intuitive sense to me - probably why I saw such a sizable jump in net flow when I replaced 1" vinyl hose/barb fittings with 1 1/2" flex PVC for the entire return run.

 

[Brew12]

That makes intuitive sense to me - probably why I saw such a sizable jump in net flow when I replaced 1" vinyl hose/barb fittings with 1 1/2" flex PVC for the entire return run.

Barbed fittings are your enemy when it comes to flow!

 

[ca1ore]

True!