What would I use to make a heatsink for my dart pump?

Blue_Ribbon

New member
Hi,

I'm looking to either build an aluminum heat sink or buy some sort of prebuilt sink that will fit around the motor on my reeflo dart pump.

I searched a bit on the net and found zip. :(


I love my cl system and the dart, but I know it's probably adding 3-4 degrees to the tank temp. The outer casing of the motor is very hot to the touch, it always has been from day 1 of it's unpacking from the box years ago.

As far as building one, I'm thinking of finding some "T" shaped aluminum panels, and cutting a slot in the vertical leg of the "T" near the top by the horizontal leg to accept a large 8" stainless steel hose clamp. I'm figuring 1/8" thick aluminum with around a 1/4" width on the horizontal part of it and making cutouts for around the cooling vents on the motor.

I could use some input if ayone has any ideas or experience. I'm still surprised that I could not find some sort of pre-made heatsink, this , if it works could be invaluable not just for my dart, it wuld help to reduce tank temps influennced by external pumps..
 

Pyrrhus

New member
Unforutunately adding a heatsink to a reeflo pump wont do much if anything to reduce water tempertatures. The volute (where water actually passes) doesnt get hot except for some stray heat from the impeller shaft seal.

The motor doesnt actually contact the water in any way and is in fact air cooled, not water cooled. The older Dart pumps had heatsinks built into the motor, but there is no differrence between them in terms of water temp increase.
 

Blue_Ribbon

New member
<a href=showthread.php?s=&postid=15528900#post15528900 target=_blank>Originally posted</a> by Pyrrhus
Unforutunately adding a heatsink to a reeflo pump wont do much if anything to reduce water tempertatures. The volute (where water actually passes) doesnt get hot except for some stray heat from the impeller shaft seal.

The motor doesnt actually contact the water in any way and is in fact air cooled, not water cooled. The older Dart pumps had heatsinks built into the motor, but there is no differrence between them in terms of water temp increase.


Hi, I do realize it is just the impeller that is transferring heat into my sysem and that if the motor housing is very hot to the touch, the impeller shat must be hotter.

Think of it as a 130+ degree probe in your water 24/7. Now what happens if you reduce it's temp by30-40 degrees? It's much less of a hot item transferring heat into my tank.

I know it's adding 3-4 degrees to my tank (it's just a lil 250g reef). I'm just looking for a quick fix to my temp problem this summer as part of my house is being remodeled and I have no AC to run through my hood to keep the lights cool.

I only need to lose 3-4 degrees to get back to a stable 80 degrees, the tank is in my basement and at 90 degrees upstairs/outside, it's 85 when the lights go out after an 8 hr photoperiod..

You dont think I could lose 2-3 degrees with a heatsink?
 

BigJay

New member
No, I don't.

1. You would do better to run a couple of cooling fans blowing air across the top of the tank (under the halides), and maybe one blowing across the dart if you're worried about it.

Evaporative cooling doesn't require the surrounding air to be cold.

2. Cut your photoperiod until the end of summer and your remodel is finished. Your corals will do perfectly fine with a 5 hour long photoperiod. Stagger your lights so they come on 1-2 hours apart, for a total run time of 5 hours for each bulb.

Less heat in the tank + less electric consumption = lower electric bills = more money for you to buy more corals.
 

mukymuk

New member
When your tank is 85 degrees when the lights go out, what is the ambient temp in your basement?

If the basement is well ventilated and not humid, you could probably put a strong fan on your tank and get the 3-4 degree's you're looking for.
 

Blue_Ribbon

New member
<a href=showthread.php?s=&postid=15529692#post15529692 target=_blank>Originally posted</a> by BigJay
No, I don't.

1. You would do better to run a couple of cooling fans blowing air across the top of the tank (under the halides), and maybe one blowing across the dart if you're worried about it.

Evaporative cooling doesn't require the surrounding air to be cold.

2. Cut your photoperiod until the end of summer and your remodel is finished. Your corals will do perfectly fine with a 5 hour long photoperiod. Stagger your lights so they come on 1-2 hours apart, for a total run time of 5 hours for each bulb.

Less heat in the tank + less electric consumption = lower electric bills = more money for you to buy more corals.

I do run a fan 24/7 blowing air into the hood from the basement air and discharge it from the hood to the outside via a 4" dryer style (not connected to my dryer or its dryer vent)vent.


Your point on evaporative cooling is taken though as you and the othr guy who replie are right, more air movement will help. *starts looking for a 6" fan instead of the 4" O have for the hood*

I run my lights at night also, maybe I should turn around the booster fan on my dryer vent style discharge into an intake and blow the 60-70 degree air across my tank.

thanks for the chaange in direction all.
 

BigJay

New member
Cutting your photoperiod will do more good than the fans.

Seriously, I run my halides for 6 hours and my actinics for 8 hours (one hour before and after the halides). My corals are fine.

See if you can put the 4" fan that you have near your dart pump to keep it cooler as well.
 

BeanAnimal

Premium Member
<a href=showthread.php?s=&postid=15529612#post15529612 target=_blank>Originally posted</a> by Blue_Ribbon
Hi, I do realize it is just the impeller that is transferring heat into my sysem and that if the motor housing is very hot to the touch, the impeller shat must be hotter.

Think of it as a 130+ degree probe in your water 24/7. Now what happens if you reduce it's temp by30-40 degrees? It's much less of a hot item transferring heat into my tank.

I know it's adding 3-4 degrees to my tank (it's just a lil 250g reef). I'm just looking for a quick fix to my temp problem this summer as part of my house is being remodeled and I have no AC to run through my hood to keep the lights cool.

I only need to lose 3-4 degrees to get back to a stable 80 degrees, the tank is in my basement and at 90 degrees upstairs/outside, it's 85 when the lights go out after an 8 hr photoperiod..

You dont think I could lose 2-3 degrees with a heatsink?

There is no way that the dart pump is adding 3-4 degrees to your system through the impeller shaft.. There is not enough surface area to transfer that much heat.

The movment of the water itself in the tank and in the pump volute creates heat (friction) that do heat the water, but there is no way around this :)

Even if the shaft was moving a significant amount of heat to the water, adding an external heatsink would have little effect.

Is your DART inside of the stand?

What type of lighting?

How many watts of lighting?

How many other pumps, powerheads, etc?

Is the tank covered?

Glass lids?

Hood airflow?

How much evaporation per day (gallons in 24 hours)?

Ambient room temperature?

Targer tank temperature?
 

frank40

Premium Member
i agree, the dart is not adding that much heat to your system.did you try reversing your lighting schedule? instead of the lights on during the day, put them on in the middle of the night when temps are cooler.
 

pecan2phat

Active member
I agree that the shaft should not be able to add that much heat to your water column but I also run a dart on an OM-4way and I noticed when I shut down the pump & closed loop a day and a half due to a leak in one of the pvc pipe plumbing, the tank temp went down exactly 2 degrees.
Never knew external magnetic or centrifugal pumps added any noticeable heat to the water column.
 
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