DC vs. AC pumps

[02tts]

After reading many threads I'ma little confused on these new DC pumps.

From what I can decipher they run quieter but do not last as long as AC pumps, compared to Panworld, Iwaki's, Little Giants and Blue Line anyway. Is this your experience?

Also, what about heat transfer, I've heard some people complain that the DC pumps add more heat to the water vs AC pumps...but I'd have to question that because from what I can see, these DC pumps can use half the wattage as a comparable AC pump. I realize AC pumps like the Blue Line have a fan, which makes the pump annoyingly loud but it's still double the wattage as some DC pumps so I have to think that heat would transfer into the water, fan or no fan.

Any thoughts from folks using both or those who have switched from any of the above brands to a DC pump from AC or back to AC from a DC...does DC add more heat to the tank? or is this not true? Is the reliability there?

A thread I read was someone comparing a Blue Line pump to a Vectra DC pump, where the Vectra added 1 degree to the water...not sure of the size of the tank in question. The vectra was externally mounted.

Look forward to your thoughts.

 

[USC-fan]

Only way ac would not heat up more, it would have to be an external air cooled pump. Most of these pump are louder and run very hot to the touch.

DC pump will be the quietest and use less power. Not sure about reliability but do not see many people on here complaining about DC pump failure. Also DC current is safer than AC.

Another thing about DC pumps, a lot of them can be controlled. I have a valve on my AC return pump so i can turn down the flow but this also cuts back on the max flow. With a DC controllable pump i wouldn't need this.

 

[02tts]

Correct, the pumps I'm referring to above are all external air cooled pumps, some have fans like the Blueline, some do not. But they are annoyingly loud and I question whether the amount of heat transfer is not the same given the DC pumps use less power....i.e. a DC 12000 or 15000 runs about 130-134W, where as a comparable Blueline or Panworld, etc. run at 390+

I'm seriously considering the DC route but I would like to hear from those who have used both and their findings, particularly with the vectra pumps.

 

[Jade5051]

After reading many threads I'ma little confused on these new DC pumps.

From what I can decipher they run quieter but do not last as long as AC pumps, compared to Panworld, Iwaki's, Little Giants and Blue Line anyway. Is this your experience?

Quieter yes. Haven't had one break down on me yet and it's hard to be that longevity of those external pumps.

Also, what about heat transfer, I've heard some people complain that the DC pumps add more heat to the water vs AC pumps...but I'd have to question that because from what I can see, these DC pumps can use half the wattage as a comparable AC pump. I realize AC pumps like the Blue Line have a fan, which makes the pump annoyingly loud but it's still double the wattage as some DC pumps so I have to think that heat would transfer into the water, fan or no fan.

Any thoughts from folks using both or those who have switched from any of the above brands to a DC pump from AC or back to AC from a DC...does DC add more heat to the tank? or is this not true? Is the reliability there?

DC pumps transfer less heat in my experience. I haven't used an external AC pump like the ones above I hear the heat transfer is minimal.

A thread I read was someone comparing a Blue Line pump to a Vectra DC pump, where the Vectra added 1 degree to the water...not sure of the size of the tank in question. The vectra was externally mounted.

Look forward to your thoughts.

I prefer DC pumps because they are adjustable, quiet and energy efficient. I don't mind replacing them more often. If sound and energy were not a concern I'd go with something else. In most of my builds sound is the largest priority.

 

[ca1ore]

External, fan cooled pump will transfer very little heat to the tank.

In terms of blueline/panworld versus Vectra - it depends. I run both and don't find either to add measurable amounts of heat to the tank. Haven't had the Vectra all that long, so I may have a different view once the Summer comes. Also, keep in mind that a pump run submerged will essentially transfer all of its heat to the water; whereas it will not if run externally.

 

[DDon]

I moved from Reeflo snapper/dart run externally on my 240 to a Vectra L1 run internally on my 270. Without a doubt the Vecrta is quieter (though comparing external vs. internal is not a direct comparison) and more energy efficient. Haven't experienced any temp issues with the DC pump. Too early to tell on reliability of the Vectra. The Reeflo was reliable but did have seal issue. Like was already mentioned no discharge valve needed with DC pump since it is adjustable.
For me, quiet and energy efficient are wins due tank being locates in living room with everything in the stand and high energy rates here.

 

[02tts]

DC vs. AC pumps

External, fan cooled pump will transfer very little heat to the tank.

In terms of blueline/panworld versus Vectra - it depends. I run both and don't find either to add measurable amounts of heat to the tank. Haven't had the Vectra all that long, so I may have a different view once the Summer comes. Also, keep in mind that a pump run submerged will essentially transfer all of its heat to the water; whereas it will not if run externally.

True, but the vectra can be run as an external pump can it not?

 

[02tts]

I moved from Reeflo snapper/dart run externally on my 240 to a Vectra L1 run internally on my 270. Without a doubt the Vecrta is quieter (though comparing external vs. internal is not a direct comparison) and more energy efficient. Haven't experienced any temp issues with the DC pump. Too early to tell on reliability of the Vectra. The Reeflo was reliable but did have seal issue. Like was already mentioned no discharge valve needed with DC pump since it is adjustable.
For me, quiet and energy efficient are wins due tank being locates in living room with everything in the stand and high energy rates here.

My tank is going into the family room/living room, since it's a big open area but I need it to be a quiet build or I'll never hear the end of it from the wife.

How's that go, happy wife = happy home...

 

[ca1ore]

True, but the vectra can be run as an external pump can it not?

Indeed, that's how I run mine. I have not historically been a fan of internal pumps , other than the occasional purpose small powerhead or wave makers.

 

[karimwassef]

I used to use all AC pumps... Reeflo, Iwaki (Japanese and US), Little Giant, Fluval, and Dolphin.

Now I've migrated to nearly 100% DC pumps - Waveline and Jebao (yes).

They're:

Much quieter
Consume less power
Generate less heat
Have controllable flow (another way to reduce power and heat)
Are more compact relative to the flow
Easier to maintain (if you've had to change a diamond seal on a dolphin, you know what I mean)
Less expensive (allows for easy backup systems)
Low cost replacement parts (power supplies, impellers)
Much safer
Don't need electrolytic capacitors replaced (big AC)
Can be backed up with a battery in case of a loss of AC mains power (no UPS needed)

They have some challenges:

1. Reliability - this isn't because the technology is inherently less reliable. It's because the aquarium hobby manufacturers are still learning and it takes time to get quality up to par. Those that do it well, charge an obscene price because the others haven't figured it out yet.
These pumps are also 'smarter' and use sequenced pulses to turn. If they jam and experience resistance in turning, they sense it and stop. This manifests itself in the pump trying to turn ... Failing... Then quitting. An AC pump would have powered through - even to the point of failure. The DC pump needs to be cleaned, or the seal is damaged, or it needs a new impeller. To overcome this, I add redundant loops and keep spares. No issues with that yet after two years.

2. Nothing else.

In time, I expect this will be the dominant pump tech in the hobby.

 

[02tts]

Thanks, I think I'm going to try the DC pumps first and hope it doesn't create a large temperature increase, otherwise I'd have to switch to Blueline or Panworlds...I just think they are too loud for my taste.

As I get older I get pickier - 10 years ago I didn't care as much :uhoh3:

 

[02tts]

Indeed, that's how I run mine. I have not historically been a fan of internal pumps , other than the occasional purpose small powerhead or wave makers.

How do you like your vectra pump...is it worth the cost vs. the other available DC pumps? What would be your other choices?

 

[karimwassef]

I hear you. 15 years I wasn't married... Now she's a lot pickier

 

[ca1ore]

How do you like your vectra pump...is it worth the cost vs. the other available DC pumps? What would be your other choices?

I really like the Vectra. I use it as an in stand closed loop pump and it moves a ton of water, is absolutely silent and ramps up and down just like my vortechs. I'm a long time reef guy and am very cautious with new tech, so I've not tried any other DC pumps. Plus my sump is in the basement so I need a high head pressure pump for that. I consistently get 10 plus years out of my AC externals; something nobody can yet claim for any of the DC pumps, even the Vectra.

 

[sleepydoc]

I currently have a Waveline DC1000 II pump and have also used a Fluval SP4 (AC) pump and a Octopus OTP AC pump. The octopus was actually dead quiet but didn't pump nearly as much water as the Fluval or the Waveline pumps. I had the Fluval pump as a circulation pump, and compared to the Waveline, it had a bit more vibration, but was actually quieter if I isolated the pipes so they didn't vibrate against the stand, the pump itself was virtually silent.

The DC10000 II pumps more water than the Fluval and doesn't have the vibration but actually has a soft, high-pitched whine when it's running, so of the two i'd have to say that the Fluval was the quieter, assuming you could keep the vibrations isolated.

DC pumps have the advantage of better controllability - you can adjust the flow up and down rather than just throttling the pump with a valve, and the DC10000II can directly interface with a neptune controller. It also has a soft start and a feed mode, which are very convenient and no AC pump has to my knowledge.

In terms of power consumption, I haven't hooked up a Kill-a-watt to compare the two. The Fluval is 88W for 1800 GPH @ 0 head vs 95W for 2800 GPH @ 0 head for the DC10000II, so the Waveline is more efficient (at least based on specs.)

A couple other factors to consider with power consumption are the power supply and the variable speed of the DC pumps. The power supply for the Waveline consumes about 10W, which you pay the electric company for, but doesn't contribute to heating of the water, so at full speed you're only adding 85W to the water (when used as a submerged pump.) The variable speed lets you dial that down if you don't need the full flow, further reducing power consumption and heat transfer.

When used as an external pump, it would depend on the pump design and how much heat the pump transfers to the water vs the air used to cool the pump. I haven't seen any comparisons of AC vs DC pumps in this regard.

As far as reliability is concerned, the DC pumps are still relatively new compared to workhorses like the Iwaki & Panworld pumps. Early DC pumps had a lot of reports of failures. From what I've read it seemed to be failure of the power supplies, possibly due to inadequate cooling rather than the pump itself. The newer generation Waveline pumps have a much improved heat sink design on the power supply (see the pic on their web site) that also allows for better air circulation. I haven't seen the reports of failures of the newer generation of pumps, so they may have resolved these issues.

So in summary:
AC pumps
- better (at least known) longevity
- potentially quiet, depending on model
DC pumps
- more efficient
- quiet, but many people bothered by the high-pitched whine
- better/more flexible controllability
- better ability to interface with Apex (depending on model)
- questions on long term reliability

 

[karimwassef]

good point on using control!

With an AC pump, I would use a valve to constrict flow. That only consumed more power or the same power, generated more or the same heat and had no effect on noise.

With a DC pump, when you throttle down the power, the pump goes slower and consumes less power and generates less heat and gets quieter.

 

[02tts]

I currently have a Waveline DC1000 II pump and have also used a Fluval SP4 (AC) pump and a Octopus OTP AC pump. The octopus was actually dead quiet but didn't pump nearly as much water as the Fluval or the Waveline pumps. I had the Fluval pump as a circulation pump, and compared to the Waveline, it had a bit more vibration, but was actually quieter if I isolated the pipes so they didn't vibrate against the stand, the pump itself was virtually silent.



The DC10000 II pumps more water than the Fluval and doesn't have the vibration but actually has a soft, high-pitched whine when it's running, so of the two i'd have to say that the Fluval was the quieter, assuming you could keep the vibrations isolated.



DC pumps have the advantage of better controllability - you can adjust the flow up and down rather than just throttling the pump with a valve, and the DC10000II can directly interface with a neptune controller. It also has a soft start and a feed mode, which are very convenient and no AC pump has to my knowledge.



In terms of power consumption, I haven't hooked up a Kill-a-watt to compare the two. The Fluval is 88W for 1800 GPH @ 0 head vs 95W for 2800 GPH @ 0 head for the DC10000II, so the Waveline is more efficient (at least based on specs.)



A couple other factors to consider with power consumption are the power supply and the variable speed of the DC pumps. The power supply for the Waveline consumes about 10W, which you pay the electric company for, but doesn't contribute to heating of the water, so at full speed you're only adding 85W to the water (when used as a submerged pump.) The variable speed lets you dial that down if you don't need the full flow, further reducing power consumption and heat transfer.



When used as an external pump, it would depend on the pump design and how much heat the pump transfers to the water vs the air used to cool the pump. I haven't seen any comparisons of AC vs DC pumps in this regard.



As far as reliability is concerned, the DC pumps are still relatively new compared to workhorses like the Iwaki & Panworld pumps. Early DC pumps had a lot of reports of failures. From what I've read it seemed to be failure of the power supplies, possibly due to inadequate cooling rather than the pump itself. The newer generation Waveline pumps have a much improved heat sink design on the power supply (see the pic on their web site) that also allows for better air circulation. I haven't seen the reports of failures of the newer generation of pumps, so they may have resolved these issues.



So in summary:

AC pumps

- better (at least known) longevity

- potentially quiet, depending on model

DC pumps

- more efficient

- quiet, but many people bothered by the high-pitched whine

- better/more flexible controllability

- better ability to interface with Apex (depending on model)

- questions on long term reliability

This is great info, thank you for taking the time to write up. Maybe I'll toy with the idea of a blue line for return and DC pump for in sump skimmer, this way I get the best of both worlds with the reliability for the return which is more important. Hmmm, may require some more research on the vectra which can be used as an external pump..I could always have a small computer style fan on low speed move enough cfm to cool the pump. Noise is a big concern and so is heat as I don't want to have to use a chiller.

On my last 240 build I had, I had a reeflo which not only added noticeable heat to the water, 2-3 degrees but also leaked within the first year. Panworld was good to me and so were blue line, only complain was the high speed fan noise as without the fan the pump didn't make too much of a noticeable sound.

I do thank you for the feedback, much obliged.

 

[02tts]

DC vs. AC pumps

good point on using control!

With an AC pump, I would use a valve to constrict flow. That only consumed more power or the same power, generated more or the same heat and had no effect on noise.

With a DC pump, when you throttle down the power, the pump goes slower and consumes less power and generates less heat and gets quieter.

Not sure that would be true...I believe piping it with a valve after the exhaust would slow the revolutions down thereby decreasing the amount of heat exhausted and power required. At least that's the way I see it, I can't speak for the power aspect as to wether the consumption is the same or not. Maybe someone who understands electricity and/or physics concepts can chime in.

What I do know is that if a DC pump, for example is 84-95w, a comparable Blueline is 390 watts...taking physics principles out I'd have to think this would equate to ac pumps transferring more heat into the water, but I could be wrong - wouldn't be the first time

 

[karimwassef]

I have AC and DC pumps connected to my Apex. So I can see the change in power consumption when I throttle one back using a DC controller and the other AC pump using a valve.

On the DC, the power clearly drops.
On the AC, the power stays the same (but it is a Dolphin pressure pump, after all)

 

[02tts]

Good to know.
I can see why DC is making more and more sense.

How hot does your ac pump get in comparison to your dolphin and does the dolphin have an external fan built in?