unsure about performance of pump under 0c

[Helldx]

Hello all its my first post in this forum. It looks like an awsome community :)

Ok here is my question:

I am curently finishing my a/c to chiller conversion. I hit temps at the evap of -23C so i should assume that fully submerge it will go down towards -30ish if lucky -40ish.

Now the probleme is the following. My pump is the mcp665 from swiftech. it is rated at 0c so I am getting worried that at sub-zero temps it will mal-function is not just totally brake or stop.

If any other people here have any experience with using this pump for a water-chiller going sub-zero, please let me know

Any other comments also would be apreciated

Thanks alot !

[epion2985]

Hello all its my first post in this forum. It looks like an awsome community :)

Ok here is my question:

I am curently finishing my a/c to chiller conversion. I hit temps at the evap of -23C so i should assume that fully submerge it will go down towards -30ish if lucky -40ish.

No. If your evap is at -20C, then your coolant will probably be around -15C. The difference is in efficiency of your heat exchanger given your system can handle the load. If its just a window ac job dunking the evap in a rez thats not that great). With good load it will be more like -5C, and your actually core will probably be around 10C.

Now the probleme is the following. My pump is the mcp665 from swiftech. it is rated at 0c so I am getting worried that at sub-zero temps it will mal-function is not just totally brake or stop.

If any other people here have any experience with using this pump for a water-chiller going sub-zero, please let me know

Any other comments also would be apreciated

Thanks alot !

Haven't seen what pump used on a chiller yet but have seen others fail, shattered body or impeller, leak, die, etc.

Try something more serious. Iwaki or Panworld mag pumps are great. Panworld 40PX is great if you are on a budget.

[Helldx]

I just found this pump for pretty cheap . Any comments on it, performance and the most important qs, will it run below-20c

http://www.marinedepot.com/md_viewItem.asp?idproduct=DN1121

[epion2985]

maybe, but probably not for long. I can't give you a sure answer but I wouldn't hold my breath if I were you.

You want something more like this:
http://www.premiumaquatics.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=PW-40PX&Category_Code=Panworld

[Helldx]

thanks for the link. Your hekp was really appreciated

[Ramaistro]

At home I have 2 pumps from the inside of an Boiler/kettle ( in Dutch it is CV ketel ) the pumps have massive headpressure, a piece of tube was dancing when I putted the power on.:fact: So maybe you can search for an old one at a company that installs new ones and removes old ones. Mines are almost completly out of metal and can survive 80°C, so i gues they can handle some cold too.

[epion2985]

At home I have 2 pumps from the inside of an Boiler/kettle ( in Dutch it is CV ketel ) the pumps have massive headpressure, a piece of tube was dancing when I putted the power on.:fact: So maybe you can search for an old one at a company that installs new ones and removes old ones. Mines are almost completly out of metal and can survive 80°C, so i gues they can handle some cold too.

Just because they can handle heat does not mean they can handle cold. In fact It's probably the opposite.

Also a huge pump means huge heat dump usually, which would destroy your chillers cooling capacity.

[Ramaistro]

Just because they can handle heat does not mean they can handle cold. In fact It's probably the opposite.

Also a huge pump means huge heat dump usually, which would destroy your chillers cooling capacity.

Yes I know what you mean but I said it because the pump is from metal and not plastic what has led for problems in the past.

I indeed forgot about the heatdump but maybe worth a try.

[Helldx]

ok well i talked to a representant of swiftech and he said they dont have any records of test with that low temps. he said it might work but condensation in the electrical components might be risky. so what i will do as he sugested is put a generous amount of dieletric grease in the electrical components. then what i thought i could do to touch it up is seal everything permanently with some industrial grade insulative adhesive. This will prevent leaks at least but seal the pump for ever !!!

so i might just give it a try. if it dies of leaks or what ever then ill buy the one that you proposed

[L33T]

:banana: :banana: :banana: :banana: :banana:

[epion2985]

ok well i talked to a representant of swiftech and he said they dont have any records of test with that low temps. he said it might work but condensation in the electrical components might be risky. so what i will do as he sugested is put a generous amount of dieletric grease in the electrical components. then what i thought i could do to touch it up is seal everything permanently with some industrial grade insulative adhesive. This will prevent leaks at least but seal the pump for ever !!!

so i might just give it a try. if it dies of leaks or what ever then ill buy the one that you proposed


Another problem is they use materials that are not meant to low temperatures, meaning they get very brittle and shatter easily on small impact or vibration. There were pictures somewhere here or on OCF of a pump housing that cracked down the side, and another of a shattered impeller.

Also a problem might be different parts shrinking at different rates causing all seals and even glued or self reinforced joints to break apart.

Good luck. Just don't think you are safe if it works for a few days, it may be a few months or a year before it will spring a leak. This is the worst part, there is no way of knowing how long it will work, just because it will work doesn't mean it wont bite you later when you are not paying attention and ruin some hardware.

[Helldx]

Another problem is they use materials that are not meant to low temperatures, meaning they get very brittle and shatter easily on small impact or vibration. There were pictures somewhere here or on OCF of a pump housing that cracked down the side, and another of a shattered impeller.

Also a problem might be different parts shrinking at different rates causing all seals and even glued or self reinforced joints to break apart.

Good luck. Just don't think you are safe if it works for a few days, it may be a few months or a year before it will spring a leak. This is the worst part, there is no way of knowing how long it will work, just because it will work doesn't mean it wont bite you later when you are not paying attention and ruin some hardware.

Thanks for the heads up :)

Anyways i know it willeventually break leak or crack . maybe 1h maybe 1year. I will just try to make it hold till i can afford the pump you recomended me. wont take long maybe 1-2 weeks .

[thesaucier]

Thanks for the heads up :)

Anyways i know it willeventually break leak or crack . maybe 1h maybe 1year. I will just try to make it hold till i can afford the pump you recomended me. wont take long maybe 1-2 weeks .


Come on back and let us know how it went with that pump. :worm:

[{.bLanK} GoD]

I've used an ehiem 1250 in my -30°C chiller for nearly a year and it was still going strong when i disassembled the chiller. :2cents:

[K404]

90% of the Iwaki pumps are only rated to 0, if they were good sub-zero (and evidence says they are) you`d think they`d shout it from the rooftops

http://www.iwakipumps.jp/e_products/e_magnetic/e_md.html

I want to buy one, but i`m worried about temperatures seeing as they dont officially work sub-zero.

Tempted by an Eheim if Blank has had no hassle with his

[epion2985]

90% of the Iwaki pumps are only rated to 0, if they were good sub-zero (and evidence says they are) you`d think they`d shout it from the rooftops

http://www.iwakipumps.jp/e_products/e_magnetic/e_md.html

I want to buy one, but i`m worried about temperatures seeing as they dont officially work sub-zero.

Tempted by an Eheim if Blank has had no hassle with his

The thing with high quality professional products is that they are seriously underrated. While iwaki's are indeed rated to 0C, they go deep below with no problems. Which is more then I can say for most of the cheap pc water cooling pumps.

While his Eheim is fine so far it doesn't mean it will be tomorrow, nor does it mean you will have the same experience. The problem with lower quality products is they are not consistent.

[{.bLanK} GoD]

The thing with high quality professional products is that they are seriously underrated. While iwaki's are indeed rated to 0C, they go deep below with no problems. Which is more then I can say for most of the cheap pc water cooling pumps.

While his Eheim is fine so far it doesn't mean it will be tomorrow, nor does it mean you will have the same experience. The problem with lower quality products is they are not consistent.

I agree.
Just because mine has gone for a year and still does, doesn't mean yours will.
I'm just stating my evidence.
Mine is running in line by the way. I wouldn't be keen on submerging it in -30°C.
I will use it again when i build another chiller. And when or if it ever breaks down. I will post results on how, why and how long it has lasted. :)
If the price between an ehiem and an iwaki was significant, I would defiantly buy another ehem. :)

[epion2985]

I agree.
Just because mine has gone for a year and still does, doesn't mean yours will.
I'm just stating my evidence.
Mine is running in line by the way. I wouldn't be keen on submerging it in -30°C.
I will use it again when i build another chiller. And when or if it ever breaks down. I will post results on how, why and how long it has lasted. :)
If the price between an ehiem and an iwaki was significant, I would defiantly buy another ehem. :)

No need for iwaki, Panworld pumps which are pretty much the same pumps and are very affordable. Case and point 40PX (md20 equivalent) for $100 vs Eheim 1250 at $70. Peace of mind and a pump for life for $30 more is a mighty sweet deal in my book.

[{.bLanK} GoD]

No need for iwaki, Panworld pumps which are pretty much the same pumps and are very affordable. Case and point 40PX (md20 equivalent) for $100 vs Eheim 1250 at $70. Peace of mind and a pump for life for $30 more is a mighty sweet deal in my book.

If that is the case for every one then I totally agree. :)
But we all know that prices for just about anything can vary emensly when comparing the same item from different countries.

Next door to my work is the "Irrigation Warehouse". I was in there when I was looking to buy a pump for my chiller. We eventually tracked down a pump that was rated for sub zero temperatures, but it was huge in comparison to the ehiem and cost three times the price. :eek:

[epion2985]

If that is the case for every one then I totally agree. :)
But we all know that prices for just about anything can vary emensly when comparing the same item from different countries.

Next door to my work is the "Irrigation Warehouse". I was in there when I was looking to buy a pump for my chiller. We eventually tracked down a pump that was rated for sub zero temperatures, but it was huge in comparison to the ehiem and cost three times the price. :eek:

These guys ship anywhere in the world so no worries about local pricing.
http://www.premiumaquatics.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=Panworld

Yeah specialty pumps are very expensive. But iwaki/panworld aquarium pumps rated for 0C cold water fish tank's are sufficient for most peoples chillers. It seems it has mostly to do with softer plastics used that don't turn as brittle when at sub zero temperatures.

[KennethChong]

My Eheim was well above my expectations for what its worth. About a year and a half in a -40 chiller. Now that I think about it, its still sitting in the container in my storage shed from my last move. I wonder how 2 years of sitting in antifreeze has effected it. :eek:

[epion2985]

only one way to find out :)

PS:
Eheim's are really above the average WC pump don't get me wrong, I respect them for what they are.

[jaguarking11]

Maybe look up automotive pumps?

Davies Craig electric booster pump is designed for cars. Therefore its designed for pretty low temperatures as well as pretty high temperatures.

This is what I'm going to use when I build my chiller.
Link-> http://www.daviescraig.com/main/display.asp?pid=27

Its rated -40c to +135c

I'm using it for regular water cooling now and I am impressed by the quality and the torque of the motor. I'm using it @5v for complete silence.

I am no expert but the data makes sense.

[epion2985]

Damn thats awesome, where can I buy one and how much are they? How loud?

[npk]

http://www.spatechnique.com/product_pages/productdetails.asp?product=17-EBP9001|401

242 usd only :D

[epion2985]

damn, someone buy it and see how quiet it is :)

[jaguarking11]

damn, someone buy it and see how quiet it is :)

I paid squat for my pump. I got it free. The company sponsored me a pump.

Im unsure if you are being sarcastic however I happen to think this thing is actually a very decent pump. I am sure there are places that sell that pump for less. However as i sated before It is my opinion that automotive pumps should work very well for chillers being that they are designed to withstand extremes.

[jaguarking11]

How loud?

@5v its quieter than my psu on a quiet setting. My psu has a 120mm fan.

On comparison @5v the pump is on the same noise level as yate loon quiet fan. @12v its noisier but my pump is hard mounted so it will resonate simply because of the hard line tubing I use.

In comparison its quieter than my mcp600 running both @ 12v.

I don't know what else to compare it to.

[epion2985]

No sarcasm at all. I really want that pump right now, but the price to too much. Wish I could get it for a more reasonable amount.