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Unread 02/06/2018, 10:03 PM   #5
outy
Moved On
 
Join Date: Oct 2004
Location: auburn CA
Posts: 4,021
Quote:
Originally Posted by mikluha View Post
Well, if these numbers are correct and both pumps produce same output power (i.e. head pressure, water flow) then Iwaki pump should produce 160W-50W = 100W of heat. Assuming 100% efficiency of Jebao pump.

Such pump would glow in the dark. Or produce really warm water.
Iwaki's do run hot, this pump you can keep your hand on and its not hot per say but it is a little more than just warm. Never warmed my water were I noticed in over a decade of use.

I have an Iwaki MD15 and that little sucker runs extremely hot, hands on pump is almost burning but I can keep it there. These small Iwaki's are judged by how many seconds you can keep your hand on, and they give warnings of just how hot they run.


As far as output, I turned down the DC pump until I matched flow, which ended up being 55W measured at the wall.

The difference here is the impeller design. The whole DC impeller probably weighs 30 X less then the Iwaki pump. Difference here is the Iwaki will last decades and the Jeboa might not last a decade, that and due to impeller design, the Iwaki has much higher head height and flow, the DC pump is almost at its limits.

Quote:
If order to verify all these claims, one needs to carefully measure flow rate and water pressure in order to calculate pump output power.
Its already done, I run my ATS off my drain return which has an overflow based on flow and with each I get a trickle out of the overflow showing 100% exact flow. Again I dialed the DC pump to match the exact flow.

Quote:
In reality, both brushless DC motors and AC motors has very close efficiency.
In a perfect world with identical designed impellers and pump designs, maybe so.

But we are talking about different pump designs and different impellers, and I'm curious if an AC pumps could be built to match said efficiency. At this point without the adjustability, its hard to say.

Quote:
However, it has nothing to do with pump efficiency.
Agreed. Bottom line is $, electricity money to be exact. Enough to buy 2 DC pumps a year.

The trade off is reliability. To date, no affordable DC pump has the reliability of Iwaki which is one of the best AC pumps on the market.


Quote:
BLDC pump is sufficient and Iwaki is overkill
I never used to worry about the electricity bill, and if one wanted a great basement pump, one bought one of these high wattage pumps, It was all we had. Finally the DC pumps have advanced enough and prices have came down low enough, its actually cost effective to switch methods. Glad I did.


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