Quote:
Originally Posted by pinballlooking
I went from adding about $100 a month to my power bill for my pool to adding $2 a month.
Well worth to change out. I even was able to sell my old pool pump.
|
Here's an objective look. I looked up a few pumps and this is what I was able to dig out. I was wrong on the mechanical efficiency guess on the low speed, but the difference is still de minimis. Pick your game. The more expensive, delicate and fragile or good coil and core both save about 1kW by switching to low speed. The difference in savings between uber expensive electronic motor vs time proven highly reliable coil&core pump in power savings is
reduction of running kilowatts by 1.04 vs 0.97 vs 0.87.
ECM pros:
Savings are roughly 1kW from switching from 3450 to 1725.
Saves 1.04kW while a very good non-electronic circuitry motor saves only 0.97kW
The ultra-low mode that saves an additional 0.14kW by turning down to 1,000RPM.
ECM cons:
Module failure means factory OEM parts required, probably $$$$$.
Susceptible to sudden failure by blowing power electronics.
May have extremely high THD, particularly odd harmonics from 3rd to 11th which is overall detrimental to power transmission and swell "carbon footprint"
Straight motor pros:
1/4 to 1/2 the purchase price of ECM variable speed.
Resilience to power surge and overload.
Gradual failure.
Operates directly on line voltage. Does not require electronic control module to function.
Readily repaired controls with off the shelf components.
Do not produce harmonics that is unfavorable in terms of system wide energy savings.
Cons:
Only saves 0.97kW rather than 1.04kw compared to ECM, so the savings is 6.7% less.
Less bragging rights.
Real comparison on C curve impeller...
Badu Eco M3 V 1.0hp 1 SF
A buncha chips and power electronics in factory OEM only control module does all the speed change and starting.
1.24kW @ 3450 72 gpm
0.20kW @ 1725 38gpm
0.064kW @ 1000 21 gpm
1.0hp 1.0 SF coil and core. Capacitor run, capacitor start by mechanical relay. Relays and coils to change speeds. probably available off the shelf.
Hayward SP15922S
1.1kW @ 3450 64 gpm
0.23kW @ 1725 33 gpm
Hayward SP2607x102S
1hp 1.0 SF. PSC,
mechanical relay speed change. probably available off the shelf.
1.28kW @3450 68 gpm
0.31kW @1725 32 gpm
When we talk about savings, we should always talk in terms of electrical terms and how it is achieved. (kWh, demand reduction, demand shifting(time of use rate etc)
That very expensive Badu M3 V pump has proprietary power electronics stuff that is fragile against power surge, or accidental overload, such as lock-up. It's got some computer chips controlling it, so more than likely that's part of the single module that must be replaced as one unit.
Surges and accidental lock ups can lead to losing the smoke in drive module which can only be replaced with factory parts.
Dollars figures are not useful, because the utility account plans vary as much as cell phone plans depending on poco, rate schedule chosen by customer, customer type, etc. Greenwashing sales tactics that use dollars and cents are designed to produce best figure to close the sale, nothing else.
Let's see for example:
Allocating the kW savings to highest possible tier rate, and possibly reducing demand charge used by very few utilities on residential.
Compared:
Cheap inefficient single speed @ full speed, no timer.
The green touting super expensive pump:
Saving at highest tier rate + demand charge at lowest speed setting compared to above and possibly the time of use savings achieved by using standard feature electronic timer to do demand shifting.