Being slowly broken down over buying a heater...

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cj133 said:
Why would a larger heat pump automatically be more efficient?
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It's not automatically more efficient. My comments were based on specs published by both Hayward and Aquacal.

Having said that, I see that the specs have been updated on both sites and are NOT the same as I what copied from there 2 years ago. All of the Hayward units are listed at 5.7 - so no difference, and for AquaCal, their SQ145 at 121K is by far the most efficient unit at 7.1. Their other two units (101K and 143K) are both listed at 6.5. These numbers are for 80/80/80.

I would still recommend the 143K for your size pool. I really think you'll be happier in the long run.
 
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NEC says you don’t load a beaker to more than 80% of capacity. So a 50 amp breaker should not have more than 40 amps of load on it.

You need an electrical upgrade for any serious Heat Pump.
 
We just took a tree down that was shading it out from 2-6pm. So now it basically is full sun from 11am-7/8pm depending on which end of summer we are on. I would love to put the panels on the roof but the roof is east and west so not really great for positioning. Definitely something I am looking at though.
 
Solar by itself will not work. Solar (especially in WI) will provide very little heat in the summer, when you don't need it, and nearly 0 when you actually need it - late spring and early fall.

I'm in Florida, and when I did the calculations, it wasn't worth the investment. To warm the pool when it's less than 85 degrees out, I would still need an alternate heat source as solar would not be able to maintain the pool temps I was looking for (85-88 degrees).... and my pool is only 7K gallons. My heat pump costs me about $30/month to run in January and February, and the cost ramps down before and after those months. In addition, for solar to work, you need to run your pump at higher RPM's to provide the necessary flow for heating. My pump running at 50% costs 85% less to run than at 100%.

If I had solar, it might reduce the monthly cost by ~$10/month... but at an install cost of ~$5K-$7K for solar, I would never recoup the cost.
 
Just a couple things.

1. Our air temps are almost never 85 F, but the solar array still pumps out 90K BTU at 70 F ambient. Colder than that and no one wants to swim anyway.

2. Running the dual Intex pumps only requires 3.8 amps@120V, and gets us to 1800 GPH with the system in play. About $20/month all in.

3. Highest efficiency on the system tends to be earlier in the season.

Keep in mind that we are quite far up North..and we do use a solar cover on the pool when not in use.
 
denwood said:
Just a couple things.

1. Our air temps are almost never 85 F, but the solar array still pumps out 90K BTU at 70 F ambient. Colder than that and no one wants to swim anyway.

2. Running the dual Intex pumps only requires 3.8 amps@120V, and gets us to 1800 GPH with the system in play. About $20/month all in.

3. Highest efficiency on the system tends to be earlier in the season.

Keep in mind that we are quite far up North..and we do use a solar cover on the pool when not in use.
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I wouldn't trust any Intex GPH ratings, ever. Not even a little.
That doesn't mean they don't get the task at hand done, just that I wouldn't go by their specifications.
 
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cj133 said:
I wouldn't trust any Intex GPH ratings, ever. Not even a little.
That doesn't mean they don't get the task at hand done, just that I wouldn't go by their specifications.
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I don't. Everything I've guoted is actual measured at the pool return GPH. 5 gallon bucket method. I have temp sensors for ambient air, pool water, solar input and solar return. Power information is gathered using a Kill A Watt type unit at the shed. Data gathering for about 5 years now. In my signature is the link to the live data link. The system started single pump/ 4 panels, then dual pump with 6, then 8 panels as we have today. I had a conventional 2 speed pump in there with the Intex, then found I could get the same flow at less than half the power use with two Intex .24 hp pumps in series.

The only way to tune a solar setup is to know definitively what your flow is. At 3 GPM per panel (40 sq/ft each) BTU dropped 25% on my system. At 3.75 GPM, it's close to theoretical max (85% efficiency) based on square footage. Having the panels plumbed in a fully parallel configuration is important too.

This is data from Monday from a 320 sq/ft array that sees full sun from around 11:30 to 5:30 at this time of year. In July, it's closer to 100K BTU at 1pm or so. Live data is logged every 5-10 min.

 
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denwood said:
I don't. Everything I've guoted is actual measured at the pool return GPH. 5 gallon bucket method. I have temp sensors for ambient air, pool water, solar input and solar return. Power information is gathered using a Kill A Watt type unit at the shed. Data gathering for about 5 years now. In my signature is the link to the live data link. The system started single pump/ 4 panels, then dual pump with 6, then 8 panels as we have today. I had a conventional 2 speed pump in there with the Intex, then found I could get the same flow at less than half the power use with two Intex .24 hp pumps in series.

The only way to tune a solar setup is to know definitively what your flow is. At 3 GPM per panel (40 sq/ft each) BTU dropped 25% on my system. At 3.75 GPM, it's close to theoretical max (85% efficiency) based on square footage. Having the panels plumbed in a fully parallel configuration is important too.

This is data from Monday from a 320 sq/ft array that sees full sun from around 11:30 to 5:30 at this time of year. In July, it's closer to 100K BTU at 1pm or so. Live data is logged every 5-10 min.

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What was the advertised GPH on those pumps?
I'm curious how far they were off.
 
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Intex rates the SF-80110-1 (.24 HP) bare pump at 2100 GPH and 1600 GPH with 12" sand filter/plumbing etc. system. I saw a measured 1028 GPH with one pump, 12" sand filter, 17' rise to 4 x 2'x20' solar panels.

With 4 x 2'x20' panels:

1. Pool Pump - Intex SF80110-1 , 0.2 amps , 1600 GPH.
2. Actual (measured) system flow with sand filter and 4 x 2'x20' solar array in use: 1028 GPH
3. Max measured BTU = 1028 x 8.33 x 6F = 51 379 BTU/hour
5. System head (max lift height to peak of roof) : 17ft

With 8 x 2'x20' panels:

Two pumps (SF80110-1 and SF80110-2) in series, with 21" sand filter and eight x 2'x20 panels (about 23 foot rise to 2nd story) is 1800 GPH.

Each Intex pump uses 1.9 amps @ 120V in operation. Together, the Intex pumps are 66% more efficient than the 3/4 HP 2-speed pump (12 amps) I was using previously and actually move more water too. I messed with quite a few configurations/pumps but the two Intex pumps are the best so far. One is plumbed before the sand filter, the other, after the sand filter. This keeps pressure in the filter below 5 psi.
 
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denwood said:
Intex rates the SF-80110-1 (.24 HP) bare pump at 2100 GPH and 1600 GPH with 12" sand filter/plumbing etc. system. I saw a measured 1028 GPH with one pump, 12" sand filter, 17' rise to 4 x 2'x20' solar panels.

With 4 x 2'x20' panels:

1. Pool Pump - Intex SF80110-1 , 0.2 amps , 1600 GPH.
2. Actual (measured) system flow with sand filter and 4 x 2'x20' solar array in use: 1028 GPH
3. Max measured BTU = 1028 x 8.33 x 6F = 51 379 BTU/hour
5. System head (max lift height to peak of roof) : 17ft

With 8 x 2'x20' panels:

Two pumps (SF80110-1 and SF80110-2) in series, with 21" sand filter and eight x 2'x20 panels (about 23 foot rise to 2nd story) is 1800 GPH.

Each Intex pump uses 1.9 amps @ 120V in operation. Together, the Intex pumps are 66% more efficient than the 3/4 HP 2-speed pump (12 amps) I was using previously and actually move more water too. I messed with quite a few configurations/pumps but the two Intex pumps are the best so far. One is plumbed before the sand filter, the other, after the sand filter. This keeps pressure in the filter below 5 psi.
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Did you measure wattage or just volt amps?

I find it hard to believe their 3/4hp would use 12A.
 
cj133 said:
Did you measure wattage or just volt amps?

I find it hard to believe their 3/4hp would use 12A.
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Not an Intex 3/4 HP…they don’t have anything that powerful. It was a 2-speed pump “PoolLine” . 12 amps was the power use in series with the Intex .24 HP pump. On low speed that pump flowed less than than the Intex .24 HP, and used nearly twice the power.

I measured the actual amps at 120V for the shed, with the gear running. Wattage is just calculated from amps. The chlorinator uses about .5 amps, so I turned it off when checking the power use of the pumps.

What I can say definitely is that the 2 Intex .24 HP pumps in series use only 3.8 amps, and have higher measured GPH than the 3/4 HP pump on high speed using 10 amps. I tested the larger 2 speed pump (tested both speeds) both alone and in series with the smaller Intex. Best flow was the two pumps in series at 1560 GPH using 11.9 amps.

It seems that the two smaller Intex pumps in series are quite efficient as I only use 3.8 amps now, and flow is at 1800 GPH. I have tweaked a bit with a Hayward pool return, and larger sand filter to peak at 1800 GPH. That 1800 GPH is with 8 solar collectors (plumbed parallel) in the loop.
 
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denwood said:
Not an Intex 3/4 HP…they don’t have anything that powerful. It was a 2-speed pump “PoolLine” . 12 amps was the power use in series with the Intex .24 HP pump. On low speed that pump flowed less than than the Intex .24 HP, and used nearly twice the power.

I measured the actual amps at 120V for the shed, with the gear running. Wattage is just calculated from amps. The chlorinator uses about .5 amps, so I turned it off when checking the power use of the pumps.

What I can say definitely is that the 2 Intex .24 HP pumps in series use only 3.8 amps, and have higher measured GPH than the 3/4 HP pump on high speed using 10 amps. I tested the larger 2 speed pump (tested both speeds) both alone and in series with the smaller Intex. Best flow was the two pumps in series at 1560 GPH using 11.9 amps.

It seems that the two smaller Intex pumps in series are quite efficient as I only use 3.8 amps now, and flow is at 1800 GPH. I have tweaked a bit with a Hayward pool return, and larger sand filter to peak at 1800 GPH. That 1800 GPH is with 8 solar collectors (plumbed parallel) in the loop.
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No,
You're mistaken on that.
Volt amps is calculated by multiplying amps x volts.

Wattage is very different when it comes to inductive AC loads and the 2 speed pump in low speed would have a terrible power factor making it seem like it's drawing a low more power than it is.

The best way I can explain it is, the peak current isn't at the same time as the peak voltage so true wattage is actually much lower and you're billed by wattage not volt amps.
Have a read : Power factor - Wikipedia

My antique refrigerators from the 30s for example can draw 2.3 amps at 120 volts but are actually only using 160 watts. Typical AC motors have really bad power factors when running at low load but it generally doesn't matter to the end user especially on small loads of only a few amps.

Basically, the bigger 2 speed pump could likely be using less actual power than the Intex but drawing more current because it's power factor is low due to the low load on the motor. Meanwhile the Intex is running at it's rated power level. The Intex may also have a capacitor to help with it's power factor but it won't change the cost to run.
 
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denwood said:
Power factors etc aside, I was interested in the relative draw of each setup vs GPH, so for those purposes the Kill A Watt (gear was connected to it) and amps works fine :). The rated amps vs measured did match up pretty closely.
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If you're using a kill-a-watt there's no reason not to measure actual power (watts) and compare. It'll even show you the power factor.
 
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cj133 said:
If you're using a kill-a-watt there's no reason not to measure actual power (watts) and compare. It'll even show you the power factor.
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Ok, so I've learned that amps isn't amps when it comes to AC motors..ha.

First of all, the unit I'm using is not actually a kill a watt...it's an EM100, my mistake. I measured the two .24 HP Intex pumps in operation and got 430 watts using the EM100. If you take the measured amps (3.72) from that EM100, I get 446 volt amps. I think the unit is accounting for power factor as it defines the displayed watts as Wattage - real power (W) where power = voltage x current x power factor - https://www.erthpower.com/wp-content/uploads/2015/06/EM100_Energy_Meter_Technical_Manual.pdf
Either way, I'm pretty sure the relative line current measurements using the EM100 in my different setups are relatively significant. One item that is not subject to power factors is a 5 gallon bucket test to measure GPH :)

Having just bypassed the timer/control panel on a new but DOA Intex SF-80110-2, yep there is a capacitor (I believe it is 40uF) in there. Intex replaced that pump, but now I have a running third pump. Having a dead control panel is a non-issue as I run the shed via automation anyway.

To be fair, the higher final GPH numbers from the series-plumbed dual Intex pumps (1800 GPH) came also as result of an accumulation of several factors as I check over my notes. None of these changes had much effect on line current measured:

1. Larger sand filter. Worth about 265 GPH.
2. Pumps arranged before and after filter instead of both before. That was worth 167 GPH when testing with the 12" sand filter (1333 GPH -> 1500 GPH)
2. Hayward pool return (swapped in place of the Intex aerator return). The Intex/Hayward pool water return swap was good for about 35 GPH.
3. Swapping out one of the Intex hoses with an ID less than 1.5" in the system on the pool return (just a six footer).

In any case, massive apology to @nwardoh as this thread is a bit off topic. I still think solar is awesome..ha.
 
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