Standby Power Usage of Intelliflo VF

[nixlimited]

I just replaced my old WhisperFlo .5 HP pump with an Intelliflo VF (011012). First things first, the difference in power efficiency and sound is mind-blowing. Granted, my WhisperFlo is on its last legs, but the VF moves the same amount of water [edit:] for much less power. And, I can hardly tell its on. Very impressed.

However, as I have recently been on a power efficiency kick, I have noticed that the IntelliFlo seems to use somewhere in the neighborhood of 20-30 Watts in standby as measured by my whole house energy monitor. That is to say, I am inferring this change based on the higher baseline power usage at night when basically everything is off. I am not sure of a good way to test the pump directly since it is hardwired, but I may experiment with flipping the subpanel breaker to cut power from it. My hope is that will not erase all of its settings.

In any event, has anyone tested these pumps' standby power usage and/or noticed an unusually high standby power draw? I have attached a graph showing power usage and approximate baseline differences before and after the pump. You can also see the massive difference in power usage (despite running the pump for 2 hours more per day.

 

[RobbieH]

I have been very impressed with my VF also. Mine never goes into standby though. I told it I have a 44,000 gallon pool and that I want it turned over once per day, and to run for 24 hours. That puts it right at the most efficient speed, luckily. It draws anywhere between 250 and 300 watts, I can live with that.

 

[mas985]

I just replaced my old WhisperFlo .5 HP pump with an Intelliflo VF (011012). First things first, the difference in power efficiency and sound is mind-blowing. Granted, my WhisperFlo is on its last legs, but the VF moves about the same amount of water for about 1/4 the power (or maybe a bit less). And, I can hardly tell its on. Very impressed.

I seriously doubt that. I don't think you are comparing apples to apples.

Based upon actual lab measurements, the difference in power at exactly the same flow rates is only about 34%. Chances are, the VF is not at the same flow rate as the Whisperflo. To match the flow rate of the Whisperflo, the Intelliflo should be set at around 68 GPM. Also, when you installed the Intelliflo, did you change any of the other plumbing?

 

[nixlimited]

I seriously doubt that. I don't think you are comparing apples to apples. Based upon actual lab measurements, the difference in power at exactly the same flow rates is only about 34%. Chances are, the VF is not at the same flow rate as the Whisperflo. To match the flow rate of the Whisperflo, the Intelliflo should be set at around 68 GPM. Also, when you installed the Intelliflo, did you change any of the other plumbing?

I am sure you are correct, though I think you missed the point of my post, which is about idle power draw. I did not have a flow meter on the system with the old WhisperFlo so I was comparing roughly based on the amount of flow it took to get a similar spillover from my raised hot tub to the pool. Very inexact. But, hey, I will take 34%.

I also failed to mention that I made some above-ground plumbing changes that should also improve flow. For example, I added a three-way valve to bypass my two heaters (solar and gas) completely since the solar heater will not do much this time of the year and I do not see the purpose in adding the restriction of the gas heater when it is not in use. I also added a better backwash valve. And I was able to eliminate about 10 90 degree elbows by re-routing the plumbing in a much more efficient way.

What's been very interesting is seeing how the restrictions in the plumbing affect the wattage at a consistent flow in GPM. For example, if I pull from just my main drain, it uses more power than if I crack open my vacuum line too. Unfortunately, if I get enough flow through the vacuum line to get the cleaner to move, then power efficiency goes down. Similarly, it uses more power to return everything to my hot-tub compared to returning to both pool and hot-tub.

I also plan to experiment with running the pump slower and longer to see where the sweet spot is. My pool is relatively small at 9000 gallons so it does not take too much to get a turnover in a day.

 

[RobbieH]

Mine's running at 1525 RPM, but I have to move 5x as much water as you to turn over once a day.

 

[mas985]

Why do you "need" to turn it over once per day? That is purely an option. Have you ever tried a 1/2 or 1/4 turn per day just to see what happens? Also, 24 hr continuous operation should never be needed.


pool-school/pump_run_time

 

[nixlimited]

Getting back on topic, has anyone measured idle power draw of the Pentair IntelliFlo VF or other similar Pentair pumps?

 

[RobbieH]

Why do you "need" to turn it over once per day? That is purely an option. Have you ever tried a 1/2 or 1/4 turn per day just to see what happens? Also, 24 hr continuous operation should never be needed.


pool-school/pump_run_time

I just got "plastered". Running it 24/7 during start up. Also, it's in the sweet spot for my pool at 1500 RPM, so it makes sense for summertime speed.

I haven't tested the pump at idle. I'm sure it draws some as there's a computer on board, and I am betting the fan runs at a slow speed at idle too. 30w seems excessive though.

 

[BW]

My Hayward EcoStar displays power consumption, and it says 23W when idle. I didn't think much of it until I realized in the off season I'm running 4 hrs @ 120W, which means my idle of 20 hrs @ 23W is costing me as much as the actual pumping!

 

[nixlimited]

My Hayward EcoStar displays power consumption, and it says 23W when idle. I didn't think much of it until I realized in the off season I'm running 4 hrs @ 120W, which means my idle of 20 hrs @ 23W is costing me as much as the actual pumping!

That's my concern. In San Diego our top rate is now 39 cents/kWh with a blended average of around 25 cents/kWh. I am in an all out assault against standby power in my house because every standby watt I kill is x24 a day.

 

[bzeller]

At 30W and an average of $0.25/kWh, that works out to about $5 a month. Not a huge deal is it?

 

[nixlimited]

At 30W and an average of $0.25/kWh, that works out to about $5 a month. Not a huge deal is it?

Certainly not, but the issue with that perspective is that when you take it across the whole house, it really does add up. In other words, 30W standby here, 30W standby there and all the sudden I am paying $20-$30 extra a month for pure standby power i.e. 100% waste. It offends my engineering side more than my wallet. And it just makes me curious from an engineering perspective. My Mac Mini only uses 10-12 watts while running applications. My AppleTV uses 2-3 watts while idle and less than 10 full tilt. What on earth does a glorified timer need with 20-30 watts?

It's interesting the way you start to view power when you know what things use. For example, I strung up 4 strands of string lights on my patio, which use the small 1" globe bulbs, with a total of 100 bulbs. They do not produce a tremendous amount of light, but give a nice glow. Little did I know that each bulb is about 5W, so now I have 500W of "ambiance" when I can light my entire house with 11W LED BR30s for about half of that power.

Anyway, for me it's really more of an efficiency game. My LED light bulbs will likely never pay themselves off, but I still enjoy the better performance coupled with the net reduction in my power usage every month.

 

[nixlimited]

Even though it is off-topic, I thought I would add that I recently had my Triton FNS D.E. filter cleaned, which dropped the power usage from around 250W at 25 GPM to 170W at 25 GPM. Pressure at 25 GPM is now around 4 PSI according to filter-top meter. I think that before it was 8-10 at the same flow. I wish I had not waited years to make these changes...

 

[jblizzle]

Even though it is off-topic, I thought I would add that I recently had my Triton FNS D.E. filter cleaned, which dropped the power usage from around 250W at 25 GPM to 170W at 25 GPM. Pressure at 25 GPM is now around 4 PSI according to filter-top meter. I think that before it was 8-10 at the same flow. I wish I had not waited years to make these changes...

That is actually a disadvantage of the VF pumps. With a single/ dual / or VS pump, as the filter get dirty, the pressure rises and the flow is decreased which lowers the power usage. We say you should watch for a 20-25% pressure rise over the clean pressure at a given pump speed to know when to clean the filter.

With the VF, as the filter gets dirty, the pressure rises and the pump increases speed (and power use) to maintain the same flow rate ... making the pressure read even higher than it would at a constant speed. You will not notice a decrease in flow in the pool and unless you see the high pressure you will not realize that suddenly you are using more power.

As I think about this, I am not sure what the proper way to determine when to clean the filter is with a VF pump since the pressure is going to rise faster as the speed increases.

 

[nixlimited]

That is actually a disadvantage of the VF pumps. With a single/ dual / or VS pump, as the filter get dirty, the pressure rises and the flow is decreased which lowers the power usage. We say you should watch for a 20-25% pressure rise over the clean pressure at a given pump speed to know when to clean the filter.

With the VF, as the filter gets dirty, the pressure rises and the pump increases speed (and power use) to maintain the same flow rate ... making the pressure read even higher than it would at a constant speed. You will not notice a decrease in flow in the pool and unless you see the high pressure you will not realize that suddenly you are using more power.

As I think about this, I am not sure what the proper way to determine when to clean the filter is with a VF pump since the pressure is going to rise faster as the speed increases.

The VF can estimate pressure and has a filter pressure setting so that at a certain point, it will manage pressure and not flow. This solves the problem you mention. You can set it for whatever target pressure you want. I believe the manual suggests something like 11 PSI over clean filter PSI. Additionally, while I agree that from a power perspective keeping a consistent flow (as with the VF) has the consequence of potentially higher power usage, from a functional (i.e. cleaning performance) perspective it is better. At the end of the day, all of this is to keep the pool clean. I would prefer not to be saving power due to a clogged filter and in so doing, letting my water get dirty.

 

[jblizzle]

I was not saying to sacrifice the pool's cleanliness for power savings. Simply trying to say that with the VF it is a little less obvious when the filter should be cleaned and thus wasting energy with the dirty filter.

But, if you are allowing the pressure to rise 11psi over the clean pressure that is WAY higher than the recommendations we make.

I have yet to clean my DE filter this year since the pressure has not risen very much. Looks like I may only do it every year in the spring before the season starts.

 

[mas985]

The VF doesn't really have a pressure sensor but calculates the pressure (i.e. head loss) based upon the RPM and wattage consumption. All three along with GPM are related so if you know two, you can solver for the other two.

But anyway, I would contend that a constant flow is NOT better from a cleaner perspective. Filters work better at lower flow rates so as the restriction increase, effectively you are forcing more water through the filter where as a VS would allow the flow rate to reduce through the filter thereby effectively improving the filtering ability.

 

[nixlimited]

But anyway, I would contend that a constant flow is NOT better from a cleaner perspective. Filters work better at lower flow rates so as the restriction increase, effectively you are forcing more water through the filter where as a VS would allow the flow rate to reduce through the filter thereby effectively improving the filtering ability.

Just for the sake of discussion, you are not really accounting for all the variables with your contention. Yes, filters work better at lower pressure. However, without knowing the relationship of filtering performance versus pressure, there is no way to contend that moving less water (i.e. lower pressure) with better filter performance is superior to moving more water (i.e. higher pressure) with lower filter performance. For example, if the reduction in water flow (on a percentage basis) is greater than the change in filter performance (on a percentage basis), then you get less filtering overall.

 

[jblizzle]

This is where the 20-25% recommendation came from. Experiments where allowing the pressure to rise much more than that ends up reducing the flow rate eventually to the point where the flow rate is just too low and you are not filtering enough water to be efficient (assuming a constant pump speed).

If you just keep increasing the pump speed to counter the flow rate reduction of a dirty filter, that is just wasting $.

It is easy to contend that at a lower flow rate at lower pressure you will use less energy than you will at a higher flow rate at higher pressure ... even if you ran the higher speed for less time.

Using a 2-speed pump as an example: On low you will move 1/2 the water as you will on high speed. So if you ran the pump on low for twice as long as you would on high, you would move the same amount of water through the filter. BUT, on low you use 1/4 the amount of power, so even though you are running twice as long, you are saving 50% of your electrical cost ... AND the water going through the filter at a lower flow rate is filtered better.

 

[nixlimited]

I really just enjoy playing with the system and trying to find the most efficient setup, water quality notwithstanding.