Pool Pump plumbing and Electrial question:

[Hench]

Okay, more like a dumb theory but want to solicit opinions regardless...

I have a 16' x 32' x 9' deep pool. I live in an area where in the day electricity is double the cost than at night. However, running the filtration system at night means lots of heat loss and water loss, therefore, it's easier to keep the pool warmer and cleaner during the day when electricity is the priciest. by moving the water during the day, I can preserve and capture the sun's heat throughout the pool, with minimal water loss under the solar cover.

I have a 90 degree elbow on a 1.5" ID pipe intake to the pump. I have no elbows on the outtake back to the pool on 1.5" ID pipe, but do have

1.25" barbs inside that outtake pipe.

Is it worth my while to take the 90 degree elbow out and use a flex pipe to have a sweeping radius to increase water flow? My filter is running at 12 PSI under current setup, but it's rated for 50 PSI.

I want to know if there is a possible gpm increase by removing that elbow. If I can move more water in less than I can save on electricity, or have the electricity being used now, move more water.

Anyone have any thots on this dumb theory?

If anyone knows of any decent pipe flow calculator website, pass it on to me.

[Dan Espen]

The terms "water flow pipe bend" bring up hits that calculate the force a bend causes, but they don't compare a sharp bend to a gradual bend.

My intuition tells me the difference is small, but when you look at this video:

you can actually see the turbulence that water being bent creates.

[harry]

The above is good advice. You can get pumps now that have a permanent magnet motor instead of an induction motor that use half the power. You might even find your pump is oversized so do the calculation.

Heat loss from PVC pipes is not great at these low temperatures. The important thing is the pool cover and how good an insulator it is. Also how well it t fits, a badly fitting one is useless. Also reduces evaporation losses.

Also frequent back washing of your filters keeps them efficient.

Determine the minimum time you need to run the plant to keep the water quality acceptable.

If the pool is used infrequently, the plant is likely to be grossly oversized and need only be run for a few hours per day.

Use flocculants to improve the filter efficiency which will mean you need to run it for fewer hours/day.

[sms]

Unfortunately, filtering at night doesn't work. You need the chlorine circulating through the system when the sun is out. It's too bad because you can save quite a bit if you have time-of-day metering.

[Hench]

When I'm talking about heat loss, I'm talking abut evaporation from the surface of the pool, not from the pipes. Most pools lose their heat from evaporation at the surface. Where I live the summer air at nighttime can be cooler than the water so the rate of evaporation can be high.

By running the pool filter at night during cheaper electrical rates, i was discovering my water bill was going uo proportionality because i had high water loss.

[Danny D]

I'm no expert ... but I don't understand how pool chlorine needs sunlight in order to work?

Anyway, as some of you know, in doing a minor plumbing re-work on my pad, and, in doing so, I've been researching this very same topic, so some of the California papers I've found may be useful to the OP.

Draft report for Residential Swimming Pools, by PG&E & Sempra Energy, dated February 19, 2007:

Measure Information Template Residential Swimming Pools, 2008 California Building Energy Efficiency Standards, Pacific Gas & Electric Company, dated July 6, 2006:

Analysis of Standards Options For Residential Pool Pumps, Motors, and Controls, Prepared for Gary B. Fernstrom, PG&E, by Davis Energy Group, Energy Solutions, dated May 12, 2004:

Staff v Workshop Before The California Energy Resources Conservation and Development Commission, In the Matter of 2008 California Building Energy Deficiency Standards, by the California Energy Commission, dated July 12, 2006:

You can get flex pvc pipe here:

[CRNG]

On Sat, 11 May 2013 06:34:18 -0400, Hench wrote in Re Re: Pool Pump plumbing and Electrial question::

You should have a cover on the pool while your run the nightly cleaning. That will significantly cut both heat and water loss.

[Hench]

Yes I do have a cover. I may be purchasing a new one this year as the old one is about at the end of it's life. Researching covers this past week.

[Hench]

Thank you for posting these links. Looks like some good reading. I appreciate it.

I'm in Canada where the weather can still get a bit chilly at night some weeks so it's been a balancing act to save electricity and preserve heated water.

[trader4]

Most of what that article says is either wrong or irrelevant

"The main reason for running the pool pump during the daylight hours is to ensure proper sanitation. Chlorine is degraded by sunlight, so there is a larger demand on the chlorine residual during the day."

Yes, some of the chlorine is going to be degraded by sunlight, but so what? I've had my pool sit all day without circulating, checked the chlorine level and there isn't a measurable difference. It's still at a perfectly acceptable range, the same at 5PM as it was at 8AM. That's what stabilizer is for.

"When the pool pump is operating, the circulation in the pool disperses the chlorine throughout the pool."

That's true, but dispersing it at night works about the same. And once dispersed, it doesn't just change dramatically in 12 hours.

"Also, most pools use some type of chlorinator that adds chlorine only when the pump is running."

I think that is flat out BS.

"By running the pump during the day, it helps keep the chlorine at a constant level."

I agree in theory, it would keep it more constant during the day. But I say it's plenty constant enough with the pump off during the day. Absent a problem, who cares.

"Use of the pool also consumes the chlorine, and most swim during the day."

Again this apparently assumes you have an inline chlorinator.

"Having the proper levels of chlorine helps kill algae spores, germs, bacteria and other contaminants as soon as they enter the pool. If the chlorine level is too low, or not dispersed evenly throughout the pool, it gives these "intruders" the possibility of gaining a toe-hold and starting to grow. This can result in cloudy water, algae blooms and even recreational water illnesses that can be transmitted between bathers."

Proper level of chlorine and filtering at night are not mutually exclusive.

"Many pool owners are starting to install alternative methods of chlorination and sanitation on their pools. These include salt chlorination and ozone. The same rules apply to these as with conventional chlorination."

Which also appears to be irrelevant.

"The only way to make sure your pool is safe for bathers is using a good quality test kit to make sure the water is properly sanitized, says Steve Bludsworth, owner of All-Pool Service & Supply in Orlando."

That's about the only thing here I agree with.

[trader4]

It doesn't need sunlight to work. In fact, just the opposite is true, sunlight kills the chlorine, which is why stabilizer is added to reduce that effect. IMO, that article is BS. It's based on the premise that when the pump isn't running, the chlorine level is going to change dramatically, to the point that proper sanitization is no longer achieved. So, they claim you have to filter during the day to keep the pool chlorine at the proper levels when people are supposed to be swimming.

Two more points. You can easily prove to yourself this is BS. If you filter at night, I'm sure you've at some point checked the chlorine level at 8PM. Is it about the same as it was at 8AM or is too low? In my experience, it does not have a noticeable change when tested.

Second, if you're concerned about keeping the water better filtered when people are in the pool or if there are a lot of people in the pool, then you can put the pump on when people are actually using it that day and then just not filter that night

making/document...

g/document...

Regarding the elbows, it's such a minor factor, IMO, it's not going to make a significant enough difference to matter. Each elbow counts as X feet of equivalent pipe in determining the effect. For a short radius 2", it's 9 ft. For a long radius, it's 3.5 ft. Typically for a pool, long radius are used, so hopefully that's what you have.

So, if you add up all the feet of pipe, all the other elbows, the filter, etc, what % difference do you think 3.5ft of pipe would make? Plus even if you went with flex PVC, to get the radius down even more, you'd have to use maybe 1.5ft of pipe anyway, so now you're only talking about a 2ft length difference.

What would make a difference is using a two speed pump, as someone else suggested. The energy required to push the water goes as the cube of the speed. So, you could run at half speed, filter twice as long, move the same amount of water and use a lot less energy.

[Hench]

Yup. A few others in this thread have suggested focusing on the pump. if removing one elbow is not going to make much impact on flow. To be honest I suspected this but wanted to hear from others...

[Danny D]

Please post what you find out about fixing pool covers!

When I moved in, I was quoted a few thousand dollars to fix mine, but some day I want to see if I can try to fix it myself.

Here's a picture I snapped for you just now:

[Danny D]

Yikes!

I have no idea 'what' radius I bought from Home Depot.

Is this a long or short radius?

[harry]

So how is the water evaporating at night, don't you have the cover on? The cover should be on at all times when the pool is out of use. Prevents evaporation. Keeps out the muck & leaves. Reduces heat loss. Reduces use of chemicals.

Most water loss through evaporation occurs when the cover is off and humidity is low, air temperature is high and there is a breeze. The pool cover stops 99% of this.

[krw]

I just used a "solar blanket" for about $200. It was still in good shape when I sold my house ten years later. It doesn't work as advertised but it does float on the surface of the pool and it is easy to put on and take off. Without an expensive reel, it does take two people to take off, though.

I found, as expected, that it's only purpose is to cut evaporative cooling and reduce water loss. When I needed to add heat to the pool, running the pump during the day worked. When I needed to shed heat, run it at night. I could vary the pool temperature up and down 2F pretty easily just doing that. I had an X10 module as the timer. Worked very well.

[harry]

That is definitely a short radius bend. Should only be used when physical constraints necessitate it. (ie restricted space)

[trader4]

Spoken like the true village idiot.

[Hench]

Yeah my results are the same as yours. I dunno what you mean by F though. My solar blanket is due to be replaced and I might buy one that has an aluminum foil/sheet in it to keep more heat in the water. Still have to research though. Sounds too good to be true at all.

[Norminn]

No cover...this isn't for swimming, and the pond is pretty well protected from stuff blowing in. There is a mock cherry tree next to the pond, and it's junk falls in...petals and stems. Most floats, some sinks. Pond is only about 18" deep at deepest, so not that hard to get stuff out with rake, brush, or shop vac. Just found a pool vacuum that gets the algae pretty well....I will leave some for the fish. Other water plants (presently only one w. lily) should take up some of the nutrients and keep the algae down. The waterfall is losing a little water, so it refreshes often....float valve for that.