mas985 said:
Rangeball,
The best way to save electrical cost is with a two speed or multi-speed pump. At the lower speeds they use much less electricity but don't lose as much flow so you end up better off. I explain some of the benifits in
this post post as well as how to pick the right pump.
Thanks for jumping in. I was hoping you'd show up
I'd read that post before, and in fact spent quite a bit of time re-reading it again after I posted this thread. Your quick factor/formulat (x3) for calculating head was very helpful. Using it I estimate my head to be right at 30.
A couple of observations:
Your filter is large enough to handle up to 90 GPM so that will probably not be a factor.
That's what I was thinking. I actually could have probably gotten by with the next size down, but this is the one the pool store installed 5 years ago. It's still working great, so I don't plan to change it until it goes down.
Given the distance to the pool, I suspect you don't have too much head loss although 1.5" line will increase it some. Most AG pumps are on the low head side. This may still work for you since you are so close to the pool.
This is good to read, hopefully I am close to 30 on head loss, which gets greater flow with most pumps I've looked at.
First we need to determine what the performance of the current pump is and then we can look at options.
How do we do this?
And next some questions:Is the Dynamo a two speed pump and is that why you are running for 24 hours?
No, the pool came with the house when we bought it 13 years ago. I knew nothing about pools, and relied heavily on the pool store. They told me best be was to run 24 hours to avoid problems. I've always done it, but after finding pool forum awhile back have had the nagging urge to cut back on run time, but have hestitated given the sold me an AG pump. However, using your formula and 30 for head loss per the manufactures chart I should be getting 70 gpm which gives me a 5 hour turnover rate, or almost 5 turnovers a day. Probably adequate
What is the service factor of the pump? Should be on the label somewhere.
I'm not at home so will have to add this later. Is it something that's like to be in their tech stuff? I'll look at their site and see. Nope, not there.
What is the current filter pressure?
10 psi. This is what it runs at with a fresh start up. When it goes up by 10 I backwash, break the filter down and clean it (side note, I use to have to do this very frequently. Since going BBB, I do it at start up, once or so mid season, and at close.)
I have nothing to compare it to. I would consider it loud, but I don't think it's from over working, if this is where you're headed.
Does the pump have trouble priming?
It's a gravity flow pump for AG pools. If I fill the pot making sure to allow water to also fill the skimmer line as much as possible, close the main drain line and turn it on, it usually has full prime within 30 seconds. Once running, I can slowly open the main drain and it will pull as well. If I try to prime with the main drain open and the skimmer line close, no go.
Why the Elminator as a new pump? (there are more effficient choices but can be more $$)
Mostly due to $$. My dad wants me to order him the chlorease SWG for his AG pool, and they had the best price for the new model. I noticed they sell pumps as well, so I checked them out. They say the eliminator is made by the #1 (whatever this means) pool equipment manufacturer and it's priced right at $260ish for the 3/4 hp model. Looking at this, I may even be ok with a 1/2 hp motor, although if I ever add anything (like a solar heater) I may be on the bubble as far as head goes, I don't know. I figure I'm spending about $90ish monthly to run my pump 24 hours daily. If I were to switch to 12 hrs and assuming no problems occured doing so, I'm at $45. If I can use less electricity with a more efficient, smaller or both motor and go to even perhaps 8 hours to get the same flow (looks to be a real possiblity as the eliminater 3/4 hp has 90 gpm at 30 head, 80 gpm at 40 and still 70 gmp at 50, where the dynamo does 70/50/20 at the same head), I figure I'm probably down below $30. I can live with this, and at the price of the eliminator it will pay for itself the first season (not computing simply running my current pump less time).
When I looked at 2 speed pumps last year, I seem to recall the were considerably more $$, and although the payback would be greater, it would take quite a bit more time to realize it do to the higher cost.
