Replacing old pump w/ energy efficient model

[gopokes65]

Have been a new pool owner all of about 8 months. Last owner didn't care for the pool whatsoever. After having the pool replastered and the coping replaced, I am now looking at replacing my primary pump. I ran the pump for about an hour and it appears that it is consuming about 3 kwh. Right now a kwh costs me about $.09. So in the summer I am running my pump about 10 hours a day, roughly about $80-100 per month. That doesn't include my booster pump to run my Creepy Crawly.

I was looking into the Intelliflo, but didn't know if it would fit my setup or even what size I should get. Here are my specs:

-Volume: approximately 23,000
-Attaced Spa w/ bubbler and waterfall
- Currently have 2HP Pentair Challenger

Can anybody help? Thanks.

 

[mas985]

With $0.09/kwh it would probably be more cost effective to go with a two speed pump. Since you have a spa, you will want the same pump size as you have now. The cheapest and easiest solution would be to swap out the 2 HP motor for a 2 HP two speed motor.

 

[gopokes65]

Thank you for your response. Do I need a 2HP or would a 1.5 HP suffice? My only concern is my spa has 6 jets.

 

[mas985]

If you are replacing just the motor, you need to match the THP (service factor * label HP) of the old motor since it is matched with the pump impeller. You can downsize BOTH the impeller and motor if you want a smaller pump but that will make your jets weaker. So if you are happy with the strength of your jets, I would recommend that you keep the same THP motor but go with a two speed so that you can run on low speed most of the time for filtering and only use high speed for the spa. Low speed energy use is about 1/4th of high speed but you need to run twice as long (half the flow rate) so you end up saving about 50% in energy costs.

 

[gopokes65]

Looked again, and I don't have a Pentair Challenger. It is a Pac-Fab. Did Pentair purchase them? or is it Pentair's off-brand? Just wondering if there is a way to figure out how old it is. Don't know that it matters? Probably will end up going with the 2 HP power Whisperflo. Are they tough to install? Should I have a professional do it?

Also is there much difference in noise between the intelliflo and the whisperpro?

 

[gopokes65]

Performance Curve Question

Just delving into pool hydraulics. Site has been a great help. Right now I have a PacFab Challenger 2 HP Pump with a 1.10 service factor. Have a PacFab Nautilus FNS 60 DE filter that can handle 120 GPM.

Took a peek at the current Pentair Challenger 2 HP Pump Performance curve (D). Assuming 50 feet of head, it looks like the flow rate is 90 GPM minute. I guess I am making a big assumption that my 12 year PacFab is equivalent to today's Pentair Challenger?

http://www.pentairpool.com/images/produ ... ve_new.jpg

Anyways, looking at getting a Whisperpro. If I want to replace the pump with an equivalent pump with regards to GPM, it appears that I can get a 1 1/2 HP with a 1.1 service factor (G) as it also produces a flow of 90 GPM assuming 50 feet of head.

http://www.pentairpool.com/images/produ ... ve_new.gif

Is this line of thinking correct?

Thanks

 

[Bama Rambler]

Re: Performance Curve Question

Your line of thinking is correct, BUT, why do you need such a huge pump. On most pools a 1 hp 2-speed pump is more than enough and doesn't use nearly as much power. Unless you have a water feature that requires a huge amount of flow or a 100k gallon pool I'd look at a much smaller pump, and make it a two speed.

 

[JasonLion]

Pentair bought Pac-Fab quite some time ago.

The IntelliFlo and WhisperFlo make about the same amount of noise when running at the same speed. However, the IntelliFlo gets quieter as the speed gets slower. At it's lowest speed it is significantly quieter.

Installing a pump is a plausible DIY project if you already have some experience with PVC plumbing. I wouldn't suggest trying it as your first attempt at pool plumbing.

 

[gopokes65]

Re: Performance Curve Question

Your line of thinking is correct, BUT, why do you need such a huge pump. On most pools a 1 hp 2-speed pump is more than enough and doesn't use nearly as much power. Unless you have a water feature that requires a huge amount of flow or a 100k gallon pool I'd look at a much smaller pump, and make it a two speed.

I do have a spa with 6 jets. Everything that I read said 15-25 GPM per jet. Best case scenario, I would need 90 GPM minimum right? Don't get me wrong, I probably would run the pump 95% at the low setting, as we need to have the heater replaced before we can really use the spa.

 

[gopokes65]

Pentair bought Pac-Fab quite some time ago.

The IntelliFlo and WhisperFlo make about the same amount of noise when running at the same speed. However, the IntelliFlo gets quieter as the speed gets slower. At it's lowest speed it is significantly quieter.

Installing a pump is a plausible DIY project if you already have some experience with PVC plumbing. I wouldn't suggest trying it as your first attempt at pool plumbing.

Thanks Jason. Yes, I have quite a bit of experience with PVC plumbing, my biggest concern is the wiring. Trying to figure out if a $300 installation fee is worth it or not.

 

[scooperhsd]

If you're comfortable with 240V - it's easy enough. Just secure the power at the breaker.
Then disconnect the motor, then reverse the steps.

 

[JasonLion]

To keep the jet action in the spa about the same as it is now you need to match your current flow rate, as you assumed. However, you can get a dual speed or variable speed pump and save a great deal on electricity by running on low speed when not using the spa. For most people a variable speed pump will only pay for it's self in electrical savings when your electric rates are $0.20/kwh or higher. If your rates are lower the two speed pump is a better deal. Going with a two speed pump will save you almost 50% of what you spend on running the pump (a little less if you use the spa a great deal).

 

[mas985]

Re: Performance Curve Question

I do have a spa with 6 jets. Everything that I read said 15-25 GPM per jet. Best case scenario, I would need 90 GPM minimum right? Don't get me wrong, I probably would run the pump 95% at the low setting, as we need to have the heater replaced before we can really use the spa.

What is the filter pressure that you are currently seeing when in spa mode?

Also, describe your spa suction plumbing. Pipe size, run length to the equipment, number runs, etc.

The Challenger has a higher head curve than the Whisperflo so depending on your current operating point, the 1.5 HP uprated Whisperflo may not be sufficient especially since it is sending flow through the filter and heater.

 

[gopokes65]

Re: Performance Curve Question

What is the filter pressure that you are currently seeing when in spa mode?

Also, describe your spa suction plumbing. Pipe size, run length to the equipment, number runs, etc.

The Challenger has a higher head curve than the Whisperflo so depending on your current operating point, the 1.5 HP uprated Whisperflo may not be sufficient especially since it is sending flow through the filter and heater.

Not for sure if I understand "spa suction plumbing". Can you elaborate?

Meant to check the pipe size last night. Pretty sure it is 2 inch. I am trying to get the specs from the builder but they are at a conference this week.

Here is my setup.

http://screencast.com/t/o7yUhTji

My spa is about 6 ft across. Green spots are the drains, blue are the skimmers. Red circle is the filter and 2 HP pump is about 2 ft to the right of the filter. Length of the pool is about 40 ft and the width is about 15 ft. Deep end is 9 ft, shallow end about 3 foot. I had estimated the length of the run to the west skimmer to be about 50 ft. That would put the spa drain about 60 ft. East skimmer is probably about 15ft and the pool drain is probably about 30 ft.

When I get home I can take a picture of the plumbing from the pump if needed, but when the system is set to pool circulation, the filter operates at 18 psi. When I set it to spa circulation, the filter operates at 22 psi.

Appreciate your patience as I try to muddle thru this.

 

[mas985]

By spa suction plumbing I mean the plumbing that goes from the spa main drain to the pump suction port.

Assuming that the pipe is 2" with only a single 60' long run and that the equipment is around the same elevation as the spa level, then your current operating point is about 70 GPM @ 70' of head so your jets may be a little on the weak side at 12 GPM/Jet but perhaps you prefer that. If you went with a WFDS-26, the operating point would be 67 GPM @ 66' of head or close to 11 GPM/jet. A WFDS-28 would be 71 GPM @ 73' of head which would be closer to what you have now.