plumbing question about a Pentair Intelliflo pump

[jamesdean]

I am considering replacing my 1 HP pump with a Pentair Intelliflow variable speed. My plumbing is 1.5" and the pump uses 2". I have 3 suctions lines and one return line. My local pool store says there is no problem stepping down to 1.5" and they have installed dozens without problem. The tech support department at Pentair says not to step down to 1.5" and if the local dealer says they can do it to get it in writing.

Problem is that I can save about $500.00 by buying the pump online and I have the mechanical ability to perform the installation. I am just not sure who to believe. My first reaction to to believe the factory but the local store is reputable and I do not think they would be doing this if there were a problem. I would also think if this were a problem Pentair would be losing much business in retrofits.

So, my question is, does anyone with experience have an opinion on whether or not this would present a problem. Thanks in advance.

[PoolDoc]

The Intelliflow can be 'turned down' to provide a sufficiently small flow so that you won't 'overdrive' the 1.5" piping. But, by doing so, you lose most of the benefit of a multi-speed pump with very high flow capability.

You could operate more efficiently by purchasing the old Hayward Super (not Super II) pump in the SMALLEST 2 speed model (3/4 HP?) and using that instead. That pump will use less electricity, and more properly sized for 1.5" piping.

Ben

[jamesdean]

Thanks Ben, would I realize any where near the savings that is being promoted going from a 1 HP to the Intellifow?

[PoolDoc]

No.

As far as I've been able to determine, the only 'extra' savings an Intelliflo can offer over a conventional pump with a high efficiency motor is the ability to 'tailor' the flow to only as much as the pool needs. You can already get 80+% of that 'tailoring' by (1) picking the right pump to start with, and (2) buying a 2 speed version of that pump with a high-E motor.

As a general rule when the pool industry promotes "savings" what's being saved is the pool store's cash flow. For example, SWCG's are often a valuable product, but they do NOT produce the "savings" claimed, when compared to a well operated BBB pool. In fact, they cost somewhat more, in most cases.

There is another circumstance where an Intelliflo or similar pump is justified. Some high end in-ground pools have multiple and complex loads that vary through out the day. For example, a pool might have a roof top solar system, a fountain, and a spa. It is possible, with an oversized Intelliflow to have a pump that can meet the maximum flow demands, but then 'turn down' efficiently when those loads are not active.

Of course, implementing such a system requires, not just good controls, but a good "control-setter" or pool mechanic. Those are all that common.

[jamesdean]

Thanks again Ben. You have given me much information to think about. What started this whole process was a flyer received promoting the following product. A discussion about this flyer with my local pool store led into the Intelliflow investigation.

Here is a link to the product advertised in the flyer. http://www.impowerdealer.com/ It appears to be a 3 speed 3/4 HP motor that would adapt directly into my existing pump. Is this more along the lines or your suggested motor only replacement and do you feel I would benefit with energy savings with this product?

Continued thanks and appreciation for your help on this.

[PoolDoc]

Actually, it looks like that motor might make things easier, given this Q & A from the page you linked:

Q: I have an automation control, but I have NO additional relays to tie the low voltage cable, can I still use the imPower motor?

A: Absolutely! You can wire imPower similarly to the single speed timer, tying the L1 and L2 connections to the filter pump relay on the automation control. The motor will run on HIGH speed for 2 hours, and then to the LOW speed for the remainder of the timer ON time. Note that the default lowest speed setting can also be changed. Please refer to the installation manual for details. Operational compliance of imPower may change dependent on local laws and regulations. Please consult your local government for a list of applicable electrical codes.

Getting controls right is one of the difficulties with 2-speed motors; many electricians do not know how to wire them. It looks like that unit can be effectively controlled with a single speed timer.