I would have to check, but I think that it is only a single run of 2" pipe.

I'm used to head being primarily a function of altitude differentials - like with a well pump or something. Since the pump and the spa are more or less on the same level, am I really generating that much head from sheer friction in the pipe?

I realize that 80' may be a long run, but is there truly that great of resistance in a 2" pipe?

The link shows a head loss chart. Note how fast head loss goes up as the number of GPM goes up. This is a direct result of the water's velocity. Speed kills.

I just got the link from Google and have no affiliation with the owner of the web site.

Scott

Here is a link that might be useful: Head loss chart

"I realize that 80' may be a long run, but is there truly that great of resistance in a 2" pipe?"

Yes, dynamic head loss is proportional to the flow rate squared! But even worse it is proportional to the pipe diameter to the fifth power!!!! Fittings to the forth power. So pipe size really makes a big difference. The jets themselves add quite a bit of head loss as well. Ideally, a 6 jet spa should have at least 2.5" pipe for single runs which would have allowed you to use a 1.5 HP pump and still hit 15 GPM/jet.

Why not just run your intelliflo back through the spa jets at a higher speed.

We have a lot of really old spas here in Seattle, and for a jet system with 6 jets, 2" piping in, and out, and 80' pipe run, a 2.0 HP pump.

But typically energy efficiency isnt a huge concern with a jet pump because they only run maybe an hour a week at most. Which even in markets where energy is expensive equates to $2 a month

Mas, you head figures are a little bit high, for a jet system that has no filter, heater etc, on it.

A 3hp would be about 100-110 on a 3hp 2" in and out even with that pipe run with a 7/16th orifice on the jet. This is based off real world analysis of this type of system.

Racket

I am confused by your last statement is that 100-110 feet of head or GPM? If I model a 3 HP with 7/16" jets (I used 3/8" before), I get 86' of head and 100 GPM which places it right in range of what your describing if it is GPM. The jets in my spa are closer to 3/8" which is why I used that.

110gpm.

7/16th is a standard orifice size for both waterway, and hydro air venturi tees, now there are about 100 different ones you can use, but those seem to be the most common.

They come with a little plastic reducer that will reduce it down to 3/8".

Thanks a lot for applicatable in formation about calculating and desiging pools and jaccuzzi

Best way and the most certain method for or on the other hand for first step of selection and calculation capacity of پمپ جکوزی

The most impoatant parameter for selection Jacuzzi pump

· First step of selection suitable pump is number of nozlle of jcacuzzi

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· For each nozell you need 0.5 or 1 hp power of pump

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· purification rate for jcacuzzi 0.5 time per hour