Horse power

[hottubdan]

So, I have seen some discussion about horsepower in some other threads.

Please understand that horsepower is only one factor for the feel of the jets.  Other factors:

Plumbing
# of jets
size of jets
size of orifaces
design of jets

As Vanguard mentioned there are no standards.  Pump manufacturers will slap on whatever label spa manufacturer asks for.  It is what is called market horse power.  Bottom line, knowing the horsepower of pumps in spas is almost irrelevant.

[loosenupspas]

GPM is significant.....gallons per minute.   HP is meaningless.  Electrical motors are measured on RPM's, not HP.  Isn't Horsepower calculated by cylinder depth and piston width, liters of displacement.  Heck I don't remember but spa pumps are about flow rates, GPM's.  Good question.....

[Chas]

There is a story floating around that if you walk into a Rolls Royce dealership (do they still exist?) and ask how many horsepower their new cars have, the answer you get will be:

"Sufficient."


I don't want to sound quite that snooty about it, but I do think that Dan is right. The number on the brochure or in the owner's manual means absolutely nothing. Could be a different rating system, Breakdown Torque, or the pump could be fitted with an oversize or undersized impeller, uprated or down rated motor or any of a dozen other things which renders the simple HP rating worthless. The important thing is the jet action in the finished spa, as installed and used.

Try wet testing, and see if you have enough action from the jets - or if you don't.

That is what you will have to live with for the next two decades. The brochure will not likely be around for two weeks after delivery.

 8-)

[Josh]

Try wet testing, and see if you have enough action from the jets - or if you don't.
 

Although I've enjoyed the lessons I've been getting in what people think the horsepower ratings actually mean (or don't mean) you're absolutely correct. The only way to really tell is to get in and soak, and see how they feel.

I tested a Hot Springs tub that had 2 4.8hp (peak) motors and felt incredibly weak compared to a Jacuzzi with two 4.2hp motors.  In this case, even though the Jacuzzi didn't have as much power, it felt so much better than it's competition....so clearly, specs aren't everything. Of course...the Jacuzzi also cost quite a bit more....so maybe it's not fair to compare it against the cheaper Hot Springs model.

I also tested a spa with 3 4HP pumps (it was a Phoenix) and I still liked the way the Jacuzzi's jets felt compared to it.  On paper...once again, the Jacuzzi was inferior in HP specs, but when actually sitting in there....it felt much better than the Phoenix that supposedly had more power pumping through it.

Of course, none of those choices was able to compare to the comfort of the LA Spas model I actually bought (which I choose to equip with 3 5HP pumps.)  I did test one of their 2 pump models, and it was good.....but the 3 pump was noticeably more powerful in the foot jets (and lounge seat) so ultimately....that's what I chose.

Now....we'll just have to see how often I sit out in that thing with all the jets on.  

[Cyn]

I believe this is all true of vacuume cleaners as well...HP means nothing.

[Repeat_Offender]

Those who say horsepower means nothing are wrong.
Improperly applied, large horsepower pumps can be made to feel inadequate due to long piping runs and improper line sizing or poorly designed jet quantities or sizes. Just as smaller horsepower pumps utilizing properly sized lines and lengths combined with well engineered jets and air induction can be made to feel more than adequate.
The plain fact is that all other factors being equal, higher horsepower pumps simply have the ability to do more work (move larger volumes of water) than their lower horsepower counterparts.

[Zep]

Josh......glad to hear you love your new LA Spas
I was not aware LA Spas had such powerful jets
How many gallons of water does your tub hold?

[Vanguard]

I believe this is all true of vacuume cleaners as well...HP means nothing.

Except they use Amps.  But its still the same deal.  I really don't care how much power my vacuum cleaner draws.  I just want to know its sucking the dirt out of my carpet.


The world would be a better place if manufacturers quit confusing consumers with horsepower.

[Vanguard]

Those who say horsepower means nothing are wrong.
Improperly applied, large horsepower pumps can be made to feel inadequate due to long piping runs and improper line sizing or poorly designed jet quantities or sizes. Just as smaller horsepower pumps utilizing properly sized lines and lengths combined with well engineered jets and air induction can be made to feel more than adequate.
The plain fact is that all other factors being equal, higher horsepower pumps simply have the ability to do more work (move larger volumes of water) than their lower horsepower counterparts.

We don't mean that HP doesn't contribute.  Primarily, we are saying that knowing the horsepower isn't going to be your deciding factor.  It is just not how one should compare spas.  Horsepower is part of the entire equation.  For sure, if you had 1hp and 100 jets, you will probably not get much action, but if you have 2hp, you might like it better.

In the end, knowing what the horsepower of the pump on a spa has no effect on whether or not you like the feel of the jets.

[kokanee001]

Half the time spent in my Vanguard is with the pumps off, just enjoying the heat and the silence...............so raspberries to hp fanatics

[Chas]

Those who say horsepower means nothing are wrong.
Improperly applied, large horsepower pumps can be made to feel inadequate due to long piping runs and improper line sizing or poorly designed jet quantities or sizes. Just as smaller horsepower pumps utilizing properly sized lines and lengths combined with well engineered jets and air induction can be made to feel more than adequate.
The plain fact is that all other factors being equal, higher horsepower pumps simply have the ability to do more work (move larger volumes of water) than their lower horsepower counterparts.

You just contradicted yourself. Your opening line says we are wrong, but then you go on to point out exactly what we have been saying: that HP numbers do not take into account the many variable such as good/poor plumbing, long/short plumbing lines, well designed/poorly designed jets, jet quantities and jet sizes.

You also mentioned air induction - some spas use a blower to force air into the jet system, and others use recycled heat as the air source - there are about as many variables as there are tub makers, times two.

Next - look at the line in your post where you said, "All other factors being equal, higher horsepower pumps simply have the ability to do more work..."

But in comparing different tubs, especially from different makers, all other factors are far from equal. Better tub makers us better designs on plumbing, jets, layout, plumbing size, and many other factors including hydraulic balance and flow characteristics. And if a system is well designed, it will flow just about as much water as the pump can put out, and simply adding a larger motor or motor/pump combination will not net higher flow. You would need to redesign the entire plumbing system, or add some jets, or up size some of the jets, or remove some plumbing restrictions, or increase filter area, or perhaps all of the above before the larger pump could move more water.

Sorry, but shopping by HP numbers on the brochure or web site simply will not tell you anything about how well or poorly a particular spa is going to work.

One more thing - three five horsepower pumps will require (750watts X 15= 11250 watts, which will take 52 amps at 220volts. To run just those three pumps, you need to have a 70 amp breaker feeding the spa. That means that no additional blowers or heaters could run at the same time. NEC only allows 80% of the breaker's rating, so 70 amps X .8 = 56 amps max. That may require a larger main electrical panel in your home!

But relax, I have repaired plenty of spas which have three pumps labeled as "5HP" and they are actually 3HP pumps with over sized impellers, or some other combination - but they are NOT truly Five Horsepower pumps.

The rating plate on the motor will prove it. In each of the cases replacing the motors with the same amp/voltage required buying 3 HP motors. In fact, recently I replaced two bad motors in a spa which had three pumps with 5HP stickers on them - and one of them was only a 1.5 HP two-speed for heating/filtering. It had a completely different motor, the pump housing was smaller, the plumbing was smaller, needless to say the impeller was smaller, and yet it had it's very own "5HP" sticker just like it's big brothers. I looked at the rating plates on the bad motors, ordered new wet end pumps accordingly, and the new pump/motor combos were 3HP with 2" plumbing. The spa worked exactly as it did when new.

So again, if the customer shopped and bought because the maker told them they had three five horse motors, they were misled. If they shopped and bought because they turned one of these tubs on in the showroom and were pleased by the amount of water moving - and if that held true to the spa which was delivered to their home, then once again I say, the HP claims and/or markings on the brochure and even the tub mean nothing.

OK, one more thing - if you can get good jet action out of smaller pump/motor combos, why wouldn't you? I mean, why pay the extra energy bill if you don't have to? Most of my customers report that they run the jets at reduced power - that is easily accomplished in HotSpring and Tiger River tubs - and I haven't had folks complain about lack of power at the jets.

Yes, some have come in and put their hand in front of the jets and reported that it wasn't as strong as brand X they had just looked at. And they were right! I have sold Caldera, and they can be set to put out far more kick at the jets than HS and many other tubs. But long-term owners tell me that too much power at the jets is just too much power. It is not comfortable, and it not used in reality, at least not on a regular basis. HS puts in a few extra-large jets for when you need the extra punch, but I think they have come up with a pretty good system using far less power overall. Even my Caldera owners tell me that they move diverters and adjust jet settings to mellow out the jets for regular use.

So again, I say to shoppers - wet test, or at least stick and hand/arm in front of working jets in a running spa to determine if you are going to get enough power from the jets.
 8-)

[In Canada eh]

To All,

  What Chas has said is correct although perhaps a little long winded  A quick and easy look at the motor HP to pump GPM ratio would go like this.

Say you have two different spas that both have one 200 GPM pump.  Spa "A" has a well designed low head or back pressure plumbing layout.  That spa may only require a 2.5 HP motor to move the 200 GPM the pump is capable of delivering.  Spa "B" has a poorly designed plumbing layout, higher head pressure with a lot of bends and elbows in the system and a lot of small jets.  That spa would require 4.5 HP to deliver the same 200 GPM.

Its all about the pump GPM and the plumbing or head pressure in the spa, the HP is some what irrelevant.  Motor performance is measured in amps and that can be converted to HP.  Pumps are measured in GPM only.  The term "4.8 HP pump" makes no sense.  The correct way to say it is 200 GPM pump with a 4.8 HP motor.

Just my 2 cents worth

[Repeat_Offender]

Chas,

Excellent points, and you're right. "All things being equal" is non-existant in the hot tub world. I guess simply put, more horsepower gives you greater "potential" for greater pressure, water movement, etc..

Joe

[Chas]

To All,

  What Chas has said is correct although perhaps a little long winded  

A LITTLE!? Wow, I just looked it over - I guess I have battled this for a long time.

Sorry to get so verbose....


Breathe Chas, breathe.

 8-)

[Zep]

could one also make many of the same "horse power means nothing"
arguments about cars?......because many cars are designed different
and some may be "designed better"?