Hot Tub Forum

Original => Hot Tub Forum => Topic started by: Detroiter on March 11, 2005, 09:56:47 am

Title: 240 vs. 120 volt
Post by: Detroiter on March 11, 2005, 09:56:47 am
Hi everyone! just wanted all here to know I have had a great time "learning" about hottubs on here and getting to kind of "know" all of the various sales and scare tatics employed by spa sales people, (just kidding lol)!
On a more serious note, I haven't come across an in- depth discussion of what the advantages vs. the disadvantages of 240 volt hook up versus 120 volt hook up. I just purchased a Marquis Spirit 2005 and am due to receive delivery in a few days, (thanks Stuart for your constant uplifting praise of this tub!) he he ....but the salesman kept telling me that 120 would be fine here in Michigan. I on the other hand, am not sure I want to wait forever for my tub to heat up after water changes or decrease temp when the pumps are in high mode here in these chilly conditions....so which way do I go? Thanks in advance for your responses.
Title: Re: 240 vs. 120 volt
Post by: wmccall on March 11, 2005, 10:07:56 am
Resisting all my Michigan Jokes
(http://graphics.fansonly.com/schools/osu/graphics/osu-top-logo-2.gif)
Go with the 240, you will be much happier in the long run. Perhaps your salesman was a siberian transplant and considers the lower peninsula as the tropics?
Title: Re: 240 vs. 120 volt
Post by: Chas on March 11, 2005, 10:12:50 am
For any spa on 110: the electrical outlet cannot support running both the jets and the heating system at the same time. So when you press the button to turn on the jets, the spa automaticly shuts off the heat. The Sprint is just under 200 gallons if I recall correctly - and well insulated. So you should have no trouble keeping it warm on 110 volts.

For folks in warm climates this is not a 'problem.' Also, most folks end up using the jets for five or ten minutes and then soaking quietly after that, and the heat will jump back to life as needed as soon as the jets go off.

But if you want to be able to run the jets for longer than that without cooling, you might want to consider going with 220.

One other item: on 110 volts the heater runs about 1500 watts max. That's enough to slowly heat the tub and just keep it there in icy conditions. On 220 most heaters jump to 4-6000 watts, and keep in mind that on 220 the heat may run whenever needed, so you can count on faster temperature changes and more stable temperatures in cold weather.

My opnion for any brand, any size tub in this regard is simply that you'll never regret going for the 220.
Title: Re: 240 vs. 120 volt
Post by: wmccall on March 11, 2005, 10:23:12 am
Quote
, so you can count on faster temperature changes and more stable temperatures in cold weather.



Another of Chas' well thought out, super helpful to the consumer posts.

On a related note, and I am about 100 miles south of you,  We had a powerfailure yesterday afternoon. (Not sure how long, nobody was home, the clocks were all flashing type of thing)   I reset all my clocks and then after dinner I left for my Thursday night activity which involves a lot of excercise. (Well. being from Michigan, you probably have heard of curling)  Last night was particularly brutal, and the whole way home I kept thinking, this is the type of night that makes owning the hot tub worthwhile.   As I was walking out to it, I had a sudden flash remembering that my tub defaults to 95 degrees after a power outage and I was dissapointed when I saw 99 flashing on the tub and I was all set for a 104 degree blast every jet, knock me out of my seat soak. I set the temp back to 104, closed the tub, went in the house, watched Survivor that I taped and when it was done (40 minutes later) I went out to a 103 degree tub.  Can't do that on 110.
Title: Re: 240 vs. 120 volt
Post by: Chas on March 11, 2005, 10:36:05 am
True -

Rule of thumb:
Most 110 tubs heat in the neighborhood of two or three degrees an hour, while most 220 tubs can do closer to ten degrees an hour.

Your mileage may vary - due to different climate, size of tub etc. - and most tubs tend to heat faster as the temp gets around the 100 mark, but this is a good rough idea.
Title: Re: 240 vs. 120 volt
Post by: wmccall on March 11, 2005, 10:56:04 am
Quote
True -

Rule of thumb:
 and most tubs tend to heat faster as the temp gets around the 100 mark, but this is a good rough idea.


And when you first fill, it seems to take forever to raise those first couple degrees.
Title: Re: 240 vs. 120 volt
Post by: Mendocino101 on March 11, 2005, 11:00:24 am
Chas and Bill are right....
IF hooking up 220 is an easy thing for you to do and fits in your budget it is always the best way to go.....One very nice thing about the 110 hook up is this ....If you want to keep it simple in the beginning you can always if you find the need to switch to 220 down the road do so....As far as I know all 110 spas can be converted to 220 and in most cases  is a very simple and easy to do...
Title: Re: 240 vs. 120 volt
Post by: Detroiter on March 11, 2005, 06:25:35 pm
Well, as I expected, you all have given me excellent points to consider.  I have now decided to do it up "right" and hook myself up with 240, Thanks again for the insight folks!
Title: Re: 240 vs. 120 volt
Post by: Lori on March 11, 2005, 06:27:32 pm
Quote
Resisting all my Michigan Jokes
(http://graphics.fansonly.com/schools/osu/graphics/osu-top-logo-2.gif)
Go with the 240, you will be much happier in the long run. Perhaps your salesman was a siberian transplant and considers the lower peninsula as the tropics?


Maybe he will stop picking on my Longhorns!  (I doubt it, though!)
Title: Re: 240 vs. 120 volt
Post by: stuart on March 11, 2005, 08:50:56 pm
I would pay the extra and get a 220, it's a bigger motor and it will keep the heat better as Chas suggested. I have many customers that enjoy the 110 option however the Spirit has been retooled with more jets and bigger jets to where I think it needs the 220 pump...
Title: Re: 240 vs. 120 volt
Post by: Bill_Stevenson on March 14, 2005, 11:06:22 am
One additional thought.  Given two identical tubs, one with 110 Volt AC and the other 220 Volt AC, the 220 VAC will draw exactly 1/2 (one half) the current that the 110 VAC version would. This is in accordance with Ohm's law, which states that the voltage divided by the resistance equals the amperage.

The practical consequence of this to the consumer is that the 220 VAC unit, by drawing less current to do a certain amount of work (i.e. pump and heat the water), will cost approximately half as much to operate in terms of your electric bill.  

Actually it is not really half because as others have pointed out, the design of all 220 VAC units that I am aware of provides for them to both heat and pump water simultaneosly.  Since the larger fraction of the total energy consumed to operate a spa derives from the heater, however, a 220 VAC unit is still going to be considerably less expensive for electricity.

Regards,

Bill
Title: Re: 240 vs. 120 volt
Post by: wmccall on March 14, 2005, 11:46:03 am
Quote
The practical consequence of this to the consumer is that the 220 VAC unit, by drawing less current to do a certain amount of work (i.e. pump and heat the water), will cost approximately half as much to operate in terms of your electric bill.  



Actually, your in error somewhat.   If all else was equal, a 240 volt tub wouldn't cost half to operate. True it would use half the current, but you pay for power, not amps (current)  If a 240 volt tub drew 10 amps for an hour that is 2400kws or 2.4 kw hours.
a 120 volt tub drawing 20 amps would consume the same power.  I'd rather run a wire for 10 amps than 20.
Ther other half of Ohms Law

    E
________
I     |  R


is

   P
_______
I      E        Power =I amps *-e Volts
Title: Re: 240 vs. 120 volt
Post by: Mendocino101 on March 14, 2005, 11:54:48 am
Bill...

THank you that is what I also thought...that the bottom line as far as cost go is amp draw....
Title: Re: 240 vs. 120 volt
Post by: Chas on March 14, 2005, 09:07:55 pm
Our esteemed moderator is correct:

The meter on the side of your house is a WATT meter. It measures in thousands of watts per hour, or 'kiliwatthours.'

Watts are Voltage multiplied by the Amperage. So if you cut the Amps in half but double the Voltage, you have the exact same number of WATTs, and so will cost exactly the same.  

The only time a 220 spa will cost less to operate is if it uses a fairly large pump to circulate through the heater. If that is true, then the fact that the 220 system heats faster can cut costs a bit.  

However, the fact that you can run the jets all night long without the tub cooling tends to allow for running the operating costs way on up there, so most folks don't see any real savings by going with 220.  

There are other reasons to do it, but it doesn't automatically save you money, and certainly not half.

Title: Re: 240 vs. 120 volt
Post by: Bill_Stevenson on March 15, 2005, 10:06:47 am
Well Chas, I will just have to repectfully disagree.  Any appliance that uses a lot of power is going to be cheaper to run on 220 than on 110.  Precisely for the reason that it draws half the current.  There are line losses and increased resistance, not to mention the time factor of getting the work done.  

I would agree with you that you won't save half in the real world, but going with 220 will definitely save you money.  This is true for big items such as central electric heating, ranges, central air conditioning systems, and spas.  Generally things that draw 30 or more amps.  

Regards,

Bill
Title: Re: 240 vs. 120 volt
Post by: Chas on March 15, 2005, 10:47:03 pm
Quote
Well Chas, I will just have to repectfully disagree.  Any appliance that uses a lot of power is going to be cheaper to run on 220 than on 110.  Precisely for the reason that it draws half the current.
But it doesn't draw half the amps. At least not when we're talkin' spas... Most 110 volt tubs draw around 13 amps. Maximum legal would be 16 amps which is  80% of the 20 amp breaker.

Most 220 tubs draw 40 amps - again 80% of their circuit breaker, but this time it's a 50 amp breaker, or some even a 60 amp breaker.
Quote
There are line losses and increased resistance, not to mention the time factor of getting the work done.  
Not if you install the correct wire. A 20 amp 110 volt line is doing much less work than a 50 amp 220 is going to do, so the line-loss and inductance/eddy current/ resistance is all lower.

We really don't need to argue - unless you want to for fun ;) You are most polite and I thank you for that.  The question is almost moot - most tubs these days have pumps which are so large they couldn't run on a 110 volt circuit if you wanted them to. But the convertible ones will only cost more on 110 if there is a pump which only runs when heating. If you have a circ pump or other tiny pump which does the heat circulation - especially if it runs all the time anyway - you won't see a savings.

But it's much more fun to have the thing hot four hours after a water change - so don't go for 110 unless you have to.