Most economical way to keep tub hot???

[pg_rider]

Is there a definitive answer as to whether it's better to 1) leave a tub at a constant temp, or 2) program it to cool off when you know you're not going to use it (like during the day while you're at work) and have it kick back on in the afternoon?  I actually have this same question with my home thermostat and have never heard a good answer!

[Chas]

Plug it into your neighbor's house.


Various brands will give you different results. If you spa has a small circ pump, most likely it would be better to leave it hot.

If your spa sits idle for a week at a time, it may be better to heat when you are ready to use it. But that depends upon how much heat it looses in the week it sits.

Sorry, no pat answer.

[nicker]

I would say there are too many veribles in that.  Time or year temp outside etc.    I leave mine alone.  100 in summer 101 in winter.   That way its ready to use when ever you want to use it and you don't have to worry about heating it up.   And even if you lowered it you would have to go very low (in my opion) to see any savings and they would be so minimal its not worth it anyway.  And that is if you even save, you may end up using more hydro with having it have to heat the water up all the time.  You would surprisd at how well a GOOD tub holds it heat and efficient they really are.

ID leave it be.

[sledjunkie]

Solar Cover

[Guzz]

I agree with birthday boy & Nicker, Circ pump, good tub, leave it alone.

[Reese]

If you do a search back a long ways, you will find some good discussions of this topic, and the differences between heating water and your home air.  As Chas said, unlike your house where setting the temp down for a few hours can generate savings, on a hot-tub the payback is much longer. Another issue on my tub is circulation/filtration.  If you set it down more than 2 degrees below water temp, it goes into summer mode and shuts off the circ pump, defeating the cleaning system.

At the risk of offending Spatech with another summary : it really depends on how long you go between uses, and because water heats slowly, how much lead time you have to reheat the tub before use.  It seemed to me the consensus was to leave the temp up.   We leave ours set at operating temp during the warm months and will set it down 5 degrees if we expect a busy week with no time to tub in the winter months.  With our 5.5 kw heater it takes only an hour to get back up to operating temp.  If we are leaving for a vacation, we set it down to 80.

p.s.  Regarding your home, I thought the data was clear.  Setback thermostats save money.  The more and the longer you set it down, the more you save.

[Brewman]

Reese nails it.  
 If it takes one hour to heat your water, assuming your spa heater consumes 5.5KW, and you pay .10 per KWH, the cost for this hour is about $.55.  

Use one week as the time you are reducing the water temperature setting.  If during that week of lower temperatures you heater stay off more than one hour vs the time it would run if you just kept the same temperature, you'll save some money.

Probably not a huge amount, but it may add up over time.  

We just keep ours always set- our spa use isn't predictable enough to vary the water temperature too much.

[imp etc]

We've set our tub on the "economy" mode, which means it only heats when it's running its filter cycle. I just set it so that the cycle runs early in the evening for two hours, right up to the time I'll usually want to get in it. At that point it's at the desired temp (HOT to answer the other topic

That also means that by the time I'm well into my soak, the temp has gone down a bit, and it's more comfortable for the late-stage of the soak.

[LINDALU]

Have only about 3 mo's. experience, but will share it with you for what it is worth.
Our tub is at our weekend home so it only gets used then.
During the really hot spell we soaked at 100, now with definate cooler temps. we currently soak at 101 / 102.
We set the temp. @ 98 when we leave after the weekend. During the really hot spell we found upon arriving that the temp. gained 2-3 degrees above the 100 that we soaked at. Actually did a cool down by removing cover and running the jets with the waterfalls wide open, which worked well to bring the temp. back down to 100.
Now we still are setting it back to 98 when we leave, and find on arrival the following weekend that the temp. is still at  our 101 soak temp.
I'm guessing that the heater is not coming on, (don't know for sure since we're not there), but that the 24/7 circ. pump may add a small amount of heat, that is just enough to keep it where we left it.
During the cold mo's. (minus 0 in U.P MI) we expect to soak at 102+. It is yet to be determined what the temp. setting will be at upon leaving, but would expect to set it around 100, maybe a little higher.
Our tub is outside on a lower deck with an upper deck above.
Don't know if this has been any help. Don't know your circumstances, but if your using on a daily basis, you probably should just keep it set at your favored soak temp. if you have a well insulated tub and a good cover.
Hope you enjoy your tub as much as we  enjoy our's

[Spiderman]

Love my Hot Spring......"Set it and forget it!"  

[Vinny]

Set and Forget it! Unless you go away then drop the temp down.

As far as your house, Reese is correct. I set mine to 60 in daytime and 65 at night in the winter and 78 in daytime and 76 at night in the summer ... I also have a programable fan thermostat that I have coming on at night in the summer to circulate air. In the winter my wife sometimes has to turn up the heat to defrost food ... drives me nuts.

[BIGPOPPA]

A couple dealers here would have you believe thermolock is the most efficiant.
Knowing what i know about hot tubs i shopped the dealer promoting thermolock insulation and i have to saythe story was great, if i didnt know any better i would have been sold.  I pissed off the sales manager and asked if it was the most efficiant and best way of insulating why do the top 5 manufacturers fully foam there spa seeing the top 5 have been in business many more years.  he went for a loss of words...

BIGPOPPA

[Vinny]

Something I forgot to say is we have it at 72 in the summer when we're home and 75 in the winter when we're home.