Power outage and freeze questions ??

[Brewman]

Steve....I am confused I thought the Artic spas were used as a heat source for small towns in the case of a power failure....did you not also read that in their brochure along with it using the space shuttle heat shield to recover heat as reenters earths atmosphere that will help it  remain hot with the cover off...or was it that their cover is used as the heat shield its self....

That's nuthin.  Cavein spas are so energy efficient that they actually feed excess electricity back to the power grid.  The tubs actually pay for themselves over time.
Brewman

[wmccall]

With the insulation methods used in spas today you needn't worry.  Most spas will be fine for 7 days in the event of a power failure during the winter.  But in the event of a prolonged power outage (greater then 7 days) following the advice stuart gave will help prevent any potential damage.

Jason,
Store manager for a D-1 & Caldera Dealer

As an example, I was having to turn my spa off at night for a few days.  The weather was in the 40s.  At 11pm at would be 102.   At 7am is was 99 when I turned the power back on.

[stuart]

Steve....I am confused I thought the Artic spas were used as a heat source for small towns in the case of a power failure....did you not also read that in their brochure along with it using the space shuttle heat shield to recover heat as reenters earths atmosphere that will help it  remain hot with the cover off...or was it that their cover is used as the heat shield its self....

They're actually looking at the possibility of building a small town on an Arctic cover!

[Elle]

As an example, I was having to turn my spa off at night for a few days.  The weather was in the 40s.  At 11pm at would be 102.   At 7am is was 99 when I turned the power back on.

I was just telling my husband how well our spa is insulated after I did my last fill.  I first did a superchlorination which required me to run my spa for over 2 hours with the cover off.  The first thing I did was turn the temp down to 80 so the heater wouldn't run.  The spa started at 101 degrees.  The outside temp was 36.  Remember no cover with jets running full power.  At the end of the 2.5 hrs the spa temp was 98.  That's insulation.

Elle

[Mendocino101]

I was just telling my husband how well our spa is insulated after I did my last fill.  I first did a superchlorination which required me to run my spa for over 2 hours with the cover off.  The first thing I did was turn the temp down to 80 so the heater wouldn't run.  The spa started at 101 degrees.  The outside temp was 36.  Remember no cover with jets running full power.  At the end of the 2.5 hrs the spa temp was 98.  That's insulation.

Elle

lol..no that's a Marquis.....

[Elle]

lol..no that's a Marquis.....

TRUE....very true....TRUE....very true  

[TimC]

Hi Everyone

Why would you need the light in the motor compartment?  Wouldn't it stay warm from the tub?

I have a HS Vanguard.  Does the Circ. pump keep the motor compartment warm during winter and when the power goes out the motor compartment lose it heat source?

[stuart]

Hi Everyone

Why would you need the light in the motor compartment?  Wouldn't it stay warm from the tub?

I have a HS Vanguard.  Does the Circ. pump keep the motor compartment warm during winter and when the power goes out the motor compartment lose it heat source?

If you lose power in the tub a light will help keep the equipment warm until you can find the problem.

[stingfan]

I've seen questions like this before and just wanted to put in my 2cents.  This is not a totally ridiculous question and some hot tub owners are not being paranoid.  We have power outages where I live that sometimes last hours.  Once, several years ago, we have a severe ice storm and my power was out for 3 days.  I have had the same question as others, how long until I have to add some warmth to the pump compartment?  I think someone earlier in this thread answered that question for me.  Thanks.

[Chas]

Yes, you are very right. I tease a bit because it's not a problem here in CA, but the answers above are correct:
Most tubs will go many days without a problem.
If you have an extreme situation, you may already have a generator on hand, or you may have to get one for other reasons - like survival...

In that case, simply putting a work light on a power cord, postioning that light in the motor compartment, and perhaps some blankets/tarps over the whole tub to keep that heat in the tub better can allow you to not worry about the tub, and have time to worry about all the other things that you have to worry about in an ice storm.

I have read on other boards about folks who have power  outages often enough that they got a generator. But they turn the heat off in the tub (too much load for the genny) and simply run the circ pump or low-speed pump to be sure the water stays in motion. This can be wired into your  house so that it automatically allows power to the pump but cuts power to the heat when the genny comes on - at least on a HotSpring it can. Other tubs you may have to simply go turn the temp all the way down, or somesuch. With this arrangement, you can go quite a while. The tub cools, of course, but generally will not freeze.

[wetone]

We have serviced tubs that have had no power for 46 hours at -14C ??F here in the great white north, Ontario.
Water temp was 102F (per customer) when the spa quit, the water was 80F when the tech got it back up and running. That's about 2 day's.
I don't think another day would have caused it to freeze.

[Brewman]

I don't know a whole lot about thermodynamics, but is it true that the heat loss from the water would slow down as the water cooled?  Seems to me that heat transfer rate is higher when the temperature differential is greater, at least I think that's what they tried to learn us in school.  But I was in school a long time ago, so just wondering.
Brewman

[Chas]

I don't know a whole lot about thermodynamics, but is it true that the heat loss from the water would slow down as the water cooled?  Seems to me that heat transfer rate is higher when the temperature differential is greater, at least I think that's what they tried to learn us in school.  But I was in school a long time ago, so just wondering.
Brewman

Yes - very much so. The last few degrees - and then the 'phase change' from liquid to ice takes quite a bit.

[stuart]

We have serviced tubs that have had no power for 46 hours at -14C ??F here in the great white north, Ontario.
Water temp was 102F (per customer) when the spa quit, the water was 80F when the tech got it back up and running. That's about 2 day's.
I don't think another day would have caused it to freeze.

Wouldn’t that confuse the heater if the topside is reading in Fahrenheit and the outside temp is being measured in Celsius?

I don't know a whole lot about thermodynamics, but is it true that the heat loss from the water would slow down as the water cooled?  Seems to me that heat transfer rate is higher when the temperature differential is greater, at least I think that's what they tried to learn us in school.  But I was in school a long time ago, so just wondering.
Brewman

Water responds to heating with the greatest increase in warmth at precisely 37 degrees C, or 98.6 degrees F.

“Water reaches its greatest density at 4 degrees C. When cooled below that point it begins to expand again, so that the solid form is less dense than the liquid. By this principal ice forms on the top of lakes and ponds, thereby insulating the water below from further cooling. This wonderful property is essential for preserving life through the natural seasons of the year.”

[HotTubMan]

Wouldn’t that confuse the heater if the topside is reading in Fahrenheit and the outside temp is being measured in Celsius?

You are right Stuart, this the main reason why a tub in Canada is less likely to freeze. The tub isn't quite sure what temperature is correct.......unless its a D-1 displaying in Celcius.