High Electricity Consumption

[mas985]

Maybe this picture will help explain. The red boxes are where there is no insulation at all. The blue box is where there is insulation. Now picture that on all 4 sides. That's a lot of uncovered tub shell.

I added a thermal photo for some reference. I drew a blue line around a spot I must have insulated well yesterday. My previous thermal image of that area showed it as a hot spot.
View attachment 625633

Understood. I agree that they may have missed some spots. This was brought up previously but if it were me, I would empty the spa and turn it on it's side (equipment down) to look at the bottom and see what is insulated and what is not. At least then you would have pics to show the manufacture to prove there is an issue.

 

[jpk207]

Understood. I agree that they may have missed some spots. This was brought up previously but if it were me, I would empty the spa and turn it on it's side (equipment down) to look at the bottom and see what is insulated and what is not. At least then you would have pics to show the manufacture to prove there is an issue.

I'm pretty certain because it's rotomolded, it doesn't have the same structure as a standard hot tub. So putting it on its side and looking into it won't tell me much. Also, I'm curious how people do this when it's hard wired to a 220v breaker. Do you disconnect all the electric from the hot tub?

 

[ajw22]

Let’s invite @RDspaguy to this discussion. I think he has dug into lots of spa insulation.

 

[jpk207]

An update on my experiment. At 9:45 am EST today I had used my hot tub and the temp was 103 when I got out. I immediately put the temp down to 80 degrees. The cover has been closed ever since. Now, at 4:15PM EST the tub water temp is reading 97. Six degrees already it has dropped. Pretty much on pace for 1 degree per hour loss.

 

[RDspaguy]

Ok, I only made it to page 3 so...
Voids in foam are easy to fill if you know where they are, and they aren't hard to find if you have access panels. I use a dowel rod, but a thermal doohickey works too. Just use a longer tube on your foam can.
Too much insulation or a lack of venting will cause equipment problems when it's hot out. Be sure you don't over-do it and cause problems for yourself later. Not sure how your warranty reads, but DIY repairs usually void them.
The majority of heat loss should be the cover and equipment area/vents. If it's not, it's a problem.
Spas usually cost a whole lot more to get hot than to keep hot, and those sales-pitch quotes are for keeping it hot, probably in the summer, in florida.
Low ambient temps can trigger freeze protection modes which run pumps to avoid freezing pipes (yes, individual pipes can freeze in a hot spa). Pumps running all night will wreak havoc on your meter reading.
That $ seems extreme, but so is the weather lately. Any possibilty that you have other devices in your home running more from the cold and affecting your bill? I'm not even running a tub right now and my bill was up 40%.

 

[jpk207]

Ok, I only made it to page 3 so...
Voids in foam are easy to fill if you know where they are, and they aren't hard to find if you have access panels. I use a dowel rod, but a thermal doohickey works too. Just use a longer tube on your foam can.
Too much insulation or a lack of venting will cause equipment problems when it's hot out. Be sure you don't over-do it and cause problems for yourself later. Not sure how your warranty reads, but DIY repairs usually void them.
The majority of heat loss should be the cover and equipment area/vents. If it's not, it's a problem.
Spas usually cost a whole lot more to get hot than to keep hot, and those sales-pitch quotes are for keeping it hot, probably in the summer, in florida.
Low ambient temps can trigger freeze protection modes which run pumps to avoid freezing pipes (yes, individual pipes can freeze in a hot spa). Pumps running all night will wreak havoc on your meter reading.
That $ seems extreme, but so is the weather lately. Any possibilty that you have other devices in your home running more from the cold and affecting your bill? I'm not even running a tub right now and my bill was up 40%.

Thanks for the info. I’m factoring in higher electricity usage for the rest of the house already, and even being conservative with the power consumption of my hot tub.

My experiment today is proving my hot tub water is losing 1 degree of heat per hour. I have a post about it higher in the thread.

 

[RDspaguy]

my hot tub water is losing 1 degree of heat per hour.

This is a factor of ambient temp.
Look, I'm not saying there isn't a problem, or that your observations vs expectations regarding the foam fill aren't valid. Definitely pitch a fit. But I think you are not giving the extreme cold of late enough of the blame. Did the foam guy at the factory get lazy? Probably. QC issue? Perhaps. But from my nearly 29 years of experience, I'd say tubs of all brands are freezing all over the place right now. And the people with shattered pipes are wishing like heck that their spa had avoided that for the low-low price of $300. Their repairs, if possible, will likely be 4-figures.
Perspective.

 

[jpk207]

This is a factor of ambient temp.
Look, I'm not saying there isn't a problem, or that your observations vs expectations regarding the foam fill aren't valid. Definitely pitch a fit. But I think you are not giving the extreme cold of late enough of the blame. Did the foam guy at the factory get lazy? Probably. QC issue? Perhaps. But from my nearly 29 years of experience, I'd say tubs of all brands are freezing all over the place right now. And the people with shattered pipes are wishing like heck that their spa had avoided that for the low-low price of $300. Their repairs, if possible, will likely be 4-figures.
Perspective.

I don’t think a hot tub heater running 6 hours per day to keep up with 1 degree heat loss per hour is happening with many people’s hot tubs though. My hot tub added over 950 Kw usage to my bill last month.

 

[dogsbody]

Hmm. So I'm just looking at your historical temperature data, and it looks like for the first three weeks of the month your average nighttime low was about -5C. That's pretty far from "brutal" - we've had quite a mild winter so far (thanks, Chinook!), and we've still woken up to -28C a few mornings, which is still a far frozen cry from, say, Winnipeg. But this is just in aid of the previous comments about heat loss (and energy use, if you're trying to make up for it) being a function of the temperature differential. Given that your tub temp is 100F, more or less (sorry about bouncing between metric and imperial, but that's just how us canucks roll), you're gonna lose heat a lot faster at -19C (ambient two nights ago) than at -5C. So if you're feeling the pinch now, just wait...

Now that I've seen the (rotomolded) shell, I get what you mean by "the corners" being a problem. Your thermogram is a mother in those corners, alright. So yeah, go yell at the dealer, because my interpretation of "extreme insulation" would be pretty far from what you're showing us, and they should either supply it or return the premium you paid - unless you want to press for a full return/refund. But if you ultimately opt for keeping it, don't screw around with those little cans meant for filling window frame gaps. Find a pro who sprays two-part foam into houses and see if he'll help you out with a small job like this, filling in the corners, etc. That's going to be much cheaper than buying the gun and foam to DIY. That stuff's pricey.

 

[jpk207]

Hmm. So I'm just looking at your historical temperature data, and it looks like for the first three weeks of the month your average nighttime low was about -5C. That's pretty far from "brutal" - we've had quite a mild winter so far, and we've still woken up to -28C a few mornings (thanks, Chinook!), and is still a far frozen cry from, say, Winnipeg. But this is just in aid of the previous comments about heat loss (and energy use, if you're trying to make up for it) being a function of the temperature differential. Given that your tub temp is 100F, more or less (sorry about bouncing between metric and imperial, but that's just how us canucks roll), you're gonna lose heat a lot faster at -19C (ambient two nights ago) than at -5C. So if you're feeling the pinch now, just wait...

Now that I've seen the (rotomolded) shell, I get what you mean by "the corners" being a problem. Your thermogram is a mother in those corners, alright. So yeah, go yell at the dealer, because my interpretation of "extreme insulation" would be pretty far from what you're showing us, and they should either supply it or return the premium you paid - unless you want to press for a full return/refund. But if you ultimately opt for keeping it, don't screw around with those little cans meant for filling window frame gaps. Find a pro who sprays two-part foam into houses and see if he'll help you out with a small job like this, filling in the corners, etc. That's going to be much cheaper than buying the gun and foam to DIY. That stuff's pricey.

Thanks. Ideally the dealer makes everything right, but if they screw me I’ll pay someone to professionally foam it up for sure.

 

[RDspaguy]

I don’t think a hot tub heater running 6 hours per day to keep up with 1 degree heat loss per hour is happening with many people’s hot tubs though. My hot tub added over 950 Kw usage to my bill last month.

If it's wired for 230v and is a 4kw it should, depending on volume, heat 4-6 degrees per hour, minus heat loss of course.
So on the low end of that output estimate at 1 degree loss per hour (on average over 24 hrs?) You need to run your heater about 6 hours. Isn't that what you're doing? 6hrs at 4kw is 24kwh, times 30 days (for convenience) is 720kwh per month. Add in pumps and accessories and I don't see how that math isn't mathing.
Your problem is 1 degree per hour, which is only happening because it's colder than a... well, it's cold.
What did they say about filling the voids? Have you tried a floating cover along with your main cover?
As for foam, you can certainly buy the two-part with the mixing nozzle if you want, but the cans will be fine for filling a few voids, and much cheaper.
It may be that your high temp areas in the corners are not voids in insulation but structural components of the shell.

 

[jpk207]

If it's wired for 230v and is a 4kw it should, depending on volume, heat 4-6 degrees per hour, minus heat loss of course.
So on the low end of that output estimate at 1 degree loss per hour (on average over 24 hrs?) You need to run your heater about 6 hours. Isn't that what you're doing? 6hrs at 4kw is 24kwh, times 30 days (for convenience) is 720kwh per month. Add in pumps and accessories and I don't see how that math isn't mathing.
Your problem is 1 degree per hour, which is only happening because it's colder than a... well, it's cold.
What did they say about filling the voids? Have you tried a floating cover along with your main cover?
As for foam, you can certainly buy the two-part with the mixing nozzle if you want, but the cans will be fine for filling a few voids, and much cheaper.
It may be that your high temp areas in the corners are not voids in insulation but structural components of the shell.

My math is correct, it's just horribly inefficient for a brand new hot tub. Modern hot tubs should not have to run the heater for 6 hours per day even in 20 F degrees. When factoring the low speed pump for circulation and using it daily, I'm well over 900Kw per month for just my hot tub. That's just not normal or efficient.

"Your problem is 1 degree per hour, which is only happening because it's colder than a... well, it's cold."
I would say anyone with an efficient well insulated hot tub side by side with mine right now will be losing maybe 1 degree every 3 hours (Not 1 degree per hour) in the same conditions. That's a huge difference. My heater is doing what it needs to do, it just has to run all the time because of the inefficient heat retention compared to a normally insulated hot tub.

I'm still waiting to hear back on my "Support ticket" but clearly this hot tun does not have the "Full foam" that I was promised. And it certainly doesn't have the "Extreme" foam add on I purchased. The floating blanket I ordered will be here early next week.

The high temp areas in the corners are definitely voids in insulation since they are completely empty (Aside from some insulation I stuck in there but that is not having much effect). Prior to me trying to squeeze some insulation in there, it's just an open pocket of air between the shell of the tub and outer cabinet.

 

[RDspaguy]

Modern hot tubs should not have to run the heater for 6 hours per day even in 20 F degrees.

Who told you that?
I'm not familiar with this brand, but the most efficient tubs are always the most expensive to buy and repair. It's a trade-off. "Full foam" in a spa with a 4" wall thickness is not the same as one with 12", but both are called the same thing. One is 1/3 the price. Which is yours?

 

[RDspaguy]

The high temp areas in the corners are definitely voids in insulation since they are completely empty (Aside from some insulation I stuck in there but that is not having much effect).

Definitely grounds for a complaint, and I would expect any reputable manufacturer to fix it without issue. If they won't, it will be easy enough to do yourself if you could stuff something in there. But in those temps it might not make much difference once it's foamed either.

 

[jpk207]

Who told you that?
I'm not familiar with this brand, but the most efficient tubs are always the most expensive to buy and repair. It's a trade-off. "Full foam" in a spa with a 4" wall thickness is not the same as one with 12", but both are called the same thing. One is 1/3 the price. Which is yours?

Mine is neither because it is missing foam insulation over 50 percent or more of the tub shell and cabinet.

 

[jpk207]

Definitely grounds for a complaint, and I would expect any reputable manufacturer to fix it without issue. If they won't, it will be easy enough to do yourself if you could stuff something in there. But in those temps it might not make much difference once it's foamed either.

It seems odd. Are you saying in 20 degree fahrenheit that if my hot tub has full insulation, or no insulation at all…..at those temps it won’t really make a difference. That seems very strange to me.

 

[jpk207]

An update on my experiment. At 9:45 am EST today I had used my hot tub and the temp was 103 when I got out. I immediately put the temp down to 80 degrees. The cover has been closed ever since. Now, at 4:15PM EST the tub water temp is reading 97. Six degrees already it has dropped. Pretty much on pace for 1 degree per hour loss.

Over exactly 24 hours my hot tub dropped from 103 to 82 degrees. 21 degrees total. I don’t think that is normal performance for late January weather for what is supposed to be a well insulated modern hot tub.

I visited the hot tub dealer in person this morning and I think he is better understanding the extent of the problem. He fired off a detailed email to the factory and warehouse manager that I proofread before he sent. Hopefully they try and improve the situation.

 

[JoyfulNoise]

He fired off a detailed email to the factory and warehouse manager that I proofread before he sent. Hopefully they try and improve the situation.

Well that’s at least a bright spot. I’m sure the dealer doesn’t want a dissatisfied customer and if he does enough business annually with that manufacturer they should want to keep their high volume distributors happy. Sure, it sucks for them to eat the cost of a replacement tub (certainly not as much as they sell them for) but a happy customer with good things to say is worth a lot more than one stupid tub. It’s basic business sense and hopefully they’re smart enough to see that.

 

[RDspaguy]

It seems odd. Are you saying in 20 degree fahrenheit that if my hot tub has full insulation, or no insulation at all…..at those temps it won’t really make a difference. That seems very strange to me.

I'm saying that full-foam is mostly a sales gimmik, dead airspace is what insulates, and heat rises so the top is where you lose it, and you will likely not notice the difference once the missing foam has been replaced.

 

[dogsbody]

"Dead airspace" only insulates when it can't move around, in this case by natural convection within the enclosure. That's the whole point of having foam, fiberglass, rockwool, etc., insulation - so that the air entrained in it stays still. THEN it insulates. However, if you have a big open space within that enclosure with a heat source on the inside and a heat loss on the outside, your simple "heat rises [out] the top" model falls apart. The air circulates, and there are losses through the outer wall. Otherwise, we'd only insulate our house attics and not bother with all that pesky, expensive, itch-generating insulation in the walls, right?