High Electricity Consumption

[jpk207]

Hi. This is my first month of usage with a brand new tub and it has increased my energy usage by 870kw. Yep you read that right. It's a Tuff Spas TT-250 hooked up to 220v with Full Foam and I paid for additional "Extreme" foam in addition. I keep at a 103 and it is defaulted to two 2 hour filter cycles per day. We use it every day for a half hour and run one 15 minute jet cycle while using. I think an inflatable hot tub would perform better. When I looked inside, at first it looks well insulated with spray foam. However, upon further inspection, there is almost no spray foam on the shell itself. It's like they just opened the panels and sprayed the components, but not the actual shell. While I had the panels off, I filled all the gaps with insulation and that appeared to have an immediate impact. But, needless to say I am really concerned and unimpressed with the performance of this hot tub....especially since the dealer said, "You're looking at $60 per month at most to run in the winter."

 

[Newdude]

Hey jpk and Welcome !!@

You picked a wicked last 30 days to run a heater up here. Besides the cold, it's been very windy most days. It's probably going to do a lot better when it's 40s like it should be right now, and even better once it warms up.

I had a similar entry level tub and it's insulation wasn't as much as I would have liked. Adding my own never got off the 'one day' project list.

 

[jpk207]

Hey jpk and Welcome !!@

You picked a wicked last 30 days to run a heater up here. Besides the cold, it's been very windy most days. It's probably going to do a lot better when it's 40s like it should be right now, and even better once it warms up.

I had a similar entry level tub and it's insulation wasn't as much as I would have liked. Adding my own never got off the 'one day' project list.

Thanks for the reply. Yeah, it's been pretty brutal cold and windy. The insulation I added I can tell already has helped. It's frustrating I was sold something that was not close to being what it was advertised, but that's the game brah.

 

[JoyfulNoise]

Are you absolutely sure you’ve got it hooked up right? Definitely set to run off 220V ?

Can you take a picture of the heater? Do you know its rating?

I’m assuming you have a foam cover for it but it might also help to cut up one of those blue bubble covers and put that on the surface of the water and then close the main cover. Hot water will evaporate into the dead space between the main cover and the water, condense, cool, and drip back down. That will remove heat energy from the water. Covering the water surface with a bubble cover will greatly reduce evaporation.

Also, what is the standby temp set at? You don’t want the tub constantly at 103F but rather let it run at a lower standby temp of 96F or 98F and then heat up as-needed. Running it a full heat all the time will basically run the heater constantly.

 

[jpk207]

Are you absolutely sure you’ve got it hooked up right? Definitely set to run off 220V ?

Can you take a picture of the heater? Do you know its rating?

I’m assuming you have a foam cover for it but it might also help to cut up one of those blue bubble covers and put that on the surface of the water and then close the main cover. Hot water will evaporate into the dead space between the main cover and the water, condense, cool, and drip back down. That will remove heat energy from the water. Covering the water surface with a bubble cover will greatly reduce evaporation.

Also, what is the standby temp set at? You don’t want the tub constantly at 103F but rather let it run at a lower standby temp of 96F or 98F and then heat up as-needed. Running it a full heat all the time will basically run the heater constantly.

I'm fairly certain it's configured properly for 220. It heats up quite fast and maintains temp when I'm in it. I get what you're saying though, since there are jumper cables and pins and what not that need to be configured to convert from 110 to 220. I think I'm good there.

The heater is 4kw and is probably this one.

The Tuff Spa has a (Supposedly) industry leading cover and based on a thermal image I took, it's holding in heat quite well. I ordered a thermal blanket and that should arrive next week.

I set it at 103 and leave it there all the time. Since we use it every single day, and articles I have read it appears leaving the hot tub set at 103 is my best option. But, it's worth trying something different...can't hurt probably.

 

[jpk207]

This is a little spreadsheet I came up with as to what my usage probably had to be last month. I am in NE Connecticut nad my rates are some of the highest in the country around $.30 per kw all in.

 

[JoyfulNoise]

I'm fairly certain it's configured properly for 220. It heats up quite fast and maintains temp when I'm in it. I get what you're saying though, since there are jumper cables and pins and what not that need to be configured to convert from 110 to 220. I think I'm good there.

The heater is 4kw and is probably this one.

The Tuff Spa has a (Supposedly) industry leading cover and based on a thermal image I took, it's holding in heat quite well. I ordered a thermal blanket and that should arrive next week.

I set it at 103 and leave it there all the time. Since we use it every single day, and articles I have read it appears leaving the hot tub set at 103 is my best option. But, it's worth trying something different...can't hurt probably.

View attachment 625407

Nice FLIR image

Are you Fire Department personnel or a former Hughes Optical/Aerospace employee . Not many people own their own FLIR cameras just for kicks

 

[Newdude]

It's frustrating I was sold something that was not close to being what it was advertised, but that's the game brah.

They weren't going to quote the unusually cold weather we are having. They were probably close for most years, or most of most years at least.

since there are jumper cables and pins and what not that need to be configured to convert from 110 to 220. I think I'm good there.

It takes 5 mins to check. The inside cover of my main board had clear instructions for the conversion. Yours should too.

I ordered a thermal blanket and that should arrive next week.

Mine helped alot, especially when I used the tub and only peeled up the corner I needed.

 

[jpk207]

Nice FLIR image

Are you Fire Department personnel or a former Hughes Optical/Aerospace employee . Not many people own their own FLIR cameras just for kicks

The FliR One Edge is a bluetooth capable iOS device and I bought specifically to see what was going on with my hot tub. I'll take another image tomorrow that might look different given I've added insulation.

 

[JoyfulNoise]

The other upside of the blue bubble mat floating on the surface is that it should produce less condensation on the inside of the main cover which can help with mildew growth. They all say that their covers are "the single greatest invention since sliced bread!!" which we all know is mainly bull sandwiches. And if you paid for the Super-Duper-Handy-Dandy MEGA LUCKY DRAGON No. 7 Insulation Treatment and all you got is what you described in the OP, then yeah, I'm not impressed. I'd hate to see what their "standard insulation" looks like ...

 

[jpk207]

They weren't going to quote the unusually cold weather we are having. They were probably close for most years, or most of most years at least.


It takes 5 mins to check. The inside cover of my main board had clear instructions for the conversion. Yours should too.

Mine helped alot, especially when I used the tub and only peeled up the corner I needed.

"They weren't going to quote the unusually cold weather we are having. They were probably close for most years, or most of most years at least."
What I meant about being sold something not as advertised is not the high energy use but rather the lack of insulation on the inside of the hot tub that was sold as "Full foam" plus Extreme insulation on top of that. This hot tub is lacking a lot of basic insulation.

"It takes 5 mins to check. The inside cover of my main board had clear instructions for the conversion. Yours should too."
I checked about an hour ago and it looks good.

 

[Newdude]

Full foam" plus Extreme insulation on top of that. This hot tub is lacking a lot of basic insulation

Ok that makes sense then as to your feelings.

Mine had an inch or so of spray foam on the bowl, and nothing on the outside wall. I never tested it by itself but estimated about $100 a month to use, maybe a little more in the cold winters. Certainly not almost $300.

 

[jpk207]

Ok that makes sense then as to your feelings.

Mine had an inch or so of spray foam on the bowl, and nothing on the outside wall. I never tested it by itself but estimated about $100 a month to use, maybe a little more in the cold winters. Certainly not almost $300.

If I can get my usage to below 600kw per month for the hot tub usage portion that will be great. Right now I calculate about 25kw per day for my hot tub electric usage.

 

[JoyfulNoise]

If I can get my usage to below 600kw per month for the hot tub usage portion that will be great. Right now I calculate about 25kw per day for my hot tub electric usage.

I would sincerely try getting your standby temp lower and seeing what impact that has on how fast it will warmup. Heat flow (Q) is proportional to temperature difference (ΔT). So the greater the delta between the water and walls and the outside air, the more energy needed to keep the water at a given temperature. Adding more insulation changes the proportionality constant, but the heat flows across a temperature gradient so reducing the difference helps too. You just have to optimize the energy savings versus your patience/tolerance for waiting to use the tub.

 

[jpk207]

I would sincerely try getting your standby temp lower and seeing what impact that has on how fast it will warmup. Heat flow (Q) is proportional to temperature difference (ΔT). So the greater the delta between the water and walls and the outside air, the more energy needed to keep the water at a given temperature. Adding more insulation changes the proportionality constant, but the heat flows across a temperature gradient so reducing the difference helps too. You just have to optimize the energy savings versus your patience/tolerance for waiting to use the tub.

If my desired bathing temp is 103, I should try 99 as my standby temp and then an hour before usage turn it to 103? I’ll give that a try. What about all the different comments that maintaining a constant temp is better than changing it?

 

[Mdragger88]

If I can get my usage to below 600kw per month for the hot tub usage portion that will be great. Right now I calculate about 25kw per day for my hot tub electric usage.

I use approximately 70kwh/day for my whole house in January.
Our outdoor temps range from 10-40 degrees F this time of year. We have had some lower temps on occasion.
I keep my tub at 104 or higher. Its a 250gal 110v roto molded foam insulated tub. I cannot locate the utility bills or the year before & year after purchase but I recall doing some math after a few winter months use and it being around a $20 increase. Our rate is around 11 cents/ kwh. So less than 1/2 of yours.
My tub maintains its temp extremely well so I have never considered adding any extra insulation. It is fully foamed and I was able to confirm this when unloading because it was on its side and was rolled into place (its round & I could see inside).
The only spot that lacks insulation is a step that the light is in.
I call it my giant yeti
I think you are justified to be a bit perturbed about your insulation as those cost a pretty penny compared to a wayfair/Home Depot special like mine. The question is, will they make it right if you choose to balk?
- side note… I have really been wanting an thermal imaging gun, now I just gotta have one!

 

[JoyfulNoise]

side note… I have really been wanting an thermal imaging gun, now I just gotta have one!

I totally see you with one

 

[jpk207]

I use approximately 70kwh/day for my whole house in January.
Our outdoor temps range from 10-40 degrees F this time of year. We have had some lower temps on occasion.
I keep my tub at 104 or higher. Its a 250gal 110v roto molded foam insulated tub. I cannot locate the utility bills or the year before & year after purchase but I recall doing some math after a few winter months use and it being around a $20 increase. Our rate is around 11 cents/ kwh. So less than 1/2 of yours.
My tub maintains its temp extremely well so I have never considered adding any extra insulation. It is fully foamed and I was able to confirm this when unloading because it was on its side and was rolled into place (its round & I could see inside).
The only spot that lacks insulation is a step that the light is in.
I call it my giant yeti
I think you are justified to be a bit perturbed about your insulation as those cost a pretty penny compared to a wayfair/Home Depot special like mine. The question is, will they make it right if you choose to balk?
- side note… I have really been wanting an thermal imaging gun, now I just gotta have one!

I called the manager of the store I bought it from, emailed him, and also submitted a support request, with photos and explanation…….pretty much crickets. So, I doubt they will own up to the terrible insulation process on my hot tub. Even still it seems like my usage is much higher than even the most poorly insulated hot tubs. I feel like something else could be causing it…..just not sure what.

 

[JoyfulNoise]

If my desired bathing temp is 103, I should try 99 as my standby temp and then an hour before usage turn it to 103? I’ll give that a try. What about all the different comments that maintaining a constant temp is better than changing it?

It’s just something you’ll have to experiment with. Keeping a tub at high temp is only going to be economical if it is well insulated and retains it heat. As an experiment you might try running it up to full temp and then kill the breaker. Then use the fancy-pants FLIR camera to see how the temperature drops. That will give you a good indication of how much heat loss is occuring. Ultimately your heater has a fixed amount of power so if the heat losses are high, then your heater has to run at full-tilt all the time to keep the temp up.

 

[JoyfulNoise]

I called the manager of the store I bought it from, emailed him, and also submitted a support request, with photos and explanation…….pretty much crickets. So, I doubt they will own up to the terrible insulation process on my hot tub. Even still it seems like my usage is much higher than even the most poorly insulated hot tubs. I feel like something else could be causing it…..just not sure what.

Perhaps of @RDspaguy is around, he might have some suggestions on what to look for on the control/equipment side. Maybe you have a really lousy circulation or jet pump and so it consumes a lot of energy just to move the water a little bit. Perhaps his experienced eyeballs can shed some light.