My hot tub uses 49% of my electricity per month...lets fix that.
- Thread starter tmprof
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tmprof
New Member
WindWizard
Solar Enthusiast
My wife loves her hot tub. I sometimes join her. It is definitely a electricity consumer. I think I figured it out to be around 3.5 kwh to 4.2 kwh per day. The 240 Volt 6kw heater was brutal so I rewired the hot tub heater to run on just one leg at 120 Volts. This made the heater more manageable at 1.5kw. When she gets in the hot tub and runs the jets it pulls enough power that it kicks on the other 4400 watt Inverter. I have two Inverters with one running all the time and the second turning on when the power load gets above 75%.
I considered all sorts of alternatives such as running a heat line from the wood boilers and such, but this approach works great, and it allows me to run the hot tub on Solar.
I considered all sorts of alternatives such as running a heat line from the wood boilers and such, but this approach works great, and it allows me to run the hot tub on Solar.
tmprof
New Member
I just read that a heat pump is a bad idea since hot tubs usually sit around 98 degrees and in the cold winter, there's no way it can pull enough heat out of the air.
Well, I know some heat pumps have the “hyper heat” function that heats up water heaters.
tmprof
New Member
if you lower the kw of the heater, wouldn't it have to run more often to keep the temp of the water high?
WindWizard
Solar Enthusiast
Yes, that is absolutely true. My wife's Hot Tub is one that has a seperate Circulator Pump that runs 24/7. That is the Pump that is used in the heater loop. The Jet Pump is a seperate 240 Volt pump so with my wife's Hot Tub the answer is no since the Circulator Pump is running all the time anyway.
I work on swimming pools and spas professionally. Proper insulation can make a massive difference in power consumption.
Having no idea what your setup looks like, I would double check to make sure that there is adequate insulation everywhere there needs to be, perhaps even upgraded insulation in places. I've seen a lot of "professional" work done to spas where they just cut out the insulation to fix the problem, and never replace it.
Having no idea what your setup looks like, I would double check to make sure that there is adequate insulation everywhere there needs to be, perhaps even upgraded insulation in places. I've seen a lot of "professional" work done to spas where they just cut out the insulation to fix the problem, and never replace it.
Donny Hucklebuck
New Member
I have a fairly new hot tub it has a small circulation pump that runs 24/7 and it has wifi control so it uses 195 w
without heating element on. I shut I’d down for the winter my electricity bill is down 40 percent.
i was thinking about changing out the small circulation pump that runs on 220v and switch it out with a different pump that’s 120v and run it off my inverter. But with everything running off a computer I think I will leave it alone and only use in the summer when it doesn’t use much heat.
Also that tankless water heater can’t run outside in the winter it would freeze up like others have mentioned
without heating element on. I shut I’d down for the winter my electricity bill is down 40 percent.
i was thinking about changing out the small circulation pump that runs on 220v and switch it out with a different pump that’s 120v and run it off my inverter. But with everything running off a computer I think I will leave it alone and only use in the summer when it doesn’t use much heat.
Also that tankless water heater can’t run outside in the winter it would freeze up like others have mentioned
Been there, doing that...
"Hot tub" is a 100 gal. Rubbermaid cattle trough:
Paloma PH6-DP I already had as I use those in the field to generate hot water to locate cold water slab leaks with an IR camera.
2 small 24VDC pumps from Amazon. The Paloma main burner will ignite at 4.6 PSI, so they are enough. 34W power to run them.
Buncha hoses and other crap. The "bubble wrap Mylar" around the trough keeps temperature loss to a minimum. Drops from 110 to 70 overnight with ambient low cold temp around 17. I can't afford the gas to keep it hot alla time, but if you start at 70, the Paloma has it up to 100+ in less than an hour.
All runs off of an old 80W SOLEC panel.
During warmer weather, I replace the Paloma with passive collectors made out of a 100' length of .7" drip tube coiled up in a frame. From April to September, I don't need the Paloma.
At night, I have to disconnect and empty the Paloma, but that takes < 1 min.
The remote temp sensor reports back to the Oregon Scientific weather station inside.
It's truly incredible how cheap the small demand water heaters are now. That Paloma was several hundred $$ when I bought it in the 90's.
Your setup is nicer, and automated. Cool.
"Hot tub" is a 100 gal. Rubbermaid cattle trough:
Paloma PH6-DP I already had as I use those in the field to generate hot water to locate cold water slab leaks with an IR camera.
2 small 24VDC pumps from Amazon. The Paloma main burner will ignite at 4.6 PSI, so they are enough. 34W power to run them.
Buncha hoses and other crap. The "bubble wrap Mylar" around the trough keeps temperature loss to a minimum. Drops from 110 to 70 overnight with ambient low cold temp around 17. I can't afford the gas to keep it hot alla time, but if you start at 70, the Paloma has it up to 100+ in less than an hour.
All runs off of an old 80W SOLEC panel.
During warmer weather, I replace the Paloma with passive collectors made out of a 100' length of .7" drip tube coiled up in a frame. From April to September, I don't need the Paloma.
At night, I have to disconnect and empty the Paloma, but that takes < 1 min.
The remote temp sensor reports back to the Oregon Scientific weather station inside.
It's truly incredible how cheap the small demand water heaters are now. That Paloma was several hundred $$ when I bought it in the 90's.
Your setup is nicer, and automated. Cool.
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tmprof
New Member
Ha! I love it
inspiration fuel...OzSolar
Whatever you did, that's what you planned.
I've hacked together at least 4 or 5 hot tubs out of both stock tanks, lamb tanks, redwood slats and Rubbermaid stock tanks. I'm sure there was a few others. Some of them used a standard 40g gas water heater that I removed the burner from and built very rudimentary firebox in. It worked... sorta.
Some used an old school, made in France, AquaStar Tankless water water, one of the first ones imported into the US in fact.
They were all really clumsy and got in the way of what I wanted to do which was sit outside and watch the stars while I soaked the day's stress away.
So nowadays I just pay the piper and enjoy my nightly soaks. Of course for me "paying the piper" only means that I'm burning through excess credits from previous months and still end up with a minimum monthly bill of $27.50.
Some used an old school, made in France, AquaStar Tankless water water, one of the first ones imported into the US in fact.
They were all really clumsy and got in the way of what I wanted to do which was sit outside and watch the stars while I soaked the day's stress away.
So nowadays I just pay the piper and enjoy my nightly soaks. Of course for me "paying the piper" only means that I'm burning through excess credits from previous months and still end up with a minimum monthly bill of $27.50.
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tmprof
New Member
tmprof
New Member
I probably could enclose the tub, but I'd loose the sunset every night.....
400bird
Solar Wizard
I love the irony in the naming here!
yodamota
Solar Enthusiast
isn't polypropylene glycol found in ice cream these days?
I have a hot tub and have been thinking about how I could use it as "storage" to dump my excess solar energy during the day, instead of net metering or storing it in a battery.
I have an mpp lvx6048wp inverter and I've been thinking of adding some more solar panels and using the extra energy to heat the hot tub
basically the idea would be that I'd set the max temp a little hotter than "ideal" and power it off solar in the day so on a sunny day it gets up to max temp. but have it shut down at night when there is no solar. and have it be "ideal" most evenings when we get in. It seems like that would be more energy efficient than sending excess solar during the day into a battery and then trying to have the hot tub run of battery power at night.
I've heard it said that it is energy inefficient to let your hot tub cool down and then try to heat it up before using it, and that you should just leave it at a constant temperature. But it's gotta be more efficient than the loss you'd get going from solar to mppt to battery during the day then back from battery to inverter to heater at night, right?
has anyone done anything similar?
some of my main questions would be:
we love our hot tub too! use it almost every night.
I have an mpp lvx6048wp inverter and I've been thinking of adding some more solar panels and using the extra energy to heat the hot tub
basically the idea would be that I'd set the max temp a little hotter than "ideal" and power it off solar in the day so on a sunny day it gets up to max temp. but have it shut down at night when there is no solar. and have it be "ideal" most evenings when we get in. It seems like that would be more energy efficient than sending excess solar during the day into a battery and then trying to have the hot tub run of battery power at night.
I've heard it said that it is energy inefficient to let your hot tub cool down and then try to heat it up before using it, and that you should just leave it at a constant temperature. But it's gotta be more efficient than the loss you'd get going from solar to mppt to battery during the day then back from battery to inverter to heater at night, right?
has anyone done anything similar?
some of my main questions would be:
- is that going to be super hard on the hot tub's control board to cut power to it every night?
- if my lvx6048wp can handle the power draw of the heater? OP said his pulls 6.1kw, this inverter says "Grid-relay feature boosts max output up to 9KW", so based on that maybe it could? mine's a 500 gallon hot tub so I'd imagine it would be similar, but I've never measured the power draw of mine.
we love our hot tub too! use it almost every night.
tmprof
New Member
I think that is a great idea! The only issue I see is if you want to get in the tub during a period where it's over heated, that might be uncomfortable. I live in Houston where it gets really hot during the summer. My hot tub rarely needs to heat even overnight during that time. Also, I lower the temp during the warm months so it feels more like a pool.
teal95
Solar Addict
We paid "pro's" last year to winterize it. I could have done a better job. They didn't drain the ozonator/UV box so it froze and broke. Then they couldn't come up with replacement part, even though they're the ones who installed it (it was a replacement/upgrade when the original ozonator failed), and I wasn't even trying to make them pay for it.
All you need is a line blower and some antifreeze, both of which should cost about the same amount as a single opening or closing. It's really easy to close a spa yourself. You could probably get by with something smaller and cheaper if it's only for a spa as well. They also come up on eBay periodically, especially mid-season (middle of winter, or middle of summer).
There's a lot of "pro" pool guys that have almost no idea what they're doing, most states don't require licensing (beyond a business license) so anybody can do it, trained or not. One of the companies I used to work for hired this guy, he claimed to have been a welder on the Alaskan pipelines, I was a helper at the time, so they sent me with him. He literally had never even pulled a plug or skimmed before, and they were sending us on technical service calls. I quit when I found out he was being paid three times what I was and I was the one doing the work because I knew how, dude couldn't even hook up a pump. I work for myself now.
I would find a more reputable pool service. I offer a reasonable freeze protection guarantee, if my work fails, I will fix the busted pipe for free. I would have been out there with that part as fast as humanly possible. Even if they can't find the exact replacement part, you should be able to find one on eBay and have them install the part, I'm a reasonable guy, but if I paid somebody $3-400 to close my spa, I expect it to be properly done, and any issues that they caused, they should fix.
teal95
Solar Addict
Wife keeps going back to the place she got it from. That's the third time I've went to their shop and they've been useless. I told her I'm not going in there again. There's a place that's much closer that doesn't sell the brand we have but every time I've been in their store they've been very helpful.
It's a swim spa, so it's huge. But yes, it still has the same places that need drained.
It's a swim spa, so it's huge. But yes, it still has the same places that need drained.
That'll help a lot. I've been adding 2 inch pink panther FOAMULAR board foam.
Also rigged up being able to use firewood to heat the tub. I still want to use electric instead of gas though ideally during the day.
Also solar water heater is on my list
I came to the same conclusion in my testing. mine is ~1200 watts but I consider it more "supplemental power" kinda keeping it the same temp it already is at
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