Coleman Tahiti Plus AirJet Inflatable Hot Tub Spa (85" x 28", 5-7 People) Expired

You are probably using more energy doing that than leaving it on regulating the temperature the whole time.

By not running the filter pump all the freaking time? I don't think so.

As for the heat expenditure, now that's debatable and it depends on how much time heater stays on vs. off in the "on 24/7" scenario. Since specific heat of weater is essentially independent of temperature, there is no difference between, say, heating the same amount of water for 20 degrees (say from 84 to 104) in one go or heating it up 2 degrees (say from 102 to 104) 10 times.

Heat transfer doesn't care how (i.e. on/off, 2hr at a time, 10min at a time, etc) you run a resistive heater (which are always 100% efficient). It just cares about delta T (the temp of the water vs outside air). The more you do to minimize average delta T (i.e. lowering tub temp) the less energy/electricity it will take.

So it sounds like g10ny is looking for a tub you can have running at ~98F and then turn on remotely 4hours in advance at work or w/e, and then come back to it about ~102-104F or w/e. This one doesn't do that....and the energy savings would be fairly low.

I'm unsure how well the pump / filter / chemical dispenser (connected to the outlet of the pump) would do if you turn off all that for long periods of time. May need to add a floating bromine dispenser to keep your chemicals to correct levels.

Now, if you wanted to bring this way lower (i.e. 50F) for a couple days, and then only use it for weekends.....that'd be a massive energy savings (i.e. M/T/W/Th cold, Fr/Sat/Sun hot) in the order of probably 50ish%


Edit - Also, obviously, insulation values are VERY important. Highly recommend adding as much R value within reason you can to top/bottom. The sides is hard, since it's curved. I personally have the smaller version of this in the basement with R15 on the bottom. If I were in canada/freezing, and it was outdoors....I would probably make a whole rigid foam board box for this thing with seals, painted. It would look like shit though lol.

Edit2 - Pretty sure the whole "takes more energy to get up to temperature in one go vs maintain that temperature" is a myth. prove me wrong lol.

Not super satisfied with the inflatable units. The wow factor is there for parties, but a major drawback for personal use is the way the "jets" work. The unit just pumps outside air into the tub floor to create the "jet" effect (unlike real spas, which mostly pump water). This gives me headaches, as it aerosolizes a lot more of the chlorine/bromine than regular tubs would — I find myself constantly draining and refilling the water just to keep it pure.

Second issue to be aware of, the heat pumps are pretty weak, so running this with jets in the winter will drop the water temp several degrees per hour. Again, fine for occasional parties, but kind of kills it for personal use otherwise.

eww. That filter gets jacked up so quick. Questionable water quality lol

Right now I set mine to 80 during the week and it is a pretty huge savings. I should try 50, but it takes more than 12 hours to wam up at 50.

Heat transfer doesn't care how (i.e. on/off, 2hr at a time, 10min at a time, etc) you run a resistive heater (which are always 100% efficient). It just cares about delta T (the temp of the water vs outside air). The more you do to minimize average delta T (i.e. lowering tub temp) the less energy/electricity it will take.

So it sounds like g10ny is looking for a tub you can have running at ~98F and then turn on remotely 4hours in advance at work or w/e, and then come back to it about ~102-104F or w/e. This one doesn't do that....and the energy savings would be fairly low.

I'm unsure how well the pump / filter / chemical dispenser (connected to the outlet of the pump) would do if you turn off all that for long periods of time. May need to add a floating bromine dispenser to keep your chemicals to correct levels.

Now, if you wanted to bring this way lower (i.e. 50F) for a couple days, and then only use it for weekends.....that'd be a massive energy savings (i.e. M/T/W/Th cold, Fr/Sat/Sun hot) in the order of probably 50ish%


Edit - Also, obviously, insulation values are VERY important. Highly recommend adding as much R value within reason you can to top/bottom. The sides is hard, since it's curved. I personally have the smaller version of this in the basement with R15 on the bottom. If I were in canada/freezing, and it was outdoors....I would probably make a whole rigid foam board box for this thing with seals, painted. It would look like shit though lol.

Edit2 - Pretty sure the whole "takes more energy to get up to temperature in one go vs maintain that temperature" is a myth. prove me wrong lol.

This is essentially a giant calorimeter with water (known specific heat,) walls (insulation helps) and a heat source (electric heater.) Ah, and a stirrer. mcDeltaT=Q=Pt. Heat loss rate is low, heater overcomes that better when inside or when well-insulated (or both.) But I do cheat on occasion and replace colder water with the capacity of the hot water heater (30-40 gal) via hose and pump.
Bio-chemical aspect: isn't nasty stuff developing faster at high temperatures? That would recommend NOT keeping it at high temps, but running it less frequently. I do add bleach tablets when turning it on for a few hours before use or/and after a heavier than usual session. Still challenging, to be honest.

This has serious keys-in-basket vibes…

Okay unusual question. Looking to purchase one for my husband for Christmas. How big is the box so I can figure out how to hide it first