Does anyone turn their temp down via timer?

[wayner]

I have a Jacuzzi tub that I use year round. I live in Toronto where the temperature can occasionally get down as low as -15C for a few days in the winter, but most days in the winter the low is around 0 to -5C. My tub has a thick cover and is well insulated.

I use my tub a few times per week but I never use the tub between midnight and 6pm on weekdays and never between midnight and noon on weekdays.

Would it make sense to turn down the temperature during the day? Or does it use just as much energy to have to reheat the tub if it cools down.

My current tub doesn't actually have a way to do this, but I am just wondering if this makes sense.

 

[Jimrahbe]

W,

I'm told it costs about the same to maintain the heat as it does to reduce the heat and that add it back.

That said, I keep the heat at 95 degrees for most of the day and it automatically kicks up to 104 between 6 pm and 10 pm, when I am most likely to use the tub.

I use my pool automation system (EasyTouch) to control the heater in the standalone spa. In my case, I set the spa to heat to 104 degrees. The Automation system monitors the spa water temp and then only lets the heater work until it reaches my desired temp.

I doubt that using a timer be able to do that...

Thanks,

Jim R.

 

[wayner]

Thanks Jim. That makes sense.

I have been told the same but I would like to see the math behind this. And surely there is a point where it makes sense to turn down the heat - like if your tub is not going to be used for a couple of weeks.

 

[wayner]

Here is a similar question for a pool. Presumably the physics is the same: Q: Is it more efficient to keep keep a swimming pool warm or let it get cold and heat it up again?

 

[ajw22]

The most energy efficient is to heat on demand. However that is the most inconvenient.

The amount of wasted energy maintaining a temperature is dependent on the amount of insulation you have to prevent heat loss.

Simply lowering the temperature to be maintained by 10 degrees starts getting into diminishing savings. It takes only a bit more energy to maintain the water at 104 rather then 94 and you spend most of the savings getting the water back to 104.

So do whatever makes you feel good. It is not going to be a big difference unless you heat on demand.

 

[phonedave]

My tub has a usage schedule.

During times when the tub in "available for use" it maintains the set point.

During "non use times" the temperate can fall up to 20 F below the set point

In reality, my tub rarely gets below 5 degrees below the set point during the "non use times". It is well insulated.