"BobK207" wrote in message
oups.com...

Bryan wrote:
wrote in message
oups.com...
Insulate it better. There is a spray for the underside of the tub
itself. Another cover for the tip is in order. Then keep it at 95, find
out how long it takes to go from 95 to 103 and educate everyone on the
fact they will have to turn it up ahead of time (and back down). The
exact numbers here are hypothetical, but the cooler you keep it the
more energy you will save.


Game plan:
Optimize insulation.
Turn down temp before work and turn it up after work. Find the lowest
temp
that still allows a reasonable return to 103. Manual or timer.
Look into timers (will tend to forget manual resulting in frustration for
all).
Look into solar assistance.
Build 2 sided privacy lattice for privacy and to optimize wind barrier.
Reduce fast food consumption and use money to pay for heating.

Thanks to everyone with all the great ideas!


Bryan-

You're right on target for your game plan.

I just moved from a house with an above ground spa (SoCal)

& I sure do miss it!

Soaking in the spa looking up at the stairs was very nice.
I thought I'd tire of it but I never did.

I used to turn the heater off when I was done with it for the night.
I would turn up again a few hours before I wanted to use it. I just
had to remember!

I don't remember ALL the details of the installation like heater power
(kW) but it was ~500 gallons (a deep 6 person, ~8x8 spa)

but I do remember if it wasn't cold outside (60F) the water never
really got cold (just not good & hot)

& if it was hot outside the spa would pretty much stay usable (103)
without turning the heater on.

If it was tempid (~90's) it would take ~2 or 3 hours to bring it up to
"good"

If yours is really 300 gallons then each kW of heater capacity will
bring your spa 1.4 degrees F per hour

I think mine was 5.5 kW & I had 500 gallons

so I could get ~ 5 degrees F per hour,

which was fine as long as I planned ahead (too lazy to do the timer)

but if I forgot..............no spa tonight ........or a tempid
soak


The closer to ambient temperature you let the spa temp fall, the more
electricity you'll save

If you've got a 3.3 kW heater you'll get about 5degs F per hour as
well.

So I would suggest you kill the heater at night when you got to bed.
The spa will probably "coast" long enough to do the midnight soak.
(night time loses are greater than daytime) & fire it up a few hours
(3 or 4) before you'll want it hot.

If you measure your water temp in the afternoon & you know when you
want it ready & you know your heater kW you can predict how soon you
need to turn it up based on heater kW

In a pinch I used to run both jet systems full speed to add to the heat
(maybe another 20% capacity)

cheers
Bob


Great information. I'll test out the 5 d per hour hypothesis. It sounds
like our tubs are/were pretty much the same.
I always wonder, though, does reheating the tub daily cost more than just
maintaining the desired temp.