" writes:

On Dec 14, 12:55Â*pm, Dan Espen wrote:
" writes:
That is the essential energy difference. Â* Now let's say
that the ambient air is 80F and the pool water is also 80F.

I've seen this stated a few times in this thread and I don't think it's
true. The pool temperature is going to be the average of daytime and
nighttime temperature plus the effect of evaporative cooling at the
water surface, plus the effect of cooling due to ground temperature.

All and all, I'd expect the pool water during the time the AC is in use
to be significantly lower than the air temperature.

Before I had my heater, with air temps in the upper 90s I'd still have
the water at 80 or so. Â*If I remember right, 82 was an all time high.

That depends on the particular climate and if the pool is
shaded or full sun. Here in NJ/NYC for example, pools that
have mostly sun are in the low 80s
without heat during July and Aug. And that is with daytime
temps in the 80s. If it's upper 90s for a couple days, pool
could be 85+ with no heater. The time folks here typically
use a pool heater, if at all, is in the beginning of the season, ie
late May, early June and again going into Sept. The
problem with that is during those periods the AC is
running the least. It's a mismatch between when it's
needed most and when the most heat is available.

I agree there are going to be some days when the pool
water temp will be below the air temp. But look at it
from this perspective. If the system works to do what
is wanted, then the pool should be 80+, no? Isn't that
a purpose of the pool heater? So, if the water is 80 - 85,
reagardless of how it gets there, I don't see that as being
a big difference versus the ambient air if you average
it out. For example, at night, the pool at times could
actually be above the ambient air temp, right?
If you;re saying, well the pool could be 75 and the
ambient air 90, sure I could see that, but that situation
has to be an exception, or else the thing isn't heating
the pool enough, right? If it's working, then you
should have 90 air, 85 water.

I have no delusion that this thing heats the pool to any significant
temperature.

The heating from the AC system heat exchanger isn't going to make much
of a difference for pool temperature but the AC system will cool better.

But the main point of the whole TOH project was to
heat the pool. That was the original problem, not that
they wanted to lower the AC bill. The lowering of the
AC bill was an additional benefit.

TOH never said heating the pool was the _main_ point at least I didn't
catch it. Maybe they mentioned pool heating first?

I think they were wrong to mention pool heating at all because
this isn't going to heat the pool enough to make a difference.

I'm in central NJ (like you).

I didn't see where they mentioned the location of the house in question but
since it's TOH, it's likely it's New England. Like us in NJ, only
worse. With the trees that guy had next to the pool, that water must be
freezing. Reminds me of swimming in the cold clear lakes of New
England. Nice water but cold, cold, cold.

--
Dan Espen