On 9/16/2020 8:47 AM, Ralph Mowery wrote:
In article ,
lid says...

My housing development down here in south Mississippi is new, with
everything either built last year or this year. Each house has the ground
loop that you described. Down here, it almost never gets down to freezing,
so the systems seem to work pretty well.



I would think that in Mississippi it would be the oppsite. YOu do not
need to worry too much about heating, but more so with cooling and
humidity control. So better to have the coils in the cooler earth than
in the much hotter air.

I often see and understand how the efficiency of the heat pumps go down
when it gets cold and you need auxillary heat. I have never seen any
refference as to how to get extra cooling from the normal air installed
heat pumps. I am sure the gound loop system would be much more efficent
than the air system even in hot weather.

Air-exchange heat pumps are just conventional A/C units when reverse
valves for A/C.

And of course it's much less efficient to discharge the waste heat from
the A/C when ambient is 100F, just as it is harder to extract heat from
40 F air for heating.

The geothermal source/sink is much more nearly stable and if properly
sized can handle both cycles. With ours, the aux heat controls by
default would kick on with a 3 F setpoint mismatch to provide more
rapid warmup after an overnight setback in the morning, but we included
a cutout to prevent them from kicking on unless outside 20F and never
missed them.

The geothermal systems also can be set up to use waste heat on cooling
cycle as preheat for hot water that can cut that cost down noticeably in
cooling season as well. That's better in warmer climates, obviously.

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