Posted By docjenser on 23 Feb 2011 03:58 AM
As we know well from open systems, heatpumps work well with
half or 2/3 the flow ....
...To use the "why do you think they recommend 3 gpm/ton" ...
Neither of those rules-of-thumb have anything at all to do
with Reynolds numbers in the loop piping:
- open loop systems have no in-ground heat exchanger
- the heat pump coax has HUGE Reynolds numbers (tens of
of thousands) at any sane flow rate. ...hmm, I wonder why.
- ISO/AHRI rules permit manufacturers to use whatever flow
rates they choose when rating heat pump COP. 3 gpm/ton,
(closed loop) is common, but by no means "standard."
WRT
me justifying standard geo design practice: Sorry, but
I'm rapidly losing interest in the subject. My single-pump,
single-circuit system is doin' just fine (at Reynolds# 5890).
As a techno-geek homeowner, it's just idle curiosity. OTOH,
if I was designing and selling geo to paying customers, I can
assure you that I'd spend whatever effort was necessary to
find the answers.