A while back I did some research on desuperheaters and high efficiency heat
pumps.... the consensus from the manufacturers is that while it sounds good,
and did work well on the older systems, there is not enough heat generated
in the new systems for the desuperheater to operate efficiently. According
to the engineers at the manufacturer, the best you can hope for is 120
degree water out of the desuperheater.....but its your money and your can
spend it any way you want.
Hi Steve, If were talking heat pumps in winter operation up north then I
might agree, but I disagree concerning the other 4500 hours where temps are
above 45 in our area, and I disagree if were talking about geothermal or
dedicated hot water and with geo it depends if the loop was shorted. I
believe we must separate heat pumps from Geos on this discussion, this
poster did mentioned geothermal. As I stated, I would agree concerning heat
pumps but only when its colder outside, maybe below 45 without doing the
math. When the temps are above 45 they too will produce a tremendous amount
of heat for hot water, so in my opinion the rep should have clarified his
statement better. Did you happen to look up in ARI and factory charts the
facts concerning this reps statements? Probably not because most of us have
a mindset not to question the 'gods' that the manufacturers put into the
field, which btw have been wrong in our companies experiences many many
times. With Geothermal an 80 gallon tank with water coming in at 45 degrees
heated to 120 amounts to substantial savings, almost 51,000 btu's. Not many
homes need water above 120. I completely understand the formula should also
consider the amount of run time/ KW required to make this hot water, but for
a rep to bluntly say what they did I think is inaccurate, all things
considered. Now, if someone wish's to dig deeper into ARI and loop design
and other things to keep this discussion going, I'm glued to the subject for
personal reasons, I was going to convert my heat pumps to using
desuperheaters in my home. If I'm in error I need to know before I cut the
The only reason I had even done my homework on desuperheaters was because a
customer had a 25 year old GEO with desuperheater, that I replaced with a
16SEER 2 stage heat pump. He wanted to know about putting a desuperheater on
the new system. I didn't have a problem with doing it, all I could do was to
give him all of the facts as I knew them and let him make that decision. I
had a hard time finding the company that actually manufactures them, I
talked to their engineers, and got their paperwork, along with with the
engineers from Rheem. I talked to the folks from Rheem *after* I had done my
homework with the desuperheater folks. The biggest question I had for the
folks at Rheem was for warranty purposes.
Thanks Steve, I REALLY would like to keep this thread going, as I stated,
one reason being personal.
I remember too that Trane had a desuperheater system years ago. I assumed
they had so many problems with hacks doing the installs and the warranty
repairs were eating their profit.
Now, the newer SEER systems do have lower discharge pressures which mean
lower discharge temps, but I don't see why they would say they can't pay
off, especially in the AC area where you live, heck, how many hours a year
do you use AC down there, 2000 or more? This higher SEER is why I was
mentioning at least 45 degrees or higher, but, I havent seen one installed
in about 10 years, so I guess its time to play around with my own equipment
and see for myself.
On Tue, 07 Aug 2007 22:38:36 -0500, geothermaljones wrote:
Central Wisconsin about 40 miles due west of Oshkosh. Ideally before the
snow flies. Am in process of renovating a small cabin (20x24) with loft
and wood foundation and full basement. New well with Grundfos constant
pressure, variable speed pump and 1" line coming into building. Small
"turtle pond" for effluent.
My idea is to have an open loop system using well water going through heat
exchanger and then discharging into pond. The specs I've received from
contractor include 2 50-gallon electric water heaters to act as reservoirs
for both heating and domestic hot water. Specs were initially for 2T unit
but, according to contractor, a 3T unit cost the same and that's now in
Your in luck...
I can put you in touch with a number of folks in your area that can get a
Hydron GSHP for you... Google Hydron Unit (or hydronunit.com?)
Reply to my e-dress (not the group) & I'll make a few calls.
I've got contacts in Green Bay & Appleton as well as the rest of the state.
I'm out of touch till next week, so don't expect an immediate reply.
Are you looking for an installer?
I'd skip the desuperheater, but that's my personal opinion.
2-50 Gal tanks sounds a bit of over kill as well.
E-me & I'll explain
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