Sorry to hear you got ripped off! I was intrigued with your post. You say your inlet water temp is 81 degrees? Where do you live (near the equator)?

With 81F loops for AC, you might as well use air source heat pumps (at least for most areas).

Where are you located and how many wells, how deep. how many feet of pipe in each? Something is wrong if you have 81F inlet..be very careful at this point.. has a manual j load calc ever been completed? I doubt the original contractor has properly sized your equipment based on his track record...Eric

Heck, we are happy to have inlet water < 90, and geo still works fine up to that temp. We design for 95 EWT.

This may be yet another thread wherein Jonr may be safely ignored...

Good engineers don't confuse "works fine" with optimal in terms of cost/performance. Or get confused as to who said what (perhaps ilgeo?). Only trolls try vague backhanded remarks about other topics.

How 'bout a man j load and location on the house?
Joe

We live in Louisiana zip code 71106, there are 9-300 ft closed loop wells with what I believe is.75 inch poly pipe and they are hooked up in parallel. I am not certain about a J load calculation.

By "works fine" I mean that the system conforms to Manuals J, D and S designs for the building it serves and provides quiet, economical, reliable, and durable service as intended by design and installation team. The notion that I would here abide, much less advocate for a system that does any less may be safely dismissed as trollish provocation to which I will not further respond.

It is common to design ground loops to provide EWT +/- 20 degrees either side of deep ground temp. In other words if deep ground temp is 60, which might loosely correspond with the path of I-40 nationwide, we'd look for summer EWT not to exceed 80 and winter EWT around 40.

Zip 71106 is northern Louisiana. Without digging up a national deep ground temp map right now I'd guess that deep ground temp near Shreveport runs in the low to mid 60s. That suggests that an EWT of 81 is well within bounds. If the system can't perform with that EWT, that's a problem.

I second Joe's request for a Man J (building load) calculation. It is the single most important prerequisite to properly selecting a system.

Brand is less important than contractor competence and integrity. I think you'll find that WF, FHP, Hydron Module, and CM all have their fans here. Browse Hydroheat carefully...

Posted By drveko on 24 Jun 2010 10:04 PM
We live in Louisiana zip code 71106, there are 9-300 ft closed loop wells with what I believe is.75 inch poly pipe and they are hooked up in parallel. I am not certain about a J load calculation.

That's a start.
By 300' wells do you mean 300' deep or 150' deep with 300' of pipe?
Must get a heat loss/gain calc. must also explore duct design.
I am not confident that existing system can't be made to work, while use of McQuay units suggest your installer may not have been certified in any of the more mainstream units, they still can work if applied correctly.
Conversely; no unit will work if applied incorrectly...i.e. too small for load, underlooped, underducted etc.
I agree with Engineer that EWT by itself does not suggest trouble, nor does electric bill (how do I know that $500 isn't a great electric bill for a given month in a home that requires 9 tons of cooling). Not enough data to tell. 
How many SF is home?
j 

I would have to agree that the brand is not nearly as important as proper design and installation. who ever works on it next should 1st do a manual J load calc and 2nd perform a assessment of duct work and 3rd field assessment.these are more important than which flavor you buy..Eric