I have two contractors biding two completely different layouts. My existing home has two LP units. One 4 ton unit in the basement and a 2.5 ton unit on the second floor. The Water-Furance contractor is wanting to use a single 6 ton dual stage unit in the basement and put duct up into the attic. This is using a ground loop in a pit. Climate Master contractor is using 2 seperate units one TTV038 in the basement and a TTS026 in the actic. Both have seperate vertical drilled loop systems 150' per ton. He also included a supplemental water heating generator where the other contractor did not. I assume the two units would do a better job but i am having a hard time justifying the additonal $11,500 premium. What are the plus and minus of the two sytems?

I usually like to save customer's money by installing one unit instead of 2 with zoned ductwork.
2 units have redundancy, not sure if necessary in the day and age of aux heat. You have to be aware that if only 1 zone calls for heat, you are putting at least 4 tons of capacity into that one zone, with the capability of putting 6 tons in one zone. So the ductwork must be accordingly sized. So a few downsides, and a few upsides. I am also a fan of preheating your hot water with the efficiency of the geosystem via desuperheater. Hard to beat 11K in savings.

There was no direct route for our trunk lines to be connected, and I was concerned that there would be airflow problems, so we chose to install two geothermal units.

Expanding on what Doc said, our 3-ton unit for the first floor, and our 2-ton unit for the second floor can both be run at 2/3 capacity. Lots of flexibility there. Depending on your climate, cooling redundancy can be nice. If two units share a common closed loop, there may be some efficiency advantages with this as well (if only one unit runs, a loop sized for two units is still utilized.)

All this said, if duct sizing is right and a proper job can be done connecting your ducts, I would opt for the single unit for lower cost and less maintenance. I don't see why a competent installer couldn't install either option for you. If you like one option over another, discuss it with the other installer to get his opinion and a quote. Personally, I don't think you should stop at two quotes.

I'd like to know what the heat loss or gain is. It is uncommon for 6.5 tons of airsource to be replaced with 6 tons of geo in my neck of the woods. I would like to know more about both installers experience before commenting on design or price.
j

PM me. I just installed a split system, 4T down and 3T up. Climatemaster to boot

Was your systems install with drilled loops or laterial lines.

If you want good advice, start with the shopper's checklist and Docs,GMs and my comments above.
You have two radically different proposals and your only follow up question is about the loops to someone who "just installed a system" whether contractor or purchaser (who knows).
No offense mhinch, but your 1st post ever suggests Jasper leave a public forum for your thoughts. Why not post them publicly.
j

Good point New to this forum type comunication. But to answer your question about the two contractors they are both two of the larger HVAC contractors in the area that have been in business for several years. I did get a quote from a much smaller contractor that does not have the pedigree of the other two which also quoted two systems that was in the middle as for as price. Both are willing to back up their designs in writing. The Water-Furance contractor is listed as a GeoPro on the Water-Furance web site were the smaller contractor was not. Not sure what that means. Meeting again with the one contractor this afternoon to look at latteral lines vs drilling. He is saying as long as we have 5' for the latteral lines we will be ok and better if the area has alot of mosisture in the area. He also said that they normally go 185' if they drill were as the other two were only going to go 150'. Is it also true you must have the hot water recovery to qualify for the 30% Federal Tax incentive?

Posted By Jasper1 on 20 Jun 2011 12:29 PM
Is it also true you must have the hot water recovery to qualify for the 30% Federal Tax incentive?

I believe this is no longer the case, but it was a requirement a few years ago (but don't take my word on it since I'm not a tax pro - get professional tax advise.)

Jasper, what part of the country are you located in?

Kentucky

Posted By geome on 20 Jun 2011 01:32 PM

Posted By Jasper1 on 20 Jun 2011 12:29 PM
Is it also true you must have the hot water recovery to qualify for the 30% Federal Tax incentive?

I believe this is no longer the case, but it was a requirement a few years ago (but don't take my word on it since I'm not a tax pro - get professional tax advise.)

Jasper, what part of the country are you located in?

Not required.
For some reason it adds a new line in front of the web add I listed. Delete everything in front of the http:   Tried to do this but when I went back and tried to 'modify' , that line doesn't show up!

<!--[if gte mso 9]> Normal 0 false false false EN-US X-NONE AR-SA http://energystar.supportportal.com/ics/support/default.asp?deptID=23018&task=knowledge&questionID=19320

 

we put in 1125' of vertical capacity in 3 wells plus what went to/from the header pit to the unit(s). As far as 30% credit check with your accountant because you must have some tax liability to use this, it can be over 6 years in NC......GET PROFESSIONAL ADVICE!
In shopping around for a project of this scope KNOWLEDGE IS POWER, ask questions, get it in writing!, don't settle for what the contractor knows will work. Have your house measured and heat loss calcs run. Study and understand these. If you're about to drop some big $'s on a system the bidders should be very tolerant of your ?'s, if not let them go up the road.