I am owner/builder of a three story (including basement) lake house in central/north alabama.  The basement is ICF construction, the main story and attic are SIPs.  Roof panels are 10 inch SIP panels at a 4 pitch.  Dimensions are basement 34 X 24 and 1st story and attic 34 X 26.

I could actually post the bid with a return on investment document as well.  I am not sure if that is OK to do on these boards.  If it is and would be useful to someone I would be happy to.

The HVAC contractor took notes on all floors and recorded information from the energy stickers on all windows and doors.  He said he would do a heat loss calcuation to size the system.  That was very good news.  He also said he would not go further than 15 feet with flexible ducting.  More good news as back in New England they don't use mostly rigid.  He intends on installing one Water Furnace Model NDV038, complete with lake loop, a Three Zone Zoning System, one zone per floor and hot water assist.  This system has a 30 SEER rating and High Efficiency MERV10 Air Filter that is standard in this unit.  It will also have a Dual Stage cooling and heating compressor and variable speed air handler that will operate at 50% speed, 80% speed, and if needed, 100% to maintain better humidity control and more even air distribution.  Price includes Three Honeywell Programmable Touch Screen Thermostats and complete duct system.  The only thing not in the price is the acutal digging of the trench to the lake which is approximately 200 feet in distance.

The price quoted is 18,775.

Option 2:

Trane XL16I Heat Pump

17 SEER

price quoted 12565

Option 3:

Trane XR14I heat Pump

13.25 Seer

price quoted 9565

I will not be using this third option.

I am assuming I will be getting the 2000 dollar federal tax credit if I go with Option 1.

Price difference between 1 and 2 is $4210.

This company does an analysis on ROI.  They did not, it appears, take into account the tax credit.  So, just to keep it apples to apples, I will not either, at this time.  ( But I will of course use it)  The analysis is based on 20 years. 

Lifetime savings:  $17054.76
Monthly Savings: 71.06
Lifetime CO2 Savings: 176091 lbs
Monthly Loan Payment: 44.49 (not sure what they base that on)
First-Year ROI:  16.67%
Net Monthly Savings: $26.57
Residual Value: $3625.00

The first years savings is 701.92, I am not sure where they got that from based on the above numbers.  I will be calling tomorrow.  So, based on 4210 plus the cost of digging the ditch, the payback should be around year 6.  Even sooner with the tax credit. 

So,  If you have slogged through these numbers and you have any comments or questions I should be asking, please let me know.

Thanks in advance for taking a look at this proposal.

I am searching for more estimates but am having no luck with anyone locally that has worked with geothermal so far.

Bill

That sounds like a heck of a price for the geo! How many tons total? You mentioned that you did ICF from foundation to roof but it looks like the rear is covered in OSB? Is it a private lake? I've always wondered if the coils were put into a public lake....what about the fisherman?....I'm a BIG fisherman....:).......The coils could get pulled/damaged with lures/anchors??

Few missing chunks of the equation, but if cost difference is about 4K after tax credit, what was the question?
J

I believe this a three ton system. The lake is public and managed by Alabama Power. They are very supportive of this technology on the lake. I did ICF only in the basement, three walls, and did SIPs for the rest. The coils would end up under the dock and hopefully won't pose a problem to the fish or the fishermen.

My basic question is can anyone tell me if this is even in the ball park for an HVAC system. Option 1 or Option 2.

Thanks

Bill

PS  Thanks for correcting me on the ICFs, I edited the opening post to show SIPs.

yes I think you can sleep peacefully with that price.
I am putting in a 5 ton two separate zones with forced air and radiant 30 seer 4.9 cop WF geo with horizontal loops, humidifier, desuperheater and air filter. I dig the loops and trim out and assist hanging duct/cutting penetrations. $21,800 seems fair to me, I don't know any better...

Kevin

"The HVAC contractor took notes on all floors and recorded information from the energy stickers on all windows and doors. He said he would do a heat loss calcuation to size the system. That was very good news. He also said he would not go further than 15 feet with flexible ducting. More good news as back in New England they don't use mostly rigid. He intends on installing one Water Furnace Model NDV038, complete with lake loop, a Three Zone Zoning System, one zone per floor and hot water assist. "

If you can get all that for $18775, jump on it!

If he took the time to enter your specific window and door performance values into the load calc, that's bonus points.

I have that same unit, 4 zones near Jax FL on 3000 SF. Summer cooling rarely more than 15-20 Kwh / day, and less than that so far for heating.

Be sure to plumb the hot water assist into its own unpowered preheat tank. I ran mine into an 85 gallon preheat tank and my hot water cost for 6 months has been $50 (family of 5)

Now I find out Bill (the OP) emailed me with more specific info and the proposal. I responded to his email but am including that here for use by and response from others here:

Hello Bill,

No problem - for FY09 I'm billed at $175 / hr with a 4 or 8 hour minimum...

Just kidding. (Those are rates for distributed controls, not HVAC)

I actually just did respond to your post on the green build site - I prefer that since more than one person benefits and other pros guide and correct me.

In reference to your quote - I'm going to focus on the WF option since that is my area of experience and I'm not much interested in the other two. One of the pleasures of working for free is ignoring things that bore me...

1) What zoning system will be used? I have and like WF Intellizone both because I like getting as much as possible from a single source and it has features such as extra LED indicators telling me what's going on. There are other perfectly OK cheaper options, and I think WF could improve how Intellizone works with humidistats - there is a dip switch that reduces cooling airflow by 15% for better dehumidification, but that's crude - I'd like to see dynamic variation of airflow based on humidity. I'm not sure if a more sophisticated option can be interfaced with WF

2) Reference is made to 3 fan speeds of 50, 80 100%. I much prefer the ECM blower with 12 available air flow settings. The ECM actually controls airflow, rather than just setting a speed. It is also quieter and more efficient. Reference is also made to a variable speed air handler, so the proposal may in fact intend to supply it.

2a) NDV038 available with larger 1 HP blower. Properly designed duct system at this tonnage should NOT require that option. An over sized blower adds cost, reduces efficiency, and doesn't allow some lower CFM settings useful for air circulation w/o heating / cooling. It is likely this is not being proposed but I'd double check that.


3) I see lake loop and trench to be supplied by others, so the $18775 is less of a bargain. Still a very good price, though, since it includes zoning and metal trunks.

4) I suggest asking for references, ideally some geo jobs.

5) Depending on your elevation from lake, pumping costs could be substantial if open loop. I assume you are planning closed loop - the slight tradeoff in heat exchanger losses will likely be more than made up in reduced pumping power and fewer fouling headaches.

6) SEER and EER aren't same. WF can be (up to) 30 EER. Your EER will vary according to actual waterside temps and flows.

7) Is your house designed so all ducts are within insulated building envelope? I can't emphasize enough how important this can be to a truly green, high efficiency system.

8) I'm not all that jazzed by ROI calcs - there are so many assumptions buried in them that they are practically guaranteed to be wrong.

I'm going to paste this into the green building thread so others may read / respond

Curt

Engineer, your e-mail might be more telling with his questions attached.
J

Kevin,

I am with you, I don't know any better!!  It doesn't sound so bad but, without some kind of comparison or "corporate knowledge" I wasn't sure what I might be getting:)

 

Bill

Curt,

Thanks for taking the time for me and everyone on this board with your expertise.  I learn a lot here.  I agree that the ROI is at best a 'shaky' figure.  But, I do believe that if properly sized and installed that it will kick butt over a traditional heat pump or any system for that matter.

Thanks again,

Bill

J,

All he asked for was my thoughts

fly840 ~ just for a reference of comparison.  My 3 ton system, WF envision 2 stage heat and cool, 2 zones, they had to install all new ductwork in a 70 year old home cost $38,000.  It sounds like you are getting a great deal. 
Plus, I want to say, for the one day I had to use AC (because our system was not operational until Sep), it cooled the house within 30 minutes and we actually had to turn it off.  We've been very happy so far with the heating (we're in Upstate NY). 

Good Luck!

WOW, thanks Ona, that is exactly what I am looking for, comparisons, etc etc.  Thank you very much for posting.

Bill

Unless you are on a location that has quite a water current be SURE you know how much the loop needs to be derated for still water. A loop just lying on the bottom in still water provides a very poor heat transfer coefficient. Pipe is cheap compared to electricity or even unrealized performance from now on. External fouling on the loop piping increases over time as well.
Shallow water heating in summer during daylight yields a further drop just when you want the most out of your A/C.

Dick

Dick,
The body of water is a slow moving river, and I am on a slough. The depth of the water should be approx 30 feet in the summer and about 22 in the winter. I am not quite sure what you mean by derated? Thanks for the info.

Bill

There is no flow to conduct the heat away from the loop pipe so that the loops must be made longer to off-set the low delta-T. The water next to the loop pipe is heated/cooled by only a few degrees and then is in equilibrium. Instead of the big delta-T you would expect from the large mass of water you only get a small change in the mire of lake bottom temperature close to the pipe. Mixing is everything in heat transfer and still water doesn't have mixing.

I live on a lake in N GA and lake loops are not permitted, BUT there are some here and they have not performed.

Dick

One brand of pond / lake heat exchanger I've seen here before is "slim jim"

What you say is true,  but "still water" is going to transfer heat a lot better than the "still dirt" you have with an earth loop.

 A pond loop will work fine as long as it is properly designed and installed.

AIR, some systems were tried with the thinking that the pond loops could be shorter than earth loops but it apparently it not the case. My statements mainly are to take note of the situation and plan accordingly. Clean pipe will no doubt work like a champ for a while. There is just no opportunity to pull it out like a boat hull and scrub the crud off. After things get silted over it will probably approach the performance of 'dirt' is my impression.

Dick