As I mentioned in my other thread ("Geothermal refit questions"), I've got three contractors involved in designing and bidding.  Things are starting to unravel.

The guys who said to oversize and do 8-ton are coming out on Wednesday to actually look at the house.  My expectations are low, but sometimes things do turn around.

The 2nd guys I had called are stretching out when they can even do a site visit.  So I don't know where that's heading.

The first guy, who initially quoted 3-ton w/propane assist, or 6-ton, is pretty active in this process.  Problem is, I'm starting to see a bunch of red flags:

• He more or less refuses to make a firm recommendation on sizing.  Literally told me he'd sell me whatever I want him to install.  Is going to rely solely on square footage plus my amateur loading numbers.  Doesn't do much for my confidence in having him properly size the system.
• That said, at the moment he's suggesting 5 or 6 ton for a standalone system.  His line right now is that it seems like 5 ton would be sufficient heating, especially with heat strips, but that a 6 ton would have the proper air handling.  On that topic he's going by square footage alone---my square footage needs 24 cfm, which would be the 6 ton unit.
• I'm definitely getting the hurry-up-and-go treatment.  Says 6-ton units are very hard to get now, and that I'm getting to the point where the 3-4 days without heat would be during pretty cold weather.  Each point has merit, but things are going too fast for something this expensive and with this much design nuance.
• Today the "oh yeah" topic of electrical service came up.  Says I need 150 amps to service the heat pump and water pumps.  150 amps?  For that I'd need a new panel and probably another line brought in.  More $$$ and more lead time by the time I coordinate the power company, my electrician, permits/inspections... Yippee.
  

So whereas I was thinking in the low $30K range, it has definitely escalated.  The HVAC work alone is $27K.  That includes installing the GTHP, reworking the main ducts for better air, refitting with two zones, and removing the existing system.  Add around $2K/ton for the outside.  No clue on the electrical work, but could be $2-3K.  And then there's the inevitable unforeseeables and more "oh yeah's" on stuff I haven't thought of.

So we are easily into the low $40K's now.  Starting to really hit my threshold of pain on payback periods.

Thoughts?  Advice?

Honestly, you are behind the 8 ball. While I make the don't wait argument, I also point out that waiting a few months could save you money and heartache. Start with references and back to ground zero; contact manufacturers to see if there is a local dealer you missed. We're almost at a point, where the good guys are to busy to answer your questions.
My next thread may be "better to wait (at this point)."
Incidently my electrician generally charges about 2-3K, so you have that one correct. Not sure what your 2K for the outside refers to. Can't see you getting to 40K. As a matter of fact I've never done a single system that cost 40K. I've had homes with multi systems that cost more, but every 'single unit' system (even including duct work or zones or vertical drilling) has been <35K.
J

The "outside work" is  drilling and pulling the water supply from the well to the house.  The over-the-phone estimate was $2K/ton, so $12K for the drilling.  So that's $27K + $12K + $3K = $42K.

Keep in mind that the $27K includes about $2K extra work for the split zoning, and include reworking the central ducts to accommodate 24 cfm.

So having to run 150 amp lines to the GHP is reality?  Is that just startup current causing the huge load?  If a heat pump drew 100 amps for an hour, that's 22 kwh, or $3/hour to run the heat pump.

Yes, I am getting more and more in the mood to put this off until spring---by the time I get the due diligence done properly the lead time could be well into the winter.  I miss the heating season, but still catch the cooling season, and in the meantime can have someone come and tighten up the attic.

Amps are based + or - on max. A 5 ton 2 stage may run on (to pick a number) as little as 37 amps. Throw in an electric aux. heater and electric water heater, and demand could suggest 150A load.
J

I don't care how busy the guy is, if he won't do an accurate load calc and only wants to be "Bubba" with the stupid rule of thumb, I'd steer clear of him. I hope there are other installers for your area. This big of a purchase deserves investigation to get the better system, which may cost you more anyway. It's not worth being oversized/underdesigned on it. Good thinking on tightening the house, too.

Keep us informed on how it's going.

I'm with Clark.  I just found out about a huge home in Dallas on Saturday that had 33 tons of conventional equipment installed.  And from the beginning, there were problems with system performance.  Finally, the owner brought in a high end HVAC guy to evaluate the problem.  His first step was to complete the Manual J load calc on the home and the report concluded the home only needed 17 tons of equipment.  So the homeowner bought about twice the equipment the home needed.   If the homeowner had known to insist on a load calc first, he could have had geothermal installed for 10% less than what he paid for conventional equipment and had half the utility bills and all the comfort.

I had another guy in Ft Worth who called 20 HVAC guys to give him a bid on an AC system and the first thing he told them was he wanted a load calc.  17 of them refused to take on the responsibility of doing a load calc and drove off without giving him a quote.

It's unbelievable what is going on out there but you should hold firm on the load calc.  It can save you a boat load of money and make your home so much more comfortable.

Third the motion. When I suggest that the good guys may be too busy to answer your questions, I mean you might have to be patient with them, not that they shouldn't have to. Waiting 'til spring is not necessary in every case. Winter digs are ok with some systems.
Dale, I'm not sure I'd spend much time with a guy that called for 20 estimates. Nor do I load out 100% of the homes in which I install fossil systems (1000 sf home for instance is going to be the smallest furnace I have...). So far I've loaded 99% of my geo customers, but will occasionally do changeouts with out a calc. where the original geo contractor is someone reliable.
J

I hear ya.  I'm not so concerned about the outside work---in fact the driller said that cold weather doesn't really affect them (although I imagine a lot of snow would complicate things).  I'm more concerned about having the heating system completely out of service for 3-4 days during the winter.

If I can find a way to do it sooner than later, I'll definitely take sooner.  But the due diligence is going to take some calendar time, and I'm really getting in the mood to fix the attic problems before upgrading the HVAC.

FWIW, the Power Company stopped out here today (24 hour turnaround, not bad!).  Turns out I have 4/0 wire coming into the meter, but it still needs to be determined whether they can run 320-400 amps into a dual-socket box.  If they need to run a new cable, I own the problem of burying an underground conduit between the house and the transformer.  To make matters worse, the transformer is across the street, so we're talking jackhammers.

If it comes to that, I'm definitely throwing in the towel.

I was actually glad he did Joe because he finally got a hold of me.  He was stunned at the number of guys who wouldn't do a load calc for him.  He said he would call a guy, tell him what he was looking for and the guy would hop in his vehicle and drive off.  He would call another one, same story.  I guess the guys are so busy they don't have to.  Interesting.

Update:

The 8-tonners came out today.  After 5-10 minutes of looking around and talking, he said he's thinking somewhere between 5 and 6.  He spent a good long time with me, and had his helper double-check my interior measurements that I used for HVAC Calc (which were pretty close apparently).  He sized the ductwork based on the main trunks and their branches (2300 cfm).  His spiel was that cfm capacity of the ducts has almost as much to do with sizing as heat load.  I.e., if the heat load calls for a unit that exceeds the capacity of the ducts, then you have a problem. 

His take on doing a detailed heat load was that he'd take the time and effort if he won the bid.  I sort-of understand this, but it's still a little backward.  So I have somewhat higher confidence in the numbers I've self-reported, but I'd really like to have a pro do it.  Still working on that.

The surprise of the afternoon was his support for Hydron Module heat pumps---I've not run into that name in my research.  He had a story that held together pretty well about why he likes them better than ClimateMaster (athough he would put in a ClimateMaster if I insisted).  Anyone have a read on this company and their products?

His approach to dual zoning will be to replace the main trunk lines and split them into the two zones.  That sounds reasonable?  He also mentioned something about having dual zones will give me a bit more lattitude with how much cfm capacity I need in the heat pump's blower, due to the fact that one zone will likely call more often than the other.  I sort-of understand this, although I'm probably not headed for a big mismatch between cfm required for the house and what the heat pump can provide.

I also got (for the second time) the datapoint that a standing column geo well only needs to put out the bleed rate (2 gpm or so) rather than the flow rate of the circulation pump.  Which makes sense to me, since you're replacing water back in the column at the same rate you are drawing it, unless of course the pump is in bleed mode.  But I've gotten contradictory info on that here on the board.  So I'm confused.

He seemed generally pretty competent and knowledgable, so I will be taking what he has to offer under serious consideration.

I also got the word that my electrical service would be able to handle a second panel up to 150A (total 350A).  So no jackhammers, but still a decent amount of electrical work to be done unfortunately.

Our heat pump of choice is Hydron

You will not go wrong a Hydron.


Don't confuse bleed GPM with the heat pump GPM needed.  They are two very different numbers.

Another update:

Finally got a call back from one of the energy audit guys.  It's starting to look like the first audit I had done should have included loading, and perhaps I just simply didn't get that in the report.  Or at the very least, he confirmed that with something like HVAC calc, an auditor is going to do essentially the same thing I'm doing and would probably get similar numbers.  So my confidence is rising with the numbers I'm self-reporting, I may just opt to revisit the numbers and assumptions one more time and call that "good enough".

Am I crazy?

The other tidbit from the audit guy was that the two contractors I'm working with (1st guy and the 8 tonner) he holds in high regard: "They know what they're doing and are two of the best around here".  The fact that they are both converging on the same specs is another good sign.

One other fact check on the Hydron units.  The guy this afternoon said that a unique feature of the Hydron is that it will do DSH in both stages, whereas most other heat pumps will only do DSH when running at full throttle.  Is this true?  Does it matter as much as he seemed to imply?

It is true that Hydron units DSH in both stages. How ever so does Climate Master. My bet is that most units do this. So it doesn't matter much.

And so do WaterFurnace's Envision series GSHPs.

Best regards,

Bill

Add a tid-bit; you shouldn't be without heat for more than 8 hours with competant installers. Even if you don't have geo hooked up. We put a unit in today,on the resistance coil, in 4 or so hours.
Hydron is a fine unit, run away from any other that's name starts with an Hy.....
J