Furnace and indoor coil must be matched to outdoor unit. For so many zones, esp when upstairs mbed is a zone by itself, a 5-ton system causes many problems. 1. The m-bed only needs 1 ton of ac. (1 ton is the amount of heat it takes to melt one ton of ice in 24 hours. For AC, this is how much heat you must pump OUT of the room.) If you zone this, you will force 5 tons of ac air into a 1-ton space. Pressure-wise, bad for furnace, bad for duct. Energy-wise, a waste of 4 tons of ac and blower capacity. 2. When a t-stat in a hot zone calls for AC, and no others call, you have short, frequent cycles loaded with fast pressurized air. Dehumidification is reduced. Condensed water on indoor coil has little time to drain, and then is re-evaporated and sent back to the air, leading to mold problems. Best to have large zones or to have two or three small individual systems (furnaces and ac units) which are more easily balanced. With your 5-ton system, suggest placing one t-stat (one zone) on each floor, regardless of tall foyer, and control temperature disparities with manual dampers. The rest of the story: This can only work with certain houses, depending on the way the ductwork has been installed. If the ductwork is not right for such simple zoning modification, the ductwork may have to be reworked. This can be a huge undertaking. Often in such cases the contractor will walk away. Then your best bet is to try to install some manual dampers to restrict air flow to certain areas so that it will be increased to others.

I would suggest telling the builder to remove the cost of HVAC from the contract, that you will take charge of that aspect of the project and coordinate with him its installation. As for the ‘HVAC guy’ that told you, “1-well per ton, at 250ft/ton”, this would likely give you a VERY efficient geothermal system. It ‘sounds’ like more loop than what’s usually required but I don’t know your geology. This could be correct; it certainly sounds conservative which is OK in my book. Best efficiency with ‘Liquid-to-Air’ geothermal heat pumps (liquid in the ground loops) occurs when boreholes are drilled one-ton per borehole, separated by at least 15-feet, connected in parallel, headers installed WITHIN the mechanical room, WITH the ability to VISUALLY measure the flow in EACH borehole! This will give you the capability to easily and quickly monitor, troubleshoot and balance the entire ground heat exchanger loop network. Money saved at this level by not doing this properly and taking shortcuts might become a VERY expensive curse later on should problems arise. You will get this money back when you cash out, sell your home and have an inspection done - if they know what they’re looking at! A mechanical room should be built in the basement or the lowest level, preferably at the center of the house; an ERV is essential. The mechanical room must also contain an ‘AS Built Book’ that documents the complete design, specs, startup procedures and detailed startup measurements, as well as all the details and detailed location of the buried ground loops. You should also have a paper copy and digital copy of this document kept elsewhere in your home as well as at least one paper and one digital copy off site for safekeeping. Included detailed pics of EVERYTHING! This like having an electro-cardiogram of your heart done when you are well so that you have ‘baseline’ data to compare to as a reference when/if things go wrong and to also prove that they were ‘right’ at time of installation. It also affords you the ability to hire any knowledgeable tech to come on-site and quickly understand what’s going on. This is important if your installer goes out of business or if you have a falling out. It’s also vital for recouping the maximum value of your system at time of resale. Stay away from attics for mechanical systems! Find the right company to do the foam insulation; giving it the appropriate amount of time to cure and outgas and you should be fine. Check references and accreditations, this applies to the geothermal contractor and duct designer/installer as well. One-way to further ensure the right size geothermal unit(s) would be to install variable speed unit(s), both fan coil and compressor. That way there’s some ‘play’ in the system and increased efficiency as well. The geo units will self adjust to whatever duct system they’re hooked up to, within reason and throttle down if there is too much capacity while still giving you proper dehumidification. Too small a system and you’re out of luck without expensive, extensive mods. Look into zoning - properly designed, installed and controlled! The thing to ‘watch out for’ with ‘fully variable’ systems are flow centers or pumps, if you will, that are also variable speed, that they do NOT throttle down to a level where ‘turbulent flow’ in the ground loops changes to ‘laminar flow’. Without delivering a seminar on ‘flow’ in this forum, suffice it to say that you will need to have a discussion with your installer on ‘Reynolds Numbers’ and let them educated you and give you the seminar. If they seem clueless or flippant on this subject then you’re dealing with the wrong people that have not been properly trained. Copy & Paste: http://www.waterfurnace.com/literature/7series/BR2700AN.pdf IMPO SR Here is a link that might be useful: International Ground Source Heat Pump Association at Oklahoma State University

Mike_Home - Thank you for the answers and advice. Here are some responses and follow-up questions. 1. SEER/EER - your answer is what I had been slowly understanding that these numbers are what drive the efficiency numbers. Rough calculations comparing my older 10 SEER unit to a 14 and 16 SEER unit plus using 1 year of energy bills, show a potential electricity improvement of $184/year for the 14 and $238.31 for the 16. Of course this is all dependent on a quality install as well as proper ducts, etc. as you've outlined in other points. 2. Payback will be uncertain as I was relocated for work. Not sure how long we'll be here and at this point, the energy savings per year is still important. 3. Understood. Before my research, I didn't realize that the furnace played such an important role in airflow. 4. My zoning explanation might have been poorly stated. The gist of what was mentioned, was that based on proper zoning, the more efficient airflow distribution within the home may allow for a 4 ton condenser. The condenser potentially wouldn't have to push air through all of the ducts at the same rate. Does that logic track with your experience? 5. Appreciate thermostat advice and handling all the features, etc. 6. The annual maintenance contract was from the contractor providing the detailed Goodman quotes. Participating in the yearly maintenance contract covers 100% of repair costs (Contractor backed, not OEM), includes a 10 year replacement warranty, and there are no dispatch or service fees for service calls. The replacement warranty is the full replacement of the failed unit rather than just repairing under the 10 year labor warranty with Goodman. If I don't do the yearly maintenance contract, there is no replacement warranty. Ever heard of this? The contractor (Goodman quotes) may have mentioned "calculations" at one point but I don't remember hearing about them doing a manual "J" load calc. As far as I can tell, Title 24 doesn't require the J calc. It does require a duct leak test performed by a certified 3rd party HERS testing company. This is required on ALL HVAC projects in CA. Rebates are only available as part of CA's Home Upgrade Program. This program has required testing and upgrades on items like ducts, whole home envelope, attic insulation, etc. I will go back to two of the contractors and ask them about performing the calculation. I am looking to replace the whole system at this point to make sure the equipment is compatible and most efficient. Goodman is making me increasingly nervous, especially with the Class Action lawsuit that was just set back last week based on a judge's ruling... As for the use of a different coil with the Goodman equipment, it seems to be very common with Goodman quotes (based on board postings like this). I think there is a relationship or commercial connection between Goodman and Aspen to drive the high use with Goodman systems. I don't know the true specs on the Ruud equipment, I was guessing a bit; I will ask for the models, etc. Thanks again!

Elmer's inquiry deserved more of a answer than your chest-thumping, self-promoting, California-bashing commercial. The climate around Katy, Texas is certainly not "one in a million." It's similar... Just "similar" but not exact... meaning different. Me and Mr. Fudd's disagreements are well documented on this board the story continually evolves from duck to rabbit season and back again. One in a million is a generalized comment... a saying. But you Mr. Ross love to find something to argue about for the sake of arguing. Distinctly different? That's rich. I find it humorous to what people like to nit pick over. It doesn't change anything. I don't change anything about the comment I made. You can disagree if you want, I still say Katy, Texas is indeed "one in a million"... at least. Ray is a one-person company. He lives in the replacement contractor world. When someone is without heat, air conditioning or hot water, it's often the first replacement contractor to arrive that "wins." Not hot water... I am not a plumber. Texas licensed for AC and heat only (HVAC). Yes essentially that is the "service" I offer as well as the part of the world I live in. Air conditioning and Furnace repair service in Katy, Texas area. When I say "service" I mean it. Every day, including summer holidays, weekends. Repairs also include equipment replacement. I myself install all new equipment I sell. I don't sub out work to sub contractors unless the contract specifies that (which is extremely rare situation). If you don't like the way I do things you're free to look elsewhere. I'm not here to tell you what your ears are aching to hear, I am here to tell you like it is. (Firmly and exponentially based on experience.) You don't have to like what I say, most of the time it's not pleasant due to a variety of reasons. In some aspects similar to the confrontational aspects of this forum boards conversations. Anyone who has viewed my posts know I come thick skinned. Disagreements do not phase me. If you want a gimmick, chase a gimmick. I could not offer the service I offer if my approach didn't work after all these years. I'd be running back around chasing my tail. You'd never get thru when you try to call me. Seriously? Think about it. Chest pounding: If you want to call it that it's your opinion. You're free to have it. My experience is my experience. 26 years. Easily verified. 13 years running my own company. Again easily verified facts. Essentially it's an advertisement. I am not paid to be here. I am here drinking my morning coffee filling in that time. If this isn't advertising my business what purpose would I have to be here? I don't come here to argue with the metamucil fan club that propetuates this board. Ha, ha... you know who you are. People search for me. All I have to do is leave bread crumbs so people can find me. AC repair service Katy, Texas area. Everyday. When I say something I mean it. Not a spam service. Don't sell your info. Don't pester you. You initiate the service you want. It's not that difficult when you know what you're doing. If you want a 20 something or 30 something coming to your home, you have to ask yourself how much experience does this guy really have? If that's what you want go for it. I've worked for companies like that... having to go back behind some newbie over and over and over. Used in not very fun ways. Follow my rules. I've been doing this longer than some of you have been alive. My methods work. Experience. What is it worth? Who else on this board in all the world listed as a pro HVAC service provider has my work ethic? Name one besides me. (beside the mini split warehouse spammer) Truth is stranger than fiction. There are people out there who read these threads and never post due to this kind of argumentative climate so frequent here. How could I know such a thing? I service the Katy, Texas area.