I received a quote for Trane vertical ground loop system as follows: Trane T2GX 5 ton system 5 Ton Vertical loop per IGSHPA standards (fully grouted) 2 pump flow center Nexia 850 2 Stage compressor ECM blower ProCool Geo thermal fill All necessary labor and material to connect to an adequate electric panel, sub panel and wiring included in the cost (panel is currently full and have Natural Gas Furnace) High Efficiency 2” Merv 11 filter Insulated plenum and return air drop. Base pad and foam sound pad under geothermal unit Canvas isolation connectors. Vendor didn't yet provide design specs for his Manual J, this was the quote he sent prior to our discussion. Manual J from another vendor arrived at 39,500 Cooling BTU and 72,400 Heating BTU which seems low on the cooling. Have a 100kBTU 78% trane gas furnace that provides more than enough heat, so the Heating BTU seemed correct. Current 22 year old 4 ton Trane runs the better part of all day during 90+ degree days. My house is probably around 4200 Sqft finished living space including basement. Have over 22 windows and 3 patio doors, but all are high efficiency Low-E High SHGC windows. This was around 27K pre tax incentive. Hot water option was around $1400 and installing 50gal buffer tank was around $1000 I haven't talked to them about this yet, but they offered an option for one additional ground loop - what would be the pros/cons of this? Is this an "in case you spring a leak" thing? Live in Northern Kentucky / Greater Cincinnati area. Awaiting a quote from 2 other vendors that sell Waterfurnace as well. Thoughts? Warning signs? Thanks!
Looks all good on paper. Not sure what the 3rd ground loop is all about. Ask them about what the pipe diameter is, and how deep the wells are.
Thanks. I got another quote from another company for a GeoComfort Compass series 4 Ton unit. This is from the company that provided the above Manual J calculation. They said my return air system was marginal for a 4 ton and suggested a 3 ton Conventional AC/Furnace and a 4 ton GeoThermal system. They are getting me design parameters today or tomorrow. This quote did NOT include electrical work to add required capacity to the electrical box and didn't include any cleanup of the drilling work. " Note that an additional 60 amp (220 volt) breaker (along with 220 volt wiring) would need to be run from the electric panel to the new Geothermal unit in order for it to work. We are not licensed electricians so that part of the project would have to be performed by a sub-contractor. Your price for that part of the service is not included with the total on the options worksheet. The driller subcontractor’s price is included in the options worksheet. Please note any drywall, painting, yard repair (from the drilling rig), etc. is not included with the attached option. " The total for this 4 Ton bid was around 27K as well. Red flags for me are the "get the electrical work done on your own" part and the "no repair included" note. But are those typical of Geo installs? Are those real red flags or not? Thanks
Yes and no. You can have a turn key install, and you will have to pay for it. Drillers usually don't do yard repair, as little as geo companies are good in landscaping. You can do it yourself, and you can have it hired. We have that discussion with our customers, and we list the prices for "landscaping" as an extra. On retrofits, we list the electrical price part of the itemized quote the customer, on new construction we specify that the electrician must do the high voltage wiring, and we do the low voltage control wiring. Geo is intimidating to many people, since they do not know much about it, so my philosophy is that we just take care of everything and do a turn key for them. BTW: Definition of thermal inertia. : the degree of slowness with which the temperature of a body approaches that of its surroundings and which is dependent upon its absorptivity, its specific heat, its thermal conductivity, its dimensions, and other factors. Other factors are especially the thermal mass surrounding the pipes, since there is more pipe in the ground in horizontal systems, there is much more thermal mass. Meaning that the loop in horizontal systems reacts to loads (either injecting heat or retrieving heat) much slower, which is what you want, compared to vertical systems. Again, this is just generally speaking.
I received another quote, this quote was very well thought out, provided all balance points and energy heating days, cooling days, etc from the Waterfurnace system. In addition to the very nice and well thought out quote, Manual J Calcs were provided along with very detailed list of what was to be done with the install in the quote. This quote was for 5 ton Waterfurnace 7 Series Before Fed rebates ~32k 5 ton Waterfurnace 5 Series Before Fed ~28.5k Manual J of 70,381 Heating / 41,229 Cooling Winter design 6* Summer design 92* Bldng Balance temp 57.1 Series 7 Max System Balance temp -0.7, Avg -5.7 Loop is Vertical .75" PE 150ft depth in 5 wells. So it should meet 100% of my heating load according to the specs, staged 10Kw elec heat would be installed as well Series 5 is similar but 8.2* and 5.2* balance Both with the communicating thermostat, internet gateway 2" Merv 11 filter, Desuperheater for water heater, buffer tank for existing water heater, 10 year P&L on waterfurnace and loop, 5yr on accessories, 50 "material" on loop. new supply air plenum for improved airflow, with canvas connector to eliminate, new return air plenum for improved airflow, with canvas connector. I really liked this contractor, but the price really seems high still. I just have no context on what it SHOULD cost in this area. My approximate payback vs a very nice Modulating Gas Furnace and 19 Seer Variable AC would be roughly 14-15 years. Payback vs current system is 11 years at $0.10 / KWH electric and $1.26 / CCF Gas I need to run scenarios on increased electric rates to see how it impacts the numbers, I think gas should stay relatively low but electric is likely to rise. Any other thoughts? Are these prices in the ball park or do they seem too high? I like this installer the most so far. They seem to have a lot of geo experience, own their own drilling equipment, etc.
The prices are excellent, especially with a vertical loop field. I could not do it for that price. The only thing which sticks out is the loop field layout. What is the antifreeze and the flow center they are using? Size of the pipes coming in the house, and how far do they have to go outside to get to the loop field?.
The loop field would be 5 wells in sort of an "X" pattern in my front yard. They said it would be a 5 ton air drilled vertical loop with " 1 U-Bend .75" PE" wells around 150ft deep. They would tie them into a manifold and use 1.25" lines into the house. They initially quoted a horizontal bore from loop field header into the side of my home, but I pointed out they could go through the side entry garage much more easily into the HVAC room. So about 24ft through the garage and at most I'd say another 50ft to the curb. So anywhere between say 30-70 ft to the manifold/header depending on where they'd put it. They said it would come out into an insulated box into the garage and that it wouldn't affect the efficiency to do it this way. I would save around $1200 to eliminate that horizontal bore. The flow center would be "1 Variable Speed ECM powered flow center which uses 60% less energy than traditional flow centers, paired with triple duty valves for maximum loop control and ease of service. He said they use a 20% methanol loop fluid mixture. I'm pretty sure they said it was pressurized though I don't see that in the bid. One interesting statement this company made was that they do NOT grout in our area unless they hit water when drilling and that they had studies from the University of Kentucky saying in our area it is actually detrimental to heat transfer to grout. The problem I am having right now is the economic analysis they worked up used $0.10 /kWh electric and $1.26 / CCF gas (which was correct) and this month rates are now $0.087 /kWh electric and $0.88 / CCF gas. This makes payback drag out even further.... Decisions decisions....
If you solely looking at monetary payback alone, maybe geo is not your thing. Let me give you an analogy: I believe the Nissan Versa S Sedan is the cheapest new car sold in America, and maybe the cheapest one to get you from A to B. But it does not sell well. Chance are you don't drive that one, but a different kind of vehicle. Why? From a payback perspective we should all drive that car for 3 years and then get a new one. Or why do you have a 4200 sqf house, when it likely be cheaper to live in a 1200 sqf house? The point is that no everything in live is about payback. You are getting such a superior system, which provides a large portion of its energy use from renewable sources. Getting stuff free for life is simply not cheap. Is it a deal breaker if your payback in forecast models goes not from 11 years to 13 years? Or do you do it anyway because you know it is the right thing to do. If you don't know that by now, just get the cheapest gas furnace and replace it again in 6-7 years. it might serve yo better. ECM powered flow center sounds good, just make sure it does not have 2 pumps, of which one of it is a constant speed 26-99. That would be detrimental for you energy savings. Grout from bottom to top should be a must. How to they connect to the surrounding ground if they do not have water, and they do not have grout? BS meter is on. Other than that this company seems to know what hey are doing.
I agree 100% that it isn't JUST a ROI question, but it certainly makes it an easier sale to spend all that money up front vs a higher end Modulating Gas Furnace and Variable HeatPump! At least when buying a car, I know I am taking it in the rear buying a luxury car in terms of ROI and I know how much I am taking it in the rear! I just want to know more about HOW bad or good it is with the Geo system. I know at certain prices, it pays out quickly, and at others, never! But the idea really appeals to me, otherwise I wouldn't have come this far in research and quotes. I got another Waterfurnace quote from another contractor that I think very much knows what they are doing. The prices came in lower, but he quoted a 4 ton unit and had lower heating and cooling Manual J values. I've asked him to confirm his numbers again. If I had to choose one, it would be this contractor or the other Waterfurnace 7 quote above. He had a lot of options for items whereas the other contractor included all the options in the price. As for the flow center they responded that they size the control center based on length of pipe to field and a field test and that it would either be the single pump variable unit or a dual pump with the 26-99 constant on with variable depending on the results of the test and length of pipe. I'm reading the research study now on the Grout vs other backfill issue. The title is "Measurement of Thermal Conductivity for Three Borehole Fill Materials used for GSHP" by Zhang and Murphy. I can provide a copy if you are interested as well. This was a study done by a professor at the University of Kentucky. Thanks Eric
Sure, provide the copy. That would be interesting. There is some BS here to size the flow center based on a field test. Pressure drop calculations are not rocket science, and every contractor should master them. The approach should be to design the loop for the lowest possible pressure drop and then use pump which has the lowest energy consumption too get enough flow going to keep the heat pump happy. The wrong approach is the put a loop field in the ground, and then figure out a pumping solution, not matter how inefficient. The loop should be designed for the lowest possible pumping power, the approach should not be to have to go with an inefficient pumping solution because not an inefficient loop field is in the ground. The 26-99 + VS flowcenter is an inefficient solution for the 7 series. We never put one in, I never will. Make sure you design the loop efficiently, then you do not need a dual stage flow center for a variable speed heat ump which will run forever.
