Central heat and air unit (standard vs geothermal)

[techman]

So saving $60/month on a 10k system is almost a 14 year payback. And thats with the "friend hookup" AND net metering. I dont have net metering or a friend "hookup". Solar still isnt justifiable IMO in my area.

All things are not equal. The average loaded $/KWH before I installed the solar was $0.07 and today it is nearly $ 0.14. On top of that we expanded the house by 500 sq-ft and we have another adult in the household. I have an extensive database on my energy and since I installed the solar our average price is $ 0.13, and I have produces 46 MWH, which results in $ 6000 of savings. Add to that $ 1000 I received for renewable energy carbon credits, I am $ 3000 shy of breakeven. That should happen in 12-18 mos.

As far as "high tech", I agree it is not. However many dealers/installers promote it as high tech and even exotic, and attach a value associated with those terms. Dealer price for an 18 seer A/A is about $ 3000-$4000 lower than a geo, for a 3 ton. The rest of the price is in the field/well. For the non-DIYer prices hit $20K, so there is a lot of margin for them today. I hope that prices will fall, but as yet there are too few installers to reach a critical mass so prices can fall.

paul

 

[MacLawn]

Right Paul, in my area of Georgia, there is only one installer. He told me he mainly installs geo in commercial buildings, very few houses because of cost. People just don't want to spend $15-20,000 upfront for geo when they can get air heat pump for 1/3 or less. My heat pump, Carrier Puron 3 ton unit was $5,900 in '03. It's 13 SEER, dual stage fan or some such. And now a 3 ton geothermal unit including ditches, etc., total shebang would be ...... $16,000!!! Also includes the water heater desuperheater (who, WHO, comes up with these names?!?). I could have a mighty high electric bill every month for $16,000!! About 8 years' worth I figure. Payback would even be longer, probably 14-16 years for our house. I just do not see how geothermal can be that expensive to install.

 

[RalphVa]

If I was building a new house, it'd be a no brainer to go geothermal. It'll definitely save you quite a bit on electricity and will likely pay out.

Friends of ours have it in their house, and their electrical bills are very low. However, for some odd reason, they've had to replace the compressor twice. Odd, because the compressor should have an easier time of it with geothermal because of the lower condensing head against ground temperature instead of air temperature..

Not retrofitting it here, because they'd have to dig up down the hill through the trees to run the condensing lines. Not room for a well, which is what our friends have for condensing.

Going instead with PV solar panels.

Oh, one good alternative to geothermal might be ductless heat pump units. The SEER on them is about 27. Don't know what it is on geothermal. We've ductless for our basement. You can put 7 or 8 different zones on each outside unit. The outside unit doesn't have the defrost, reverse flow needed in conventional units to defrost the coils in the winter.

Ralph

 

[techman]

However, for some odd reason, they've had to replace the compressor twice. Odd, because the compressor should have an easier time of it with geothermal because of the lower condensing head against ground temperature instead of air temperature..

You are right about the compressor. A problem like that points to another problem. One compressor you might say factory defect, but two usually means there is an issue. Restrictions in the refrigerant in the unit, heat exchanger issue, etc. But all of the noted units have sensors that monitor internal temps, which would normally catch a problem. If not a HVAC tech could monitor a few temps and pressures to isolate a problem.

paul

 

[truckdiagnostics]

Not buying the price comparisons. If you have high end house with forced air AC and in floor heat, you have boiler and AC unit. Geothermal can do with one unit. In this case I maintain your looking at the $2,000 increase and rebate takes care of that. Apples to apples quote your forced air furnace with AC. Then quote your Water Furnace series 500 with water coil in the plenum, and back out the AC. Then factor in your saving on your domestic hot water. I believe people are being walked into the upper end units with the bells and whistles and saying it is $8,000 more and that is just not the case. I also maintain if the system is design correctly, you don't need the unit with the variable this and that and can get close to the same savings. The unit with the bells and whistles is making up for poor design??

 

[s219]

We've had geo for two years now in our new home, and I'd do it again in a heartbeat. It's quiet, powerful, and costs peanuts to run. Tax credit made it nearly a wash compared to the conventional system we were looking at.

 

[Loadstar]

The unit with the bells and whistles is making up for poor design??

No, if anything more bells and whistles exaggerate issues of poor design.

 

[DKCDKC]

Built a new house in 2001 with a geo system - three zones. I have it maintained every two to three years. Only problem after initial adjustments has been a thermostat - replaced it. Very reliable system and uses less than half the energy in my previous and larger home. Any way I figure it, this system has paid for itself years ago.

 

[jk96]

We've had Geo installed for a year and a half now. This was new construction build so our cost included ductwork and desuper as well. Total cost was $38,000 for two 4 ton units with 6 total zones including basement. (We could have gotten by on 4-5 tons easily but that's another story) Subtract 30% tax credit and $750 per ton rebate from utility and our total cost was about $21,000. We are very happy so far. One thing nice about system is how quiet and comfortable the house is. Set the temp and forget it. You don't even notice its running.

Performance wise I'm happy so far. We are all electric with 27' vaulted living room and loft and 10' ceilings throughout. Total sq/ft is 3550 first and second floor and we are using less electricity than our old home of 2,100 sq/ft with even bigger savings during the winter since the old house was on propane.

 

[JimRB]

Rambling.

We built our house in 1997. 1700 sf of wood framed conditioned space and a 1,000 feet of basement conditioned, half wood framed. Translated the basement concrete half has no isulation on the concrete walls. The last 3 feet of concrete is above ground and cold inside the house in the winter. 2x6 framing in basement with almost 9 foot height. 2x4 framing in upper levels. 9' on first floor and 8 foot on second floor. Open/high sloped ceiling in living room. 1/2" foam insulation board with no house wrap. No taping or caulking of insulation board and OSB. Mistake not doing house wrap. That will be fixed some day when I do siding maintenance. Double paned windows. Mistake not doing LowE windows, but we ran out of money so we are paying for that forever. We installed a basic Climatemaster 3 ton unit with slinky horizontal trenches. No booster heat. Hot water heater option. It just plumbs in to the existing 50 gallon electric water heater. All electric house with a well. 2 adults. 7-10 horses and a few dogs. Thermostat 78 in summer, 76 in winter. Basement is conditioned which keeps the woodworking tools from rusting. Air supply vents are restricted down there but it is still quite comfortable in the basement.

The EMC did a manuel J calc at 2.5 tons. I would have to dig up the calculation but I do recall the 2.5.

The coil rusted out the beginning of year 7. I gather typical of coils in all AC units of the time. It was replaced out of warranty.

We use between 10,000 kwh and 14,000 kwh per year over 18 years. KWH have increased over the years. I have suspicions that the cellulose insulation has settled and may be affecting the KWH consumption. On the other hand we once had one computer running and now have 3 and two UPSs. we have also had a few really cold snaps and some really hot spells that did not seem to happen early in the house's life. We use less electricity than my neighbors.

I need to take infared pictures of my house in the summer and winter. I gather it is relatively cheap to get an IR adapter for an Iphone but I live in a Droid world.

Two of the neighbors have replaced their outside compressors. I am not sure about the other two neighbors.

The hot water heat does not have the 240V turned on 6 months or more of the year. If the AC or heat is running a fair bit of the day or night then the geothermal makes enough hot water for us.

It can get hot 30 miles east of Atlanta. It can get cold. Typical summer day is up to 90 and typical winter ranges from 30-50. It can dip down to 10F or colder in the winter. We pull about 5 gallons of condensate every day in the summer. I dripped into a bucket to measure. The air temp is more constant without the surges I have seen from older style AC or heating sytems. My parents have a 5 year old furnace with natural gas and and AC. It has multistage air speed. That unit does not have the radical temp swings that you would see in a 30 year old system. That comment of tmep surges may reflect old technology as I believe all furnaces these days are required to be more energy efficient than the units 30 years ago. Anyhow the Climatemaster works when it is 100F and works when it is 0F out. It just runs longer. It works even when we had that 2 weeks of cold snap 0-10F recently. I do not know what kind of weather they have in Texas but a geothermal can work well in central Georgia in red clay.

I have no recollection of the premium paid. 1997 installed price for the 3 ton with 3 slinky trenches was $8,400. I was spending less on electricity in the new house than I was in a 1,000 sf apartment. The temps were much more even and comfortable in the new place. Our house is about 2.5 times bigger than that apartment. If I had the time I would visit the EMC to see if they can share comparable house consumptions.