Geothermal heating/cooling

Discussion in 'General Conversation' started by truck, Feb 22, 2006.

  1. truck

    truck New Member

    Messages:
    156
    State:
    williamsburg ohio
    Any one out there have one of these systems or know anyone that does?Am thinking about doing it.
     
  2. Gator

    Gator New Member

    Messages:
    1,116
    State:
    Ludowici GA
    I wish I knew more about them as I have seen them but never used one.
     

  3. bearcat

    bearcat Member

    Messages:
    925
    State:
    Nokomis, Illinois
    I know several home owners here in ILL that have them. They really like them but they are exspensive to install. Most require 4 deep wells. Some as many as ten. Also heard , dont know for sure, they work better where it dont get below 25 or 30 degrees in the winter.
     
  4. truck

    truck New Member

    Messages:
    156
    State:
    williamsburg ohio
    One of the main reasons I have been checking in to it is because I already have a well that the house use to run off of for the water.Everything else I have read says water temp below 6ft deep usauly does not vary more than 1 deg all year and heating/cooling bills can go down up to 60%.Will see am waiting on the cost of the system.
     
  5. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    never seen one, but I would suspect you could do a search on google for reviews on them
     
  6. rpcathunter

    rpcathunter New Member

    Messages:
    51
    State:
    Fort Worth, Texas
    I have installed 3 of these when I worked for a electric co-op in Ok. they are wonderful. They cost more to put in initially, but they pay for there self, cheap to run, if you got the room a slinky versus the well type works real good but both have there ups and downs.If your just replaceing a bad or worn out air to air unit I say go for it!
     
  7. Catfishhunter

    Catfishhunter New Member

    Messages:
    332
    State:
    Lanesville, In.
    Truck, I have one in my home and I love it. It it like a heat pump but, instead of heating the air 15 deg. above the outside temp., the ground stays a constance 55 deg. year around and it heats 15 deg. above that. Also, it is tied into my water heater and in the winter it heats 60% of the water and in the summer it will heat it 100%. Every once in awhile the auxiliary will kick in but, not very often. Yea there is a big expense up front but, it you plan on staying there awhile it will pay off...
     
  8. N2Ducks

    N2Ducks New Member

    Messages:
    75
    State:
    Texas
    A bunch of people have them down here. They work great. I am a mechanical engineering student.They are expensive to start up, but after a while they pay for themselves.Just as long as the ground temp dosen't get to extreme. If it does it will cost you more for them to go deeper.
     
  9. Bigun

    Bigun New Member

    Messages:
    234
    State:
    Burnet, TX
    These systems are significantly more efficent than nearly any thing else. It is fundamentally cheaper to move energy than it is to create it. There are lots of different types of these systems. Here in central Texas the heating cycle and the cooling cycle are nearly balanced on a year round basis. This helps. You need to find good compitent advice in the area that you live. This is something that a good contractor or consultant can put a pencil to the problem and give detailed analysis of cost and payback. I put in 4 200 ft.bore holes for a friend for a closed loop system about 20 years ago. His electric bill was running $75/mo when mine was running $300 to$400/mo for similar sized houses in the same area. You need to stay where you are long enough to recoup the larger initial investment. This type of improvement will make a property easier to sell but probably not recapture much of the initial cost difference if sold. There are lots of improvements occurring in this relatively new field. I have been retired for a couple of years now. They were rapidly improving the additives to the grout to increase the thermal performance. This was helping system efficency and resulting in reduced footage of bore hole.
     
  10. dickieboy

    dickieboy New Member

    Messages:
    17
    State:
    Cedar Grove, TN
    Tuck,

    I’ll try to explain this and not get too technical. The reason they are more efficient is that they utilize the earth as a free energy source. During the heating season they ‘rob’ heat from the constant 55 degree earth temperature. ‘Deheated’ water enters the ground loop circulates through the loop gathering energy, heat, and then transfers it via heat exchanger to the refrigerant in the indoor unit, heat pump. The compressor then pressurizes this refrigerant, sends it trough the indoor coil, evaporator, where the fan blows air to transfer the heat into the house. Once the heat exchanger absorbs the heat from the water it returns to the ground to start the cycle again. Sometimes during extremely cold weather the unit is just too small to generate enough heat to maintain the space temperature. This is when the auxillary kicks in to suppliment as C'hunter mentioned.

    During cooling cycle, the heat/water transfer described above is reversed. The ground absorbs the energy, heat, transferred from the house to the water. Since the condensing occurs at a much lower temperature, 55 degrees from the earth coupled water, than typical summer outdoors temperatures, which are much higher (80-90) the compressor doesn’t have to work as hard thus saving electrical amps, i.e. money.

    If you install yours as suggested to your domestic water well pump you will have to dispose of the water as there will be no way to pump it back into the ground. A creek, pond or other would be appropriate. This is a rare installation but absolutely not unheard of. The reason for the high initial cost is that most are closed loop systems, which require many shallow wells or a few deep ones. The more tons of cooling you need the more surface area contact the loop will need with the earth thus the more wells. If you can figure out what to do with the water, your installation would be considerably less expensive. The typical payback on the initial investment of a closed loop is about 4 years but since yours would be cheaper you could expect a payback of say 2-3 yrs.

    Does any of this make sense?
     
  11. truck

    truck New Member

    Messages:
    156
    State:
    williamsburg ohio
    Thanks for all the replys,I am getting real sick of the price of propane!!!I am hoping to do it this year.Daryl
     
  12. Bigun

    Bigun New Member

    Messages:
    234
    State:
    Burnet, TX
    First let me say that there are a lot of factors that are site specific. For instance the ground temperature a few feet down is basically the mean average temperature for that Latitude. Dallas TX may be 65°f and Oklahoma City may be 60°f and Platt Nebraska may be 55°f. For the cooling cycle the Thermal efficency equation is a function of the difference between the residence temperature and the sink temperature that the heat is being rejected to. On a 100° day the normal sink tempeature is that 100° . Oklahoma City is going to be more efficent than Dallas with a 5°f better sink temperature but Dallas is going to be a lot more efficent rejecting heat to a 65°f sink than a 100°f sink.
    There are many specific considerations that are not this apparrent. For an open loop system where well water is used for instance. The first factor is what is the pumping depth. I had a friend that had one of the first instrumented houses with an open loop system outside Columbus OH. His pumping level was >50 ft. using a 0.5hp pump. My pumping level is 350 ft. and uses a 1.5hp pump. The closed loop system since it is only required to overcome friction the borehole depth is immaterial. The pump size is 0.1 hp . In my case just pumping the water to the surface is the equivalent to about a ton and a half of airconditiong running. Some states require a Permit for an injection well if you are going to put the water back under ground.:sad: The well for the open loop system may be already costed out for supplying the house. The two well open loop system and the closed loop system both recapture energy and therefore are more efficent than would be indicated by just considering the normal sink temperature. Probably more than you wanted to hear but back to the original recommendation get compitent local help. Additional information along with a list of current qualified contractors is avaliable from the National Water Well Association. I think their site is NWWA.org HVAC contractor orginations, and NSPE National association of Professional Engineers probably make refferals also. Sorry this got so long.