GeoThermal Systems - Worth the $$?

[InlineDieselFan]

A few big questions you have to have to ask and answer.

How long will you be living in the house? Less than 5 years, don't go geothermal.

If you are paying someone to dothe install? Where are they coming from? This was a big problem we had when we built, the nearest installer was several hours away.

From my research of a few years back before building, it was the people that lived in the real cold in the winter and real hot in the summer that benefitted the most. Living here in the PNW, we have a few cold and a few hot days, but usually pretty mild. It would take upwards of 15 years to pay for itself in our mostly mild temps.

steve

 

[Sigarms]

How long will you be living in the house? Less than 5 years, don't go geothermal.

If you are paying someone to dothe install? Where are they coming from? This was a big problem we had when we built, the nearest installer was several hours away.

From my research of a few years back before building, it was the people that lived in the real cold in the winter and real hot in the summer that benefitted the most. Living here in the PNW, we have a few cold and a few hot days, but usually pretty mild. It would take upwards of 15 years to pay for itself in our mostly mild temps.

Very good points.

Personal opinion is GeoThermal is the way to go, if you have the money.

Problem as I see it is there are not many companies that do this type of system, and if the company doing the bidding is smart and stands behind their work (been in business a long time), your quote will always be on the extreme high side due to "oh, crap" issues (when you don't have a lot of compitition in your business, pencils don't have to sharpened as much).

IMO next best system to look at is a zoned variable speed duel fuel sytem.

Forgot to add that if you went with radiant heat, you'll LOVE it (in floor I'm guessing, and some guys can get innovative by zoning and wrapping pex tubing around the walls of showers and tubs so the walls will stay warm), but the question then is the cost worth that type of system for the "average" winters you have, and you still have to address your A/C system (added costs which you can't tie into your heating system).

 

[Paddy]

Diesel power,

So you used a standard air-to-air heat pump? and used your your "outside air" from a 400' x 6" dia pipe? Interesting. I'll guess you had to build some sort of shroud around the Heat pump. The reason Geo-thermal systems use water is because water can hold so much more energy per cubic foot, 4.19 j/cc to raise temp by 1 deg C. I can't remember what air is but I'll guess at least 50 times more. If your getting higher temps than you like from your air suply, it's likely due to not enough air volume burried. Either way, you save some because you are lowering the air temp in summer compared to Summer air and visa versa in winter. It's a bit hard for me to imagine my big heat pump getting enough air flow from a 6" dia pipe. Does your mix some outside air?

Ideally, burried copper line with freon is best from an efficiency point of view. The reasons; cooper is one of the best conductors, two, froen would require a fraction of the volume of water or air. And lastly, one less conversion loss. In a traditional Geo system it goes from loop water-freon-air ducted in the house.

Tell us more about your system. As I said, it's very interesting and works for you.

 

[Paddy]

Investing in energy savings is a funny biz. Maximizing insulation is a great way to save big $$. Getting cheap energy is also a great way. The Geo way uses your money is an odd way. Ele you buy is used to get/pump free energy. I have seen tables where the price of a btu delivered in to your home via heating;

ele element heat- Geo 33%
Natural gas-Geo 60% ?? But this is a guess and is totaly based on NG price. In other words, when gas is cheap, you save less.

When you save via insulation, you are limited to wall thickness ( unless you are looking into vacuum at 250 R per inch!!) and those darn windows. Even the best windows have very low R value. I have looked in to vacuum but untill oil reaches 200$ a barrel, I don't think it will ever pay back. Extruded foam is the next best R per inch at R-5 per inch. Fiber glass is R-3.45 per inch but with studs it's quite a bit lower. I will be going with 6 " of foam sandwiched in concrete, R-30. I want to solve the window issue by creating some sort of Foam Shutter that can be closed like a garage door.

The problem with all these energy saving; Any two major steps, say geo-themal or max insulation is the net return. You will always get a deminishing returns. Say you have $1000 a year energy bills for easy math. The insulation and the Geo thermal systems claim a 25% savings each. One installed system will save $250, installing both will save ...$750x 25%=$187 +$250=$437. Not the $500 you might expect. So each time you invest in another cost saving technique, the actual savings drop compared to if it is the only thing you do.

You can imagine if you had 6 or 7 energy saving method with investments, the return on investment may take 30 years!

 

[thcri]

Diesel power,
Ideally, burried copper line with freon is best from an efficiency point of view. The reasons; cooper is one of the best conductors, two, froen would require a fraction of the volume of water or air. And lastly, one less conversion loss. In a traditional Geo system it goes from loop water-freon-air ducted in the house..

There is a Manufacture out of Florida that use to do that. I think they still are in business anyway. They contacted us once about putting in a system that they pre-sold in our area. Their loop got awful expensive because of all the pre-work that you had to do with sand beds/plots. My concern is if there is a leak it would be a pain to fix or even find the leak.

murph

 

[Dennis R.]

Built home 2 years ago, installed a pump and dump. My well, so the water doesn't cost anything except the electricity. The used water, well, I dump it into my fish pond, which keeps the water level up through the dry spells, and keeps the ice a little thin around the exit. Cost effective? Not initially, but I figured it will pay for itself in about 6 years. After that.....gravey! Had some initial problems in the beginning working the bugs out of it.....it was the first system installed by this plumber...so if I ever had to do it again, I would find someone well experienced with installation. We love the in-floor heat. You can stand with the door open in the middle of winter and don't even feel a draft. Everything is warmer. In the summer we have a high-efficency cooling system in the attic and one in the basement. A little noisey when it comes on, but it works great. The house is comfortably cool through-out. So, yes, do it! You won't be sorry!

 

[hockeypuck]

I have wired up a few of the closed loop geothermal units and I would never put one in my house. That is a lot of equipment to maintain and keep. Remember that you will have an rather large increase in your electric bill due to the heat pump and well pump. I would rather put my money into foam insulation and good windows. Doing radiant heat in a concrete slab or 1.5" of a lightweight concrete with an efficient oil or gas burner would be the way I would do it if I was to start from scratch. We loose power where I live 2 or 3 times a winter. You would need a rather large generator to run a geothermal system. If you do go geothermal, I would back it up with a wood pellet forced hot air furnace. On the really cold days when the geothermal will struggle it is good to have a good back up.

puck

 

[techman]

Remember that you will have an rather large increase in your electric bill due to the heat pump and well pump.

puck

There is no well pump in a closed loop system, only a small circulator. There is the electric for the heat pump, but the draw is much lower than an equivalent air source heat pump.

As far as the equipment complexity, it actually has fewer moving parts than an air source unit, if you count the defrost controller, etc. Also the circulator motor=the fan motor. But the equipment is usually located indoors in the basement. The favorable environment (compared to outside) results in much longer life of the unit (usually considered 25+ years). The ground loop is gauranted by many for 50 years.

You will not match the overall efficiency with any other heat/cool combo. Oil, NG and propane vary quite a bit in price, while electric is much more stable.

paul

 

[daddywags]

I have had a "Water Furnace" for 8 years. It uses a closed loop and the loop is warranted for 50 years. I had a problem with an air bubble when it was first installed, but once that was resolved it runs great. It is super good in cooling mode, but works very well in heating also. My house is 3800+ Square feet, with 6" walls. My electric bills run 150.00 winter, 125.00 Summer, 90-100.00 spring and fall. We have all electric home and have 2 freezers and a large wood shop that uses a lot of power. The heat is around 110 degrees and feels nice and warm. We love the system and would do it again.

 

[dooleysm]

We put a closed loop system in our 2300 sq ft (not including basement) 2 story house 2 years ago. Summers are humid and in the low-mid 90's, winters are rarely in single digits, but do get a few cold snaps. Our house is all electric excpet for propane stove. Our electric bill rarely exceeds $100. Only in the coldest months, and event then, it's never over $125.

The heat coming out of the registers is not hot like gas or wood heat, but we keep our thermostat at 72, so we're rarely cold in the house. I keep it at 68-70 in the summer and never hesitate to lower it if it's real hot outside. We get the free pre-heated water in the summer when the A/C is on. De-super heater or something like that I think it's called. It's a water-water heat exchanger inside the geothermal unit that outputs wamr water to a holding tank that feeds our water heater. The holding tank is a cheap water heater that's not wired up. It cost $150 to buy, but the local electric provider offers a $150 rebate on electric water heaters, so it was free.