View Full Version : Geothermal
07-18-2007, 12:08 AM
I got a link to this site from the Fine Homebuilding site. I've done some major renovations and got a lot of good advice from that site. The one aspect I have never taken on myself, and don't intend to is the HVAC install. My HVAC guy was very old when I last used him, very trustworthy and did a great job but he is now out of the business let alone 70 miles away.
That said, I have a recently purchased property this is fairly distressed and in need of major rehab. The property is located in Grundy county IL, which is about 65 miles south of Chicago, and is on a lake. The current heat is provided by resistance baseboard heat and the A/C is two window units. It is a 4 bedroom house with a large vaulted ceiling in the living room and a very low ceiling in the kitchen and dining room.
Interestingly enough, the window unit in the upstairs room and the window unit in the bedroom downstairs can keep the house very cool even on 95 degree days provided I place fans in the doorway to move the cool air out. Natural convection brings the warm air back in above the fans. The electrical bills are not that bad but the house is currently used only on weekends.
So to get to the point of this whole thread, I am looking to replace the resistance baseboard units and the window units with a central HVAC unit and I have a couple of questions as this is not something I can tackle myself.
1. Are there any members on this board that service the Grundy county area that are competent in geothermal HVAC. The lake is really deep and not far from the house and remains cold at depth through the summer.
2. Is Geothermal the way to go? I also have a well but I have read that there are pitfalls associated with that and a well is not the best place to go especially with a lake so close.
3. If there are no members on the board doing this, what is the best way to find a competent contractor to work on this? What are the questions I should ask on geothermal and what should I know going forward to find a competent contractor to do this install
PS, I don’t have natural gas available at this site only electricity. .
Thanks in advance for your help
07-18-2007, 10:57 PM
I just had installed a geothermal heat pump system as a replacement for an existing conventional HVAC system. System became operational last week. Residence is in a suburb of Dallas.
My observations, going through the process of hiring an HVAC contractor through completion, are:
1. Installation is key - you've got to find someone who understands geothermal HP equipment.
2. Proper HVAC design is no less important - Manual J, D, S, etc. are just as needed.
3. For a closed loop system like what I had installed, you need a fair amout of yard space. (I needed enough space for 8 wells, spaced 15 - 20 feet apart, each down to a depth of 300 feet).
Parenthetically, I had installed WaterFurance equipment - Envision 3 and 5 ton modes, including 2 speed compressors and variable speed blower motors, also with desuperheat water option, and without any auxiliary heat option. The 3 ton unit is zoned, using WF's Intellizone controller and Belimo motor dampers. Incoming water temperature is 77 degrees - about a mile of pipe in the ground.
Hope this helps. I'd be happy to answer any questions. It's been an interesting two month period of installation.
07-26-2007, 01:39 AM
Thanks for the information. I agree with installation and that is why I am trying to find a good installer her. Thank for your response
07-26-2007, 10:13 AM
An additional thought on finding a qualified geothermal installer:
I ended up finding my installer via WaterFurnace directly. I.e., choose the manufacturer of the geothermal equipment that you want to use, then ask the local rep for installer recommendations.
In my case, WF was only interested in recommending installers that would make WF look good. I was successful in finding a good installer.
Go to WaterFurnace.com. There is a dealer locater using your Zip Code on this site.
07-26-2007, 03:41 PM
Going geo is a good (but a bit expensive) option for the house. Being close to the lake is not a bad thing, but it may not be much of a benefit either. Once you drill and get below the bedrock layer, the ground temps are pretty constant year round. Usually in the 50-55 deg range. Seasonal usage can raise or lower these temps up to 15 deg due to local heating/cooling around the borehole site. If there is an aquifer that you hit, which we usually do in this area, the subterranean water migration will help keep the temp variation even less.
If you are close to the lake and own lakefront property, you could consider a loop in the lake, if it doesn't freeze solid in the winter. This would consist of a flat coil of special plastic tubing submerged to the bottom of the lake. A separate water loop would be in the tubing independent of the lake water.
On average, you will need 300-500' of tubing per ton in the lake for a submerged loop. If you drill boreholes, the average is about 150-175' per ton of drill depth. 2 to 3 wells, 200-300' each is average for a single home.
Waterfurnace is a good brand. I sell ClimateMaster, www.climatemaster.com, which I prefer. The two units are nearly identical in cost and performance. You can go to: www.geoexchange.org to get a list of qualified installers, drillers and consultants for geo heating in your area.
07-26-2007, 05:02 PM
I've just moved into a 3100sq/ft house in SugarLand TX, and am torn between geothermal and the carrier infinity 2 speed systems.
Its seems no matter how I look at it the GEO with 7 - 350ft deep wells in my front yard it just wont pay for itself anytime soon unless the price of electriciy doubles or triples. Its great on for the EER/SEER super efficient, and it tops, but at that price in 10 years I bet carrier will have an air-to-air system that is almost as efficient and can be replaced twice for the same price with some brushless rare magnet compressor or something... what am I missing?
I love the geothermal idea, but I'm hard pressed to justify it. Does it really save that much money? Also I hear that unless the wells are spaced at least 20ft apart you run the risk of loosing your thermal earthsink in 10 years which is the major cost of the system.
07-26-2007, 07:38 PM
You need to understand that there are essentially four different methods of earth couplings. You've managed, through this site, to touch on all four. One is a close loop field, which are horizontal, serpentine loops buried in the ground. This system requires extensive excavation of the property and the amount of geographical area needed depends on the size of the system (tons) needed. The second type of earth coupling is the closed loop well system. With this system, typically, multiple holes are drilled to a particular depth (again, depens on the load in tons). You are not seeking water with these holes, just depth. Into those holes loops of tubing are placed and it is through this tubing that the water or water/anti-freeze mix is pumped. The third type of system is the 'open well' and consists of generally a single, deep well (same issue, depth depends on tonnage) and utilizes two concentric pipes, one drawing water from the well and the other returning water to the well. The final one is the one you've specified, which is of course, the ground level water source, such as a lake with adequate depth.
I think you'll find that the costs of a high efficiency conventional system (propane gas w/AC or straight electromechanical heat pump for example) is not a lot different from the geo system for both ducts and equipment. It's the earth coupling that ups the cost of the geo system. But at least in our area, the return on investment is incredible. We did an 8,000 square foot house in our area a year ago. The client went through our New England winter and his heating energy bills were about 1/3 of those with equal sized homes, in his neighborhood, heating with natural gas. Likewise, his summertime cooling bills are about 1/4 of the conventional air-to-air cooling systems. Now that is todays prices. I can't predict the future but it sure looks to me like it belongs more to the renewable energy and electricity and fuel cells are right up there at the top of the list in that department. I know that locally, all of the town around me are investigating wind turbines to help keep the cost of electricity down. In one seaside town near us, they're forecasting an electric rate of 1/2 what it is now (they have a private electric company owned by the town) when all their wind trubines (they'll have a total of 6) are up and running. That's $.04/KWH. Makes geothermal with variable speed technology look might nice I'd say.
We too favor the ClimateMaster product and all our clients for the last two years have settled on the Tranquility model with 2-stage operation. Good stuff. You can research for a ClimateMaster dealer by visiting their website www.climatemaster.com and finding the closets distributor. A phone call to the distributor will get you going to help with the decison making process. :)
07-26-2007, 11:00 PM
Thanks for the replies and the links as well as the valuable information. The house is actually on a hill very close to the water so trenching to the lake may be an option. The water from the well is still very cold and the lake freezes to 8 or 9 inches in the winter but I would think I could get the tubing into the water below the freeze line. I would really like to pursue this option despite the additional cost, and have even had thought of putting up a small wind generator but I think that is long term. I have a tall hill where I could locate it. My electric bills are pretty darn high in the winter so I think the overall ROI would be pretty quick.
There was much very valuable information and I honestly thank you for taking the time to reply. I have bookmarked the links and even found a couple of installers, but only two that are within 30 to 40 minutes away. That was the only discouraging part. There is nobody in the immeadiate area.
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