geofurnace + radiant heating... thoughts???

[Dirty Harry]

My fiancee & I are getting ready to begin designing our new home. I have 9 acres with an older ('77) stick-built kit home plunked down in the middle of it. It's a 1-story ranch-style house that's starting to fall apart; poorly laid out floorplan and the full basement always floods in the spring & fall. I want to tear it down and re-build on the same site, install drainage tile under the current spot & build the land up another 2-3 feet, to eliminate ground water problems.

We really want to try and be more energy efficient in the construction of our new home. (I converted all lighting in my old house to fluorescent & LED some years back, which helped a bit on electric bills.) For better R-factor insulation properties and an overall simpler, sturdier construction we are thinking of using pre-fabbed insulated panels for the walls & roof. (Insulspan, a maker of these panels, is only stone's throw from our town.) We're thinking 6" walls and a 9" roof would make it pretty dang cozy and weather-proof for the Great Lakes area.

Anyhow, I have been reading and hearing a little about so-called geo furnace / water furnaces. Does anyone here have this system or can offer some practical insight into whether or not this is actually something worth pursuing... or is it just an unworkable, pie-in-the-sky scam??? We'd also like to utilize radiant heating instead of forced air. Any practical experience with radiant would be very welcome also. Thanks very much everyone!

[jerbear]

Not sure about geothermal heating, but radiant heating is the way to go. I install swimming pools with radiant heat in the floors. A customer of mine heats his pool with a used motor oil boiler. Keeps his pool open all year round here in IL. He also has pex tubing in his driveway to heat it. No plowing! Basement floor is heated too. Pretty sweet set up. He gets the used motor oil FREE from places, and ya can't beat free!

[micmac]

We looked into Geothermal as we are considering / in the process of having a house built. The idea being that the air or water is maintained at a nominal temp of around 50 degrees from the earth. Then it can be heated or cooled accordingly. You still need a mechanism to heat or cool the the air or water so it's not free energy but its much more efficient. The problems are you need some land for the ground loop (not an issue for you) but I do think there are vertical systems. Right now they are very expensive. However there is a tax credit that can be applied that reduces the cost. The issue I had that it would take approximately 10 years to recoup the cost overage and at that point you getting to the range where equipment needs to be replaced and the cost starts over again. If you have a reputable company install it, these systems aren't scams. However you have to be more interested in efficiency and getting away from dependency on petroleum fuels than any actual in pocket cost savings. I do however think that this is the future of home heating. Especially with gas prices rising fast. As more are installed they will become cheaper and just as common as oil burning furnaces.

As radiant heat goes I hear it's wonderful but if it breaks out comes the floor. I'd make sure you had a good warrantee that will cover that expense on top fixing the equipment.

[plott hound]

i work for an HVAC company and we install in floor radiant heat.its not cheap to install or operate it but the comfort level is amazing.as for geothermal we stay away from it.the sales pitch here is "free heat from the ground".well let me tell you its not free.they need a supplementary back up for cold days because the units cant provide enough heat.also they work on the same principal as an air to air heat pump,so you end up with a compressor running 24-7 to provide heat.wheres the savings in that?we recomend hi-eff gas furnace's with modulating gas valve and dc motor.modulating gas valve brings in more gas at lets say 1% increments untill the heat call is satisfied.so the furnace never runs full bore but runs longer giving you a more even heat,without the wild temperture swings.the dc fan motor uses less hydro to run.for people that run the furnace fan 24-7 it can save you about 350 bux a year in hydro.another option for rural folk is an outdoor wood furnace/boiler.these are great if you have access to lots of cheap wood.hope this helps with your decision.

[Beeman]

Go infloor in the basement slab. If your doing it yourself, make sure you pressurize the system with air during the pour so you can check for leaks during the pour and quickly fix it. If all possible, don't splice (join the loop under the slab with a brass fitting).. any joints will add to a contamination problem over time (so, in other words.. don't try to use the cutoffs under the slab). Inslab is great and efficient since you are heated from the ground, and will also be helpful during a power outage in the winter (large heat reserve). Put in flex conduit to the center of your zones (if you have more than one), that way you can fish in a sensor after the pour and control the zone temperature from the slab heat instead of air heat (you can do air too, but slab takes a long time to change and hard to control by air).

You will need ventilation anyways if you go with radiant heating - best to get a ventilator with a air mover w/heat coil/dehumidifier (and cooling coil if you'd like). That way you can just stick with one heat source (boiler).

If you would like to open up the option to go with used oil/wood/thermal.. etc, run two water lines (insulated) from your boiler room 8ft underground to an area where you would like your supply house to be (build a little shack to house the unit). Make sure you run electrical out there, and an open conduit for control wiring (back to boiler room in house).

For ground thermal you could run a pipe from your "well?" to your house and suck heat out of the well water. You'd have to find a place to dump the used water though (an old well?). You could also try the geothermal, I don't know the costs on that, but its the same idea as sucking heat from your ground water.

Heating with hydronic allows you to easliy connect your domestic hot water/solar panels/hot tub/infloor/garage pad all together and is a pretty nice way to go. If you wanted to as another neat feature, run inslab heat through your sidewalks and parking slab for easy snow removal.

As for the building.. I have been very Very impressed with those pour-in concrete Styrofoam lego blocks. Seems to be all the rage over here these days. The cost is a little more, you get a house built out of concrete and insulated at R30 (I think) on all the outer walls. Pour your footings/place lego blocks/pour in concrete - boom, house outter shell done.

[Beeman]

Also, build your garage first!! Or, check with the rules in your county/MD and change your current house into a storage shed or a shop.. if there's not too much wrong with the current house you might be able to get away keeping it up and using it as something else (:P call it a horse barn!).

[Rock Doctor]

another option for rural folk is an outdoor wood furnace/boiler.these are great if you have access to lots of cheap wood.hope this helps with your decision.

I know several guys that have this. Basically it's an extra heat exchanger mounted in your Gas Furnace. Heated glycol is circulated through , and the system uses your existing furnace blower to move the heat. If you run out of wood in the Outdoor Heater, the indoor Gas Furnace takes over.

Some guys also have a heating circut that runs through their Hot Water Tank.

I want to do this, but lack of time and initiative are a problem at the moment

RD

[jeffery9076]

check this out

considering this to heat some greenhouses George's Workshop - Order Page

[gearhead1937]

We build our house about 4 years ago and went with geothermal. Love it. 1700 square feet with a full walk out basement (3400 total square feet) My electric bills are half what my father inlaws. His house is only 1200 square feet w/o a walk out basement. I keep my house warmer than he does also. As far as the emergency back-up heat I have never had to use it. Temps here in the winter are usually around 10ish degrees F. We also went with 2 inches of closed cell spray foam and then regular batt insulation. I wouldn't do it any other way. Cost was about $5000 more than a conventional HVAC system. Paying for itself quickly ($200-$300 cheaper per month.)

[rdr]

a nother vote for a water stove . u can get gas or oil as a back up . more heat than u will ever use . but stay away from the units with only 45 to 80 gal of water . u need at least 350 to 600 gal of water . . and good suply of wood . robbie

[mike bar]

My brother went geothermal using an overflow of well water, about 5 years ago and still would recomend it, heat and a/c. As far as your house goes, r-40 in ceilings and r-20 walls should be enough. I would stress care in sealing the vapour barrier. Have you checked out how they build r 2000 homes. I started building these in the mid 80's and in my opinion this is the only way to go. a good quality air exchanger makes a huge difference too.

[Dirty Harry]

Since we'll be using SIPs (Structural Insulated Panel) for the outer shell, a high-volume exchanger is standard with them. The house is very air-tight with this construction/assembly method. Thanks for all the replies... and keep 'em coming!