Hi,
I am planning to build a new home in MD. Very much interested to try Geothermal for heating and cooling, with radiant heat floor all over the house 3500sq. I might need 5-6 tons
Planning to install WaterFurnace product, in particular Envision. Would be very interested to listen to your points of view. Moreover, for Radian heat floor I am thinking to Warmboard
http://www.waterfurnace.com/products.aspx?prd=Envision
Thanks in advance
Steve
Replies
Why would you need both?
both what?
The Water Furnances I'm familiar with (I'll admit, it's not the most recent versions) are forced air handlers. Excess heat produced during the cooling cycle is deposited into the water heater.
Are you planning on using the radiant floor as this excess heat depository in addition to the air, or are you using some new form (of Waterfurnace) that only uses the radiant? If so, where's your cooling (AC) function?
If the radiant is in addition to, then you really don't have a fail-safe backup. That would require a different heat source.
(Typed a longer reply, then lost the connection - darn!).
Tell us more about the terrain there, type of ground connection (slinky, drilled well, lake, etc).
I argue for first making the new house superinsulated (depending of definition), to cut the heat needed in the first place. That will make the house much more comfortable, so maybe means of distributing the heat less important, because the house will be much more isothermal, with no cold spots. All sorts of ways to get high energy efficiency - double wall, ICF, SIP (Frenchy will be along shortly for his std lecture on SIP!).
Then think about how to heat the house. With less heat needed, whatever you pick will be less costly to buy and operate. Whatever you decide, make sure all aspects of the house and the means of heating/cooling it fit together well.
Plenty of info via Google on building a good house and on ground source heat pumps. Tell us a lot more, and you'll get less generic responses. Good luck with the project.
Thanks Dick for reply. The lot is flat and I am planning to use close loop slinky.
Thanks
Steve
Peter Peiffer has a great saying that "you should cut your energy consumption to 50% better than code before investing in high end alt energy generation such as geothermal or PV."
I think you would find that it is so cost effective to jack up the insulation and airtightness and add some passive solar that the energy needed to heat and cool a well designed house doesn't justify a super high end heating system.
If you are going with the radiant floor anyway it might be worth while to link it to a solar water heater as discussed here http://www.chandlerdesignbuild.com/files/demandWaterHeaters.pdf Two or three flat panels will generate much more hot water than you can use for washing and will go along way towards heating the floor in the edge seasons as well as in the middle of the winter if you link it up to a demand water heater. All of this would be much less expensive up front than what you are looking at. I'm biased because it's what I have at my own house.
In areas with long summers such as NC we see a lot of maintenance cost on the geo-thermals in August on systems with undersized loops so be sure to check references on your installer and make sure they've done a bomb proof Man-J load calculation and have enough loop in the ground.
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"You cannot work hard enough to make up for a sloppy estimate."
Called WaterFurnace dealer they coded $40K, very expensive
Warmborad is very expensive too, it costs 5.99/sf.
Thanks
Steve
I've seen the geothermal loop systems as low as $22,000 but the cost savings is made by shorting on the ground loops and with the summer cooling load here in clay soils you end up trying to dump BTU's into 70 degree dry clay by august and the system can get overstressed.We're trying warm board on a solar/ Rinnai radiant system with a water jacket outdoor wood stove for backup. It's a 2,300 SF house and it added about $4,000 over 3/4" advantech with staple up radiant. The main issue I have with warm board is the embodied energy content of all that aluminum. We have calculated that the embodied BTU content of one beer can equals 12 beer bottles in terms of embodied energy content so obviously the righteous thing is to avoid unnecessary use of aluminum in your day to day life by drinking local American made single barrel bourbon. Still a building material like Warmboard has a long life cycle that compensates for it's higher embodied energy content. A can of beer has a very short life cycle around the Chandler Design-Build office. (as does a bottle of bourbon to be honest) but we expect to be using the radiant floor system for many years.What I absolutely love about Warmboard is you can run a primary-secondary radiant loop like a slab and keep the loop temps very cool comparable to primary only staple up which I have in my office here running at 135 degrees under the plywood with the return to the heat exchanger at 110 degrees. which is generally hotter than my solar storage tanks so I don't get benefit from the solar if the tanks are less that the outflow temperature. With a slab or Warmboard on primary/secondary pumping I can get outflow temps at 70 degrees and that enables me to harvest BTUs out of my solar storage array. CheersM------------------
"You cannot work hard enough to make up for a sloppy estimate."
I am planning to build a house with a similar system to what you are descibing. Mine is a 1700 ft2 rancher with a full basement.
The geothermal installer is a friend of mine and he has recommended the Waterfurnace system to heat water for the the infloor heat. (I still have to see if the bank will lend me the money to go this system because it is roughly twice the price of RIF heat with a boiler.) However, I have to agree with the other guys in that, first you have to pay attention to the building envelope - you have to keep the heat that you generate inside the house.
I have also looked at Warmboard for the main floor but I haven't found a local dealer and haven't seen any comments on this site about it even though it has been mentioned a couple of times over the last few months. I'll be watching this thread. Hopefully someone has some experience with the Warmboard.
Hi
This is my first winter in our new house with a geothermal system so
I am very curious how cost affective it will be to! The house is 2500 sf
with lots of glass and some high ceilings. The house was built in 1972
and the heating system is ten years old. So I think it is a good example of an expensive system in a not so tight shell. the verdict...
No idea yet.
But last month the electric bill was 300 bucks.That is everything heat, hot water, stove etc. Also a big friggin hot tub out back.
So I don't know it seems pretty good so far, but not great.